Science.gov

Sample records for airborne minefield detection

  1. Materiel requirements for airborne minefield detection system

    NASA Astrophysics Data System (ADS)

    Bertsche, Karl A.; Huegle, Helmut

    1997-07-01

    Within the concept study, Material Requirements for an airborne minefield detection systems (AMiDS) the following topics were investigated: (i) concept concerning airborne minefield detection technique sand equipment, (ii) verification analysis of the AMiDS requirements using simulation models and (iii) application concept of AMiDS with regard o tactics and military operations. In a first approach the problems concerning unmanned airborne minefield detection techniques within a well-defined area were considered. The complexity of unmanned airborne minefield detection is a result of the following parameters: mine types, mine deployment methods, tactical requirements, topography, weather conditions, and the size of the area to be searched. In order to perform the analysis, a simulation model was developed to analyze the usability of the proposed remote controlled air carriers. The basic flight patterns for the proposed air carriers, as well as the preparation efforts of military operations and benefits of such a system during combat support missions were investigated. The results of the conceptual study showed that a proposed remote controlled helicopter drone could meet the stated German MOD scanning requirements of mine barriers. Fixed wing air carriers were at a definite disadvantage because of their inherently large turning loops. By implementing a mine detection system like AMiDS minefields can be reconnoitered before an attack. It is therefore possible either to plan, how the minefields can be circumvented or where precisely breaching lanes through the mine barriers are to be cleared for the advancing force.

  2. Wideband radar for airborne minefield detection

    NASA Astrophysics Data System (ADS)

    Clark, William W.; Burns, Brian; Dorff, Gary; Plasky, Brian; Moussally, George; Soumekh, Mehrdad

    2006-05-01

    Ground Penetrating Radar (GPR) has been applied for several years to the problem of detecting both antipersonnel and anti-tank landmines. RDECOM CERDEC NVESD is developing an airborne wideband GPR sensor for the detection of minefields including surface and buried mines. In this paper, we describe the as-built system, data and image processing techniques to generate imagery, and current issues with this type of radar. Further, we will display images from a recent field test.

  3. Knowledge-based architecture for airborne mine and minefield detection

    NASA Astrophysics Data System (ADS)

    Agarwal, Sanjeev; Menon, Deepak; Swonger, C. W.

    2004-09-01

    One of the primary lessons learned from airborne mid-wave infrared (MWIR) based mine and minefield detection research and development over the last few years has been the fact that no single algorithm or static detection architecture is able to meet mine and minefield detection performance specifications. This is true not only because of the highly varied environmental and operational conditions under which an airborne sensor is expected to perform but also due to the highly data dependent nature of sensors and algorithms employed for detection. Attempts to make the algorithms themselves more robust to varying operating conditions have only been partially successful. In this paper, we present a knowledge-based architecture to tackle this challenging problem. The detailed algorithm architecture is discussed for such a mine/minefield detection system, with a description of each functional block and data interface. This dynamic and knowledge-driven architecture will provide more robust mine and minefield detection for a highly multi-modal operating environment. The acquisition of the knowledge for this system is predominantly data driven, incorporating not only the analysis of historical airborne mine and minefield imagery data collection, but also other "all source data" that may be available such as terrain information and time of day. This "all source data" is extremely important and embodies causal information that drives the detection performance. This information is not being used by current detection architectures. Data analysis for knowledge acquisition will facilitate better understanding of the factors that affect the detection performance and will provide insight into areas for improvement for both sensors and algorithms. Important aspects of this knowledge-based architecture, its motivations and the potential gains from its implementation are discussed, and some preliminary results are presented.

  4. Airborne far-IR minefield imaging system (AFIRMIS): description and preliminary results

    NASA Astrophysics Data System (ADS)

    Simard, Jean-Robert; Mathieu, Pierre; Larochelle, Vincent; Bonnier, Deni

    1998-09-01

    In minefield detection, two main types of operation can be identified. First, there is the detection of surface-laid minefield. This scenario is encountered largely in tactical operations (troop movement, beach landing) where the speed at which the minefield is deployed or the strategic barrier that they represent exceed the need to bury them. Second, there is the detection of buried minefield which is encountered mainly in peacekeeping missions or clearance operations. To address these two types of minefield detection process, we propose an airborne far-infrared minefield imaging system (AFIRMIS). This passive and active imaging system fuses the information from the emissivity, the reflectivity and the 3-dimensional profile of the target/background scene in order to improve the probability of detection and to reduce the false alarm rate. This paper describes the proposed imaging system and presents early active imaging results of surface-laid mines.

  5. Minefield edge detection using a novel chemical vapor sensing technique

    NASA Astrophysics Data System (ADS)

    Fisher, Mark E.; Sikes, John

    2003-09-01

    Nomadics has developed a novel sensing technology that detects the chemical signature of explosives emanating from buried landmines. Canines have demonstrated the ability to detect these signatures, but use of canines for this task presents a number of logistical and physical limitations that can be overcome by use of chemical sensors. Nomadics is the exclusive licensee of novel amplifying fluorescent polymer materials developed by the Massachusetts Institute of Technology (MIT). These materials enable detection of ultra-trace concentrations of nitroaromatic compounds such as TNT, the most commonly utilized explosive in the production of landmines. When vapors of nitroaromatics are presented to the sensor, the fluorescent polymers emit light at a greatly reduced intensity, a property that enables rapid detection of trace quantities of explosives using relatively low-cost electronics and optics. Studies performed by Jenkins et al suggest that the chemical signature of a landmine is heterogeneous and can be dispersed a significant distance from the location of the mine. Because the signature is not highly localized and is not characterized by a well-defined concentration gradient, the sensor may have difficulty indicating the exact position of a mine, especially in high-density minefields. Conversely, if the chemical signature extends some distance from the mine position, the sensor may have utility in detecting the edges of minefields. In combat scenarios, this will allow commanders to select safe paths for personnel and vehicles. This paper will present the latest findings related to minefield edge detection at several test sites.

  6. Remote Sensing Minefield Area Reduction: Model-Based Approaches for the Extraction of Minefield Indicators

    NASA Astrophysics Data System (ADS)

    Katartzis, A.; Vanhamel, I.; Chan, J. C.-W.; Sahli, H.

    2004-09-01

    The use of high resolution commercial satellite and airborne images for the survey of landmine suspected areas has been suggested recently in the context of Mine Action to (i) map the hazardous area (suspected minefield), and (ii) possibly reduce its extend. Minefields may be identified using methods that directly detect and confirm the location of landmines. Next to this approach, indirect indicators, closely related to the occurrence of the minefields themselves can be used. Such indicators correspond either to direct military activities, e.g. trenches, embankments, protection walls, bunkers, foxholes, fences, etc, or changes in the landscape, e.g. abandoned arable land, unused roads, foot paths and tracks through fields, etc. The present work investigates model-based approaches for the (semi-) automatic extraction of some of the indirect minefield indicators from high resolution airborne images.

  7. Identifying minefields and verifying clearance: adapting statistical methods for UXO target detection

    NASA Astrophysics Data System (ADS)

    Gilbert, Richard O.; O'Brien, Robert F.; Wilson, John E.; Pulsipher, Brent A.; McKinstry, Craig A.

    2003-09-01

    It may not be feasible to completely survey large tracts of land suspected of containing minefields. It is desirable to develop a characterization protocol that will confidently identify minefields within these large land tracts if they exist. Naturally, surveying areas of greatest concern and most likely locations would be necessary but will not provide the needed confidence that an unknown minefield had not eluded detection. Once minefields are detected, methods are needed to bound the area that will require detailed mine detection surveys. The US Department of Defense Strategic Environmental Research and Development Program (SERDP) is sponsoring the development of statistical survey methods and tools for detecting potential UXO targets. These methods may be directly applicable to demining efforts. Statistical methods are employed to determine the optimal geophysical survey transect spacing to have confidence of detecting target areas of a critical size, shape, and anomaly density. Other methods under development determine the proportion of a land area that must be surveyed to confidently conclude that there are no UXO present. Adaptive sampling schemes are also being developed as an approach for bounding the target areas. These methods and tools will be presented and the status of relevant research in this area will be discussed.

  8. Self-healing minefield

    NASA Astrophysics Data System (ADS)

    Rolader, Glenn E.; Rogers, John; Batteh, Jad

    2004-07-01

    The Self Healing Minefield (SHM) is comprised of a networked system of mobile anti-tank landmines. When the mines detect a breach, each calculates an appropriate response, and some fire small rockets to "hop" into the breach path, healing the breach. The purpose of the SHM is to expand the capabilities of traditional obstacles and provide an effective anti-tank obstacle that does not require Anti-Personnel (AP) submunitions. The DARPA/ATO sponsored program started in June 2000 and culminated in a full 100-unit demonstration at Fort Leonard Wood, MO in April 2003. That program went from "a concept" to a prototype system demonstration in approximately 21 months and to a full tactically significant demonstration in approximately 33 months. Significant accomplishments included the following: (1) Demonstration of a working, scalable (order of a hundred nodes), ad hoc, self-healing RF network. (2) Demonstration of an innovative distributed time synchronization scheme that does not rely on GPS. (3) Demonstration of a non-GPS based, self-mapping, relative geolocation system. (4) Development of an innovative distributed safe, arm, and fire system that allows for independent firing of eight rockets within a single node. (5) Development of a small rocket design with a novel geometry that meets the propulsion requirements.

  9. False-alarm mitigation and feature-based discrimination for airborne mine detection

    NASA Astrophysics Data System (ADS)

    Menon, Deepak; Agarwal, Sanjeev; Ganju, Ritesh; Swonger, C. W.

    2004-09-01

    The aim of an anomaly detector is to locate spatial target locations that show significantly different spectral/spatial characteristics as compared to the background. Typical anomaly detectors can achieve a high probability of detection, however at the cost of significantly high false alarm rates. For successful minefield detection there is a need for a further processing step to identify mine-like targets and/or reject non-mine targets in order to improve the mine detection to false alarm ratio. In this paper, we discuss a number of false alarm mitigation (FAM) modalities for MWIR imagery. In particular, we investigate measures based on circularity, gray scale shape profile and reflection symmetry. The performance of these modalities is evaluated for false alarm mitigation using real airborne MWIR data at different times of the day and for different spectral bands. We also motivate a feature based clustering and discrimination scheme based on these modalities to classify similar targets. While false alarm mitigation is primarily used to reject non-mine like targets, feature based clustering can be used to select similar-looking mine-like targets. Minefield detection can subsequently proceed on each localized cluster of similar looking targets.

  10. Airborne hyperspectral detection of small changes.

    PubMed

    Eismann, Michael T; Meola, Joseph; Stocker, Alan D; Beaven, Scott G; Schaum, Alan P

    2008-10-01

    Hyperspectral change detection offers a promising approach to detect objects and features of remotely sensed areas that are too difficult to find in single images, such as slight changes in land cover and the insertion, deletion, or movement of small objects, by exploiting subtle differences in the imagery over time. Methods for performing such change detection, however, must effectively maintain invariance to typically larger image-to-image changes in illumination and environmental conditions, as well as misregistration and viewing differences between image observations, while remaining sensitive to small differences in scene content. Previous research has established predictive algorithms to overcome such natural changes between images, and these approaches have recently been extended to deal with space-varying changes. The challenges to effective change detection, however, are often exacerbated in an airborne imaging geometry because of the limitations in control over flight conditions and geometry, and some of the recent change detection algorithms have not been demonstrated in an airborne setting. We describe the airborne implementation and relative performance of such methods. We specifically attempt to characterize the effects of spatial misregistration on change detection performance, the efficacy of class-conditional predictors in an airborne setting, and extensions to the change detection approach, including physically motivated shadow transition classifiers and matched change filtering based on in-scene atmospheric normalization. PMID:18830283

  11. Approaches to detection of airborne biological agents

    NASA Astrophysics Data System (ADS)

    Chang, An-Cheng; Tabacco, Mary Beth

    2009-05-01

    Three approaches to detection of biological agents based on biological processes will be presented. The first example demonstrates the use of dendrimers to deliver a membrane-impermeable fluorescent dye into live bacteria, similar to viral infection and delivery of DNA/RNA into a bacterial cell. The second example mimics collection and capture of airborne biological particles by the respiratory mucosa through the use of a hygroscopic sensing membrane. The third example is based on the use of multiple fluorescent probes with diverse functionalities to detect airborne biological agents in a manner similar to the olfactory receptors in the nasal tract.

  12. Semantic risk estimation of suspected minefields based on spatial relationships analysis of minefield indicators from multi-level remote sensing imagery

    NASA Astrophysics Data System (ADS)

    Chan, Jonathan Cheung-Wai; Sahli, Hichem; Wang, Yuhang

    2005-06-01

    This paper presents semantic risk estimation of suspected minefields using spatial relationships of minefield indicators extracted from multi-level remote sensing. Both satellite image and pyramidal airborne acquisitions from 900m to 30m flying heights with resolutions from 1m to 2cm resolutions are used for identification of minefield indicators. R-Histogram [1] is a quantitative representation of spatial relationship between two objects in an image. Eight spatial relationships can be generated: 1) LEFT OF, 2) RIGHT OF, 3) ABOVE, 4) BELOW, 5) NEAR, 6) FAR, 7) INSIDE, 8) OUTSIDE. R-Histogram semantics are first generated from selected indicators and metrics such as topological proximity and directional relationships are trained for soft classification of risk index (normalized as 0-1). We presented a framework of how semantic metadata generated from remote sensing images are used in risk estimation. The resultant risk index identified seven out of twelve mine accidents occurred at high risk region. More importantly, comparison with ground truth obtained after mine clearance show that three out of the four identified pattern minefields falls into the area estimated at very high risk. A parcel-based per-field risk estimation can also be easily generated to show the usefulness of the risk index.

  13. Airborne multisensor system for the autonomous detection of land mines

    NASA Astrophysics Data System (ADS)

    Scheerer, Klaus

    1997-07-01

    A concept of a modular multisensor system for use on an airborne platform is presented. THe sensor system comprises two high resolution IR sensors working in the mid and far IR spectral regions, a RGB video camera with its sensitivity extended to the near IR in connection with a laser illuminator, and a radar with a spatial resolution adapted to the expected mine sizes. The sensor concept emerged from the evaluation of comprehensive static and airborne measurements on numerous buried and unburied mines. The measurements were performed on single mines and on minefields, layed down according to military requirements. The system has an on-board realtime image processing capability and is intended to operate autonomously with a data link to a mobile groundstation. Data from a navigation unit serve to transform the location of identified mines into a geodetic coordinate system. The system will be integrated into a cylindrical structure of about 40 cm diameter. This may be a drone or simply a tube which can be mounted on any carrier whatever. The realization of a simplified demonstrator for captive flight tests is planned by 1998.

  14. Comparative performance between compressed and uncompressed airborne imagery

    NASA Astrophysics Data System (ADS)

    Phan, Chung; Rupp, Ronald; Agarwal, Sanjeev; Trang, Anh; Nair, Sumesh

    2008-04-01

    The US Army's RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD), Countermine Division is evaluating the compressibility of airborne multi-spectral imagery for mine and minefield detection application. Of particular interest is to assess the highest image data compression rate that can be afforded without the loss of image quality for war fighters in the loop and performance of near real time mine detection algorithm. The JPEG-2000 compression standard is used to perform data compression. Both lossless and lossy compressions are considered. A multi-spectral anomaly detector such as RX (Reed & Xiaoli), which is widely used as a core algorithm baseline in airborne mine and minefield detection on different mine types, minefields, and terrains to identify potential individual targets, is used to compare the mine detection performance. This paper presents the compression scheme and compares detection performance results between compressed and uncompressed imagery for various level of compressions. The compression efficiency is evaluated and its dependence upon different backgrounds and other factors are documented and presented using multi-spectral data.

  15. Airborne multispectral detection of regrowth cotton fields

    NASA Astrophysics Data System (ADS)

    Westbrook, John K.; Suh, Charles P.-C.; Yang, Chenghai; Lan, Yubin; Eyster, Ritchie S.

    2015-01-01

    Effective methods are needed for timely areawide detection of regrowth cotton plants because boll weevils (a quarantine pest) can feed and reproduce on these plants beyond the cotton production season. Airborne multispectral images of regrowth cotton plots were acquired on several dates after three shredding (i.e., stalk destruction) dates. Linear spectral unmixing (LSU) classification was applied to high-resolution airborne multispectral images of regrowth cotton plots to estimate the minimum detectable size and subsequent growth of plants. We found that regrowth cotton fields can be identified when the mean plant width is ˜0.2 m for an image resolution of 0.1 m. LSU estimates of canopy cover of regrowth cotton plots correlated well (r2=0.81) with the ratio of mean plant width to row spacing, a surrogate measure of plant canopy cover. The height and width of regrowth plants were both well correlated (r2=0.94) with accumulated degree-days after shredding. The results will help boll weevil eradication program managers use airborne multispectral images to detect and monitor the regrowth of cotton plants after stalk destruction, and identify fields that may require further inspection and mitigation of boll weevil infestations.

  16. Airborne myxomycete spores: detection using molecular techniques

    NASA Astrophysics Data System (ADS)

    Kamono, Akiko; Kojima, Hisaya; Matsumoto, Jun; Kawamura, Kimitaka; Fukui, Manabu

    2009-01-01

    Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.

  17. Windshear detection and avoidance - Airborne systems survey

    NASA Technical Reports Server (NTRS)

    Bowles, Roland L.

    1990-01-01

    Functional requirements for airborne windshear detection and warning systems are discussed in terms of the threat posed to civil aircraft operations. A preliminary set of performance criteria for predictive windshear detection and warning systems is defined. Candidate airborne remote sensor technologies based on microwave Doppler radar, Doppler laser radar (lidar), and infrared radiometric techniques are discussed in the context of overall system requirements, and the performance of each sensor is assessed for representative microburst environments and ground clutter conditions. Preliminary simulation results demonstrate that all three sensors show potential for detecting windshear, and provide adequate warning time to allow flight crews to avoid the affected area or escape from the encounter. Radar simulation and analysis show that by using bin-to-bin automatic gain control, clutter filtering, limited detection range, and suitable antenna tilt management, windshear from wet microbursts can be accurately detected. Although a performance improvement can be obtained at higher radar frequency, the baseline X-band system also detected the presence of windshear hazard for a dry microburst. Simulation results of end-to-end performance for competing coherent lidar systems are presented.

  18. Airborne optical detection of oil on water.

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Arvesen, J. C.

    1972-01-01

    Airborne measurements were made over controlled oil-spill test sites to evaluate various techniques, utilizing reflected sunlight, for detecting oil on water. The results of these measurements show that (1) maximum contrast between oil and water is in the UV and red portions of the spectrum; (2) minimum contrast is in the blue-green; (3) differential polarization appears to be a very promising technique; (4) no characteristic absorption bands, which would permit one oil to be distinguished from another, were discovered in the spectral regions measured; (5) sky conditions greatly influence the contrast between oil and water; and (6) highest contrast was achieved under overcast sky conditions.

  19. Airborne change detection system for the detection of route mines

    NASA Astrophysics Data System (ADS)

    Donzelli, Thomas P.; Jackson, Larry; Yeshnik, Mark; Petty, Thomas E.

    2003-09-01

    The US Army is interested in technologies that will enable it to maintain the free flow of traffic along routes such as Main Supply Routes (MSRs). Mines emplaced in the road by enemy forces under cover of darkness represent a major threat to maintaining a rapid Operational Tempo (OPTEMPO) along such routes. One technique that shows promise for detecting enemy mining activity is Airborne Change Detection, which allows an operator to detect suspicious day-to-day changes in and around the road that may be indicative of enemy mining. This paper presents an Airborne Change Detection that is currently under development at the US Army Night Vision and Electronic Sensors Directorate (NVESD). The system has been tested using a longwave infrared (LWIR) sensor on a vertical take-off and landing unmanned aerial vehicle (VTOL UAV) and a midwave infrared (MWIR) sensor on a fixed wing aircraft. The system is described and results of the various tests conducted to date are presented.

  20. 14 CFR 135.173 - Airborne thunderstorm detection equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne thunderstorm detection equipment... Aircraft and Equipment § 135.173 Airborne thunderstorm detection equipment requirements. (a) No person may... the aircraft is equipped with either approved thunderstorm detection equipment or approved...

  1. 14 CFR 135.173 - Airborne thunderstorm detection equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne thunderstorm detection equipment... Aircraft and Equipment § 135.173 Airborne thunderstorm detection equipment requirements. (a) No person may... the aircraft is equipped with either approved thunderstorm detection equipment or approved...

  2. 14 CFR 135.173 - Airborne thunderstorm detection equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne thunderstorm detection equipment... Aircraft and Equipment § 135.173 Airborne thunderstorm detection equipment requirements. (a) No person may... the aircraft is equipped with either approved thunderstorm detection equipment or approved...

  3. 14 CFR 135.173 - Airborne thunderstorm detection equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne thunderstorm detection equipment... Aircraft and Equipment § 135.173 Airborne thunderstorm detection equipment requirements. (a) No person may... the aircraft is equipped with either approved thunderstorm detection equipment or approved...

  4. 14 CFR 135.173 - Airborne thunderstorm detection equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne thunderstorm detection equipment... Aircraft and Equipment § 135.173 Airborne thunderstorm detection equipment requirements. (a) No person may... the aircraft is equipped with either approved thunderstorm detection equipment or approved...

  5. Impact detection on airborne multilayered structures

    NASA Astrophysics Data System (ADS)

    Noharet, Bertrand; Chazelas, Jean; Bonniau, Philippe; Lecuellet, Jerome; Turpin, Marc J.

    1995-04-01

    This paper reviews the progress of an ongoing research program at Thomson-CSF and Bertin & Cie which addresses an optical fiber system dedicated to the assessment of impact induced damages on airborne multilayered structures. The method is based on the use of embedded high birefringence optical fiber sensors and distributed white light interfero-polarimetry. The first part is devoted to the transduction process efficiency within optical fibers depending on the applied force intensity, direction versus the fiber eigen axes and the interaction length. To understand the behavior of these optical fibers and calibrate the detection system, experiments have been conducted on elliptical core fibers, `bow-tie' fibers and side-hole fibers and showed a wide range of available sensitivities. The second step is related to the inclusion of optical fibers in a sandwich structure representative of an airborne dome, and composed of foam between glass/epoxy composite skins. Different designs of grooves in the foam and tube sheathings have been investigated to support and protect the optical fiber. Impacts have been performed on the structure in the 1 to 10 Joules energy range. Experimental impact location and energy measurements have been achieved for a variety of stress fields.

  6. Sensor fusion for airborne landmine detection

    NASA Astrophysics Data System (ADS)

    Schatten, Miranda A.; Gader, Paul D.; Bolton, Jeremy; Zare, Alina; Mendez-Vasquez, Andres

    2006-05-01

    Sensor fusion has become a vital research area for mine detection because of the countermine community's conclusion that no single sensor is capable of detecting mines at the necessary detection and false alarm rates over a wide variety of operating conditions. The U. S. Army Night Vision and Electronic Sensors Directorate (NVESD) evaluates sensors and algorithms for use in a multi-sensor multi-platform airborne detection modality. A large dataset of hyperspectral and radar imagery exists from the four major data collections performed at U. S. Army temperate and arid testing facilities in Autumn 2002, Spring 2003, Summer 2004, and Summer 2005. There are a number of algorithm developers working on single-sensor algorithms in order to optimize feature and classifier selection for that sensor type. However, a given sensor/algorithm system has an absolute limitation based on the physical phenomena that system is capable of sensing. Therefore, we perform decision-level fusion of the outputs from single-channel algorithms and we choose to combine systems whose information is complementary across operating conditions. That way, the final fused system will be robust to a variety of conditions, which is a critical property of a countermine detection system. In this paper, we present the analysis of fusion algorithms on data from a sensor suite consisting of high frequency radar imagery combined with hyperspectral long-wave infrared sensor imagery. The main type of fusion being considered is Choquet integral fusion. We evaluate performance achieved using the Choquet integral method for sensor fusion versus Boolean and soft "and," "or," mean, or majority voting.

  7. Airborne pipeline leak detection: UV or IR?

    NASA Astrophysics Data System (ADS)

    Babin, François; Gravel, Jean-François; Allard, Martin

    2016-05-01

    This paper presents a study of different approaches to the measurement of the above ground vapor plume created by the spill caused by a small 0.1 l/min (or less) leak in an underground liquid petroleum pipeline. The scenarios are those for the measurement from an airborne platform. The usual approach is that of IR absorption, but in the case of liquid petroleum products, there are drawbacks that will be discussed, especially when using alkanes to detect a leak. The optical measurements studied include UV enhanced Raman lidar, UV fluorescence lidar and IR absorption path integrated lidars. The breadboards used for testing the different approaches will be described along with the set-ups for leak simulation. Although IR absorption would intuitively be the most sensitive, it is shown that UV-Raman could be an alternative. When using the very broad alkane signature in the IR, the varying ground spectral reflectance are a problem. It is also determined that integrated path measurements are preferred, the UV enhanced Raman measurements showing that the vapor plume stays very close to the ground.

  8. Research on airborne infrared leakage detection of natural gas pipeline

    NASA Astrophysics Data System (ADS)

    Tan, Dongjie; Xu, Bin; Xu, Xu; Wang, Hongchao; Yu, Dongliang; Tian, Shengjie

    2011-12-01

    An airborne laser remote sensing technology is proposed to detect natural gas pipeline leakage in helicopter which carrying a detector, and the detector can detect a high spatial resolution of trace of methane on the ground. The principle of the airborne laser remote sensing system is based on tunable diode laser absorption spectroscopy (TDLAS). The system consists of an optical unit containing the laser, camera, helicopter mount, electronic unit with DGPS antenna, a notebook computer and a pilot monitor. And the system is mounted on a helicopter. The principle and the architecture of the airborne laser remote sensing system are presented. Field test experiments are carried out on West-East Natural Gas Pipeline of China, and the results show that airborne detection method is suitable for detecting gas leak of pipeline on plain, desert, hills but unfit for the area with large altitude diversification.

  9. Citrus greening detection using airborne hyperspectral and multispectral imaging techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imaging can provide unique spectral signatures for diseased vegetation. Airborne multispectral and hyperspectral imaging can be used to detect potentially infected trees over a large area for rapid detection of infected zones. This paper proposes a method to detect the citrus greening...

  10. Citrus greening disease detection using airborne multispectral and hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imaging can provide unique spectral signatures for diseased vegetation. Airborne hyperspectral imaging can be used to detect potentially infected trees over a large area for rapid detection of infected zones. Ground inspection and management can be focused on these infected zones rath...

  11. Study on airborne multispectral imaging fusion detection technology

    NASA Astrophysics Data System (ADS)

    Ding, Na; Gao, Jiaobo; Wang, Jun; Cheng, Juan; Gao, Meng; Gao, Fei; Fan, Zhe; Sun, Kefeng; Wu, Jun; Li, Junna; Gao, Zedong; Cheng, Gang

    2014-11-01

    The airborne multispectral imaging fusion detection technology is proposed in this paper. In this design scheme, the airborne multispectral imaging system consists of the multispectral camera, the image processing unit, and the stabilized platform. The multispectral camera can operate in the spectral region from visible to near infrared waveband (0.4-1.0um), it has four same and independent imaging channels, and sixteen different typical wavelengths to be selected based on the different typical targets and background. The related experiments were tested by the airborne multispectral imaging system. In particularly, the camouflage targets were fused and detected in the different complex environment, such as the land vegetation background, the desert hot background and underwater. In the spectral region from 0.4 um to 1.0um, the three different characteristic wave from sixteen typical spectral are selected and combined according to different backgrounds and targets. The spectral image corresponding to the three characteristic wavelengths is resisted and fused by the image processing technology in real time, and the fusion video with typical target property is outputted. In these fusion images, the contrast of target and background is greatly increased. Experimental results confirm that the airborne multispectral imaging fusion detection technology can acquire multispectral fusion image with high contrast in real time, and has the ability of detecting and identification camouflage objects from complex background to targets underwater.

  12. Airborne lidar detection of subsurface oceanic scattering layers

    NASA Technical Reports Server (NTRS)

    Hoge, Frank E.; Wright, C. Wayne; Krabill, William B.; Buntzen, Rodney R.; Gilbert, Gary D.

    1988-01-01

    The airborne lidar detection and cross-sectional mapping of submerged oceanic scattering layers are reported. The field experiment was conducted in the Atlantic Ocean southeast of Assateague Island, VA. NASA's Airborne Oceanographic Lidar was operated in the bathymetric mode to acquire on-wavelength 532-nm depth-resolved backscatter signals from shelf/slope waters. Unwanted laser pulse reflection from the air-water interface was minimized by spatial filtering and off-nadir operation. The presence of thermal stratification over the shelf was verified by the deployment of airborne expendable bathythermographs. Optical beam transmission measurements acquired from a surface truthing vessel indicated the presence of a layer of turbid water near the sea floor over the inner portion of the shelf.

  13. Airborne lidar detection of subsurface oceanic scattering layers.

    PubMed

    Hoge, F E; Wright, C W; Krabill, W B; Buntzen, R R; Gilbert, G D; Swift, R N; Yungel, J K; Berry, R E

    1988-10-01

    The airborne lidar detection and cross-sectional mapping of submerged oceanic scattering layers are reported. The field experiment was conducted in the Atlantic Ocean southeast of Assateague Island, VA. NASA's Airborne Oceanographic Lidar was operated in the bathymetric mode to acquire on-wavelength 532-nm depth-resolved backscatter signals from shelf/slope waters. Unwanted laser pulse reflection from the airwater interface was minimized by spatial filtering and off-nadir operation. The presence of thermal stratification over the shelf was verified by the deployment of airborne expendable bathythermographs. Optical beam transmission measurements acquired from a surface truthing vessel indicated the presence of a layer of turbid water near the sea floor over the inner portion of the shelf. PMID:20539503

  14. Airborne measured analytic signal for UXO detection

    SciTech Connect

    Gamey, T.J.; Holladay, J.S.; Mahler, R.

    1997-10-01

    The Altmark Tank Training Range north of Haldensleben, Germany has been in operation since WWI. Weapons training and testing has included cavalry, cannon, small arms, rail guns, and tank battalions. Current plans are to convert the area to a fully digital combat training facility. Instead of using blank or dummy ordnance, hits will be registered with lasers and computers. Before this can happen, the 25,000 ha must be cleared of old debris. In support of this cleanup operation, Aerodat Inc., in conjunction with IABG of Germany, demonstrated a new high resolution magnetic survey technique involving the measurement of 3-component magnetic gradient data. The survey was conducted in May 1996, and covered 500 ha in two blocks. The nominal line spacing was 10 m, and the average sensor altitude was 7 m. The geologic column consisted of sands over a sedimentary basin. Topographic relief was generally flat with approximately 3 m rolling dunes and occasional man-made features such as fox holes, bunkers, tank traps and reviewing stands. Trees were sparse and short (2-3 metres) due to frequent burn off and tank activity. As such, this site was nearly ideal for low altitude airborne surveying.

  15. Minefield reconnaissance and detector system

    DOEpatents

    Butler, M.T.; Cave, S.P.; Creager, J.D.; Johnson, C.M.; Mathes, J.B.; Smith, K.J.

    1994-04-26

    A multi-sensor system is described for detecting the presence of objects on the surface of the ground or buried just under the surface, such as anti-personnel or anti-tank mines or the like. A remote sensor platform has a plurality of metal detector sensors and a plurality of short pulse radar sensors. The remote sensor platform is remotely controlled from a processing and control unit and signals from the remote sensor platform are sent to the processing and control unit where they are individually evaluated in separate data analysis subprocess steps to obtain a probability score for each of the pluralities of sensors. These probability scores are combined in a fusion subprocess step by comparing score sets to a probability table which is derived based upon the historical incidence of object present conditions given that score set. A decision making rule is applied to provide an output which is optionally provided to a marker subprocess for controlling a marker device to mark the location of found objects. 7 figures.

  16. Minefield reconnaissance and detector system

    DOEpatents

    Butler, Millard T.; Cave, Steven P.; Creager, James D.; Johnson, Charles M.; Mathes, John B.; Smith, Kirk J.

    1994-01-01

    A multi-sensor system (10) for detecting the presence of objects on the surface of the ground or buried just under the surface, such as anti-personnel or anti-tank mines or the like. A remote sensor platform (12) has a plurality of metal detector sensors (22) and a plurality of short pulse radar sensors (24). The remote sensor platform (12) is remotely controlled from a processing and control unit (14) and signals from the remote sensor platform (12) are sent to the processing and control unit (14) where they are individually evaluated in separate data analysis subprocess steps (34, 36) to obtain a probability "score" for each of the pluralities of sensors (22, 24). These probability scores are combined in a fusion subprocess step (38) by comparing score sets to a probability table (130) which is derived based upon the historical incidence of object present conditions given that score set. A decision making rule is applied to provide an output which is optionally provided to a marker subprocess (40) for controlling a marker device (76) to mark the location of found objects.

  17. Minefield reconnaissance and detector system

    SciTech Connect

    Butler, M.T.; Cave, S.P.; Creager, J.D.; Johnson, C.M.; Mathes, J.B.; Smith, K.J.

    1991-12-31

    This invention is comprised of a multi-sensor system for detecting the presence of objects on the surface of the ground or buried just under the surface, such as anti-personnel or anti-tank mines or the like, is disclosed. A remote sensor platform has a plurality of metal detector sensors and a plurality of short pulse radar sensors. The remote sensor platform is remotely controlled from a processing and control unit and signals from the remote sensor platform are sent to the processing and control unit where they are individually evaluated in separate data analysis subprocess steps to obtain a probability ``score`` for each of the pluralities of sensors. These probability scores are combined in a fusion subprocess step by comparing score sets to a probability table which is derived based upon the historical incidence of object present conditions given that score set. A decision making rule is applied to provide an output which is optionally provided to a marker subprocess for controlling a marker device to mark the location of found objects.

  18. Tread lightly through these accounting minefields.

    PubMed

    Sherman, H D; Young, S D

    2001-01-01

    In the current economic climate, there is tremendous pressure--and personal incentive for managers--to report sales growth and meet investors' revenue expectations. As a result, more companies have been issuing misleading financial reports, according to the SEC, especially involving game playing around earnings. But it's shareholders who suffer from aggressive accounting strategies; they don't get a true sense of the financial health of the company, and when problems come to light, the shares they're holding can plummet in value. How can investors and their representatives on corporate boards spot trouble before it blows up in their faces? According to the authors, they should keep their eyes peeled for common abuses in six areas: revenue measurement and recognition, provisions and reserves for uncertain future costs, asset valuation, derivatives, related party transactions, and information used for bench-marking performance. If a disaster strikes, it will most likely be in one of these accounting minefields. This article examines the hazards of each minefield in turn, using examples like Metallgesellschaft, Xerox, MicroStrategy, and Lernout & Hauspie. It also provides a set of questions to ask in order to determine where a company's accounting practices might be overly aggressive. For those whose greatest interest is in fairly valuing the business--not presenting it in the best possible light--these questions are the first line of defense against creative accounting. Accounting game players are adroit, but it's both foolish and dangerous, contend the authors, to declare oneself ignorant and hence powerless against their machinations. They argue that members of corporate boards need to be financially literate. PMID:11447613

  19. Detecting Airborne Mercury by Use of Polymer/Carbon Films

    NASA Technical Reports Server (NTRS)

    Shevade, Abhijit; Ryan, Margaret; Homer, Margie; Kisor, Adam; Jewell, April; Yen, Shiao-Pin; Manatt, Kenneth; Blanco, Mario; Goddard, William

    2009-01-01

    Films made of certain polymer/carbon composites have been found to be potentially useful as sensing films for detecting airborne elemental mercury at concentrations on the order of tens of parts per billion or more. That is to say, when the polymer/carbon composite films are exposed to air containing mercury vapor, their electrical resistances decrease by measurable amounts. Because airborne mercury is a health hazard, it is desirable to detect it with great sensitivity, especially in enclosed environments in which there is a risk of a mercury leak from lamps or other equipment. The present effort to develop polymerbased mercury-vapor sensors complements the work reported in NASA Tech Briefs Detecting Airborne Mercury by Use of Palladium Chloride (NPO- 44955), Vol. 33, No. 7 (July 2009), page 48 and De tecting Airborne Mer cury by Use of Gold Nanowires (NPO-44787), Vol. 33, No. 7 (July 2009), page 49. Like those previously reported efforts, the present effort is motivated partly by a need to enable operation and/or regeneration of sensors under relatively mild conditions more specifically, at temperatures closer to room temperature than to the elevated temperatures (greater than 100 C ) needed for regeneration of sensors based on noble-metal films. The present polymer/carbon films are made from two polymers, denoted EYN1 and EYN2 (see Figure 1), both of which are derivatives of poly-4-vinyl pyridine with amine functional groups. Composites of these polymers with 10 to 15 weight percent of carbon were prepared and solution-deposited onto the JPL ElectronicNose sensor substrates for testing. Preliminary test results showed that the resulting sensor films gave measurable indications of airborne mercury at concentrations on the order of tens of parts per billion (ppb) or more. The operating temperature range for the sensing films was 28 to 40 C and that the sensor films regenerated spontaneously, without heating above operating temperature (see Figure 2).

  20. Airborne reconnaissance XIII; Proceedings of the Meeting, San Diego, CA, Aug. 7-9, 1989

    NASA Technical Reports Server (NTRS)

    Henkel, Paul A. (Editor); Lagesse, Francis R. (Editor); Schurter, Wayne W. (Editor)

    1989-01-01

    The present conference on airborne reconnaissance discusses topics in imagery exploitation, reconsystem modeling and analysis, and reconnaissance optics and electronics configurations. Attention is given to airborne minefield detection, the optimization of an IR linescanner for RPV operations, real-time display of IR linescanner data for RPVs, three-dimensional model-guided site recognition, the AMIDARS high-performance real-time display, and MMW sensor image analysis. Also discussed are reconnaissance concepts for the 3-5 micron spectral window, sensor concept development for hazard detection, a stabilization system for a large aperture camera, three-axis image stabilization with a two-axis mirror, the results of performance tests on the TOW target collimator design, and the replacement of film by electrooptic media in advanced tactical airborne reconnaissance.

  1. Detecting Airborne Mercury by Use of Palladium Chloride

    NASA Technical Reports Server (NTRS)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Jewell, April; Manatt, Kenneth; Torres, Julia; Soler, Jessica; Taylor, Charles

    2009-01-01

    Palladium chloride films have been found to be useful as alternatives to the gold films heretofore used to detect airborne elemental mercury at concentrations of the order of parts per billion (ppb). Somewhat more specifically, when suitably prepared palladium chloride films are exposed to parts-per-billion or larger concentrations of airborne mercury, their electrical resistances change by amounts large enough to be easily measurable. Because airborne mercury adversely affects health, it is desirable to be able to detect it with high sensitivity, especially in enclosed environments in which there is a risk of leakage of mercury from lamps or other equipment. The detection of mercury by use of gold films involves the formation of gold/mercury amalgam. Gold films offer adequate sensitivity for detection of airborne mercury and could easily be integrated into an electronic-nose system designed to operate in the temperature range of 23 to 28 C. Unfortunately, in order to regenerate a gold-film mercury sensor, one must heat it to a temperature of 200 C for several minutes in clean flowing air. In preparation for an experiment to demonstrate the present sensor concept, palladium chloride was deposited from an aqueous solution onto sets of gold electrodes and sintered in air to form a film. Then while using the gold electrodes to measure the electrical resistance of the films, the films were exposed, at a temperature of 25 C, to humidified air containing mercury at various concentrations from 0 to 35 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury in room-temperature air at concentrations of at least 2.5 ppb and can readily be regenerated at temperatures <40 C.

  2. Airborne radar technology for windshear detection

    NASA Technical Reports Server (NTRS)

    Hibey, Joseph L.; Khalaf, Camille S.

    1988-01-01

    The objectives and accomplishments of the two-and-a-half year effort to describe how returns from on-board Doppler radar are to be used to detect the presence of a wind shear are reported. The problem is modeled as one of first passage in terms of state variables, the state estimates are generated by a bank of extended Kalman filters working in parallel, and the decision strategy involves the use of a voting algorithm for a series of likelihood ratio tests. The performance issue for filtering is addressed in terms of error-covariance reduction and filter divergence, and the performance issue for detection is addressed in terms of using a probability measure transformation to derive theoretical expressions for the error probabilities of a false alarm and a miss.

  3. Airborne multispectral detecting system for marine mammals survey

    NASA Astrophysics Data System (ADS)

    Podobna, Yuliya; Sofianos, James; Schoonmaker, Jon; Medeiros, Dustin; Boucher, Cynthia; Oakley, Daniel; Saggese, Steve

    2010-04-01

    This work presents an electro-optical multispectral capability that detects and monitors marine mammals. It is a continuance of Whale Search Radar SBIR program funded by PMA-264 through NAVAIR. A lightweight, multispectral, turreted imaging system is designed for airborne and ship based platforms to detect and monitor marine mammals. The system tests were conducted over the Humpback whale breeding and calving area in Maui, Hawaii. The results of the tests and the system description are presented. The development of an automatic whale detection algorithm is discussed as well as methodology used to turn raw survey data into quantifiable data products.

  4. Semi-automated based ground-truthing GUI for airborne imagery

    NASA Astrophysics Data System (ADS)

    Phan, Chung; Lydic, Rich; Moore, Tim; Trang, Anh; Agarwal, Sanjeev; Tiwari, Spandan

    2005-06-01

    Over the past several years, an enormous amount of airborne imagery consisting of various formats has been collected and will continue into the future to support airborne mine/minefield detection processes, improve algorithm development, and aid in imaging sensor development. The ground-truthing of imagery is a very essential part of the algorithm development process to help validate the detection performance of the sensor and improving algorithm techniques. The GUI (Graphical User Interface) called SemiTruth was developed using Matlab software incorporating signal processing, image processing, and statistics toolboxes to aid in ground-truthing imagery. The semi-automated ground-truthing GUI is made possible with the current data collection method, that is including UTM/GPS (Universal Transverse Mercator/Global Positioning System) coordinate measurements for the mine target and fiducial locations on the given minefield layout to support in identification of the targets on the raw imagery. This semi-automated ground-truthing effort has developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD), Countermine Division, Airborne Application Branch with some support by the University of Missouri-Rolla.

  5. DETECTION AND IDENTIFICATION OF TOXIC AIR POLLUTANTS USING AIRBORNE LWIR HYPERSPECTRAL IMAGING

    EPA Science Inventory

    Airborne longwave infrared LWIR) hyperspectral imagery was utilized to detect and identify gaseous chemical release plumes at sites in sourthern Texzas. The Airborne Hysperspectral Imager (AHI), developed by the University of Hawaii was flown over a petrochemical facility and a ...

  6. Feasibility Study of Radiometry for Airborne Detection of Aviation Hazards

    NASA Technical Reports Server (NTRS)

    Gimmestad, Gary G.; Papanicolopoulos, Chris D.; Richards, Mark A.; Sherman, Donald L.; West, Leanne L.; Johnson, James W. (Technical Monitor)

    2001-01-01

    Radiometric sensors for aviation hazards have the potential for widespread and inexpensive deployment on aircraft. This report contains discussions of three aviation hazards - icing, turbulence, and volcanic ash - as well as candidate radiometric detection techniques for each hazard. Dual-polarization microwave radiometry is the only viable radiometric technique for detection of icing conditions, but more research will be required to assess its usefulness to the aviation community. Passive infrared techniques are being developed for detection of turbulence and volcanic ash by researchers in this country and also in Australia. Further investigation of the infrared airborne radiometric hazard detection approaches will also be required in order to develop reliable detection/discrimination techniques. This report includes a description of a commercial hyperspectral imager for investigating the infrared detection techniques for turbulence and volcanic ash.

  7. A Retrospective Demographic and Clinicopathologic Review of Deaths Resulting from Minefield Explosions During Migrants' Attempts to Enter Greece from Turkey Between 1997 and 2008.

    PubMed

    Pavlidis, Pavlos; Karakasi, Valeria

    2016-05-01

    Until 2008, the easternmost land borders of the European Union (Greek-Turkish land zone) were planted with minefields spanning 11 km. Therefore, numerous fatalities occurred in peacetime as migrants attempted to avoid Greek border checks. Numerous fatal incidents (51) were detected inside the Greek minefields between 1997 and 2008. Determination of age, sex, time of death, and nationality were evaluated in every case. The injuries' anatomical dispersion, their severity, and the mechanism of death were examined in relation to the victims' position at the moment of the explosion. Data research indicated that all victims were male, aged 18-30 in their majority, crossing border minefields mainly during the night. Their distance and position in relation to the point of detonation was a key factor in the trauma localization and severity. This review highlights the devastating consequences of the residual mines during peacetime, a situation that continues to be a persistent international problem. PMID:27122401

  8. Detecting inertial effects with airborne matter-wave interferometry.

    PubMed

    Geiger, R; Ménoret, V; Stern, G; Zahzam, N; Cheinet, P; Battelier, B; Villing, A; Moron, F; Lours, M; Bidel, Y; Bresson, A; Landragin, A; Bouyer, P

    2011-01-01

    Inertial sensors relying on atom interferometry offer a breakthrough advance in a variety of applications, such as inertial navigation, gravimetry or ground- and space-based tests of fundamental physics. These instruments require a quiet environment to reach their performance and using them outside the laboratory remains a challenge. Here we report the first operation of an airborne matter-wave accelerometer set up aboard a 0g plane and operating during the standard gravity (1g) and microgravity (0g) phases of the flight. At 1g, the sensor can detect inertial effects more than 300 times weaker than the typical acceleration fluctuations of the aircraft. We describe the improvement of the interferometer sensitivity in 0g, which reaches 2 x 10-4 ms-2 / √Hz with our current setup. We finally discuss the extension of our method to airborne and spaceborne tests of the Universality of free fall with matter waves. PMID:21934658

  9. Detecting inertial effects with airborne matter-wave interferometry

    PubMed Central

    Geiger, R.; Ménoret, V.; Stern, G.; Zahzam, N.; Cheinet, P.; Battelier, B.; Villing, A.; Moron, F.; Lours, M.; Bidel, Y.; Bresson, A.; Landragin, A.; Bouyer, P.

    2011-01-01

    Inertial sensors relying on atom interferometry offer a breakthrough advance in a variety of applications, such as inertial navigation, gravimetry or ground- and space-based tests of fundamental physics. These instruments require a quiet environment to reach their performance and using them outside the laboratory remains a challenge. Here we report the first operation of an airborne matter-wave accelerometer set up aboard a 0g plane and operating during the standard gravity (1g) and microgravity (0g) phases of the flight. At 1g, the sensor can detect inertial effects more than 300 times weaker than the typical acceleration fluctuations of the aircraft. We describe the improvement of the interferometer sensitivity in 0g, which reaches 2 x 10-4 ms-2 / √Hz with our current setup. We finally discuss the extension of our method to airborne and spaceborne tests of the Universality of free fall with matter waves. PMID:21934658

  10. Airborne Doppler radar detection of low altitude windshear

    NASA Technical Reports Server (NTRS)

    Bracalente, Emedio M.; Jones, William R.; Britt, Charles L.

    1990-01-01

    As part of an integrated windshear program, the Federal Aviation Administration, jointly with NASA, is sponsoring a research effort to develop airborne sensor technology for the detection of low altitude windshear during aircraft take-off and landing. One sensor being considered is microwave Doppler radar operating at X-band or above. Using a Microburst/Clutter/Radar simulation program, a preliminary feasibility study was conducted to assess the performance of Doppler radars for this application. Preliminary results from this study are presented. Analysis show, that using bin-to-bin Automatic Gain Control (AGC), clutter filtering, limited detection range, and suitable antenna tilt management, windshear from a wet microburst can be accurately detected 10 to 65 seconds (.75 to 5 km) in front of the aircraft. Although a performance improvement can be obtained at higher frequency, the baseline X-band system that was simulated detected the presence of a windshear hazard for the dry microburst. Although this study indicates the feasibility of using an airborne Doppler radar to detect low altitude microburst windshear, further detailed studies, including future flight experiments, will be required to completely characterize the capabilities and limitations.

  11. Airborne detection of asperities: Linking aerogravimetry surveys and earthquake studies

    NASA Astrophysics Data System (ADS)

    Meyer, U.; Boedecker, G.

    2003-04-01

    During the last decade, airborne gravimetric surveys have become a reliable and useful geophysical method to explore mid to large scale geologic settings. Ocean continent boundaries down to seamounts are detectable using conventional scalar, platform stabilized airborne gravimetry systems. New systems such as 3-D strap-down instruments promise a better spatial resolution recovering the gravity vector. Airborne gravimetric gradiometer systems are already able to detect small scale gradients in high spatial resolution. Following this trend in aerogravimetry, new research applications are emerging. One of the most challenging and interesting new aspects of airborne gravimetry is the systematic search for asperity structures. Asperities are patches of the oceanic or continental crust that are able to store more stress than the surrounding material. If due to stress overload or other mechanic forces the asperity breaks, up to mega-thrust earthquakes are triggered. The character of an asperity to carry more stress than the weaker environment must be related to its physical properties such as composition, thickness and density. Questions connected to define and detect an asperity are: How large is an asperity? Do asperities have sharp boundaries? Are asperities isolated structures? Do asperities have special gravimetric signatures? Wells et al. (2000) found that off southern Chile slip maxima from earthquakes coincide with forearc gravity lows. It is well accepted that in this region seismicity is a product of the subduction on the active continental margin. It is still debated whether subducted asperities from the oceanic plate are individual earthquake sources or if they i.e. trigger the break of asperities in the continental crust. Apart from this, very few investigations have been made trying to connect gravimetry and asperities. Therefore, the GeoForschungsZentrum Potsdam in collaboration with Bayerische Akademie der Wissenschaften in Munich , FU Berlin

  12. Chemical detection using the airborne thermal infrared imaging spectrometer (TIRIS)

    SciTech Connect

    Gat, N.; Subramanian, S.; Sheffield, M.; Erives, H.; Barhen, J.

    1997-04-01

    A methodology is described for an airborne, downlooking, longwave infrared imaging spectrometer based technique for the detection and tracking of plumes of toxic gases. Plumes can be observed in emission or absorption, depending on the thermal contrast between the vapor and the background terrain. While the sensor is currently undergoing laboratory calibration and characterization, a radiative exchange phenomenology model has been developed to predict sensor response and to facilitate the sensor design. An inverse problem model has also been developed to obtain plume parameters based on sensor measurements. These models, the sensors, and ongoing activities are described.

  13. Detection and tracking of humans from an airborne platform

    NASA Astrophysics Data System (ADS)

    van Eekeren, Adam W. M.; Dijk, Judith; Burghouts, Gertjan

    2014-10-01

    Airborne platforms are recording large amounts of video data. Extracting the events which are needed to see is a time-demanding task for analysts. The reason for this is that the sensors record hours of video data in which only a fraction of the footage contains events of interest. For the analyst, it is hard to retrieve such events from the large amounts of video data by hand. A way to extract information more automatically from the data is to detect all humans within the scene. This can be done in a real-time scenario (both on-board as on the ground station) for strategic and tactical purposes and in an offline scenario where the information is analyzed after recording to acquire intelligence (e.g. a daily life pattern). In this paper, we evaluate three different methods for object detection from a moving airborne platform. The first one is a static person detection algorithm. The main advantage of this method is that it can be used on single frames, and therefor does not depend on the stabilization of the platform. The main disadvantage of this method is that the number of pixels needed for the detection is pretty large. The second method is based on detection of motion-in-motion. Here the background is stabilized, and clusters of pixels that move with respect to this stabilized background are detected as moving object. The main advantage is that all moving objects are detected, the main disadvantage is that it heavily depends on the quality of the stabilization. The third method combines both previous detection methods. The detections are tracked using a histogram-based tracker, so that missed detections can be filled in and a trajectory of all objects can be determined. We demonstrate the tracking performance using the three different detections methods on the publicly available UCF-ARG aerial dataset. The performance is evaluated for two human actions (running and digging) and varying object sizes. It is shown that a combined detection approach (static person

  14. Airborne sensors for detecting large marine debris at sea.

    PubMed

    Veenstra, Timothy S; Churnside, James H

    2012-01-01

    The human eye is an excellent, general-purpose airborne sensor for detecting marine debris larger than 10 cm on or near the surface of the water. Coupled with the human brain, it can adjust for light conditions and sea-surface roughness, track persistence, differentiate color and texture, detect change in movement, and combine all of the available information to detect and identify marine debris. Matching this performance with computers and sensors is difficult at best. However, there are distinct advantages over the human eye and brain that sensors and computers can offer such as the ability to use finer spectral resolution, to work outside the spectral range of human vision, to control the illumination, to process the information in ways unavailable to the human vision system, to provide a more objective and reproducible result, to operate from unmanned aircraft, and to provide a permanent record that can be used for later analysis. PMID:21300380

  15. An airborne real-time hyperspectral target detection system

    NASA Astrophysics Data System (ADS)

    Skauli, Torbjorn; Haavardsholm, Trym V.; Kåsen, Ingebjørg; Arisholm, Gunnar; Kavara, Amela; Opsahl, Thomas Olsvik; Skaugen, Atle

    2010-04-01

    An airborne system for hyperspectral target detection is described. The main sensor is a HySpex pushbroom hyperspectral imager for the visible and near-infrared spectral range with 1600 pixels across track, supplemented by a panchromatic line imager. An optional third sensor can be added, either a SWIR hyperspectral camera or a thermal camera. In real time, the system performs radiometric calibration and georeferencing of the images, followed by image processing for target detection and visualization. The current version of the system implements only spectral anomaly detection, based on normal mixture models. Image processing runs on a PC with a multicore Intel processor and an Nvidia graphics processing unit (GPU). The processing runs in a software framework optimized for large sustained data rates. The platform is a Cessna 172 aircraft based close to FFI, modified with a camera port in the floor.

  16. Detecting Airborne Mercury by Use of Gold Nanowires

    NASA Technical Reports Server (NTRS)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Soler, Jessica; Mung, Nosang; Nix, Megan

    2009-01-01

    Like the palladium chloride (PdCl2) films described in the immediately preceding article, gold nanowire sensors have been found to be useful for detecting airborne elemental mercury at concentrations on the order of parts per billion (ppb). Also like the PdCl2 films, gold nanowire sensors can be regenerated under conditions much milder than those necessary for regeneration of gold films that have been used as airborne-Hg sensors. The interest in nanowire sensors in general is prompted by the expectation that nanowires of a given material covering a given surface may exhibit greater sensitivity than does a film of the same material because nanowires have a greater surface area. In preparation for experiments to demonstrate this sensor concept, sensors were fabricated by depositing gold nanowires, variously, on microhotplate or microarray sensor substrates. In the experiments, the electrical resistances were measured while the sensors were exposed to air at a temperature of 25 C and relative humidity of about 30 percent containing mercury at various concentrations from 2 to 70 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury at ppb concentrations in room-temperature air and can be regenerated by exposure to clean flowing air at temperatures <40 C.

  17. Airborne Detection and Tracking of Geologic Leakage Sites

    NASA Astrophysics Data System (ADS)

    Jacob, Jamey; Allamraju, Rakshit; Axelrod, Allan; Brown, Calvin; Chowdhary, Girish; Mitchell, Taylor

    2014-11-01

    Safe storage of CO2 to reduce greenhouse gas emissions without adversely affecting energy use or hindering economic growth requires development of monitoring technology that is capable of validating storage permanence while ensuring the integrity of sequestration operations. Soil gas monitoring has difficulty accurately distinguishing gas flux signals related to leakage from those associated with meteorologically driven changes of soil moisture and temperature. Integrated ground and airborne monitoring systems are being deployed capable of directly detecting CO2 concentration in storage sites. Two complimentary approaches to detecting leaks in the carbon sequestration fields are presented. The first approach focuses on reducing the requisite network communication for fusing individual Gaussian Process (GP) CO2 sensing models into a global GP CO2 model. The GP fusion approach learns how to optimally allocate the static and mobile sensors. The second approach leverages a hierarchical GP-Sigmoidal Gaussian Cox Process for airborne predictive mission planning to optimally reducing the entropy of the global CO2 model. Results from the approaches will be presented.

  18. Detection of Airborne Lactococcal Bacteriophages in Cheese Manufacturing Plants▿

    PubMed Central

    Verreault, Daniel; Gendron, Louis; Rousseau, Geneviève M.; Veillette, Marc; Massé, Daniel; Lindsley, William G.; Moineau, Sylvain; Duchaine, Caroline

    2011-01-01

    The dairy industry adds starter bacterial cultures to heat-treated milk to control the fermentation process during the manufacture of many cheeses. These highly concentrated bacterial populations are susceptible to virulent phages that are ubiquitous in cheese factories. In this study, the dissemination of these phages by the airborne route and their presence on working surfaces were investigated in a cheese factory. Several surfaces were swabbed, and five air samplers (polytetrafluoroethylene filter, polycarbonate filter, BioSampler, Coriolis cyclone sampler, and NIOSH two-stage cyclone bioaerosol personal sampler) were tested. Samples were then analyzed for the presence of two Lactococcus lactis phage groups (936 and c2), and quantification was done by quantitative PCR (qPCR). Both lactococcal phage groups were found on most swabbed surfaces, while airborne phages were detected at concentrations of at least 103 genomes/m3 of air. The NIOSH sampler had the highest rate of air samples with detectable levels of lactococcal phages. This study demonstrates that virulent phages can circulate through the air and that they are ubiquitous in cheese manufacturing facilities. PMID:21115712

  19. Airborne Turbulence Detection and Warning ACLAIM Flight Test Results

    NASA Technical Reports Server (NTRS)

    Hannon, Stephen M.; Bagley, Hal R.; Soreide, Dave C.; Bowdle, David A.; Bogue, Rodney K.; Ehernberger, L. Jack

    1999-01-01

    The Airborne Coherent Lidar for Advanced Inflight Measurements (ACLAIM) is a NASA/Dryden-lead program to develop and demonstrate a 2 micrometers pulsed Doppler lidar for airborne look-ahead turbulence detection and warning. Advanced warning of approaching turbulence can significantly reduce injuries to passengers and crew aboard commercial airliners. The ACLAIM instrument is a key asset to the ongoing Turbulence component of NASA's Aviation Safety Program, aimed at reducing the accident rate aboard commercial airliners by a factor of five over the next ten years and by a factor of ten over the next twenty years. As well, the advanced turbulence warning capability can prevent "unstarts" in the inlet of supersonic aircraft engines by alerting the flight control computer which then adjusts the engine to operate in a less fuel efficient, and more turbulence tolerant, mode. Initial flight tests of the ACLAIM were completed in March and April of 1998. This paper and presentation gives results from these initial flights, with validated demonstration of Doppler lidar wind turbulence detection several kilometers ahead of the aircraft.

  20. Detection of windthrown trees using airborne laser scanning

    NASA Astrophysics Data System (ADS)

    Nyström, Mattias; Holmgren, Johan; Fransson, Johan E. S.; Olsson, Håkan

    2014-08-01

    In this study, a method has been developed for the detection of windthrown trees under a forest canopy, using the difference between two elevation models created from the same high density (65 points/m2) airborne laser scanning data. The difference image showing objects near the ground was created by subtracting a standard digital elevation model (DEM) from a more detailed DEM created using an active surface algorithm. Template matching was used to automatically detect windthrown trees in the difference image. The 54 ha study area is located in hemi-boreal forest in southern Sweden (Lat. 58°29‧ N, Long. 13°38‧ E) and is dominated by Norway spruce (Picea abies) with 3.5% deciduous species (mostly birch) and 1.7% Scots pine (Pinus sylvestris). The result was evaluated using 651 field measured windthrown trees. At individual tree level, the detection rate was 38% with a commission error of 36%. Much higher detection rates were obtained for taller trees; 89% of the trees taller than 27 m were detected. For pine the individual tree detection rate was 82%, most likely due to the more easily visible stem and lack of branches. When aggregating the results to 40 m square grid cells, at least one tree was detected in 77% of the grid cells which according to the field measurements contained one or more windthrown trees.

  1. The MINEFIELD Exercise: "The Challenge" in Entrepreneurship Education.

    ERIC Educational Resources Information Center

    Robinson, Peter B.

    1996-01-01

    The MINEFIELD exercise is an experiential learning activity in entrepreneurship education which simulates a group escape from a prisoner of war camp. This article describes the scenario, probable outcomes, and game variations. Debriefing questions highlight concepts like vision and mission, strategies versus tactics, management versus leadership,…

  2. Windshear avoidance - Requirements and proposed system for airborne lidar detection

    NASA Technical Reports Server (NTRS)

    Targ, Russell; Bowles, Roland L.

    1988-01-01

    A generalized windshear hazard index is derived from considerations of wind conditions and an aircraft's present and potential altitude. Based on a systems approach to the windshear threat, lidar appears to be a viable methodology for windshear detection and avoidance, even in conditions of moderately heavy precipitation. The airborne CO2 and Ho:YAG lidar windshear detection systems analyzed can each give the pilot information about the line-of-sight component of windshear threat from his present position to a region extending 1 to 3 km in front of the aircraft. This constitutes a warning time of 15 to 45 s. The technology necessary to design, build and test such a brassboard 10.6-micron CO2 lidar is at hand.

  3. Algorithms for airborne Doppler radar wind shear detection

    NASA Technical Reports Server (NTRS)

    Gillberg, Jeff; Pockrandt, Mitch; Symosek, Peter; Benser, Earl T.

    1992-01-01

    Honeywell has developed algorithms for the detection of wind shear/microburst using airborne Doppler radar. The Honeywell algorithms use three dimensional pattern recognition techniques and the selection of an associated scanning pattern forward of the aircraft. This 'volumetric scan' approach acquires reflectivity, velocity, and spectral width from a three dimensional volume as opposed to the conventional use of a two dimensional azimuthal slice of data at a fixed elevation. The algorithm approach is based on detection and classification of velocity patterns which are indicative of microburst phenomenon while minimizing the false alarms due to ground clutter return. Simulation studies of microburst phenomenon and x-band radar interaction with the microburst have been performed and results of that study are presented. Algorithm performance indetection of both 'wet' and 'dry' microbursts is presented.

  4. Progress in Development of an Airborne Turbulence Detection System

    NASA Technical Reports Server (NTRS)

    Hamilton, David W.; Proctor, Fred H.

    2006-01-01

    Aircraft encounters with turbulence are the leading cause of in-flight injuries (Tyrvanas 2003) and have occasionally resulted in passenger and crew fatalities. Most of these injuries are caused by sudden and unexpected encounters with severe turbulence in and around convective activity (Kaplan et al 2005). To alleviate this problem, the Turbulence Prediction and Warning Systems (TPAWS) element of NASA s Aviation Safety program has investigated technologies to detect and warn of hazardous in-flight turbulence. This effort has required the numerical modeling of atmospheric convection: 1) for characterizing convectively induced turbulence (CIT) environments, 2) for defining turbulence hazard metrics, and 3) as a means of providing realistic three-dimensional data sets that can be used to test and evaluate turbulence detection sensors. The data sets are being made available to industry and the FAA for certification of future airborne turbulence-detection systems (ATDS) with warning capability. Early in the TPAWS project, a radar-based ATDS was installed and flight tested on NASA s research aircraft, a B-757. This ATDS utilized new algorithms and hazard metrics that were developed for use with existing airborne predictive windshear radars, thus avoiding the installation of new hardware. This system was designed to detect and warn of hazardous CIT even in regions with weak radar reflectivity (i.e. 5-15 dBz). Results from an initial flight test of the ATDS were discussed in Hamilton and Proctor (2002a; 2002b). In companion papers (Proctor et al 2002a; 2002b), a numerical simulation of the most significant encounter from that flight test was presented. Since the presentation of these papers a second flight test has been conducted providing additional cases for examination. In this paper, we will present results from NASA s flight test and a numerical model simulation of a turbulence environment encountered on 30 April 2002. Progress leading towards FAA certification of

  5. Airborne polarized lidar detection of scattering layers in the ocean.

    PubMed

    Vasilkov, A P; Goldin, Y A; Gureev, B A; Hoge, F E; Swift, R N; Wright, C W

    2001-08-20

    A polarized lidar technique based on measurements of waveforms of the two orthogonal-polarized components of the backscattered light pulse is proposed to retrieve vertical profiles of the seawater scattering coefficient. The physical rationale for the polarized technique is that depolarization of backscattered light originating from a linearly polarized laser beam is caused largely by multiple small-angle scattering from particulate matter in seawater. The magnitude of the small-angle scattering is determined by the scattering coefficient. Therefore information on the vertical distribution of the scattering coefficient can be derived potentially from measurements of the time-depth dependence of depolarization in the backscattered laser pulse. The polarized technique was verified by field measurements conducted in the Middle Atlantic Bight of the western North Atlantic Ocean that were supported by in situ measurements of the beam attenuation coefficient. The airborne polarized lidar measured the time-depth dependence of the backscattered laser pulse in two orthogonal-polarized components. Vertical profiles of the scattering coefficient retrieved from the time-depth depolarization of the backscattered laser pulse were compared with measured profiles of the beam attenuation coefficient. The comparison showed that retrieved profiles of the scattering coefficient clearly reproduce the main features of the measured profiles of the beam attenuation coefficient. Underwater scattering layers were detected at depths of 20-25 m in turbid coastal waters. The improvement in dynamic range afforded by the polarized lidar technique offers a strong potential benefit for airborne lidar bathymetric applications. PMID:18360476

  6. Airborne system for detection and location of radio interference sources

    NASA Astrophysics Data System (ADS)

    Audone, Bruno; Pastore, Alberto

    1992-11-01

    The rapid expansion of telecommunication has practically saturated every band of Radio Frequency Spectrum; a similar expansion of electrical and electronic devices has affected all radio communications which are, in some way, influenced by a large amount of interferences, either intentionally or unintentionally produced. Operational consequences of these interferences, particularly in the frequency channels used for aeronautical services, can be extremely dangerous, making mandatory a tight control of Electromagnetic Spectrum. The present paper analyzes the requirements and the problems related to the surveillance, for civil application, of the Electromagnetic Spectrum between 20 and 1000 MHz, with particular attention to the detection and location of radio interference sources; after a brief introduction and the indication of the advantages of an airborne versus ground installation, the airborne system designed by Alenia in cooperation with Italian Ministry of Post and Telecommunication, its practical implementation and the prototype installation on board of a small twin turboprop aircraft for experimentation purposes is presented. The results of the flight tests are also analyzed and discussed.

  7. Object-based detection of vehicles in airborne data

    NASA Astrophysics Data System (ADS)

    Schilling, Hendrik; Bulatov, Dimitri; Middelmann, Wolfgang

    2015-10-01

    Robust detection of vehicles in airborne data is a challenging task since a high variation in the object signatures - depending on data resolution - and often a small contrast between objects and background lead to high false classification rates and missed detections. Despite these facts, many applications require reliable results which can be obtained in a short time. In this paper, an object-based approach for vehicle detection in airborne laser scans (ALS) and photogrammetrically reconstructed 2.5D data is described. The focus of this paper lies on a robust object segmentation algorithm as well as the identification of features for a reliable separation between vehicles and background (all nonevehicle objects) on different scenes. The described method is based on three consecutive steps, namely, object segmentation, feature extraction and supervised classification. In the first step, the 2.5D data is segmented and possible targets are identified. The segmentation progress is based on the morphological top-hat filtering, which leaves areas that are smaller than a given filter size and higher (brighter) than their surroundings. The approach is chosen due to the low computational effort of this filter, which allows a fast computation even for large areas. The next step is feature extraction. Based on the initial segmentation, features for every identified object are extracted. In addition to frequently used features like height above ground, object area, or point distribution, more complex features like object planarity, entropy in the intensity image, and lineness measures are used. The last step contains classification of each object. For this purpose, a random forest classifier (RF) using the normalized features extracted in the previous step is chosen. RFs are suitable for high dimensional and nonlinear problems. In contrast to other approaches (e.g. maximum likelihood classifier), RFs achieves good results even with relatively small training samples.

  8. Molecular detection of airborne Coccidioides in Tucson, Arizona.

    PubMed

    Chow, Nancy A; Griffin, Dale W; Barker, Bridget M; Loparev, Vladimir N; Litvintseva, Anastasia P

    2016-08-01

    Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detecting Coccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides. PMID:27143633

  9. Molecular detection of airborne Coccidioides in Tucson, Arizona

    USGS Publications Warehouse

    Chow, Nancy A.; Griffin, Dale W.; Barker, Bridget M.; Loparev, Vladimir N.; Litvintseva, Anastasia P.

    2016-01-01

    Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detectingCoccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides.

  10. Airborne-mercury detection by resonant UV laser pumping.

    PubMed

    Bahns, J T; Lynds, L; Stwalley, W C; Simmons, V; Robinson, T; Bililign, S

    1997-05-15

    Optical pumping of the Hg(0) (6s (1)S(0) --> 6p (3)P(1)) transition at 253.7 nm (in air) leads to extremely fast energy transfer and strong laser-induced-fluorescence (LIF) from the Hg(0) (7s(3)S(1) --> 6p (3)P(2)) green transition at 546.2 nm, which is not directly populated by the laser. Ionization occurs simultaneously and becomes particularly strong at reduced background pressures. These observations are consistent with the existence of a multiphoton process followed by electron collisional excitation. Preliminary studies are made to evaluate these phenomena for detecting elemental airborne mercury by LIF and point monitoring with an ionization detector. Measured sensitivities of 2 and 10 parts in 10(9) (ppb), respectively, at 0.1-Torr air pressure are projected to increase to 1 x 10(-4) and 1 x 10(-5) ppb after relevant system optimization. PMID:18185642

  11. Detection of single graves by airborne hyperspectral imaging.

    PubMed

    Leblanc, G; Kalacska, M; Soffer, R

    2014-12-01

    Airborne hyperspectral imaging (HSI) was assessed as a potential tool to locate single grave sites. While airborne HSI has shown to be useful to locate mass graves, it is expected the location of single graves would be an order of magnitude more difficult due to the smaller size and reduced mass of the targets. Two clearings were evaluated (through a blind test) as potential sites for containing at least one set of buried remains. At no time prior to submitting the locations of the potential burial sites from the HSI were the actual locations of the sites released or shared with anyone from the analysis team. The two HSI sensors onboard the aircraft span the range of 408-2524nm. A range of indicators that exploit the narrow spectral and spatial resolutions of the two complimentary HSI sensors onboard the aircraft were calculated. Based on the co-occurrence of anomalous pixels within the expected range of the indicators three potential areas conforming to our underlying assumptions of the expected spectral responses (and spatial area) were determined. After submission of the predicted burial locations it was revealed that two of the targets were located within GPS error (10m) of the true burial locations. Furthermore, due to the history of the TPOF site for burial work, investigation of the third target is being considered in the near future. The results clearly demonstrate promise for hyperspectral imaging to aid in the detection of buried remains, however further work is required before these results can justifiably be used in routine scenarios. PMID:25447169

  12. Ice island detection and characterization with airborne synthetic aperture radar

    SciTech Connect

    Jeffries, M.O.; Sackinger, W.M. )

    1990-04-15

    A 1:300,000 scale airborne synthetic aperture radar (SAR) image of an area of the Arctic Ocean adjacent to the Queen Elizabeth Islands, Canadian High Arctic, is examined to determine the number and characteristics of ice islands in the image and to assess the capability of airborne and satellite SAR to detect ice islands. Twelve ice islands have been identified, and their dimensions range from as large as 5.7 km by 8.7 km to as small as 0.15 km by 0.25 km. A significant SAR characteristic of the shelf ice portions of ice islands is a return with a ribbed texture of alternating lighter and darker grey tones resulting from the indulating shelf ice surfaces of the ice islands. The appearance of the ribbed texture varies according to the ice islands' orientation relative to the illumination direction and consequently the incidence angle. Some ice islands also include extensive areas of textureless dark tone attached to the shelf ice. The weak returns correspond to (1) multiyear landfast sea ice that was attached to the front of the Ward Hunt Ice Shelf at the time of calving and which has remained attached since then and (2) multiyear pack ice that has become attached and consolidated since the calving, indicating that ice islands can increase their area and mass significantly as they drift. Ice islands are easily discernible in SAR images and for the future SAR represents a promising technique to obtain a census of ice islands in the Arctic Ocean. However, any SAR-based census probably will be conservative because ice islands smaller than 300-400 m across are likely to remain undetected, particularly in areas of heavy ice ridging which produces strong SAR clutter.

  13. Fe2O3 nanoparticles for airborne organophosphate detection

    NASA Astrophysics Data System (ADS)

    Phillips, Joshua; Soliz, Jennifer; Hauser, Adam

    Dire need for early detection of organophosphates (OP) exists in both civilian (pesticide/herbicide buildup) and military (G/V nerve agents) spheres. Nanoparticle materials are excellent candidates for the detection and/or decontamination of hazardous materials, owing to their large surface to volume ratios and tailored surface functionality. Within this category, metal oxides include structures that are stable with the range of normal environmental conditions (temperature, humidity), but have strong, specific reaction mechanisms (hydrolysis, oxidation, catalysis, stoichiometric reaction) with toxic compounds. In this talk, we will present on the suitability of Fe2O3 nanoparticles as airborne organophosphate detectors. 23 nm particles were exposed to a series of organophosphate compounds (dimethyl methylphosphonate, dimethyl chlorophosphonate, diisopropyl methylphosphonate), and studied by x-ray magnetic circular dichroism and x-ray absorption spectroscopy to confirm the stoichiometric Fe2O3 to FeO mechanism and determine magnetic sensor feasibility. AC Impedance Spectroscopy shows both high sensitivity and selectivity via frequency dependence in both impedance and resistivity, suggesting some feasibility for impedimetric devices. We acknowledge funding under Army Research Office STIR Award #W911F-15-1-0104. J.R.S. acknowledges funding from the Defense Threat Reduction Agency under Projects BA13PHM210 and BA07PRO104. J.R.S. also acknowledges funding under a NRC fellowship.

  14. Preliminary report on self-healing minefield (frogs) concepts and utility in battle

    SciTech Connect

    Greenwalt, R J; Magnoli, D

    2000-01-13

    The purpose of this study is to determine battlefield effectiveness of the self-healing minefield (''Frogs'') concept system compared to basecases of the standard AP/AT (anti-personnel/anti-tank) mixed minefield, the AT (anti-tank) pure minefield, and no minefields. This involves tactical modeling where a basecase with and without mines is compared to the concept system. However, it is first necessary to establish system characteristics and behavior of the Frog mine and minefield in order to do the tactical modeling. This initial report provides emerging insights into various minefield parameters in order to allow better program definition early in the conceptual development. In the following sections of this report, we investigate the self-healing minefield's ground pattern and several concepts for movement (''jump'') of a mine. Basic enemy breaching techniques are compared for the different mine movement concepts. These results are then used in the (Joint Conflict and Tactical Simulation) JCATS tactical model to evaluate minefield effects in a combat situation. The three basecases and the Frogs concept are used against a North Korean mechanized rifle battalion and outcomes are compared. Preliminary results indicate: (1) Possible breaching techniques for the self-healing minefield were proposed and compared through simulation modeling. Of these, the best breaching counter to the self-healing minefield is the ''wide-lane'' breach technique. (2) Several methods for mine movement are tested and the optimal method from this group was selected for use in the modeling. However, continued work is needed on jump criteria; a more sophisticated model may reduce the advantage of the breach counter. (3) The battle scenario used in this study is a very difficult defense for Blue. In the three baseline cases (no mines, AT mines only, and mixed AT/AP minefield), Blue loses. Only in the Frog case does Blue win, and it is a high casualty win.

  15. ADELE: an Airborne Instrument to Detect Relativistic Runaway

    NASA Astrophysics Data System (ADS)

    Hazelton, B. J.; Grefenstette, B. W.; Smith, D. M.; Dwyer, J. R.

    2006-12-01

    The Airborne Detector for Energetic Lightning Emissions (ADELE) is an instrument currently under development to detect x-ray and gamma-ray emissions from thunderstorms. Phenomena of interest include terrestrial gamma-ray flashes (TGFs), hard x-ray bursts from lightning leaders, and minute-scale changes in the gamma-ray background due to gradual relativistic runaway. ADELE will be mounted in research aircraft such as the NSF/NCAR Gulfstream V operated under the HIAPER program. Missions will be flown directly above low thunderstorms and to the sides of taller thunderstorms to observe lightning-related phenomena near their origin. The ADELE detectors will be designed to maximize dynamic range, with large-area detectors for faint events and extremely fast detectors and electronics to prevent saturation during nearby events with high count rates. The goal is to capture thousands of gammas per TGF as opposed to the dozens captured by detectors in orbit. A flat-plate antenna will measure fast electric-field transients simultaneously. Campaigns will be carried out in the Great Plains, Florida, and the Caribbean beginning in 2009. We are seeking collaborators to make simultaneous observations of radio atmospherics, transient luminous events, and other electrical phenomena during these campaigns.

  16. Roof heat loss detection using airborne thermal infrared imagery

    NASA Astrophysics Data System (ADS)

    Kern, K.; Bauer, C.; Sulzer, W.

    2012-12-01

    As part of the Austrian and European attempt to reduce energy consumption and greenhouse gas emissions, thermal rehabilitation and the improvement of the energy efficiency of buildings became an important topic in research as well as in building construction and refurbishment. Today, in-situ thermal infrared measurements are routinely used to determine energy loss through the building envelope. However, in-situ thermal surveys are expensive and time consuming, and in many cases the detection of the amount and location of waste heat leaving building through roofs is not possible with ground-based observations. For some years now, a new generation of high-resolution thermal infrared sensors makes it possible to survey heat-loss through roofs at a high level of detail and accuracy. However, to date, comparable studies have mainly been conducted on buildings with uniform roof covering and provided two-dimensional, qualitative information. This pilot study aims to survey the heat-loss through roofs of the buildings of the University of Graz (Austria) campus by using high-resolution airborne thermal infrared imagery (TABI 1800 - Thermal Airborne Broadband imager). TABI-1800 acquires data in a spectral range from 3.7 - 4.8 micron, a thermal resolution of 0.05 °C and a spatial resolution of 0.6 m. The remote sensing data is calibrated to different roof coverings (e.g. clay shingle, asphalt shingle, tin roof, glass) and combined with a roof surface model to determine the amount of waste heat leaving the building and to identify hot spots. The additional integration of information about the conditions underneath the roofs into the study allows a more detailed analysis of the upward heat flux and is a significant improvement of existing methods. The resulting data set provides useful information to the university facility service for infrastructure maintenance, especially in terms of attic and roof insulation improvements. Beyond that, the project is supposed to raise public

  17. Detection of multiple airborne targets from multisensor data

    NASA Astrophysics Data System (ADS)

    Foltz, Mark A.; Srivastava, Anuj; Miller, Michael I.; Grenander, Ulf

    1995-08-01

    Previously we presented a jump-diffusion based random sampling algorithm for generating conditional mean estimates of scene representations for the tracking and recongition of maneuvering airborne targets. These representations include target positions and orientations along their trajectories and the target type associated with each trajectory. Taking a Bayesian approach, a posterior measure is defined on the parameter space by combining sensor models with a sophisticated prior based on nonlinear airplane dynamics. The jump-diffusion algorithm constructs a Markov process which visits the elements of the parameter space with frequencies proportional to the posterior probability. It consititutes both the infinitesimal, local search via a sample path continuous diffusion transform and the larger, global steps through discrete jump moves. The jump moves involve the addition and deletion of elements from the scene configuration or changes in the target type assoviated with each target trajectory. One such move results in target detection by the addition of a track seed to the inference set. This provides initial track data for the tracking/recognition algorithm to estimate linear graph structures representing tracks using the other jump moves and the diffusion process, as described in our earlier work. Target detection ideally involves a continuous research over a continuum of the observation space. In this work we conclude that for practical implemenations the search space must be discretized with lattice granularity comparable to sensor resolution, and discuss how fast Fourier transforms are utilized for efficient calcuation of sufficient statistics given our array models. Some results are also presented from our implementation on a networked system including a massively parallel machine architecture and a silicon graphics onyx workstation.

  18. Species identification of airborne molds and its significance for the detection of indoor pollution

    SciTech Connect

    Fradkin, A.; Tobin, R.S.; Tario, S.M.; Tucic-Porretta, M.; Malloch, D.

    1987-01-01

    The present study was undertaken to investigate species composition and prevalence of culturable particles of airborne fungi in 27 homes in Toronto, Canada. Its major objective is to examine the significance of species identification for the detection of indoor pollution.

  19. Trueness, Precision, and Detectability for Sampling and Analysis of Organic Species in Airborne Particulate Matter

    EPA Science Inventory

    Recovery. precision, limits of detection and quantitation, blank levels, calibration linearity, and agreement with certified reference materials were determined for two classes of organic components of airborne particulate matter, polycyclic aromatic hydrocarbons and hopanes usin...

  20. Target detection algorithm for airborne thermal hyperspectral data

    NASA Astrophysics Data System (ADS)

    Marwaha, R.; Kumar, A.; Raju, P. L. N.; Krishna Murthy, Y. V. N.

    2014-11-01

    Airborne hyperspectral imaging is constantly being used for classification purpose. But airborne thermal hyperspectral image usually is a challenge for conventional classification approaches. The Telops Hyper-Cam sensor is an interferometer-based imaging system that helps in the spatial and spectral analysis of targets utilizing a single sensor. It is based on the technology of Fourier-transform which yields high spectral resolution and enables high accuracy radiometric calibration. The Hypercam instrument has 84 spectral bands in the 868 cm-1 to 1280 cm-1 region (7.8 μm to 11.5 μm), at a spectral resolution of 6 cm-1 (full-width-half-maximum) for LWIR (long wave infrared) range. Due to the Hughes effect, only a few classifiers are able to handle high dimensional classification task. MNF (Minimum Noise Fraction) rotation is a data dimensionality reducing approach to segregate noise in the data. In this, the component selection of minimum noise fraction (MNF) rotation transformation was analyzed in terms of classification accuracy using constrained energy minimization (CEM) algorithm as a classifier for Airborne thermal hyperspectral image and for the combination of airborne LWIR hyperspectral image and color digital photograph. On comparing the accuracy of all the classified images for airborne LWIR hyperspectral image and combination of Airborne LWIR hyperspectral image with colored digital photograph, it was found that accuracy was highest for MNF component equal to twenty. The accuracy increased by using the combination of airborne LWIR hyperspectral image with colored digital photograph instead of using LWIR data alone.

  1. Airborne Hyperspectral Imagery for the Detection of Agricultural Crop Stress

    NASA Technical Reports Server (NTRS)

    Cassady, Philip E.; Perry, Eileen M.; Gardner, Margaret E.; Roberts, Dar A.

    2001-01-01

    Multispectral digital imagery from aircraft or satellite is presently being used to derive basic assessments of crop health for growers and others involved in the agricultural industry. Research indicates that narrow band stress indices derived from hyperspectral imagery should have improved sensitivity to provide more specific information on the type and cause of crop stress, Under funding from the NASA Earth Observation Commercial Applications Program (EOCAP) we are identifying and evaluating scientific and commercial applications of hyperspectral imagery for the remote characterization of agricultural crop stress. During the summer of 1999 a field experiment was conducted with varying nitrogen treatments on a production corn-field in eastern Nebraska. The AVIRIS (Airborne Visible-Infrared Imaging Spectrometer) hyperspectral imager was flown at two critical dates during crop development, at two different altitudes, providing images with approximately 18m pixels and 3m pixels. Simultaneous supporting soil and crop characterization included spectral reflectance measurements above the canopy, biomass characterization, soil sampling, and aerial photography. In this paper we describe the experiment and results, and examine the following three issues relative to the utility of hyperspectral imagery for scientific study and commercial crop stress products: (1) Accuracy of reflectance derived stress indices relative to conventional measures of stress. We compare reflectance-derived indices (both field radiometer and AVIRIS) with applied nitrogen and with leaf level measurement of nitrogen availability and chlorophyll concentrations over the experimental plots (4 replications of 5 different nitrogen levels); (2) Ability of the hyperspectral sensors to detect sub-pixel areas under crop stress. We applied the stress indices to both the 3m and 18m AVIRIS imagery for the entire production corn field using several sub-pixel areas within the field to compare the relative

  2. AIRBORNE, OPTICAL REMOTE SENSNG OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION

    SciTech Connect

    Jerry Myers

    2005-04-15

    Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. The scope of the work involved designing and developing an airborne, optical remote sensor capable of sensing methane and, if possible, ethane for the detection of natural gas pipeline leaks. Flight testing using a custom dual wavelength, high power fiber amplifier was initiated in February 2005. Ophir successfully demonstrated the airborne system, showing that it was capable of discerning small amounts of methane from a simulated pipeline leak. Leak rates as low as 150 standard cubic feet per hour (scf/h) were detected by the airborne sensor.

  3. Numerical investigation of coal seam gas detection using airborne electromagnetics

    NASA Astrophysics Data System (ADS)

    Abdulla, Mohamed

    The use of airborne electromagnetic (AEM) techniques has been mostly utilized in the mining industry. The various AEM systems enable fast data acquisition to detect zones of interest in exploration and in some cases are used to delineate targets on a production scale. For coal seam gas (CSG) reservoirs, reservoir thickness and the resistivity contrast present a new challenge to the present AEM systems in terms of detectability. Our research question began with the idea of using AEM methods in the detection of thin reservoirs. CSG reservoirs resemble thin reservoirs that have been and are currently being produced. In this thesis we present the results of a feasibility analysis of AEM study on coal seam reservoirs using synthetic models. The aim of the study is to contribute and bridge the gap of the scientific literature on AEM systems in settings such as CSG exploration. In the models we have chosen to simulate both in 1-D and 3-D, the CSG target resistivity was varied from a resistive to a conductive target (4 ohm.m, 150 ohm.m, and 667 ohm.m) to compare the different responses while the target thickness was fixed to resemble a stack of coal seams at that interval. Due to the differences in 1-D and 3-D modelling, we also examine the differences resulting from each modelling set up. The results of the 1-D forward modeling served as a first order understanding of the detection depths by AEM for CSG reservoirs. Three CSG reservoir horizontally layered earth model scenarios were examined, half-space, conductive/resistive and resistive/conductive. The response behavior for each of the three scenarios differs with the differing target resistivities. The 1-D modeling in both the halfspace and conductive/resistive models shows detection at depths beyond 300 m for three cases of target resistivity outlined above. After the 300-m depth, the response falls below the assumed noise floor level of 5% response difference. However, when a resistive layer overlies a conductive host

  4. Detecting tropical forest biomass dynamics from repeated airborne lidar measurements

    NASA Astrophysics Data System (ADS)

    Meyer, V.; Saatchi, S. S.; Chave, J.; Dalling, J. W.; Bohlman, S.; Fricker, G. A.; Robinson, C.; Neumann, M.; Hubbell, S.

    2013-08-01

    Reducing uncertainty of terrestrial carbon cycle depends strongly on the accurate estimation of changes of global forest carbon stock. However, this is a challenging problem from either ground surveys or remote sensing techniques in tropical forests. Here, we examine the feasibility of estimating changes of tropical forest biomass from two airborne lidar measurements of forest height acquired about 10 yr apart over Barro Colorado Island (BCI), Panama. We used the forest inventory data from the 50 ha Center for Tropical Forest Science (CTFS) plot collected every 5 yr during the study period to calibrate the estimation. We compared two approaches for detecting changes in forest aboveground biomass (AGB): (1) relating changes in lidar height metrics from two sensors directly to changes in ground-estimated biomass; and (2) estimating biomass from each lidar sensor and then computing changes in biomass from the difference of two biomass estimates, using two models, namely one model based on five relative height metrics and the other based only on mean canopy height (MCH). We performed the analysis at different spatial scales from 0.04 ha to 10 ha. Method (1) had large uncertainty in directly detecting biomass changes at scales smaller than 10 ha, but provided detailed information about changes of forest structure. The magnitude of error associated with both the mean biomass stock and mean biomass change declined with increasing spatial scales. Method (2) was accurate at the 1 ha scale to estimate AGB stocks (R2 = 0.7 and RMSEmean = 27.6 Mg ha-1). However, to predict biomass changes, errors became comparable to ground estimates only at a spatial scale of about 10 ha or more. Biomass changes were in the same direction at the spatial scale of 1 ha in 60 to 64% of the subplots, corresponding to p values of respectively 0.1 and 0.033. Large errors in estimating biomass changes from lidar data resulted from the uncertainty in detecting changes at 1 ha from ground census data

  5. Detection of Perfectly-Conducting Targets with Airborne Electromagnetic Systems

    NASA Astrophysics Data System (ADS)

    Smiarowski, Adam

    A significant problem with exploring for electrically conductive mineral deposits with airborne electromagnetic (AEM) methods is that many of the most valuable sulphide deposits are too conductive to be detected with conventional systems. High-grade sulphide deposits with bulk electrical conductivities on the order of 100,000 S/m can appear as "perfect conductors" to most EM systems because the decay of secondary fields (the "time constant" of the deposit) generated in the target by the system transmitter takes much longer than the short measuring time of EM systems. Their EM response is essentially undetectable with off-time measurements. One solution is to make measurements during the transmitter on-time when the secondary field of the target produced by magnetic flux exclusion is large. The difficulty is that the secondary field must be measured in the presence of a primary field which is orders of magnitude larger. The goal of this thesis is to advance the methodology of making AEM measurements during transmitter on-time by analysing experimental data from three different AEM systems. The first system analysed is a very large separation, two helicopter system where geometry is measured using GPS sensors. In order to calculate the primary field at the receiver with sufficient accuracy, the very large (nominally 400 m) separation requires geometry to be known to better than 1 m. Using the measured geometry to estimate and remove the primary field, I show that a very conductive target can be detected at depths of 200m using the total secondary field. I then used fluxgate magnetometers to correct for receiver rotation which allowed the component of the secondary field to be determined. The second system I examined was a large separation fixed-wing AEM system. Using a towed receiver bird with a smaller (≈ 135m) separation, the geometry must be known much more accurately. In the absence of direct measurement of this geometry, I used a least-squares prediction

  6. A medium resolution minefield model suitable for entity-level resolution combat simulations

    SciTech Connect

    Powell, E.T.

    1994-06-09

    A new, flexible, and realistic representation of conventional minefields in entity-level resolution combat simulations is presented. The model includes important aspects of minefield effects on battlefield entities and of breaching devices on minefields. The model is designed at ``medium resolution,`` that is, it is general enough to depict a wide variety of tactical situations accurately; however, it only represents tactically significant aspects of mine warfare, discarding or aggregating details, thus minimizing computer memory and speed requirements. This paper describes the model in detail, its implementation in the Janus simulation code, and its use in a preliminary analysis effort related to the effect of delay on the tactical battlefield.

  7. An implementation of a medium resolution minefield model in the Joint Conflict Model

    SciTech Connect

    Pimper, J.E.; Matone, J.

    1995-01-13

    An implementation of a new, flexible, and realistic representation of conventional minefields in the Joint Conflict Model (JCM) is presented. The model includes important aspects of minefield effects on battlefield entities and of breaching devices on minefields. The model is designed at ``medium resolution,`` that is, it is general enough to depict a wide variety of tactical situations accurately; however, it only represents tactically significant aspects of mine warfare, discarding or aggregating details, thus minimizing computer memory and speed requirements. This paper describes the model in detail, its implementation in the JCM simulation code, and its use in a preliminary analysis effort related to the effect of delay on the tactical battlefield.

  8. Real-time remote detection and measurement for airborne imaging spectroscopy: a case study with methane

    NASA Astrophysics Data System (ADS)

    Thompson, D. R.; Leifer, I.; Bovensmann, H.; Eastwood, M.; Fladeland, M.; Frankenberg, C.; Gerilowski, K.; Green, R. O.; Kratwurst, S.; Krings, T.; Luna, B.; Thorpe, A. K.

    2015-06-01

    Localized anthropogenic sources of atmospheric CH4 are highly uncertain and temporally variable. Airborne remote measurement is an effective method to detect and quantify these emissions. In a campaign context, the science yield can be dramatically increased by real-time retrievals that allow operators to coordinate multiple measurements of the most active areas. This can improve science outcomes for both single- and multiple-platform missions. We describe a case study of the NASA/ESA CO2 and Methane Experiment (COMEX) campaign in California during June and August/September 2014. COMEX was a multi-platform campaign to measure CH4 plumes released from anthropogenic sources including oil and gas infrastructure. We discuss principles for real-time spectral signature detection and measurement, and report performance on the NASA Next Generation Airborne Visible Infrared Spectrometer (AVIRIS-NG). AVIRIS-NG successfully detected CH4 plumes in real-time at Gb s-1 data rates, characterizing fugitive releases in concert with other in situ and remote instruments. The teams used these real-time CH4 detections to coordinate measurements across multiple platforms, including airborne in situ, airborne non-imaging remote sensing, and ground-based in situ instruments. To our knowledge this is the first reported use of real-time trace gas signature detection in an airborne science campaign, and presages many future applications.

  9. An airborne system for detection of volcanic surface deformations

    NASA Technical Reports Server (NTRS)

    Lunine, J.

    1980-01-01

    A technique is proposed for measuring volcanic deformation on the order of centimeters per day to centimeters per year. An airborne multifrequency pulsed radar, tracking passive ground reflectors spaced at 1 kilometer intervals over a 50 square kilometer area is employed. Identification of targets is accomplished by Doppler and range resolution techniques, with final relative position measurements accomplished by phase comparison of multifrequency signals. Atmospheric path length errors are corrected by an airborne refractometer, meteorological instruments, or other refractive index measuring devices. Anticipated system accuracy is 1-2 cm, with measuring times on the order of minutes. Potential problems exist in the high intrinsic data assimilation rate required of the system to overcome ground backscatter noise.

  10. Technology for the detection of airborne intruders approaching the high-security high-value asset

    NASA Astrophysics Data System (ADS)

    Greneker, Eugene F., III

    1995-05-01

    Security plans to protect high-value assets usually concentrate on stopping potential ground intruders before they reach the asset. Barriers, such as fences, are the first line of defense against the found intruder, providing a delay mechanism. The sight of 10 to 12 foot high fencing topped with razor wire, guard towers, and roving patrols also serves as a psychological deterrent to the potential ground intrusion sensors between an outer and an inner barrier. This visible 'hardness' of a high-value asset makes airborne penetration more attractive, even though the airborne intruder may require training in the use of an aircraft or other airborne conveyance system. Certain airborne intrusion scenarios allow an adversary to penetrate much deeper and faster through delay and defense systems designed to deter the ground intruder. Since an airborne intruder can quickly reach the high-value asset, early detection critical to asset defense. Early detection of the airborne intruder also ensures appropriate use of the deadly force doctrine because the guard force has time to coordinate the response.

  11. An airborne laser fluorosensor for the detection of oil on water

    NASA Technical Reports Server (NTRS)

    Kim, H. H.; Hickman, G. D.

    1973-01-01

    The successful operation of an airborne laser fluorosensor system is reported that makes it possible to detect and map surface oil, either of natural-seepage or spill origin, on large bodies of water. Preliminary results indicate that the sensitivity of the instrument exceeds that of conventional passive remote sensors currently available for oil spill detection.

  12. Real-time detection of airborne asbestos by light scattering from magnetically re-aligned fibers.

    PubMed

    Stopford, Christopher; Kaye, Paul H; Greenaway, Richard S; Hirst, Edwin; Ulanowski, Zbigniew; Stanley, Warren R

    2013-05-01

    Inadvertent inhalation of asbestos fibers and the subsequent development of incurable cancers is a leading cause of work-related deaths worldwide. Currently, there is no real-time in situ method for detecting airborne asbestos. We describe an optical method that seeks to address this deficiency. It is based on the use of laser light scattering patterns to determine the change in angular alignment of individual airborne fibers under the influence of an applied magnetic field. Detection sensitivity estimates are given for both crocidolite (blue) and chrysotile (white) asbestos. The method has been developed with the aim of providing a low-cost warning device to trades people and others at risk from inadvertent exposure to airborne asbestos. PMID:23669992

  13. Real-time remote detection and measurement for airborne imaging spectroscopy: a case study with methane

    NASA Astrophysics Data System (ADS)

    Thompson, D. R.; Leifer, I.; Bovensmann, H.; Eastwood, M.; Fladeland, M.; Frankenberg, C.; Gerilowski, K.; Green, R. O.; Kratwurst, S.; Krings, T.; Luna, B.; Thorpe, A. K.

    2015-10-01

    Localized anthropogenic sources of atmospheric CH4 are highly uncertain and temporally variable. Airborne remote measurement is an effective method to detect and quantify these emissions. In a campaign context, the science yield can be dramatically increased by real-time retrievals that allow operators to coordinate multiple measurements of the most active areas. This can improve science outcomes for both single- and multiple-platform missions. We describe a case study of the NASA/ESA CO2 and MEthane eXperiment (COMEX) campaign in California during June and August/September 2014. COMEX was a multi-platform campaign to measure CH4 plumes released from anthropogenic sources including oil and gas infrastructure. We discuss principles for real-time spectral signature detection and measurement, and report performance on the NASA Next Generation Airborne Visible Infrared Spectrometer (AVIRIS-NG). AVIRIS-NG successfully detected CH4 plumes in real-time at Gb s-1 data rates, characterizing fugitive releases in concert with other in situ and remote instruments. The teams used these real-time CH4 detections to coordinate measurements across multiple platforms, including airborne in situ, airborne non-imaging remote sensing, and ground-based in situ instruments. To our knowledge this is the first reported use of real-time trace-gas signature detection in an airborne science campaign, and presages many future applications. Post-analysis demonstrates matched filter methods providing noise-equivalent (1σ) detection sensitivity for 1.0 % CH4 column enhancements equal to 141 ppm m.

  14. Comparison of different detection methods for citrus greening disease based on airborne multispectral and hyperspectral imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus greening or Huanglongbing (HLB) is a devastating disease spread in many citrus groves since first found in 2005 in Florida. Multispectral (MS) and hyperspectral (HS) airborne images of citrus groves in Florida were taken to detect citrus greening infected trees in 2007 and 2010. Ground truthi...

  15. Airborne Wind Shear Detection and Warning Systems: Third Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1991-01-01

    Papers presented at the conference on airborne wind shear detection and warning systems are compiled. The following subject areas are covered: terms of reference; case study; flight management; sensor fusion and flight evaluation; Terminal Doppler Weather Radar data link/display; heavy rain aerodynamics; and second generation reactive systems.

  16. Remote identification of potential boll weevil host plants: Airborne multispectral detection of regrowth cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Regrowth cotton plants can serve as potential hosts for boll weevils during and beyond the production season. Effective methods for timely areawide detection of these host plants are critically needed to expedite eradication in south Texas. We acquired airborne multispectral images of experimental...

  17. Detecting tropical forest biomass dynamics from repeated airborne Lidar measurements

    NASA Astrophysics Data System (ADS)

    Meyer, V.; Saatchi, S. S.; Chave, J.; Dalling, J.; Bohlman, S.; Fricker, G. A.; Robinson, C.; Neumann, M.

    2013-02-01

    Reducing uncertainty of terrestrial carbon cycle depends strongly on the accurate estimation of changes of global forest carbon stock. However, this is a challenging problem from either ground surveys or remote sensing techniques in tropical forests. Here, we examine the feasibility of estimating changes of tropical forest biomass from two airborne Lidar measurements acquired about 10 yr apart over Barro Colorado Island (BCI), Panama from high and medium resolution airborne sensors. The estimation is calibrated with the forest inventory data over 50 ha that was surveyed every 5 yr during the study period. We estimated the aboveground forest biomass and its uncertainty for each time period at different spatial scales (0.04, 0.25, 1.0 ha) and developed a linear regression model between four Lidar height metrics and the aboveground biomass. The uncertainty associated with estimating biomass changes from both ground and Lidar data was quantified by propagating measurement and prediction errors across spatial scales. Errors associated with both the mean biomass stock and mean biomass change declined with increasing spatial scales. Biomass changes derived from Lidar and ground estimates were largely (36 out 50 plots) in the same direction at the spatial scale of 1 ha. Lidar estimation of biomass was accurate at the 1 ha scale (R2 = 0.7 and RMSEmean = 28.6 Mg ha-1). However, to predict biomass changes, errors became comparable to ground estimates only at about 10-ha or more. Our results indicate that the 50-ha BCI plot lost a~significant amount of biomass (-0.8 ± 2.2 Mg ha-1 yr-1) over the past decade (2000-2010). Over the entire island and during the same period, mean AGB change is -0.4 ± 3.7 Mg ha-1 yr-1. Old growth forests lost biomass (-0.7 ± 3.5 Mg ha-1 yr-1), whereas the secondary forests gained biomass (+0.4 ± 3.4 Mg ha-1 yr-1). Our analysis demonstrates that repeated Lidar surveys, even with two different sensors, is able to estimate biomass changes in old

  18. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  19. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  20. Use of Airborne Thermal Imagery to Detect and Monitor Inshore Oil Spill Residues During Darkness Hours.

    PubMed

    GRIERSON

    1998-11-01

    / Trials were conducted using an airborne video system operating in the visible, near-infrared, and thermal wavelengths to detect two known oil spill releases during darkness at a distance of 10 nautical miles from the shore in St. Vincent's Gulf, South Australia. The oil spills consisted of two 20-liter samples released at 2-h intervals, one sample consisted of paraffinic neutral material and the other of automotive diesel oil. A tracking buoy was sent overboard in conjunction with the release of sample 1, and its movement monitored by satellite relay. Both oil residues were overflown by a light aircraft equipped with thermal, visible, and infrared imagers at a period of approximately 1 h after the release of the second oil residue. Trajectories of the oil residue releases were also modeled and the results compared to those obtained by the airborne video and the tracking buoy. Airborne imagery in the thermal wavelengths successfully located and mapped both oil residue samples during nighttime conditions. Results from the trial suggest that the most advantageous technique would be the combined use of the tracking beacon to obtain an approximate location of the oil spill and the airborne imagery to ascertain its extent and characteristics.KEY WORDS: Airborne video; Thermal imagery; Global positioning; Oil-spill monitoring; Tracking beacon PMID:9732519

  1. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms.

    PubMed

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-01-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration. PMID:26522006

  2. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    PubMed Central

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-01-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration. PMID:26522006

  3. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    NASA Astrophysics Data System (ADS)

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-11-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration.

  4. Detection of karst structures using airborne EM and VLF

    SciTech Connect

    Beard, L.P. Nyquist, J.E.; Carpenter, P.J.

    1994-12-31

    Through the combined use of multi-frequency helicopter electromagnetic and VLF data, it is possible to detect and delineate a wide variety of karst structures and possibly to assess their interconnectedness. Multi-frequency EM Can detect karst features if some element of the structure is conductive. This conductive aspect may derive from thick, moist soils in the depression commonly associated with a doline, from conductive fluids in the cavity, or from conductive sediments in the cavity if these occupy a significant portion of it. Multiple loop configurations may also increase the likelihood of detecting karst features. Preliminary evidence indicates total field VLF measurements may be able to detect interconnected karst pathways, so long as the pathways are water or sediment filled. Neither technique can effectively detect dry, resistive air-filled cavities.

  5. Detection of airborne bacteria with disposable bio-precipitator and NanoGene assay.

    PubMed

    Lee, Eun-Hee; Chua, Beelee; Son, Ahjeong

    2016-09-15

    We demonstrated the detection of airborne bacteria by a disposable bio-precipitator and NanoGene assay combination. The bio-precipitator employed micro corona discharge at 1960V and at less than 35µA to simultaneously charge, capture and lyse the airborne bacteria. This was enabled by the use of a 15μL liquid anode. Using a custom exposure setup, the target bacterium Bacillus subtilis in the atomization solution was rendered airborne. After exposure, the liquid anode in the bio-precipitator was subsequently measured for DNA concentration and analyzed with the NanoGene assay. As the bacterial concentration increased from 0.0104 to 42.6 g-DCW/L the released DNA concentration in the liquid anode increased from 2.10±1.57 to 75.00±7.15ng/μL. More importantly, the NanoGene assay showed an increase in normalized fluorescence (gene quantification) from 18.03±1.18 to 49.71±1.82 as the bacterial concentrations increased from 0.0104 to 42.6 g-DCW/L. the electrical power consumption of the bio-precipitator was shown to be amenable for portable use. In addition, the detection limit of bio-precipitator and NanoGene assay combination in the context of environmentally relevant levels of airborne bacteria was also discussed. PMID:27130988

  6. ASSESSMENT OF THE REMOTE MINEFIELD DETECTION SYSTEM (REMIDS)

    EPA Science Inventory

    Millions of acres of government land are contaminated with unexploded ordnance (UXO), a result of years of testing and training in the armed forces. As part of the effort to prepare some of this land for use other than as test ranges, programs are underway to develop methods to s...

  7. Airborne Optical and Thermal Remote Sensing for Wildfire Detection and Monitoring.

    PubMed

    Allison, Robert S; Johnston, Joshua M; Craig, Gregory; Jennings, Sion

    2016-01-01

    For decades detection and monitoring of forest and other wildland fires has relied heavily on aircraft (and satellites). Technical advances and improved affordability of both sensors and sensor platforms promise to revolutionize the way aircraft detect, monitor and help suppress wildfires. Sensor systems like hyperspectral cameras, image intensifiers and thermal cameras that have previously been limited in use due to cost or technology considerations are now becoming widely available and affordable. Similarly, new airborne sensor platforms, particularly small, unmanned aircraft or drones, are enabling new applications for airborne fire sensing. In this review we outline the state of the art in direct, semi-automated and automated fire detection from both manned and unmanned aerial platforms. We discuss the operational constraints and opportunities provided by these sensor systems including a discussion of the objective evaluation of these systems in a realistic context. PMID:27548174

  8. A Field Evaluation of Airborne Techniques for Detection of Unexploded Ordnance

    SciTech Connect

    Bell, D.; Doll, W.E.; Hamlett, P.; Holladay, J.S.; Nyquist, J.E.; Smyre, J.; Gamey, T.J.

    1999-03-14

    US Defense Department estimates indicate that as many as 11 million acres of government land in the U. S. may contain unexploded ordnance (UXO), with the cost of identifying and disposing of this material estimated at nearly $500 billion. The size and character of the ordnance, types of interference, vegetation, geology, and topography vary from site to site. Because of size or composition, some ordnance is difficult to detect with any geophysical method, even under favorable soil and cultural interference conditions. For some sites, airborne methods may provide the most time and cost effective means for detection of UXO. Airborne methods offer lower risk to field crews from proximity to unstable ordnance, and less disturbance of sites that maybe environmentally sensitive. Data were acquired over a test site at Edwards AFB, CA using airborne magnetic, electromagnetic, multispectral and thermal sensors. Survey areas included sites where trenches might occur, and a test site in which we placed deactivated ordnance, ranging in size from small ''bomblets'' to large bombs. Magnetic data were then acquired with the Aerodat HM-3 system, which consists of three cesium magnetometers within booms extending to the front and sides of the helicopter, and mounted such that the helicopter can be flown within 3m of the surface. Electromagnetic data were acquired with an Aerodat 5 frequency coplanar induction system deployed as a sling load from a helicopter, with a sensor altitude of 15m. Surface data, acquired at selected sites, provide a comparison with airborne data. Multispectral and thermal data were acquired with a Daedelus AADS 1268 system. Preliminary analysis of the test data demonstrate the value of airborne systems for UXO detection and provide insight into improvements that might make the systems even more effective.

  9. Flight Tests of the DELICAT Airborne LIDAR System for Remote Clear Air Turbulence Detection

    NASA Astrophysics Data System (ADS)

    Vrancken, Patrick; Wirth, Martin; Ehret, Gerhard; Witschas, Benjamin; Veerman, Henk; Tump, Robert; Barny, Hervé; Rondeau, Philippe; Dolfi-Bouteyre, Agnès; Lombard, Laurent

    2016-06-01

    An important aeronautics application of lidar is the airborne remote detection of Clear Air Turbulence which cannot be performed with onboard radar. We report on a DLR-developed lidar system for the remote detection of such turbulent areas in the flight path of an aircraft. The lidar, consisting of a high-power UV laser transmitter and a direct detection system, was installed on a Dutch research aircraft. Flight tests executed in 2013 demonstrated the performance of the lidar system to detect local subtle variations in the molecular backscatter coefficient indicating the turbulence some 10 to 15 km ahead.

  10. Airborne hyperspectral and LiDAR data integration for weed detection

    NASA Astrophysics Data System (ADS)

    Tamás, János; Lehoczky, Éva; Fehér, János; Fórián, Tünde; Nagy, Attila; Bozsik, Éva; Gálya, Bernadett; Riczu, Péter

    2014-05-01

    Agriculture uses 70% of global available fresh water. However, ca. 50-70% of water used by cultivated plants, the rest of water transpirated by the weeds. Thus, to define the distribution of weeds is very important in precision agriculture and horticulture as well. To survey weeds on larger fields by traditional methods is often time consuming. Remote sensing instruments are useful to detect weeds in larger area. In our investigation a 3D airborne laser scanner (RIEGL LMS-Q680i) was used in agricultural field near Sopron to scouting weeds. Beside the airborne LiDAR, hyperspectral imaging system (AISA DUAL) and air photos helped to investigate weed coverage. The LiDAR survey was carried out at early April, 2012, before sprouting of cultivated plants. Thus, there could be detected emerging of weeds and direction of cultivation. However airborne LiDAR system was ideal to detect weeds, identification of weeds at species level was infeasible. Higher point density LiDAR - Terrestrial laser scanning - systems are appropriate to distinguish weed species. Based on the results, laser scanner is an effective tool to scouting of weeds. Appropriate weed detection and mapping systems could contribute to elaborate water and herbicide saving management technique. This publication was supported by the OTKA project K 105789.

  11. Airborne Remote Sensing for Detection of Irrigation Canal Leakage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional field survey methods for detection of water leaks in irrigation canal systems are costly and time consuming. In this study, a rapid, cost-effective method was developed for identifying irrigation canal locations likely to have leaks and/or seepage. The method involves the use of a mult...

  12. Progress on detection of radioactivity by airborne equipment

    USGS Publications Warehouse

    Stead, Frank W.

    1949-01-01

    Coincidence and anti-coincidence counting rate meters and also an air conductivity meter have been installed in a transport plane to measure gamma radiation from ground sources. Materials containing 0.01 percent uranium can be detected at 500 feet and at an airspeed of 150 miles per hour.

  13. Airborne remote sensing to detect greenbug stress to wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation indices calculated from the quantity of reflected electromagnetic radiation have been used to quantify levels of stress to plants. Greenbugs cause stress to wheat plants and therefore multi-spectral remote sensing may be useful for detecting greenbug infested wheat fields. The objective...

  14. Ultrawideband synthetic vision sensor for airborne wire detection

    NASA Astrophysics Data System (ADS)

    Fontana, Robert J.; Larrick, J. F.; Cade, Jeffrey E.; Rivers, Eugene P., Jr.

    1998-07-01

    A low cost, miniature ultra wideband (UWB) radar has demonstrated the ability to detect suspended wires and other small obstacles at distances exceeding several hundred feet using an average output power of less than 10 microwatts. Originally developed as a high precision UWB radar altimeter for the Navy's Program Executive Office for Unmanned Aerial Vehicles and Cruise Missiles, an improved sensitivity version was recently developed for the Naval Surface Warfare Center (NSWC Dahlgren Division) as part of the Marine Corps Warfighting Laboratory's Hummingbird program for rotary wing platforms. Utilizing a short pulse waveform of approximately 2.5 nanoseconds in duration, the receiver processor exploits the leading edge of the radar return pulse to achieve range resolutions of less than one foot. The resultant 400 MHz bandwidth spectrum produces both a broad frequency excitation for enhanced detection, as well as a low probability of intercept and detection (LPI/D) signature for covert applications. This paper describes the design and development of the ultra wideband sensor, as well as performance results achieved during field testing at NSWC's Dahlgren, VA facility. These results are compared with those achieved with a high resolution EHF radar and a laser-based detection system.

  15. System for rapid detection of antibiotic resistance of airborne pathogens

    NASA Astrophysics Data System (ADS)

    Fortin, M.; Noiseux, I.; Mouslinkina, L.; Vernon, M. L.; Laflamme, C.; Filion, G.; Duchaine, C.; Ho, J.

    2009-05-01

    This project uses function-based detection via a fundamental understanding of the genetic markers of AR to distinguish harmful organisms from innocuous ones. This approach circumvents complex analyses to unravel the taxonomic details of 1399 pathogen species, enormously simplifying detection requirements. Laval Hospital's fast permeabilization strategy enables AR revelation in <1hr. Packaging the AR protocols in liquid-processing cartridges and coupling these to our in-house miniature fiber optic flow cell (FOFC) provides first responders with timely information on-site. INO's FOFC platform consists of a specialty optical fiber through which a hole is transversally bored by laser micromachining. The analyte solution is injected into the hole of the fiber and the particles are detected and counted. The advantage with respect to classic free space FC is that alignment occurs in the fabrication process only and complex excitation and collection optics are replaced by optical fibers. Moreover, we use a sheathless configuration which has the advantage of increase the portability of the system, to reduce excess biohazard material and the need for weekly maintenance. In this paper we present the principle of our FOFC along with a, demonstration of the basic capability of the platform for detection of bacillus cereus spores using permeabilized staining.

  16. Airborne Windshear Detection and Warning Systems. Fifth and Final Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E. (Compiler)

    1994-01-01

    The Fifth (and Final) Combined Manufacturers' and Technologists' Airborne Windshear Review Meeting was hosted jointly by the NASA Langley Research Center (LaRC) and the Federal Aviation Administration (FAA) in Hampton, Virginia, on September 28-30, 1993. The purpose of the meeting was to report on the highly successful windshear experiments conducted by government, academic institutions, and industry; to transfer the results to regulators, manufacturers, and users; and to set initiatives for future aeronautics technology research. The formal sessions covered recent developments in windshear flight testing; windshear modeling, flight management, and ground-based systems; airborne windshear detection systems; certification and regulatory issues; development and applications of sensors for wake vortex detection; and synthetic and enhanced vision systems.

  17. Use of airborne thermal imagery to detect and monitor inshore oil spill residues during darkness hours

    SciTech Connect

    Grierson, I.T.

    1998-11-01

    Trials were conducted using an airborne video system operating in the visible, near-infrared, and thermal wavelengths to detect two known oil spill releases during darkness at a distance of 10 nautical miles from the shore in St. Vincent`s Gulf, South Australia. The oil spills consisted of two 20-liter samples released at 2-h intervals, one sample consisted of paraffinic neutral material and the other of automotive diesel oil. A tracking buoy was sent overboard in conjunction with the release of sample 1, and its movement monitored by satellite relay. Both oil residues were overflown by a light aircraft equipped with thermal, visible, and infrared imagers at a period of approximately 1 h after the release of the second oil residue. Trajectories of the oil residue releases were also modeled and the results compared to those obtained by the airborne video and the tracking buoy. Airborne imagery in the thermal wavelengths successfully located and mapped both oil residue samples during nighttime conditions. Results from the trial suggest that the most advantageous technique would be the combined use of the tracking beacon to obtain an approximate location of the oil spill and the airborne imagery to ascertain its extent and characteristics.

  18. Microfluidics-based integrated airborne pathogen detection systems

    NASA Astrophysics Data System (ADS)

    Northrup, M. Allen; Alleman-Sposito, Jennifer; Austin, Todd; Devitt, Amy; Fong, Donna; Lin, Phil; Nakao, Brian; Pourahmadi, Farzad; Vinas, Mary; Yuan, Bob

    2006-09-01

    Microfluidic Systems is focused on building microfluidic platforms that interface front-end mesofluidics to handle real world sample volumes for optimal sensitivity coupled to microfluidic circuitry to process small liquid volumes for complex reagent metering, mixing, and biochemical analysis, particularly for pathogens. MFSI is the prime contractor on two programs for the US Department of Homeland Security: BAND (Bioagent Autonomous Networked Detector) and IBADS (Instantaneous Bio-Aerosol Detection System). The goal of BAND is to develop an autonomous system for monitoring the air for known biological agents. This consists of air collection, sample lysis, sample purification, detection of DNA, RNA, and toxins, and a networked interface to report the results. For IBADS, MFSI is developing the confirmatory device which must verify the presence of a pathogen with 5 minutes of an air collector/trigger sounding an alarm. Instrument designs and biological assay results from both BAND and IBADS will be presented.

  19. Detection and delineation of buildings from airborne ladar measurements

    NASA Astrophysics Data System (ADS)

    Swirski, Yoram; Wolowelsky, Karni; Adar, Renen; Figov, Zvi

    2004-11-01

    Automatic delineation of buildings is very attractive for both civilian and military applications. Such applications include general mapping, detection of unauthorized constructions, change detection, etc. For military applications, high demand exists for accurate building change updates, covering large areas, and over short time periods. We present two algorithms coupled together. The height image algorithm is a fast coarse algorithm operating on large areas. This algorithm is capable of defining blocks of buildings and regions of interest. The point-cloud algorithm is a fine, 3D-based, accurate algorithm for building delineation. Since buildings may be separated by alleys, whose width is similar or narrower than the LADAR resolution, the height image algorithm marks those crowded buildings as a single object. The point-cloud algorithm separates and accurately delineates individual building boundaries and building sub-sections utilizing roof shape analysis in 3D. Our focus is on the ability to cover large areas with accuracy and high rejection of non-building objects, like trees. We report a very good detection performance with only few misses and false alarms. It is believed that LADAR measurements, coupled with good segmentation algorithms, may replace older systems and methods that require considerable manual work for such applications.

  20. Detection of Coxiella burnetii DNA in Inhalable Airborne Dust Samples from Goat Farms after Mandatory Culling

    PubMed Central

    Hogerwerf, Lenny; Still, Kelly; Heederik, Dick; van Rotterdam, Bart; de Bruin, Arnout; Nielen, Mirjam; Wouters, Inge M.

    2012-01-01

    Coxiella burnetii is thought to infect humans primarily via airborne transmission. However, air measurements of C. burnetii are sparse. We detected C. burnetii DNA in inhalable and PM10 (particulate matter with an aerodynamic size of 10 μm or less) dust samples collected at three affected goat farms, demonstrating that low levels of C. burnetii DNA are present in inhalable size fractions. PMID:22582072

  1. Feasibility study of detection of hazardous airborne pollutants using passive open-path FTIR

    NASA Astrophysics Data System (ADS)

    Segal-Rosenheimer, M.; Dubowski, Y.; Jahn, C.; Schäfer, K.; Gerl, G.; Linker, R.

    2010-04-01

    In recent years open-path FTIR systems (active and passive) have demonstrated great potential and success for monitoring air pollution, industrial stack emissions, and trace gas constituents in the atmosphere. However, most of the studies were focused mainly on monitoring gaseous species and very few studies have investigated the feasibility of detecting bio-aerosols and dust by passive open-path FTIR measurements. The goal of the present study was to test the feasibility of detecting a cloud of toxic aerosols by a passive mode open-path FTIR. More specifically, we are focusing on the detection of toxic organophosphorous nerve agents for which we use Tri-2-ethyl-hexyl-phosphate as a model compound. We have determined the compounds' optical properties, which were needed for the radiative calculations, using a procedure developed in our laboratory. In addition, measurements of the aerosol size distribution in an airborne cloud were performed, which provided the additional input required for the radiative transfer model. This allowed simulation of the radiance signal that would be measured by the FTIR instrument and hence estimation of the detection limit of such a cloud. Preliminary outdoor measurements have demonstrated the possibility of detecting such a cloud using two detection methods. However, even in a simple case consisting of the detection of a pure airborne cloud, detection is not straightforward and reliable identification of the compound would require more advanced methods than simple correlation with spectral library.

  2. Detection of fault structures with airborne LiDAR point-cloud data

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Du, Lei

    2015-08-01

    The airborne LiDAR (Light Detection And Ranging) technology is a new type of aerial earth observation method which can be used to produce high-precision DEM (Digital Elevation Model) quickly and reflect ground surface information directly. Fault structure is one of the key forms of crustal movement, and its quantitative description is the key to the research of crustal movement. The airborne LiDAR point-cloud data is used to detect and extract fault structures automatically based on linear extension, elevation mutation and slope abnormal characteristics. Firstly, the LiDAR point-cloud data is processed to filter out buildings, vegetation and other non-surface information with the TIN (Triangulated Irregular Network) filtering method and Burman model calibration method. TIN and DEM are made from the processed data sequentially. Secondly, linear fault structures are extracted based on dual-threshold method. Finally, high-precision DOM (Digital Orthophoto Map) and other geological knowledge are used to check the accuracy of fault structure extraction. An experiment is carried out in Beiya Village of Yunnan Province, China. With LiDAR technology, results reveal that: the airborne LiDAR point-cloud data can be utilized to extract linear fault structures accurately and automatically, measure information such as height, width and slope of fault structures with high precision, and detect faults in areas with vegetation coverage effectively.

  3. Feature Line Based Building Detection and Reconstruction from Oblique Airborne Imagery

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Jiang, W.; Zhang, J.

    2015-05-01

    In this paper, a feature line based method for building detection and reconstruction from oblique airborne imagery is presented. With the development of Multi-View Stereo technology, increasing photogrammetric softwares are provided to generate textured meshes from oblique airborne imagery. However, errors in image matching and mesh segmentation lead to the low geometrical accuracy of building models, especially at building boundaries. To simplify massive meshes and construct accurate 3D building models, we integrate multi-view images and meshes by using feature lines, in which contour lines are used for building detection and straight skeleton for building reconstruction. Firstly, through the contour clustering method, buildings can be quickly and robustly detected from meshes. Then, a feature preserving mesh segmentation method is applied to accurately extract 3D straight skeleton from meshes. Finally, straight feature lines derived from multi-view images are used to rectify inaccurate parts of 3D straight skeleton of buildings. Therefore, low quality model can be refined by the accuracy improvement of mesh feature lines and rectification with feature lines of multi-view images. The test dataset in Zürich is provided by ISPRS/EuroSDR initiative Benchmark on High Density Image Matching for DSM Computation. The experiments reveal that the proposed method can obtain convincing and high quality 3D building models from oblique airborne imagery.

  4. Design and Development of a Scanning Airborne Direct Detection Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce; McGill, Matthew; Schwemmer, Geary; Hardesty, Michael; Brewer, Alan; Wilkerson, Thomas; Atlas, Robert; Sirota, Marcos; Lindemann, Scott

    2006-01-01

    In the fall of 2005 we began developing an airborne scanning direct detection molecular Doppler lidar. The instrument is being built as part of the Tropospheric Wind Lidar Technology Experiment (TWiLiTE), a three year project selected by the NASA Earth Sun Technology Office under the Instrument Incubator Program. The TWiLiTE project is a collaboration involving scientists and engineers from NASA Goddard Space Flight Center, NOAA ESRL, Utah State University Space Dynamics Lab, Michigan Aerospace Corporation and Sigma Space Corporation. The TWiLiTE instrument will leverage significant research and development investments made by NASA Goddard and it's partners in the past several years in key lidar technologies and sub-systems (lasers, telescopes, scanning systems, detectors and receivers) required to enable spaceborne global wind lidar measurement. These sub-systems will be integrated into a complete molecular direct detection Doppler wind lidar system designed for autonomous operation on a high altitude aircraft, such as the NASA WB57. The WB57 flies at an altitude of 18 km and from this vantage point the nadir viewing Doppler lidar will be able to profile winds through the full troposphere. The TWiLiTE integrated airborne Doppler lidar instrument will be the first demonstration of a airborne scanning direct detection Doppler lidar and will serve as a critical milestone on the path to a future spaceborne tropospheric wind system. In addition to being a technology testbed for space based tropospheric wind lidar, when completed the TWiLiTE high altitude airborne lidar will be used for studying mesoscale dynamics and storm research (e.g. winter storms, hurricanes) and could be used for calibration and validation of satellite based wind systems such as ESA's Aeolus Atmospheric Dynamics Mission. The TWiLiTE Doppler lidar will have the capability to profile winds in clear air from the aircraft altitude of 18 km to the surface with 250 m vertical resolution and < 2mls

  5. Biologically inspired multilevel approach for multiple moving targets detection from airborne forward-looking infrared sequences.

    PubMed

    Li, Yansheng; Tan, Yihua; Li, Hang; Li, Tao; Tian, Jinwen

    2014-04-01

    In this paper, a biologically inspired multilevel approach for simultaneously detecting multiple independently moving targets from airborne forward-looking infrared (FLIR) sequences is proposed. Due to the moving platform, low contrast infrared images, and nonrepeatability of the target signature, moving targets detection from FLIR sequences is still an open problem. Avoiding six parameter affine or eight parameter planar projective transformation matrix estimation of two adjacent frames, which are utilized by existing moving targets detection approaches to cope with the moving infrared camera and have become the bottleneck for the further elevation of the moving targets detection performance, the proposed moving targets detection approach comprises three sequential modules: motion perception for efficiently extracting motion cues, attended motion views extraction for coarsely localizing moving targets, and appearance perception in the local attended motion views for accurately detecting moving targets. Experimental results demonstrate that the proposed approach is efficient and outperforms the compared state-of-the-art approaches. PMID:24695135

  6. Optical cloud detection from a disposable airborne sensor

    NASA Astrophysics Data System (ADS)

    Nicoll, Keri; Harrison, R. Giles; Brus, David

    2016-04-01

    In-situ measurement of cloud droplet microphysical properties is most commonly made from manned aircraft platforms due to the size and weight of the instrumentation, which is both costly and typically limited to sampling only a few clouds. This work describes the development of a small, lightweight (<200g), disposable, optical cloud sensor which is designed for use on routine radiosonde balloon flights and also small unmanned aerial vehicle (UAV) platforms. The sensor employs the backscatter principle, using an ultra-bright LED as the illumination source, with a photodiode detector. Scattering of the LED light by cloud droplets generates a small optical signal which is separated from background light fluctuations using a lock-in technique. The signal to noise obtained permits cloud detection using the scattered LED light, even in daytime. During recent field tests in Pallas, Finland, the retrieved optical sensor signal has been compared with the DMT Cloud and Aerosol Spectrometer (CAS) which measures cloud droplets in the size range from 0.5 to 50 microns. Both sensors were installed at the hill top observatory of Sammaltunturi during a field campaign in October and November 2015, which experienced long periods of immersion inside cloud. Preliminary analysis shows very good agreement between the CAPS and the disposable cloud sensor for cloud droplets >5micron effective diameter. Such data and calibration of the sensor will be discussed here, as will simultaneous balloon launches of the optical cloud sensor through the same cloud layers.

  7. Space-time airborne disease mapping applied to detect specific behaviour of varicella in Valencia, Spain.

    PubMed

    Iftimi, Adina; Montes, Francisco; Santiyán, Ana Míguez; Martínez-Ruiz, Francisco

    2015-01-01

    Airborne diseases are one of humanity's most feared sicknesses and have regularly caused concern among specialists. Varicella is an airborne disease which usually affects children before the age of 10. Because of its nature, varicella gives rise to interesting spatial, temporal and spatio-temporal patterns. This paper studies spatio-temporal exploratory analysis tools to detect specific behaviour of varicella in the city of Valencia, Spain, from 2008 to 2013. These methods have shown a significant association between the spatial and the temporal component, confirmed by the space-time models applied to the data. High relative risk of varicella is observed in economically disadvantaged regions, areas less involved in vaccination programmes. PMID:26530821

  8. Airborne Windshear Detection and Warning Systems. Fifth and Final Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E. (Compiler)

    1994-01-01

    The Fifth Combined Manufacturers' and Technologists' Airborne Windshear Review Meeting was hosted by the NASA Langley Research Center and the Federal Aviation Administration in Hampton, Virginia, on September 28-30, 1993. The purpose was to report on the highly successful windshear experiments conducted by government, academic institutions, and industry; to transfer the results to regulators, manufacturers, and users; and to set initiatives for future aeronautics technology research. The formal sessions covered recent developments in windshear flight testing, windshear modeling, flight management, and ground-based systems, airborne windshear detection systems, certification and regulatory issues, and development and applications of sensors for wake vortices and for synthetic and enhanced vision systems. This report was compiled to record and make available the technology updates and materials from the conference.

  9. Detection of Airborne Stachybotrys chartarum Macrocyclic Trichothecene Mycotoxins in the Indoor Environment

    PubMed Central

    Brasel, T. L.; Martin, J. M.; Carriker, C. G.; Wilson, S. C.; Straus, D. C.

    2005-01-01

    The existence of airborne mycotoxins in mold-contaminated buildings has long been hypothesized to be a potential occupant health risk. However, little work has been done to demonstrate the presence of these compounds in such environments. The presence of airborne macrocyclic trichothecene mycotoxins in indoor environments with known Stachybotrys chartarum contamination was therefore investigated. In seven buildings, air was collected using a high-volume liquid impaction bioaerosol sampler (SpinCon PAS 450-10) under static or disturbed conditions. An additional building was sampled using an Andersen GPS-1 PUF sampler modified to separate and collect particulates smaller than conidia. Four control buildings (i.e., no detectable S. chartarum growth or history of water damage) and outdoor air were also tested. Samples were analyzed using a macrocyclic trichothecene-specific enzyme-linked immunosorbent assay (ELISA). ELISA specificity was tested using phosphate-buffered saline extracts of the fungal genera Aspergillus, Chaetomium, Cladosporium, Fusarium, Memnoniella, Penicillium, Rhizopus, and Trichoderma, five Stachybotrys strains, and the indoor air allergens Can f 1, Der p 1, and Fel d 1. For test buildings, the results showed that detectable toxin concentrations increased with the sampling time and short periods of air disturbance. Trichothecene values ranged from <10 to >1,300 pg/m3 of sampled air. The control environments demonstrated statistically significantly (P < 0.001) lower levels of airborne trichothecenes. ELISA specificity experiments demonstrated a high specificity for the trichothecene-producing strain of S. chartarum. Our data indicate that airborne macrocyclic trichothecenes can exist in Stachybotrys-contaminated buildings, and this should be taken into consideration in future indoor air quality investigations. PMID:16269780

  10. Airborne detection of diffuse carbon dioxide emissions at Mammoth Mountain, California

    USGS Publications Warehouse

    Gerlach, T.M.; Doukas, M.P.; McGee, K.A.; Kessler, R.

    1999-01-01

    We report the first airborne detection of CO2 degassing from diffuse volcanic sources. Airborne measurement of diffuse CO2 degassing offers a rapid alternative for monitoring CO2 emission rates at Mammoth Mountain. CO2 concentrations, temperatures, and barometric pressures were measured at ~2,500 GPS-referenced locations during a one-hour, eleven-orbit survey of air around Mammoth Mountain at ~3 km from the summit and altitudes of 2,895-3,657 m. A volcanic CO2 anomaly 4-5 km across with CO2 levels ~1 ppm above background was revealed downwind of tree-kill areas. It contained a 1-km core with concentrations exceeding background by >3 ppm. Emission rates of ~250 t d-1 are indicated. Orographic winds may play a key role in transporting the diffusely degassed CO2 upslope to elevations where it is lofted into the regional wind system.We report the first airborne detection of CO2 degassing from diffuse volcanic sources. Airborne measurement of diffuse CO2 degassing offers a rapid alternative for monitoring CO2 emission rates at Mammoth Mountain. CO2 concentrations, temperatures, and barometric pressures were measured at approximately 2,500 GPS-referenced locations during a one-hour, eleven-orbit survey of air around Mammoth Mountain at approximately 3 km from the summit and altitudes of 2,895-3,657 m. A volcanic CO2 anomaly 4-5 km across with CO2 levels approximately 1 ppm above background was revealed downwind of tree-kill areas. It contained a 1-km core with concentrations exceeding background by >3 ppm. Emission rates of approximately 250 t d-1 are indicated. Orographic winds may play a key role in transporting the diffusely degassed CO2 upslope to elevations where it is lofted into the regional wind system.

  11. Failure detection of liquid cooled electronics in sealed packages. [in airborne information management system

    NASA Technical Reports Server (NTRS)

    Hoadley, A. W.; Porter, A. J.

    1991-01-01

    The theory and experimental verification of a method of detecting fluid-mass loss, expansion-chamber pressure loss, or excessive vapor build-up in NASA's Airborne Information Management System (AIMS) are presented. The primary purpose of this leak-detection method is to detect the fluid-mass loss before the volume of vapor on the liquid side causes a temperature-critical part to be out of the liquid. The method detects the initial leak after the first 2.5 pct of the liquid mass has been lost, and it can be used for detecting subsequent situations including the leaking of air into the liquid chamber and the subsequent vapor build-up.

  12. Remote detection of heated ethanol plumes by airborne passive Fourier transform infrared spectrometry.

    PubMed

    Tarumi, Toshiyasu; Small, Gary W; Combs, Roger J; Kroutil, Robert T

    2003-11-01

    Methodology is developed for the automated detection of heated plumes of ethanol vapor with airborne passive Fourier transform infrared spectrometry. Positioned in a fixed-wing aircraft in a downward-looking mode, the spectrometer is used to detect ground sources of ethanol vapor from an altitude of 2000-3000 ft. Challenges to the use of this approach for the routine detection of chemical plumes include (1) the presence of a constantly changing background radiance as the aircraft flies, (2) the cost and complexity of collecting the data needed to train the classification algorithms used in implementing the plume detection, and (3) the need for rapid interferogram scans to minimize the ground area viewed per scan. To address these challenges, this work couples a novel ground-based data collection and training protocol with the use of signal processing and pattern recognition methods based on short sections of the interferogram data collected by the spectrometer. In the data collection, heated plumes of ethanol vapor are released from a portable emission stack and viewed by the spectrometer from ground level against a synthetic background designed to simulate a terrestrial radiance source. Classifiers trained with these data are subsequently tested with airborne data collected over a period of 2.5 years. Two classifier architectures are compared in this work: support vector machines (SVM) and piecewise linear discriminant analysis (PLDA). When applied to the airborne test data, the SVM classifiers perform best, failing to detect ethanol in only 8% of the cases in which it is present. False detections occur at a rate of less than 0.5%. The classifier performs well in spite of differences between the backgrounds associated with the ground-based and airborne data collections and the instrumental drift arising from the long time span of the data collection. Further improvements in classification performance are judged to require increased sophistication in the ground

  13. AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPLINE LEAK DETECTION

    SciTech Connect

    Jerry Myers

    2004-05-12

    Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. The third six-month technical report contains a summary of the progress made towards finalizing the design and assembling the airborne, remote methane and ethane sensor. The vendor has been chosen and is on contract to develop the light source with the appropriate linewidth and spectral shape to best utilize the Ophir gas correlation software. Ophir has expanded upon the target reflectance testing begun in the previous performance period by replacing the experimental receiving optics with the proposed airborne large aperture telescope, which is theoretically capable of capturing many times more signal return. The data gathered from these tests has shown the importance of optimizing the fiber optic receiving fiber to the receiving optic and has helped Ophir to optimize the design of the gas cells and narrowband optical filters. Finally, Ophir will discuss remaining project issues that may impact the success of the project.

  14. AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION

    SciTech Connect

    Jerry Myers

    2003-11-12

    Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. This second six-month technical report summarizes the progress made towards defining, designing, and developing the hardware and software segments of the airborne, optical remote methane and ethane sensor. The most challenging task to date has been to identify a vendor capable of designing and developing a light source with the appropriate output wavelength and power. This report will document the work that has been done to identify design requirements, and potential vendors for the light source. Significant progress has also been made in characterizing the amount of light return available from a remote target at various distances from the light source. A great deal of time has been spent conducting laboratory and long-optical path target reflectance measurements. This is important since it helps to establish the overall optical output requirements for the sensor. It also reduces the relative uncertainty and risk associated with developing a custom light source. The data gathered from the optical path testing has been translated to the airborne transceiver design in such areas as: fiber coupling, optical detector selection, gas filters, and software analysis. Ophir will next, summarize the design progress of the transceiver hardware and software development. Finally, Ophir will discuss remaining project issues that may impact the success of the project.

  15. Detection of airborne psychrotrophic bacteria and fungi in food storage refrigerators.

    PubMed

    Altunatmaz, Sema Sandikci; Issa, Ghassan; Aydin, Ali

    2012-10-01

    The purpose of this study was to determine the microbiological air quality (psychrotrophic bacteria and airborne fungi) and distribution of fungi in different types of ready-to-eat (RTE) food-storage refrigerators (n=48) at selected retail stores in the city of Edirne, Turkey. Refrigerators were categorized according to the type of RTE food-storage: meat products, vegetables, desserts, or a mix of food types. Microbiological quality of air samples was evaluated by using a Mas-100 Eco Air Sampler. Four refrigerators (all containing meat products, 8.3%) produced air samples with undetectable microorganisms. The highest detected mean value of airborne psychrotrophic bacteria and fungi was 82.3 CFU/m(3) and 54.6 CFU/m(3), respectively and were found in mixed-food refrigerators. The dominant airborne fungal genera found were Penicillium (29.0%), Aspergillus (12.0%), Mucor (9%), Cladosporium (8%), Botyrtis (7%), and Acremonium (6%). By definition, RTE food does not undergo a final treatment to ensure its safety prior to consumption. Therefore, ensuring a clean storage environment for these foods is important to prevent food-borne disease and other health risks. PMID:24031974

  16. Flight Testing of an Advanced Airborne Natural Gas Leak Detection System

    SciTech Connect

    Dawn Lenz; Raymond T. Lines; Darryl Murdock; Jeffrey Owen; Steven Stearns; Michael Stoogenke

    2005-10-01

    ITT Industries Space Systems Division (Space Systems) has developed an airborne natural gas leak detection system designed to detect, image, quantify, and precisely locate leaks from natural gas transmission pipelines. This system is called the Airborne Natural Gas Emission Lidar (ANGEL) system. The ANGEL system uses a highly sensitive differential absorption Lidar technology to remotely detect pipeline leaks. The ANGEL System is operated from a fixed wing aircraft and includes automatic scanning, pointing system, and pilot guidance systems. During a pipeline inspection, the ANGEL system aircraft flies at an elevation of 1000 feet above the ground at speeds of between 100 and 150 mph. Under this contract with DOE/NETL, Space Systems was funded to integrate the ANGEL sensor into a test aircraft and conduct a series of flight tests over a variety of test targets including simulated natural gas pipeline leaks. Following early tests in upstate New York in the summer of 2004, the ANGEL system was deployed to Casper, Wyoming to participate in a set of DOE-sponsored field tests at the Rocky Mountain Oilfield Testing Center (RMOTC). At RMOTC the Space Systems team completed integration of the system and flew an operational system for the first time. The ANGEL system flew 2 missions/day for the duration for the 5-day test. Over the course of the week the ANGEL System detected leaks ranging from 100 to 5,000 scfh.

  17. Urban Building Collapse Detection Using Very High Resolution Imagery and Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Wang, X.; Li, P.

    2013-07-01

    The increasing availability of very high resolution (VHR) remotely sensed images makes it possible to detect and assess urban building damages in the aftermath of earthquake disasters by using these data. However, the accuracy obtained using spectral features from VHR data alone is comparatively low, since both undamaged and collapsed buildings are spectrally similar. The height information provided by airborne LiDAR (Light Detection And Ranging) data is complementary to VHR imagery. Thus, combination of these two datasets will be beneficial to the automatic and accurate extraction of building collapse. In this study, a hierarchical multi-level method of building collapse detection using bi-temporal (pre- and post-earthquake) VHR images and postevent airborne LiDAR data was proposed. First, buildings, bare ground, vegetation and shadows were extracted using post-event image and LiDAR data and masked out. Then building collapse was extracted using the bi-temporal VHR images of the remaining area with a one-class classifier. The proposed method was evaluated using bi-temporal VHR images and LiDAR data of Port au Prince, Haiti, which was heavily hit by an earthquake in January 2010. The method was also compared with some existing methods. The results showed that the method proposed in this study significantly outperformed the existing methods, with improvement range of 47.6% in kappa coefficient. The proposed method provided a fast and reliable way of detecting urban building collapse, which can also be applied to relevant applications.

  18. Efficiency of Airborne Sample Analysis Platform (ASAP) bioaerosol sampler for pathogen detection.

    PubMed

    Sharma, Anurag; Clark, Elizabeth; McGlothlin, James D; Mittal, Suresh K

    2015-01-01

    The threat of bioterrorism and pandemics has highlighted the urgency for rapid and reliable bioaerosol detection in different environments. Safeguarding against such threats requires continuous sampling of the ambient air for pathogen detection. In this study we investigated the efficacy of the Airborne Sample Analysis Platform (ASAP) 2800 bioaerosol sampler to collect representative samples of air and identify specific viruses suspended as bioaerosols. To test this concept, we aerosolized an innocuous replication-defective bovine adenovirus serotype 3 (BAdV3) in a controlled laboratory environment. The ASAP efficiently trapped the surrogate virus at 5 × 10(3) plaque-forming units (p.f.u.) [2 × 10(5) genome copy equivalent] concentrations or more resulting in the successful detection of the virus using quantitative PCR. These results support the further development of ASAP for bioaerosol pathogen detection. PMID:26074900

  19. Efficiency of Airborne Sample Analysis Platform (ASAP) bioaerosol sampler for pathogen detection

    PubMed Central

    Sharma, Anurag; Clark, Elizabeth; McGlothlin, James D.; Mittal, Suresh K.

    2015-01-01

    The threat of bioterrorism and pandemics has highlighted the urgency for rapid and reliable bioaerosol detection in different environments. Safeguarding against such threats requires continuous sampling of the ambient air for pathogen detection. In this study we investigated the efficacy of the Airborne Sample Analysis Platform (ASAP) 2800 bioaerosol sampler to collect representative samples of air and identify specific viruses suspended as bioaerosols. To test this concept, we aerosolized an innocuous replication-defective bovine adenovirus serotype 3 (BAdV3) in a controlled laboratory environment. The ASAP efficiently trapped the surrogate virus at 5 × 103 plaque-forming units (p.f.u.) [2 × 105 genome copy equivalent] concentrations or more resulting in the successful detection of the virus using quantitative PCR. These results support the further development of ASAP for bioaerosol pathogen detection. PMID:26074900

  20. Probability voting and SVM-based vehicle detection in complex background airborne traffic video

    NASA Astrophysics Data System (ADS)

    Lei, Bo; Li, Qingquan; Zhang, Zhijie; Wang, Chensheng

    2012-11-01

    This paper introduces a novel vehicle detection method combined with probability voting based hypothesis generation (HG) and SVM based hypothesis verification (HV) specialized for the complex background airborne traffic video. In HG stage, a statistic based road area extraction method is applied and the lane marks are eliminated. Remained areas are clustered, and then the canny algorithm is performed to detect edges in clustered areas. A voting strategy is designed to detect rectangle objects in the scene. In HV stage, every possible vehicle area is rotated to align the vehicle along the vertical direction, and the vertical and horizontal gradients of them are calculated. SVM is adopted to classify vehicle and non-vehicle. The proposed method has been applied to several traffic scenes, and the experiment results show it's effective and veracious for the vehicle detection.

  1. An airborne laser fluorosensor for the detection of oil on water

    NASA Technical Reports Server (NTRS)

    Kim, H. H.; Hickman, G. D.

    1975-01-01

    An airborne laser fluorosensor for the detection of oil derivatives on water has been tested. The system transmits 337 nm UV radiation at the rate of 100 pulses per second and monitors fluorescent emission at 540 nm. Daylight flight tests were made over the areas of controlled oil spills and additional reconnaissance flights were made over a 50 km stretch of the Delaware River to establish ambient oil baseline in the river. The results show that the device is capable of monitoring and mapping out extremely low level oil on water which cannot be identified by ordinary photographic method.

  2. Visual real-time detection, recognition and tracking of ground and airborne targets

    NASA Astrophysics Data System (ADS)

    Kovács, Levente; Benedek, Csaba

    2011-03-01

    This paper presents methods and algorithms for real-time visual target detection, recognition and tracking, both in the case of ground-based objects (surveyed from a moving airborne imaging sensor) and flying targets (observed from a ground-based or vehicle mounted sensor). The methods are highly parallelized and partially implemented on GPU, with the goal of real-time speeds even in the case of multiple target observations. Real-time applicability is in focus. The methods use single camera observations, providing a passive and expendable alternative for expensive and/or active sensors. Use cases involve perimeter defense and surveillance situations, where passive detection and observation is a priority (e.g. aerial surveillance of a compound, detection of reconnaissance drones, etc.).

  3. Landmine detection using passive hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    McFee, John E.; Anger, Cliff; Achal, Steve; Ivanco, Tyler

    2007-04-01

    Airborne hyperspectral imaging has been studied since the late 1980s as a tool to detect minefields for military countermine operations and for level I clearance for humanitarian demining. Hyperspectral imaging employed on unmanned ground vehicles may also be used to augment or replace broadband imagers to detect individual mines. This paper will discuss the ability of different optical wavebands - the visible/near infrared (VNIR), shortwave infrared (SWIR) and thermal infrared (TIR) - to detect surface-laid and buried mines. The phenomenology that determines performance in the different bands is discussed. Hyperspectral imagers have usually been designed and built for general purpose remote sensing applications and often do not meet the requirements of mine detection. The DRDC mine detection research program has sponsored the development by Itres Research of VNIR, SWIR and TIR instruments specifically intended for mine detection. The requirements for such imagers are described, as well as the instruments. Some results of mine detection experiments are presented. To date, reliable day time detection of surface-laid mines in non-real-time, independent of solar angle, time of day and season has been demonstrated in the VNIR and SWIR. Real-time analysis, necessary for military applications, has been demonstrated from low speed ground vehicles and recently from airborne platforms. Reliable, repeatable detection of buried mines has yet to be demonstrated, although a recently completed TIR hyperspectral imager will soon be tested for such a capability.

  4. Colorimetric Detection of an Airborne Remote Photocatalytic Reaction Using a Stratified Ag Nanoparticle Sheet.

    PubMed

    Degawa, Ryo; Wang, Pangpang; Tanaka, Daisuke; Park, Susie; Sakai, Nobuyuki; Tatsuma, Tetsu; Okamoto, Koichi; Tamada, Kaoru

    2016-08-16

    Photocatalysts are practically used for decomposition of harmful and fouling organic compounds. Among the photocatalytic reactions, remote oxidation via airborne species is a relatively slow process, so that a sensitive technique for its detection has been awaiting. Here, we investigated an airborne remote photocatalytic reaction of a TiO2 photocatalyst modified with Pt nanoparticles as co-catalysts via the color change caused by a decomposition of a multilayered silver nanoparticle sheet. The silver nanoparticle sheet fabricated by the Langmuir-Schaefer method on a gold substrate exhibits a unique multicolor depending upon the number of layers. The color originates from multiple light trapping in the stratified sheets that has a metamaterial characteristic along with an intra- and interlayer coupling of localized surface plasmon resonance (LSPR). The stepwise decomposition of the sheets was confirmed by the colorimetric data, which exhibited not only a monotonic decrease but also a maximized absorption of light when the film thickness reached the optimal thickness for light trapping or when the oxidation of the Ag core started. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and surface plasmon resonance (SPR) spectroscopy data provided a complete view of the decomposition process of this inorganic-organic nanocomposite film, and simulation by the transfer-matrix method explained a simultaneous plasmonic response rationally. The influence of the humidity and gas flow rate on the airborne remote photocatalytic reaction kinetics was examined by this colorimetric detection method, and it suggests that H2O in air plays an essential role in the reaction. PMID:27445001

  5. AIRBORNE, OPTICAL REMOTE SENSING OF METHANE AND ETHANE FOR NATURAL GAS PIPELINE LEAK DETECTION

    SciTech Connect

    Jerry Myers

    2003-05-13

    Ophir Corporation was awarded a contract by the U. S. Department of Energy, National Energy Technology Laboratory under the Project Title ''Airborne, Optical Remote Sensing of Methane and Ethane for Natural Gas Pipeline Leak Detection'' on October 14, 2002. This six-month technical report summarizes the progress for each of the proposed tasks, discusses project concerns, and outlines near-term goals. Ophir has completed a data survey of two major natural gas pipeline companies on the design requirements for an airborne, optical remote sensor. The results of this survey are disclosed in this report. A substantial amount of time was spent on modeling the expected optical signal at the receiver at different absorption wavelengths, and determining the impact of noise sources such as solar background, signal shot noise, and electronic noise on methane and ethane gas detection. Based upon the signal to noise modeling and industry input, Ophir finalized the design requirements for the airborne sensor, and released the critical sensor light source design requirements to qualified vendors. Responses from the vendors indicated that the light source was not commercially available, and will require a research and development effort to produce. Three vendors have responded positively with proposed design solutions. Ophir has decided to conduct short path optical laboratory experiments to verify the existence of methane and absorption at the specified wavelength, prior to proceeding with the light source selection. Techniques to eliminate common mode noise were also evaluated during the laboratory tests. Finally, Ophir has included a summary of the potential concerns for project success and has established future goals.

  6. Use of airborne and terrestrial lidar to detect ground displacement hazards to water systems

    USGS Publications Warehouse

    Stewart, J.P.; Hu, Jiawen; Kayen, R.E.; Lembo, A.J., Jr.; Collins, B.D.; Davis, C.A.; O'Rourke, T. D.

    2009-01-01

    We investigate the use of multiepoch airborne and terrestrial lidar to detect and measure ground displacements of sufficient magnitude to damage buried pipelines and other water system facilities that might result, for example, from earthquake or rainfall-induced landslides. Lidar scans are performed at three sites with coincident measurements by total station surveying. Relative horizontal accuracy is evaluated by measurements of lateral dimensions of well defined objects such as buildings and tanks; we find misfits ranging from approximately 5 to 12 cm, which is consistent with previous work. The bias and dispersion of lidar elevation measurements, relative to total station surveying, is assessed at two sites: (1) a power plant site (PP2) with vegetated steeply sloping terrain; and (2) a relatively flat and unvegetated site before and after trenching operations were performed. At PP2, airborne lidar showed minimal elevation bias and a standard deviation of approximately 70 cm, whereas terrestrial lidar did not produce useful results due to beam divergence issues and inadequate sampling of the study region. At the trench site, airborne lidar showed minimal elevation bias and reduced standard deviation relative to PP2 (6-20 cm), whereas terrestrial lidar was nearly unbiased with very low dispersion (4-6 cm). Pre- and posttrench bias-adjusted normalized residuals showed minimal to negligible correlation, but elevation change was affected by relative bias between epochs. The mean of elevation change bias essentially matches the difference in means of pre- and posttrench elevation bias, whereas elevation change standard deviation is sensitive to the dispersion of individual epoch elevations and their correlation coefficient. The observed lidar bias and standard deviations enable reliable detection of damaging ground displacements for some pipelines types (e.g., welded steel) but not all (e.g., concrete with unwelded, mortared joints). ?? ASCE 2009.

  7. Detection of airborne carbon nanotubes based on the reactivity of the embedded catalyst.

    PubMed

    Neubauer, N; Kasper, G

    2015-01-01

    A previously described method for detecting catalyst particles in workplace air((1,2)) was applied to airborne carbon nanotubes (CNT). It infers the CNT concentration indirectly from the catalytic activity of metallic nanoparticles embedded as part of the CNT production process. Essentially, one samples airborne CNT onto a filter enclosed in a tiny chemical reactor and then initiates a gas-phase catalytic reaction on the sample. The change in concentration of one of the reactants is then determined by an IR sensor as measure of activity. The method requires a one-point calibration with a CNT sample of known mass. The suitability of the method was tested with nickel containing (25 or 38% by weight), well-characterized multi-walled CNT aerosols generated freshly in the lab for each experiment. Two chemical reactions were investigated, of which the oxidation of CO to CO2 at 470°C was found to be more effective, because nearly 100% of the nickel was exposed at that temperature by burning off the carbon, giving a linear relationship between CO conversion and nickel mass. Based on the investigated aerosols, a lower detection limit of 1 μg of sampled nickel was estimated. This translates into sampling times ranging from minutes to about one working day, depending on airborne CNT concentration and catalyst content, as well as sampling flow rate. The time for the subsequent chemical analysis is on the order of minutes, regardless of the time required to accumulate the sample and can be done on site. PMID:25271474

  8. Airborne Influenza A Is Detected in the Personal Breathing Zone of Swine Veterinarians.

    PubMed

    O'Brien, Kate M; Nonnenmann, Matthew W

    2016-01-01

    The 2009 H1N1 pandemic emphasized a need to evaluate zoonotic transmission of influenza A in swine production. Airborne influenza A virus has been detected in swine facilities during an outbreak. However, the personal exposure of veterinarians treating infected swine has not been characterized. Two personal bioaerosol samplers, the NIOSH bioaerosol sampler and the personal high-flow inhalable sampler head (PHISH), were placed in the breathing zone of veterinarians treating swine infected with either H1N1 or H3N2 influenza A. A greater number of viral particles were recovered from the NIOSH bioaerosol sampler (2094 RNA copies/m3) compared to the PHISH sampler (545 RNA copies/m3). In addition, the majority of viral particles were detected by the NIOSH bioaerosol sampler in the >4 μm size fraction. These results suggest that airborne influenza A virus is present in the breathing zone of veterinarians treating swine, and the aerosol route of zoonotic transmission of influenza virus should be further evaluated among agricultural workers. PMID:26867129

  9. Airborne Influenza A Is Detected in the Personal Breathing Zone of Swine Veterinarians

    PubMed Central

    O’Brien, Kate M.; Nonnenmann, Matthew W.

    2016-01-01

    The 2009 H1N1 pandemic emphasized a need to evaluate zoonotic transmission of influenza A in swine production. Airborne influenza A virus has been detected in swine facilities during an outbreak. However, the personal exposure of veterinarians treating infected swine has not been characterized. Two personal bioaerosol samplers, the NIOSH bioaerosol sampler and the personal high-flow inhalable sampler head (PHISH), were placed in the breathing zone of veterinarians treating swine infected with either H1N1 or H3N2 influenza A. A greater number of viral particles were recovered from the NIOSH bioaerosol sampler (2094 RNA copies/m3) compared to the PHISH sampler (545 RNA copies/m3). In addition, the majority of viral particles were detected by the NIOSH bioaerosol sampler in the >4 μm size fraction. These results suggest that airborne influenza A virus is present in the breathing zone of veterinarians treating swine, and the aerosol route of zoonotic transmission of influenza virus should be further evaluated among agricultural workers. PMID:26867129

  10. Airborne infrared-hyperspectral mapping for detection of gaseous and solid targets

    NASA Astrophysics Data System (ADS)

    Puckrin, E.; Turcotte, C. S.; Lahaie, P.; Dubé, D.; Farley, V.; Lagueux, P.; Marcotte, F.; Chamberland, M.

    2010-04-01

    Airborne hyperspectral ground mapping is being used in an ever-increasing extent for numerous applications in the military, geology and environmental fields. The different regions of the electromagnetic spectrum help produce information of differing nature. The visible, near-infrared and short-wave infrared radiation (400 nm to 2.5 μm) has been mostly used to analyze reflected solar light, while the mid-wave (3 to 5 μm) and long-wave (8 to 12 μm or thermal) infrared senses the self-emission of molecules directly, enabling the acquisition of data during night time. The Telops Hyper-Cam is a rugged and compact infrared hyperspectral imager based on the Fourier-transform technology. It has been used on the ground in several field campaigns, including the demonstration of standoff chemical agent detection. More recently, the Hyper-Cam has been integrated into an airplane to provide airborne measurement capabilities. The technology offers fine spectral resolution (up to 0.25 cm-1) and high accuracy radiometric calibration (better than 1 degree Celsius). Furthermore, the spectral resolution, spatial resolution, swath width, integration time and sensitivity are all flexible parameters that can be selected and optimized to best address the specific objectives of each mission. The system performance and a few measurements have been presented in previous publications. This paper focuses on analyzing additional measurements in which detection of fertilizer and Freon gas has been demonstrated.

  11. An integrated GPS-FID system for airborne gas detection of pipeline right-of-ways

    SciTech Connect

    Gehue, H.L.; Sommer, P.

    1996-12-31

    Pipeline integrity, safety and environmental concerns are of prime importance in the Canadian natural gas industry. Terramatic Technology Inc. (TTI) has developed an integrated GPS/FID gas detection system known as TTI-AirTrac{trademark} for use in airborne gas detection (AGD) along pipeline right-of-ways. The Flame Ionization Detector (FID), which has traditionally been used to monitor air quality for gas plants and refineries, has been integrated with the Global Positioning System (GPS) via a 486 DX2-50 computer and specialized open architecture data acquisition software. The purpose of this technology marriage is to be able to continuously monitor air quality during airborne pipeline inspection. Event tagging from visual surveillance is used to determine an explanation of any delta line deviations (DLD). These deviations are an indication of hydrocarbon gases present in the plume that the aircraft has passed through. The role of the GPS system is to provide mapping information and coordinate data for ground inspections. The ground based inspection using a handheld multi gas detector will confirm whether or not a leak exists.

  12. Immunologic, spectrophotometric and nucleic acid based methods for the detection and quantification of airborne pollen

    PubMed Central

    Rittenour, William R.; Hamilton, Robert G.; Beezhold, Donald H.; Green, Brett J.

    2015-01-01

    Microscopic identification of pollen morphological phenotypes has been the traditional method used to identify and quantify pollen collected by air monitoring stations worldwide. Although this method has enabled a semi-standardized approach for the assessment of pollen exposure, limitations including labor intensiveness, required expertise, examiner bias, and the inability to differentiate species, genera, and in some cases families have limited data derived from the these stations. Recent advances in chemical, biochemical and molecular detection methods have provided standardized alternatives to this microscopic approach. In this review, we examine the applicability of alternative methodologies, in particular nucleic acid based assays involving the quantitative polymerase chain reaction, for the standardized detection of airborne pollen. PMID:22342607

  13. Multi-Target Detection from Full-Waveform Airborne Laser Scanner Using Phd Filter

    NASA Astrophysics Data System (ADS)

    Fuse, T.; Hiramatsu, D.; Nakanishi, W.

    2016-06-01

    We propose a new technique to detect multiple targets from full-waveform airborne laser scanner. We introduce probability hypothesis density (PHD) filter, a type of Bayesian filtering, by which we can estimate the number of targets and their positions simultaneously. PHD filter overcomes some limitations of conventional Gaussian decomposition method; PHD filter doesn't require a priori knowledge on the number of targets, assumption of parametric form of the intensity distribution. In addition, it can take a similarity between successive irradiations into account by modelling relative positions of the same targets spatially. Firstly we explain PHD filter and particle filter implementation to it. Secondly we formulate the multi-target detection problem on PHD filter by modelling components and parameters within it. At last we conducted the experiment on real data of forest and vegetation, and confirmed its ability and accuracy.

  14. Polarization differences in airborne ground penetrating radar performance for landmine detection

    NASA Astrophysics Data System (ADS)

    Dogaru, Traian; Le, Calvin

    2016-05-01

    The U.S. Army Research Laboratory (ARL) has investigated the ultra-wideband (UWB) radar technology for detection of landmines, improvised explosive devices and unexploded ordnance, for over two decades. This paper presents a phenomenological study of the radar signature of buried landmines in realistic environments and the performance of airborne synthetic aperture radar (SAR) in detecting these targets as a function of multiple parameters: polarization, depression angle, soil type and burial depth. The investigation is based on advanced computer models developed at ARL. The analysis includes both the signature of the targets of interest and the clutter produced by rough surface ground. Based on our numerical simulations, we conclude that low depression angles and H-H polarization offer the highest target-to-clutter ratio in the SAR images and therefore the best radar performance of all the scenarios investigated.

  15. Detection and Classification of Individual Airborne Microparticles using Laser Ablation Mass Spectroscopy and Multivariate Analysis

    SciTech Connect

    Gieray, R.A.; Lazar, A.; Parker, E.P.; Ramsey, J. M.; Reilly, P.T.A.; Rosenthal, S.E.; Trahan, M.W.; Wagner, J.S.; Whitten, W.B.

    1999-04-27

    We are developing a method for the real-time analysis of airborne microparticles based on laser ablation mass spectroscopy. Airborne particles enter an ion trap mass spectrometer through a differentially-pumped inlet, are detected by light scattered from two CW laser beams, and sampled by a 10 ns excimer laser pulse at 308 nm as they pass through the center of the ion trap electrodes. After the laser pulse, the stored ions are separated by conventional ion trap methods. In this work thousands of positive and negative ion spectra were collected for eighteen different species: six bacteria, six pollen, and six particulate samples. The data were then averaged and analyzed using the Multivariate Patch Algorithm (MPA), a variant of traditional multivariate anal ysis. The MPA correctly identified all of the positive ion spectra and 17 of the 18 negative ion spectra. In addition, when the average positive and negative spectra were combined the MPA correctly identified all 18 species. Finally, the MPA is also able to identify the components of computer synthesized mixtures of the samples studied

  16. Detection of a buoyant coastal wastewater discharge using airborne hyperspectral and infrared imagery

    NASA Astrophysics Data System (ADS)

    Marmorino, George O.; Smith, Geoffrey B.; Miller, W. D.; Bowles, Jeffrey H.

    2010-01-01

    Municipal wastewater discharged into the ocean through a submerged pipe, or outfall, can rise buoyantly to the sea surface, resulting in a near-field mixing zone and, in the presence of an ambient ocean current, an extended surface plume. In this paper, data from a CASI (Compact Airborne Spectrographic Imager) and an airborne infrared (IR) camera are shown to detect a municipal wastewater discharge off the southeast coast of Florida, U.S.A., through its elevated levels of chromophoric dissolved organic matter plus detrital material (CDOM) and cooler sea surface temperatures. CDOM levels within a ~15-m-diameter surface 'boil' are found to be about twice those in the ambient shelf water, and surface temperatures near the boil are lower by ~0.4°C, comparable to the vertical temperature difference across the ambient water column. The CASI and IR imagery show a nearly identically shaped buoyant plume, consistent with a fully surfacing discharge, but the IR data more accurately delineate the area of most rapid dilution as compared with previous in-situ measurements. The imagery also allows identification of ambient oceanographic processes that affect dispersion and transport in the far field. This includes an alongshore front, which limits offshore dispersion of the discharge, and shoreward-propagating nonlinear internal waves, which may be responsible for an enhanced onshore transport of the discharge.

  17. Detection of lying tree stems from airborne laser scanning data using a line template matching algorithm

    NASA Astrophysics Data System (ADS)

    Lindberg, E.; Hollaus, M.; Mücke, W.; Fransson, J. E. S.; Pfeifer, N.

    2013-10-01

    Dead wood is an important habitat characteristic in forests. However, dead wood lying on the ground below a canopy is difficult to detect from remotely sensed data. Data from airborne laser scanning include measurement of surfaces below the canopy, thus offering the potential to model objects on the ground. This paper describes a new line template matching algorithm for detecting lines along the ground. The line template matching is done directly to the laser point cloud and results in a raster showing the support of the line in each raster cell. Line elements are vectorized based on the raster to represent lying tree stems. The results have been validated versus field-measured lying tree stems. The number of detected lines was 845, of which 268 could be automatically linked to the 651 field-measured stems. The line template matching produced a raster which visually showed linear elements in areas where lying tree stems where present, but the result is difficult to compare with the field measurements due to positioning errors. The study area contained big piles of storm-felled trees in some places, which made it an unusually complex test site. Longer line structures such as ditches and roads also resulted in detected lines and further analysis is needed to avoid this, for example by specifically detecting longer lines and removing them.

  18. Utilization of an Airborne Plant Chlorophyll Imaging System for Detection of Septic System Malfunction

    NASA Technical Reports Server (NTRS)

    Spiering, Bruce A.; Carter, Gregory A.

    2001-01-01

    Malfunctioning, or leaking, sewer systems increase the supply of water and nutrients to surface vegetation. Excess nutrients and harmful bacteria in the effluent pollute ground water and local water bodies and are dangerous to humans and the aquatic ecosystems. An airborne multispectral plant chlorophyll imaging system (PCIS) was used to identify growth patterns in the vegetation covering onsite and public sewer systems. The objective was to evaluate overall performance of the PCIS as well as to determine the best operational configuration for this application. The imaging system was flown in a light aircraft over selected locations Mobile County, Alabama. Calibration panels were used to help characterize instrument performance. Results demonstrated that the PCIS performed well and was capable of detecting septic leakage patterns from altitudes as high as 915 m. From 915 m, 6 of 18 sites were suspected to have sewage leakage. Subsequent ground inspections confirmed leakage on 3 of the 6 sites. From 610 m, 3 of 8 known leakage sites were detected. Tree cover and shadows near residential structures prevented detection of several known malfunctioning systems. Also some leakages known to occur in clear areas were not detected. False detections occurred in areas characterized by surface water drainage problems or recent excavation.

  19. Detection of Collapsed Buildings by Classifying Segmented Airborne Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    Elberink, S. O.; Shoko, M. A.; Fathi, S. A.; Rutzinger, M.

    2011-09-01

    Rapid mapping of damaged regions and individual buildings is essential for efficient crisis management. Airborne laser scanner (ALS) data is potentially able to deliver accurate information on the 3D structures in a damaged region. In this paper we describe two different strategies how to process ALS point clouds in order to detect collapsed buildings automatically. Our aim is to detect collapsed buildings using post event data only. The first step in the workflow is the segmentation of the point cloud detecting planar regions. Next, various attributes are calculated for each segment. The detection of damaged buildings is based on the values of these attributes. Two different classification strategies have been applied in order to test whether the chosen strategy is capable of detect- ing collapsed buildings. The results of the classification are analysed and assessed for accuracy against a reference map in order to validate the quality of the rules derived. Classification results have been achieved with accuracy measures from 60-85% complete- ness and correctness. It is shown that not only the classification strategy influences the accuracy measures; also the validation meth- odology, including the type and accuracy of the reference data, plays a major role.

  20. An airborne FLIR detection and warning system for low altitude wind shear

    NASA Technical Reports Server (NTRS)

    Sinclair, Peter C.; Kuhn, Peter M.

    1991-01-01

    It is shown through some preliminary flight measurement research that a forward looking infrared radiometer (FLIR) system can be used to successfully detect the cool downdraft of downbursts (microbusts/macrobursts) and thunderstorm gust front outflows that are responsible for most of the low altitude wind shear (LAWS) events. The FLIR system provides a much greater safety margin for the pilot than that provided by reactive designs such as inertial air speed systems. Preliminary results indicate that an advanced airborne FLIR system could provide the pilot with remote indication of microburst (MB) hazards along the flight path ahead of the aircraft. Results of a flight test of a prototype FLIR system show that a minimum warning time of one to four minutes (5 to 10 km), depending on aircraft speed, is available to the pilot prior to the microburst encounter.

  1. Airborne laser scanner measurements for the detection of sinkholes and their changes

    NASA Astrophysics Data System (ADS)

    Bielenberg, Olaf; Meyer, Uwe; Heyde, Ingo

    2010-05-01

    The Dead Sea Transform (DST) is a system of left-lateral strike-slip faults that accommodates the relative motion between the African and Arabian plates. Furthermore the water level of the Dead Sea is sinking rapidly at an average of one meter per year. Because of this the salt lake has already lost one third of its surface and along the parched shores are formed daily new sinkholes that are up to 20 meters deep. About 1000 of these sudden incident sinkholes have formed in the meanwhile the shoreline of the Dead Sea. They represent danger both to life and property, disrupt life in the area, and aversely affect building and development. During the measurement campaign for the Dead Sea Integrated Research Project (DESIRE) 2007 the coastal area was flown to the south of Ein Gedi also with a laser mirror scanner constructed by RIEGL to detect relevant sinkholes. The airborne survey area covers a surface of approximately 20 by 4 km. The data acquisition was done by flights in North-South direction in 20 strips with an overlap of 50 percent. For the data analysis focused on the software TopPIT of Trimble Geospatial was used. The aim of the airborne survey was the calculation of a digital terrain model (DTM) but also the creation of an inventory of existing sinkholes, that can be used to detect temporal changes by comparison with future recordings. Moreover, the efficiency of the method used should be demonstrated as an appropriate procedure compared with traditional field data collection.

  2. Using Airborne Laser Altimetry to Detect Topographic Change at Long Valley Caldera California

    NASA Technical Reports Server (NTRS)

    Hofton, M. A.; Minster, J.-B.; Ridgway, J. R.; Williams, N. P.; Blair, J. B.; Rabine, D. L.; Bufton, J. L.

    2000-01-01

    The topography of the Long Valley caldera, California, was sampled using airborne laser altimetry in 1993, 1995, and 1997 to test the feasibility of using airborne laser altimetry for monitoring deformation of volcanic origin. Results show the laser altimeters are able to resolve subtle topographic features such as a gradual slope and to detect small transient changes in lake elevation. Crossover and repeat pass analyses of laser tracks indicate decimeter-level vertical precision is obtained over flat and low-sloped terrain for altimeter systems performing waveform digitization. Comparisons with complementary, ground-based CPS data at a site close to Bishop airport indicate that the laser and GPS-derived elevations agree to within the error inherent in the measurement and that horizontal locations agree to within the radius of the laser footprint. A comparison of the data at two sites, one where no change and the other where the maximum amount of vertical uplift is expected, indicates approximately 10 cm of relative uplift occurred 1993-1997, in line with predictions from continuous CPS measurements in the region. Extensive terrain mapping flights during the 1995 and 1997 missions demonstrate some of the unique abilities of laser altimetry; the straightforward creation of high resolution, high accuracy digital elevation models of overflown terrain, and the ability to determine ground topography in the presence of significant ground cover such as dense tree canopies. These capabilities make laser altimetry an attractive technique for quantifying topographic change of volcanic origin, especially in forested regions of the world where other remote sensing instruments have difficulty detecting the underlying topography.

  3. Using Airborne Laser Altimetry to Detect Topographic Change at Long Valley Caldera, California

    NASA Technical Reports Server (NTRS)

    Hofton, M. A.; Minster, J.-B.; Ridgway, J. R.; Williams, N. P.; Blair, J.-B.; Rabine, D. L.; Bufton, J. L.

    1999-01-01

    The topography of the Long Valley caldera, California, was sampled using airborne laser altimetry in 1993, 1995, and 1997 to test the feasibility of using airborne laser altimetry for monitoring deformation of volcanic origin. Results show the laser altimeters are able to resolve subtle topographic features such as a gradual slope and to detect small transient changes in lake elevation. Crossover and repeat pass analyses of laser tracks indicate decimeter-level vertical precision is obtained over flat and low-sloped terrain for altimeter systems performing waveform digitization. Comparisons with complementary, ground-based GPS data at a site close to Bishop airport indicate that the laser and GPS-derived elevations agree to within the error inherent in the measurement and that horizontal locations agree to within the radius of the laser footprint. A comparison of the data at two sites, one where no change and the other where the maximum amount of vertical uplift is expected, indicates approximately 10 cm of relative uplift occurred 1993-1997, in line with predictions from continuous GPS measurements in the region. Extensive terrain mapping flights during the 1995 and 1997 missions demonstrate some of the unique abilities of laser altimetry; the straightforward creation of high resolution, high accuracy digital elevation models of overflown terrain, and the ability to determine ground topography in the presence of significant ground cover such as dense tree canopies. These capabilities make laser altimetry an attractive technique for quantifying topographic change of volcanic origin, especially in forested regions of the world where other remote sensing instruments have difficulty detecting the underlying topography.

  4. Detection and Classification of Changes in Buildings from Airborne Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Xu, S.; Vosselman, G.; Oude Elberink, S.

    2013-10-01

    Building change detection serves to investigate illegal buildings. Illegal built or removed structures, especially those concealed among gable roofs such as dormers, are difficult to track among potentially millions of buildings. Nevertheless, they can be efficiently located in changed areas. An approach is proposed to automatically detect and classify changes in buildings from two epochs of Airborne Laser Scanning Data. Both datasets are classified into water, ground, building, vegetation and undefined objects in advance. After generalization of a 3D surface separation map, we verify changes by making rules on the separation map. Changes belonging to buildings are then classified into roof, wall, dormers, vehicles, construction above roof and undefined objects. As the ALS data has accuracy in strip difference of lower than 5 cm within the same epoch and from different epochs, changes that are larger than 10 cm were detected. Building changes, which areas are larger than 4 m2, are identified as change. By inspection, nearly all changes are detected and approximately 80% changes are correctly classified.

  5. Airborne Nanoparticle Detection By Sampling On Filters And Laser-Induced Breakdown Spectroscopy Analysis

    NASA Astrophysics Data System (ADS)

    Dewalle, Pascale; Sirven, Jean-Baptiste; Roynette, Audrey; Gensdarmes, François; Golanski, Luana; Motellier, Sylvie

    2011-07-01

    Nowadays, due to their unique physical and chemical properties, engineered nanoparticles are increasingly used in a variety of industrial sectors. However, questions are raised about the safety of workers who produce and handle these particles. Therefore it is necessary to assess the potential exposure by inhalation of these workers. There is thereby a need to develop a suitable instrumentation which can detect selectively the presence of engineered nanoparticles in the ambient atmosphere. In this paper Laser-Induced Breakdown Spectroscopy (LIBS) is used to meet this target. LIBS can be implemented on site since it is a fast and direct technique which requires no sample preparation. The approach consisted in sampling Fe2O3 and TiO2 nanoparticles on a filter, respectively a mixed cellulose ester membrane and a polycarbonate membrane, and to measure the surface concentration of Fe and Ti by LIBS. Then taking into account the sampling parameters (flow, duration, filter surface) we could calculate a detection limit in volume concentration in the atmosphere. With a sampling at 10 L/min on a 10 cm2 filter during 1 min, we obtained detection limits of 56 μg/m3 for Fe and 22 μg/m3 for Ti. These figures, obtained in real time, are significantly below existing workplace exposure recommendations of the EU-OSHA and of the NIOSH. These results are very encouraging and will be completed in a future work on airborne carbon nanotube detection.

  6. Uncertainty assessment and probabilistic change detection using terrestrial and airborne lidar

    NASA Astrophysics Data System (ADS)

    Jalobeanu, André; Kim, Angela M.; Runyon, Scott C.; Olsen, R. C.; Kruse, Fred A.

    2014-06-01

    Change detection using remote sensing has become increasingly important for characterization of natural disasters. Pre- and post-event LiDAR data can be used to identify and quantify changes. The main challenge consists of producing reliable change maps that are robust to differences in collection conditions, free of processing artifacts, and that take into account various sources of uncertainty such as different point densities, different acquisition geometries, georeferencing errors and geometric discrepancies. We present a simple and fast technique that accounts for these sources of uncertainty, and enables the creation of statistically significant change detection maps. The technique makes use of Bayesian inference to estimate uncertainty maps from LiDAR point clouds. Incorporation of uncertainties enables a change detection that is robust to noise due to ranging, position and attitude errors, as well as "roughness" in vegetation scans. Validation of the method was done by use of small-scale models scanned with a terrestrial LiDAR in a laboratory setting. The method was then applied to two airborne collects of the Monterey Peninsula, California acquired in 2011 and 2012. These data have significantly different point densities (8 vs. 40 pts/m2) and some misregistration errors. An original point cloud registration technique was developed, first to correct systematic shifts due to GPS and INS errors, and second to help measure large-scale changes in a consistent manner. Sparse changes were detected and interpreted mostly as construction and natural landscape evolution.

  7. Fusion of remotely sensed data from airborne and ground-based sensors to enhance detection of cotton plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study investigated the use of aerial multispectral imagery and ground-based hyperspectral data for the discrimination of different crop types and timely detection of cotton plants over large areas. Airborne multispectral imagery and ground-based spectral reflectance data were acquired at the sa...

  8. Enhanced detection of water and ground surface in airborne laser bathymetry data using waveform stacking

    NASA Astrophysics Data System (ADS)

    Roncat, Andreas; Mandlburger, Gottfried

    2016-04-01

    The past years have seen an increasing scientific interest in high-resolution topographic data of fluvial geomorphology. Moreover, from an administrative perspective, the European Union's water framework directive and the flood directive formulate further requirements on monitoring fluvial landscapes. For capturing the geomorphology of shallow water bodies, e.g. creeks and rivers, airborne laser bathymetry (ALB) has become a method of choice. These instruments operate in the green wavelength domain, enabling for the laser to penetrate the water column. As the water surface is the boundary between two media, i.e. between air and water, and from a physical perspective represents the locus where the laser beam is bent and decelerated. Therefore, the detection of this boundary is crucial for retrieving the channel morphology correctly. However, in case of low signal-to-noise ratio (SNR) these detection may fail for single laser shots. This gives the motivation for increasing the SNR by simulating a bigger laser footprint by means of stacking adjacent laser waveforms in a spatial neighbourhood, e.g. a slanted cylinder. On the one hand, this implies a reduction in spatial resolution; on the other hand though, it means an increase in reliability of the results, both in the detection of the water surface and enabling for assessing the turbidity of water column. The presented approach is evaluated by means of a multi-temporal airbone laser bathymetry dataset captured over the river Pielach and neigbhouring standing water bodies in Loosdorf, Lower Austria.

  9. The detection and measurement of microburst wind shear by an airborne lidar system

    NASA Technical Reports Server (NTRS)

    Robinson, Paul A.; Bowles, Roland L.; Targ, Russell

    1993-01-01

    The NASA Lockheed Missiles and Space Company (LMSC) Coherent Lidar Airborne Shear Sensor (CLASS) employs coherent lidar technology as a basis for a forward-looking predictive wind shear detection system. Line of sight wind velocities measured ahead of the aircraft are combined with aircraft state parameters to relate the measured wind change (or shear) ahead of an aircraft to its performance loss or gain. In this way the system can predict whether a shear detected ahead of the aircraft poses a significant threat to the aircraft and provide an advance warning to the flight crew. Installed aboard NASA's Boeing 737 research aircraft, the CLASS system is flown through convective microburst wind shears in Denver, Co., and Orlando, Fl. Some preliminary flight test results are presented. It is seen that the system was able to detect and measure wind shears ahead of the aircraft in the relatively dry Denver environment, but its performance was degraded in the high humidity and heavy rain in Orlando.

  10. Effective localized collection and identification of airborne species through electrodynamic precipitation and SERS-based detection

    PubMed Central

    Lin, En-Chiang; Fang, Jun; Park, Se-Chul; Johnson, Forrest W.; Jacobs, Heiko O.

    2013-01-01

    Various nanostructured sensor designs currently aim to achieve or claim single molecular detection by a reduction of the active sensor size. However, a reduction of the sensor size has the negative effect of reducing the capture probability considering the diffusion-based analyte transport commonly used. Here we introduce and apply a localized programmable electrodynamic precipitation concept as an alternative to diffusion. The process provides higher collection rates of airborne species and detection at lower concentration. As an example, we compare an identical nanostructured surfaced-enhanced Raman spectroscopy sensor with and without localized delivery and find that the sensitivity and detection time is improved by at least two orders of magnitudes. Localized collection in an active-matrix array-like fashion is also tested, yielding hybrid molecular arrays on a single chip over a broad range of molecular weights, including small benzenethiol (110.18 Da) and 4-fluorobenzenethiol (128.17 Da), or large macromolecules such as anti-mouse IgG (~150 kDa). PMID:23535657

  11. Real-time single airborne nanoparticle detection with nanomechanical resonant filter-fiber

    PubMed Central

    Schmid, Silvan; Kurek, Maksymilian; Adolphsen, Jens Q.; Boisen, Anja

    2013-01-01

    Nanomechanical resonators have an unprecedented mass sensitivity sufficient to detect single molecules, viruses or nanoparticles. The challenge with nanomechanical mass sensors is the direction of nano-sized samples onto the resonator. In this work we present an efficient inertial sampling technique and gravimetric detection of airborne nanoparticles with a nanomechanical resonant filter-fiber. By increasing the nanoparticle momentum the dominant collection mechanism changes from diffusion to more efficient inertial impaction. In doing so we reach a single filter-fiber collection efficiency of 65 ± 31% for 28 nm silica nanoparticles. Finally, we show the detection of single 100 nm silver nanoparticles. The presented method is suitable for environmental or security applications where low-cost and portable monitors are demanded. It also constitutes a unique technique for the fundamental study of single filter-fiber behavior. We present the direct measurement of diffusive nanoparticle collection on a single filter-fiber qualitatively confirming Langmuir's model from 1942. PMID:23411405

  12. Detecting pruning of individual stems using Airborne Laser Scanning data captured from an Unmanned Aerial Vehicle

    NASA Astrophysics Data System (ADS)

    Wallace, Luke; Watson, Christopher; Lucieer, Arko

    2014-08-01

    Modern forest management involves implementing optimal pruning regimes. These regimes aim to achieve the highest quality timber in the shortest possible rotation period. Although a valuable addition to forest management activities, tracking the application of these treatments in the field to ensure best practice management is not economically viable. This paper describes the use of Airborne Laser Scanner (ALS) data to track the rate of pruning in a Eucalyptus globulus stand. Data is obtained from an Unmanned Aerial Vehicle (UAV) and we describe automated processing routines that provide a cost-effective alternative to field sampling. We manually prune a 500 m2 plot to 2.5 m above the ground at rates of between 160 and 660 stems/ha. Utilising the high density ALS data, we first derived crown base height (CBH) with an RMSE of 0.60 m at each stage of pruning. Variability in the measurement of CBH resulted in both false positive (mean rate of 11%) and false negative detection (3.5%), however, detected rates of pruning of between 96% and 125% of the actual rate of pruning were achieved. The successful automated detection of pruning within this study highlights the suitability of UAV laser scanning as a cost-effective tool for monitoring forest management activities.

  13. Relationship between airborne detection of influenza A virus and the number of infected pigs

    PubMed Central

    Corzo, Cesar A.; Romagosa, Anna; Dee, Scott; Gramer, Marie; Morrison, Robert B; Torremorell, Montserrat

    2012-01-01

    Influenza A virus infects a wide range of species including both birds and mammals (including humans). One of the key routes by which the virus can infect populations of animals is by aerosol transmission. This study explored the relationship between number of infected pigs and the probability of detecting influenza virus RNA in bioaerosols through the course of an acute infection. Bioaerosols were collected using a cyclonic collector in two groups of 7 week-old pigs that were experimentally infected by exposure with a contact infected pig (seeder pig). After contact exposure, individual pig nasal swab samples were collected daily and air samples were collected three times per day for 8 days. All samples were tested for influenza by real-time reverse transcriptase (RRT)-PCR targeting the influenza virus matrix gene. All pigs' nasal swabs became influenza virus RRT-PCR positive upon exposure to the infected seeder pig. Airborne influenza was detected in 28/43 (65%) air samples. The temporal dynamics of influenza virus detection in air samples was in close agreement with the nasal shedding pattern in the infected pigs. First detection of positive bioaerosols happened at 1 day post contact (DPC). Positive bioaerosols were consistently detected between 3 and 6 DPC, a time when most pigs were also shedding virus in nasal secretions. Overall, the odds of detecting a positive air sample increased 2.2 times for every additional nasal swab positive pig in the group. In summary, there was a strong relationship between the number of pigs shedding influenza virus in nasal secretions and the generation of bioaerosols during the course of an acute infection. PMID:23164957

  14. Clutter filter design considerations for Airborne Doppler radar detection of windshear

    NASA Technical Reports Server (NTRS)

    Baxa, Ernest G., Jr.

    1990-01-01

    The problem of clutter rejection when processing down-looking Doppler radar returns from a low altitude airborne platform is a paramount problem. With radar as a remote sensor for detecting and predicting windshear in the vicinity of an urban airport, dynamic range requirements can exceed 50 dB because of high clutter to signal ratios. This presentation describes signal processing considerations in the presence of distributed and/or discrete clutter interference. Previous analyses have considered conventional range cell processing of radar returns from a rigidly mounted radar platform using either the Fourier or the pulse-pair method to estimate average windspeed and windspeed variation within a cell. Clutter rejection has been based largely upon analyzing a particular environment in the vicinity of the radar and employing a variety of techniques to reduce interference effects including notch filtering, Fourier domain line editing, and use of clutter maps. For the airborne environment the clutter characteristics may be somewhat different. Conventional clutter rejection methods may have to be changed and new methods will probably be required to provide useful signal to noise ratios. Various considerations are described. A major thrust has been to evaluate the effect of clutter rejection filtering upon the ability to derive useful information from the post-filter radar data. This analysis software is briefly described. Finally, some ideas for future analysis are considered including the use of adaptive filtering for clutter rejection and the estimation of windspeed spatial gradient directly from radar returns as a means of reducing the effects of clutter on the determination of a windshear hazard.

  15. An improved procedure for detection and enumeration of walrus signatures in airborne thermal imagery

    USGS Publications Warehouse

    Burn, Douglas M.; Udevitz, Mark S.; Speckman, Suzann G.; Benter, R. Bradley

    2009-01-01

    In recent years, application of remote sensing to marine mammal surveys has been a promising area of investigation for wildlife managers and researchers. In April 2006, the United States and Russia conducted an aerial survey of Pacific walrus (Odobenus rosmarus divergens) using thermal infrared sensors to detect groups of animals resting on pack ice in the Bering Sea. The goal of this survey was to estimate the size of the Pacific walrus population. An initial analysis of the U.S. data using previously-established methods resulted in lower detectability of walrus groups in the imagery and higher variability in calibration models than was expected based on pilot studies. This paper describes an improved procedure for detection and enumeration of walrus groups in airborne thermal imagery. Thermal images were first subdivided into smaller 200 x 200 pixel "tiles." We calculated three statistics to represent characteristics of walrus signatures from the temperature histogram for each the. Tiles that exhibited one or more of these characteristics were examined further to determine if walrus signatures were present. We used cluster analysis on tiles that contained walrus signatures to determine which pixels belonged to each group. We then calculated a thermal index value for each walrus group in the imagery and used generalized linear models to estimate detection functions (the probability of a group having a positive index value) and calibration functions (the size of a group as a function of its index value) based on counts from matched digital aerial photographs. The new method described here improved our ability to detect walrus groups at both 2 m and 4 m spatial resolution. In addition, the resulting calibration models have lower variance than the original method. We anticipate that the use of this new procedure will greatly improve the quality of the population estimate derived from these data. This procedure may also have broader applicability to thermal infrared

  16. An improved procedure for detection and enumeration of walrus signatures in airborne thermal imagery

    NASA Astrophysics Data System (ADS)

    Burn, Douglas M.; Udevitz, Mark S.; Speckman, Suzann G.; Benter, R. Bradley

    2009-10-01

    In recent years, application of remote sensing to marine mammal surveys has been a promising area of investigation for wildlife managers and researchers. In April 2006, the United States and Russia conducted an aerial survey of Pacific walrus ( Odobenus rosmarus divergens) using thermal infrared sensors to detect groups of animals resting on pack ice in the Bering Sea. The goal of this survey was to estimate the size of the Pacific walrus population. An initial analysis of the U.S. data using previously-established methods resulted in lower detectability of walrus groups in the imagery and higher variability in calibration models than was expected based on pilot studies. This paper describes an improved procedure for detection and enumeration of walrus groups in airborne thermal imagery. Thermal images were first subdivided into smaller 200 × 200 pixel "tiles." We calculated three statistics to represent characteristics of walrus signatures from the temperature histogram for each tile. Tiles that exhibited one or more of these characteristics were examined further to determine if walrus signatures were present. We used cluster analysis on tiles that contained walrus signatures to determine which pixels belonged to each group. We then calculated a thermal index value for each walrus group in the imagery and used generalized linear models to estimate detection functions (the probability of a group having a positive index value) and calibration functions (the size of a group as a function of its index value) based on counts from matched digital aerial photographs. The new method described here improved our ability to detect walrus groups at both 2 m and 4 m spatial resolution. In addition, the resulting calibration models have lower variance than the original method. We anticipate that the use of this new procedure will greatly improve the quality of the population estimate derived from these data. This procedure may also have broader applicability to thermal

  17. Remote detection of water stress in orchard canopies using MODIS/ASTER airborne simulator (MASTER) data

    NASA Astrophysics Data System (ADS)

    Cheng, Tao; Riaño, David; Koltunov, Alexander; Whiting, Michael L.; Ustin, Susan L.

    2011-09-01

    Vegetation canopy water content (CWC) is an important parameter for monitoring natural and agricultural ecosystems. Previous studies focused on the observation of annual or monthly variations in CWC but lacked temporal details to study vegetation physiological activities within a diurnal cycle. This study provides an evaluation of detecting vegetation diurnal water stress using airborne data acquired with the MASTER instrument. Concurrent with the morning and afternoon acquisitions of MASTER data, an extensive field campaign was conducted over almond and pistachio orchards in southern San Joaquin Valley of California to collect CWC measurements. Statistical analysis of the field measurements indicated a significant decrease of CWC from morning to afternoon. Field measured CWC was linearly correlated to the normalized difference infrared index (NDII) calculated with atmospherically corrected MASTER reflectance data using either FLAASH or empirical line (EL). Our regression analysis demonstrated that both atmospheric corrections led to a root mean square error (RMSE) of approximately 0.035 kg/m2 for the estimation of CWC (R2=0.42 for FLAASH images and R2=0.45 for EL images). Remote detection of the subtle decline in CWC awaits an improved prediction of CWC. Diurnal CWC maps revealed the spatial patterns of vegetation water status in response to variations in irrigation treatment.

  18. Detection of abandoned mines/caves using airborne LWIR hyperspectral data

    NASA Astrophysics Data System (ADS)

    Shen, Sylvia S.; Roettiger, Kurt A.

    2012-09-01

    The detection of underground structures, both natural and man-made, continues to be an important requirement in both the military/intelligence and civil communities. There are estimates that as many as 70,000 abandoned mines/caves exist across the nation. These mines represent significant hazards to public health and safety, and they are of concern to Government agencies at the local, state, and federal levels. NASA is interested in the detection of caves on Mars and the Moon in anticipation of future manned space missions. And, the military/ intelligence community is interested in detecting caves, mines, and other underground structures that may be used to conceal the production of weapons of mass destruction or to harbor insurgents or other persons of interest by the terrorists. Locating these mines/caves scattered over millions of square miles is an enormous task, and limited resources necessitate the development of an efficient and effective broad area search strategy using remote sensing technologies. This paper describes an internally-funded research project of The Aerospace Corporation (Aerospace) to assess the feasibility of using airborne hyperspectral data to detect abandoned cave/mine entrances in a broad-area search application. In this research, we have demonstrated the potential utility of using thermal contrast between the cave/mine entrance and the ambient environment as a discriminatory signature. We have also demonstrated the use of a water vapor absorption line at12.55 μm and a quartz absorption feature at 9.25 μm as discriminatory signatures. Further work is required to assess the broader applicability of these signatures.

  19. Use of airborne remote sensing to detect riverside Brassica rapa to aid in risk assessment of transgenic crops

    NASA Astrophysics Data System (ADS)

    Elliott, Luisa M.; Mason, David C.; Allainguillaume, Joel; Wilkinson, Mike J.

    2009-11-01

    High resolution descriptions of plant distribution have utility for many ecological applications but are especially useful for predictive modeling of gene flow from transgenic crops. Difficulty lies in the extrapolation errors that occur when limited ground survey data are scaled up to the landscape or national level. This problem is epitomized by the wide confidence limits generated in a previous attempt to describe the national abundance of riverside Brassica rapa (a wild relative of cultivated rapeseed) across the United Kingdom. Here, we assess the value of airborne remote sensing to locate B. rapa over large areas and so reduce the need for extrapolation. We describe results from flights over the river Nene in England acquired using Airborne Thematic Mapper (ATM) and Compact Airborne Spectrographic Imager (CASI) imagery, together with ground truth data. It proved possible to detect 97% of flowering B. rapa on the basis of spectral profiles. This included all stands of plants that occupied >2m square (>5 plants), which were detected using single-pixel classification. It also included very small populations (<5 flowering plants, 1-2m square) that generated mixed pixels, which were detected using spectral unmixing. The high detection accuracy for flowering B. rapa was coupled with a rather large false positive rate (43%). The latter could be reduced by using the image detections to target fieldwork to confirm species identity, or by acquiring additional remote sensing data such as laser altimetry or multitemporal imagery.

  20. Performance metrics for state-of-the-art airborne magnetic and electromagnetic systems for mapping and detection of unexploded ordnance

    NASA Astrophysics Data System (ADS)

    Doll, William E.; Bell, David T.; Gamey, T. Jeffrey; Beard, Les P.; Sheehan, Jacob R.; Norton, Jeannemarie

    2010-04-01

    Over the past decade, notable progress has been made in the performance of airborne geophysical systems for mapping and detection of unexploded ordnance in terrestrial and shallow marine environments. For magnetometer systems, the most significant improvements include development of denser magnetometer arrays and vertical gradiometer configurations. In prototype analyses and recent Environmental Security Technology Certification Program (ESTCP) assessments using new production systems the greatest sensitivity has been achieved with a vertical gradiometer configuration, despite model-based survey design results which suggest that dense total-field arrays would be superior. As effective as magnetometer systems have proven to be at many sites, they are inadequate at sites where basalts and other ferrous geologic formations or soils produce anomalies that approach or exceed those of target ordnance items. Additionally, magnetometer systems are ineffective where detection of non-ferrous ordnance items is of primary concern. Recent completion of the Battelle TEM-8 airborne time-domain electromagnetic system represents the culmination of nearly nine years of assessment and development of airborne electromagnetic systems for UXO mapping and detection. A recent ESTCP demonstration of this system in New Mexico showed that it was able to detect 99% of blind-seeded ordnance items, 81mm and larger, and that it could be used to map in detail a bombing target on a basalt flow where previous airborne magnetometer surveys had failed. The probability of detection for the TEM-8 in the blind-seeded study area was better than that reported for a dense-array total-field magnetometer demonstration of the same blind-seeded site, and the TEM-8 system successfully detected these items with less than half as many anomaly picks as the dense-array total-field magnetometer system.

  1. Bioaerosol emissions and detection of airborne antibiotic resistance genes from a wastewater treatment plant

    NASA Astrophysics Data System (ADS)

    Li, Jing; Zhou, Liantong; Zhang, Xiangyu; Xu, Caijia; Dong, Liming; Yao, Maosheng

    2016-01-01

    Air samples from twelve sampling sites (including seven intra-plant sites, one upwind site and four downwind sites) from a wastewater treatment plant (WWTP) in Beijing were collected using a Reuter Centrifugal Sampler High Flow (RCS); and their microbial fractions were studied using culturing and high throughput gene sequence. In addition, the viable (fluorescent) bioaerosol concentrations for 7 intra-plant sites were also monitored for 30 min each using an ultraviolet aerodynamic particle sizer (UV-APS). Both air and water samples collected from the plant were investigated for possible bacterial antibiotic resistance genes and integrons using polymerase chain reaction (PCR) coupled with gel electrophoresis. The results showed that the air near sludge thickening basin was detected to have the highest level of culturable bacterial aerosols (up to 1697 CFU/m3) and fungal aerosols (up to 930 CFU/m3). For most sampling sites, fluorescent peaks were observed at around 3-4 μm, except the office building with a peak at 1.5 μm, with a number concentration level up to 1233-6533 Particles/m3. About 300 unique bacterial species, including human opportunistic pathogens, such as Comamonas Testosteroni and Moraxella Osloensis, were detected from the air samples collected over the biological reaction basin. In addition, we have detected the sul2 gene resistant to cotrimoxazole (also known as septra, bactrim and TMP-SMX) and class 1 integrase gene from the air samples collected from the screen room and the biological reaction basin. Overall, the screen room, sludge thickening basin and biological reaction basin imposed significant microbial exposure risks, including those from airborne antibiotic resistance genes.

  2. Large-scale road detection in forested mountainous areas using airborne topographic lidar data

    NASA Astrophysics Data System (ADS)

    Ferraz, António; Mallet, Clément; Chehata, Nesrine

    2016-02-01

    In forested mountainous areas, the road location and characterization are invaluable inputs for various purposes such as forest management, wood harvesting industry, wildfire protection and fighting. Airborne topographic lidar has become an established technique to characterize the Earth surface. Lidar provides 3D point clouds allowing for fine reconstruction of ground topography while preserving high frequencies of the relief: fine Digital Terrain Models (DTMs) is the key product. This paper addresses the problem of road detection and characterization in forested environments over large scales (>1000 km2). For that purpose, an efficient pipeline is proposed, which assumes that main forest roads can be modeled as planar elongated features in the road direction with relief variation in orthogonal direction. DTMs are the only input and no complex 3D point cloud processing methods are involved. First, a restricted but carefully designed set of morphological features is defined as input for a supervised Random Forest classification of potential road patches. Then, a graph is built over these candidate regions: vertices are selected using stochastic geometry tools and edges are created in order to fill gaps in the DTM created by vegetation occlusion. The graph is pruned using morphological criteria derived from the input road model. Finally, once the road is located in 2D, its width and slope are retrieved using an object-based image analysis. We demonstrate that our road model is valid for most forest roads and that roads are correctly retrieved (>80%) with few erroneously detected pathways (10-15%) using fully automatic methods. The full pipeline takes less than 2 min per km2 and higher planimetric accuracy than 2D existing topographic databases are achieved. Compared to these databases, additional roads can be detected with the ability of lidar sensors to penetrate the understory. In case of very dense vegetation and insufficient relief in the DTM, gaps may exist in

  3. Automatic 3D Building Detection and Modeling from Airborne LiDAR Point Clouds

    NASA Astrophysics Data System (ADS)

    Sun, Shaohui

    Urban reconstruction, with an emphasis on man-made structure modeling, is an active research area with broad impact on several potential applications. Urban reconstruction combines photogrammetry, remote sensing, computer vision, and computer graphics. Even though there is a huge volume of work that has been done, many problems still remain unsolved. Automation is one of the key focus areas in this research. In this work, a fast, completely automated method to create 3D watertight building models from airborne LiDAR (Light Detection and Ranging) point clouds is presented. The developed method analyzes the scene content and produces multi-layer rooftops, with complex rigorous boundaries and vertical walls, that connect rooftops to the ground. The graph cuts algorithm is used to separate vegetative elements from the rest of the scene content, which is based on the local analysis about the properties of the local implicit surface patch. The ground terrain and building rooftop footprints are then extracted, utilizing the developed strategy, a two-step hierarchical Euclidean clustering. The method presented here adopts a "divide-and-conquer" scheme. Once the building footprints are segmented from the terrain and vegetative areas, the whole scene is divided into individual pendent processing units which represent potential points on the rooftop. For each individual building region, significant features on the rooftop are further detected using a specifically designed region-growing algorithm with surface smoothness constraints. The principal orientation of each building rooftop feature is calculated using a minimum bounding box fitting technique, and is used to guide the refinement of shapes and boundaries of the rooftop parts. Boundaries for all of these features are refined for the purpose of producing strict description. Once the description of the rooftops is achieved, polygonal mesh models are generated by creating surface patches with outlines defined by detected

  4. Detection of Extreme Climate Event Impacts to Terrestrial Productivity From Airborne Hyperspectral Imagery

    NASA Astrophysics Data System (ADS)

    Desai, A. R.; DuBois, S.; Singh, A.; Serbin, S.; Goulden, M.; Baldocchi, D. D.; Oechel, W. C.; Kruger, E. L.; Townsend, P. A.

    2015-12-01

    Changes in drought frequency and intensity are likely to be some of the largest climate anomalies to influence the net productivity of ecosystems, especially in already water-limited regions. However, the physiological mechanisms that drive this response are limited by primarily infrequent and small-scale leaf-level measurements. Here, we integrated eddy covariance flux tower estimates of gross primary productivity (GPP) across an elevation-gradient in California with airborne imagery from the NASA HyspIRI Preparatory campaign to evaluate the potential of hyperspectral imagery to detect responses of GPP to prolonged drought. We observed a number of spectral features in the visible, infrared, and shortwave infrared regions that yielded stronger linkages than traditional broadband indices with space and time variation in GPP across a range of ecosystems in California experiencing water stress in the past three years. Further, partial least squares regression (PLSR) modeling offers the ability to generate predictive models of GPP from narrowband hyperspectral remote sensing that directly links plant chemistry and spectral properties to productivity, and could serve as a significant advance over broadband remote sensing of GPP anomalies.

  5. A new method of building footprints detection using airborne laser scanning data and multispectral image

    NASA Astrophysics Data System (ADS)

    Luo, Yiping; Jiang, Ting; Gao, Shengli; Wang, Xin

    2010-10-01

    It presents a new approach for detecting building footprints in a combination of registered aerial image with multispectral bands and airborne laser scanning data synchronously obtained by Leica-Geosystems ALS40 and Applanix DACS-301 on the same platform. A two-step method for building detection was presented consisting of selecting 'building' candidate points and then classifying candidate points. A digital surface model(DSM) derived from last pulse laser scanning data was first filtered and the laser points were classified into classes 'ground' and 'building or tree' based on mathematic morphological filter. Then, 'ground' points were resample into digital elevation model(DEM), and a Normalized DSM(nDSM) was generated from DEM and DSM. The candidate points were selected from 'building or tree' points by height value and area threshold in nDSM. The candidate points were further classified into building points and tree points by using the support vector machines(SVM) classification method. Two classification tests were carried out using features only from laser scanning data and associated features from two input data sources. The features included height, height finite difference, RGB bands value, and so on. The RGB value of points was acquired by matching laser scanning data and image using collinear equation. The features of training points were presented as input data for SVM classification method, and cross validation was used to select best classification parameters. The determinant function could be constructed by the classification parameters and the class of candidate points was determined by determinant function. The result showed that associated features from two input data sources were superior to features only from laser scanning data. The accuracy of more than 90% was achieved for buildings in first kind of features.

  6. Oil Spill Detection along the Gulf of Mexico Coastline based on Airborne Imaging Spectrometer Data

    NASA Astrophysics Data System (ADS)

    Arslan, M. D.; Filippi, A. M.; Guneralp, I.

    2013-12-01

    The Deepwater Horizon oil spill in the Gulf of Mexico between April and July 2010 demonstrated the importance of synoptic oil-spill monitoring in coastal environments via remote-sensing methods. This study focuses on terrestrial oil-spill detection and thickness estimation based on hyperspectral images acquired along the coastline of the Gulf of Mexico. We use AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) imaging spectrometer data collected over Bay Jimmy and Wilkinson Bay within Barataria Bay, Louisiana, USA during September 2010. We also employ field-based observations of the degree of oil accumulation along the coastline, as well as in situ measurements from the literature. As part of our proposed spectroscopic approach, we operate on atmospherically- and geometrically-corrected hyperspectral AVIRIS data to extract image-derived endmembers via Minimum Noise Fraction transform, Pixel Purity Index-generation, and n-dimensional visualization. Extracted endmembers are then used as input to endmember-mapping algorithms to yield fractional-abundance images and crisp classification images. We also employ Multiple Endmember Spectral Mixture Analysis (MESMA) for oil detection and mapping in order to enable the number and types of endmembers to vary on a per-pixel basis, in contast to simple Spectral Mixture Analysis (SMA). MESMA thus better allows accounting for spectral variabiltiy of oil (e.g., due to varying oil thicknesses, states of degradation, and the presence of different oil types, etc.) and other materials, including soils and salt marsh vegetation of varying types, which may or may not be affected by the oil spill. A decision-tree approach is also utilized for comparison. Classification results do indicate that MESMA provides advantageous capabilities for mapping several oil-thickness classes for affected vegetation and soils along the Gulf of Mexico coastline, relative to the conventional approaches tested. Oil thickness-mapping results from MESMA

  7. Gravity for Detecting Caves: Airborne and Terrestrial Simulations Based on a Comprehensive Karstic Cave Benchmark

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Sampietro, Daniele; Pivetta, Tommaso; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Rossi, Lorenzo; Fabbri, Julius; Mansi, Ahmed Hamdi

    2016-04-01

    Underground caves bear a natural hazard due to their possible evolution into a sink hole. Mapping of all existing caves could be useful for general civil usages as natural deposits or tourism and sports. Natural caves exist globally and are typical in karst areas. We investigate the resolution power of modern gravity campaigns to systematically detect all void caves of a minimum size in a given area. Both aerogravity and terrestrial acquisitions are considered. Positioning of the gravity station is fastest with GNSS methods the performance of which is investigated. The estimates are based on a benchmark cave of which the geometry is known precisely through a laser-scan survey. The cave is the Grotta Gigante cave in NE Italy in the classic karst. The gravity acquisition is discussed, where heights have been acquired with dual-frequency geodetic GNSS receivers and Total Station. Height acquisitions with non-geodetic low-cost receivers are shown to be useful, although the error on the gravity field is larger. The cave produces a signal of -1.5 × 10-5 m/s2, with a clear elliptic geometry. We analyze feasibility of airborne gravity acquisitions for the purpose of systematically mapping void caves. It is found that observations from fixed wing aircraft cannot resolve the caves, but observations from slower and low-flying helicopters or drones do. In order to detect the presence of caves the size of the benchmark cave, systematic terrestrial acquisitions require a density of three stations on square 500 by 500 m2 tiles. The question has a large impact on civil and environmental purposes, since it will allow planning of urban development at a safe distance from subsurface caves. The survey shows that a systematic coverage of the karst would have the benefit to recover the position of all of the greater existing void caves.

  8. Airborne Wind Shear Detection and Warning Systems: First Combined Manufacturers' and Technologists' Conference

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1988-01-01

    The purpose of the meeting was to transfer significant, ongoing results gained during the first year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-looking technology concepts and for technologists to gain an understanding of FAA certification requirements and the problems encountered by the manufacturers during the development of airborne equipment.

  9. Laboratory analysis and airborne detection of materials stimulated to luminesce by the sun

    USGS Publications Warehouse

    Hemphill, W.R.; Theisen, A.F.; Tyson, R.M.

    1984-01-01

    The Fraunhofer line discriminator (FLD) is an airborne electro-optical device used to image materials which have been stimulated to luminesce by the Sun. Such materials include uranium-bearing sandstone, sedimentary phosphate rock, marine oil seeps, and stressed vegetation. Prior to conducting an airborne survey, a fluorescence spectrometer may be used in the laboratory to determine the spectral region where samples of the target material exhibit maximum luminescence, and to select the optimum Fraunhofer line. ?? 1984.

  10. Use of spectral vegetation indices derived from airborne hyperspectral imagery for detection of European corn borer infestation in Iowa corn plots

    EPA Science Inventory

    Eleven spectral vegetation indices that emphasize foliar plant pigments were calculated using airborne hyperspectral imagery and evaluated in 2004 and 2005 for their ability to detect experimental plots of corn manually inoculated with Ostrinia nubilalis (Hübner) neonate larvae. ...

  11. Aerodynamic sampling for landmine trace detection

    NASA Astrophysics Data System (ADS)

    Settles, Gary S.; Kester, Douglas A.

    2001-10-01

    Electronic noses and similar sensors show promise for detecting buried landmines through the explosive trace signals they emit. A key step in this detection is the sampler or sniffer, which acquires the airborne trace signal and presents it to the detector. Practicality demands no physical contact with the ground. Further, both airborne particulates and molecular traces must be sampled. Given a complicated minefield terrain and microclimate, this becomes a daunting chore. Our prior research on canine olfactory aerodynamics revealed several ways that evolution has dealt with such problems: 1) proximity of the sniffer to the scent source is important, 2) avoid exhaling back into the scent source, 3) use an aerodynamic collar on the sniffer inlet, 4) use auxiliary airjets to stir up surface particles, and 5) manage the 'impedance mismatch' between sniffer and sensor airflows carefully. Unfortunately, even basic data on aerodynamic sniffer performance as a function of inlet-tube and scent-source diameters, standoff distance, etc., have not been previously obtained. A laboratory-prototype sniffer was thus developed to provide guidance for landmine trace detectors. Initial experiments with this device are the subject of this paper. For example, a spike in the trace signal is observed upon starting the sniffer airflow, apparently due to rapid depletion of the available signal-laden air. Further, shielding the sniffer from disruptive ambient airflows arises as a key issue in sampling efficiency.

  12. Automated Detection of Selective Logging in Amazon Forests Using Airborne Lidar Data and Pattern Recognition Algorithms

    NASA Astrophysics Data System (ADS)

    Keller, M. M.; d'Oliveira, M. N.; Takemura, C. M.; Vitoria, D.; Araujo, L. S.; Morton, D. C.

    2012-12-01

    Selective logging, the removal of several valuable timber trees per hectare, is an important land use in the Brazilian Amazon and may degrade forests through long term changes in structure, loss of forest carbon and species diversity. Similar to deforestation, the annual area affected by selected logging has declined significantly in the past decade. Nonetheless, this land use affects several thousand km2 per year in Brazil. We studied a 1000 ha area of the Antimary State Forest (FEA) in the State of Acre, Brazil (9.304 ○S, 68.281 ○W) that has a basal area of 22.5 m2 ha-1 and an above-ground biomass of 231 Mg ha-1. Logging intensity was low, approximately 10 to 15 m3 ha-1. We collected small-footprint airborne lidar data using an Optech ALTM 3100EA over the study area once each in 2010 and 2011. The study area contained both recent and older logging that used both conventional and technologically advanced logging techniques. Lidar return density averaged over 20 m-2 for both collection periods with estimated horizontal and vertical precision of 0.30 and 0.15 m. A relative density model comparing returns from 0 to 1 m elevation to returns in 1-5 m elevation range revealed the pattern of roads and skid trails. These patterns were confirmed by ground-based GPS survey. A GIS model of the road and skid network was built using lidar and ground data. We tested and compared two pattern recognition approaches used to automate logging detection. Both segmentation using commercial eCognition segmentation and a Frangi filter algorithm identified the road and skid trail network compared to the GIS model. We report on the effectiveness of these two techniques.

  13. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    PubMed

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. PMID:26773821

  14. Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

    NASA Astrophysics Data System (ADS)

    Sahawneh, Laith Rasmi

    , sense and avoid, minimum sensing range, airborne collision detection and avoidance, collision detection, collision risk assessment, collision avoidance, conflict detection, conflict avoidance, path planning.

  15. Airborne Wind Shear Detection and Warning Systems: Third Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1991-01-01

    The Third Combined Manufacturers' and Technologists' Conference was held in Hampton, Va., on October 16-18, 1990. The purpose of the meeting was to transfer significant on-going results of the NASA/FAA joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  16. Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1990-01-01

    The Second Combined Manufacturers' and Technologists' Conference hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) was held in Williamsburg, Virginia, on October 18 to 20, 1988. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  17. Airborne Wind Shear Detection and Warning Systems: Fourth Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Passman, Robert H. (Compiler)

    1992-01-01

    The purpose of the meeting was to transfer significant ongoing results of the NASA/FAA joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements. The present document was compiled to record the essence of the technology updates and discussions which follow each.

  18. Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

    NASA Astrophysics Data System (ADS)

    Sahawneh, Laith Rasmi

    , sense and avoid, minimum sensing range, airborne collision detection and avoidance, collision det

  19. Inkjet-printed silver nanoparticle paper detects airborne species from crystalline explosives and their ultratrace residues in open environment.

    PubMed

    Wang, Jianping; Yang, Liang; Liu, Bianhua; Jiang, Haihe; Liu, Renyong; Yang, Jingwei; Han, Guangmei; Mei, Qingsong; Zhang, Zhongping

    2014-04-01

    An electronic nose can detect highly volatile chemicals in foods, drugs, and environments, but it is still very much a challenge to detect the odors from crystalline compounds (e.g., solid explosives) with a low vapor pressure using the present chemosensing techniques in such way as a dog's olfactory system can do. Here, we inkjet printed silver nanoparticles (AgNPs) on cellulose paper and established a Raman spectroscopic approach to detect the odors of explosive trinitrotoluene (TNT) crystals and residues in the open environment. The layer-by-layer printed AgNP paper was modified with p-aminobenzenethiol (PABT) for efficiently collecting airborne TNT via a charge-transfer reaction and for greatly enhancing the Raman scattering of PABT by multiple spectral resonances. Thus, a Raman switch concept by the Raman readout of PABT for the detection of TNT was proposed. The AgNPs paper at different sites exhibited a highly uniform sensitivity to TNT due to the layer-by-layer printing, and the sensitive limit could reach 1.6 × 10(-17) g/cm(2) TNT. Experimentally, upon applying a beam of near-infrared low-energy laser to slightly heat (but not destruct) TNT crystals, the resulting airborne TNT in the open environment was probed at the height of 5 cm, in which the concentration of airborne species was lower than 10 ppt by a theoretical analysis. Similarly, the odors from 1.4 ppm TNT in soil and 7.2, 2.9, and 5.7 ng/cm(2) TNT on clothing, leather, and envelope, respectively, were also quickly sensed for 2 s without destoying these inspected objects. PMID:24605843

  20. Airborne 2-Micron Double Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurement

    NASA Astrophysics Data System (ADS)

    Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan; Murchison, Luke

    2016-06-01

    An airborne 2-micron double-pulsed Integrated Path Differential Absorption (IPDA) lidar has been developed for atmospheric CO2 measurements. This new instrument has been flown in spring of 2014 for a total of ten flights with 27 flight hours. This IPDA lidar provides high precision measurement capability by unambiguously eliminating contamination from aerosols and clouds that can bias the results.

  1. Airborne 2-Micron Double Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurement

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan; Murchison, Luke

    2015-01-01

    An airborne 2-micron double-pulsed Integrated Path Differential Absorption (IPDA) lidar has been developed for atmospheric CO2 measurements. This new 2-miron pulsed IPDA lidar has been flown in spring of 2014 for total ten flights with 27 flight hours. It provides high precision measurement capability by unambiguously eliminating contamination from aerosols and clouds that can bias the IPDA measurement.

  2. Detection of soil properties with airborne hyperspectral measurements of bare fields.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne remote sensing data, using a hyperspectral (HSI) camera, were collected for a flight over two fields with a total of 128 ha. of recently seeded and nearly bare soil. The within-field spatial distribution of several soil properties was found by using multiple linear regression to select the ...

  3. Detection of airborne Salmonella enteritidis in the environment of experimentally infected laying hens by an electrostatic sampling device.

    PubMed

    Gast, Richard K; Mitchell, Bailey W; Holt, Peter S

    2004-01-01

    Bacteriologic culturing of environmental samples taken from sources such as manure pits and egg belts has been the principal screening tool in programs for identifying commercial laying flocks that have been exposed to Salmonella enteritidis and are thus at risk to produce contaminated eggs. Because airborne dust and aerosols can carry bacteria, air sampling offers a potentially efficient and inexpensive alternative for detecting S. enteritidis in poultry house environments. In the present study, an electrostatic air sampling device was applied to detect S. enteritidis in a room containing experimentally infected, caged laying hens. After oral inoculation of hens with a phage type 13a S. enteritidis strain, air samples were collected onto agar plates with the electrostatic sampling device, an impaction air sampler, and by passive exposure to the settling of aerosols and dust. Even though the floor of the room was cleaned once per week (removing most manure, dust, and feathers), air samples were positive for S. enteritidis for up to 4 wk postinoculation. On the basis of both the number of S. enteritidis colonies observed on incubated agar plates and the frequency of positive results, the efficiency of the electrostatic device was significantly greater than that of the passive exposure plates (especially at short collection intervals) and was similar to that of the far more expensive impaction sampler. The electrostatic device, used for a 3-hr sampling interval, detected airborne S. enteritidis on 75% of agar plates over the 4 wk of the study. PMID:15077808

  4. An automated front-end monitor for anthrax surveillance systems based on the rapid detection of airborne endospores.

    PubMed

    Yung, Pun To; Lester, Elizabeth D; Bearman, Greg; Ponce, Adrian

    2007-11-01

    A fully automated anthrax smoke detector (ASD) has been developed and tested. The ASD is intended to serve as a cost effective front-end monitor for anthrax surveillance systems. The principle of operation is based on measuring airborne endospore concentrations, where a sharp concentration increase signals an anthrax attack. The ASD features an air sampler, a thermal lysis unit, a syringe pump, a time-gated spectrometer, and endospore detection chemistry comprised of dipicolinic acid (DPA)-triggered terbium ion (Tb(3+)) luminescence. Anthrax attacks were simulated using aerosolized Bacillus atrophaeus spores in fumed silica, and corresponding Tb-DPA intensities were monitored as a function of time and correlated to the number of airborne endospores collected. A concentration dependence of 10(2)-10(6) spores/mg of fumed silica yielded a dynamic range of 4 orders of magnitude and a limit of detection of 16 spores/L when 250 L of air were sampled. Simulated attacks were detected in less than 15 min. PMID:17514759

  5. Analysis and improved design considerations for airborne pulse Doppler radar signal processing in the detection of hazardous windshear

    NASA Technical Reports Server (NTRS)

    Lee, Jonggil

    1990-01-01

    High resolution windspeed profile measurements are needed to provide reliable detection of hazardous low altitude windshear with an airborne pulse Doppler radar. The system phase noise in a Doppler weather radar may degrade the spectrum moment estimation quality and the clutter cancellation capability which are important in windshear detection. Also the bias due to weather return Doppler spectrum skewness may cause large errors in pulse pair spectral parameter estimates. These effects are analyzed for the improvement of an airborne Doppler weather radar signal processing design. A method is presented for the direct measurement of windspeed gradient using low pulse repetition frequency (PRF) radar. This spatial gradient is essential in obtaining the windshear hazard index. As an alternative, the modified Prony method is suggested as a spectrum mode estimator for both the clutter and weather signal. Estimation of Doppler spectrum modes may provide the desired windshear hazard information without the need of any preliminary processing requirement such as clutter filtering. The results obtained by processing a NASA simulation model output support consideration of mode identification as one component of a windshear detection algorithm.

  6. Land mine detection applying holographic neural technology (HNeT)

    NASA Astrophysics Data System (ADS)

    Sutherland, John G.; Radzelovage, William C.

    2007-04-01

    Provided is a summary of Holographic Neural Technology (HNeT) and its application in detecting land mines using airborne Synthetic Aperture Radar (SAR) imagery. Tests were performed for three surface mine classes (small metallic, large metallic, and medium-sized plastic) located within variable indigenous background clutter (bare dirt, short/tall grass). This work has been performed as part of the Wide Area Airborne Minefield Detection (WAAMD) Program at the U. S. Army Night Vision Labs and Electronic Sensors Directorate in Fort Belvoir, VA. The ATR algorithm applied was Holographic Neural Technology (HNeT); a neuromorphic model based upon non-linear phase coherence/de-coherence principles. The HNeT technology provides rapid learning capabilities and an advanced capability in learning and generalization of non-linear relationships. Described is a summary of the underlying HNeT technology and the methodologies applied in the training of the neuromorphic system for mine detection using target images (land mines) and back ground clutter images. Provided also is a summary description of the software tools applied in the development of the mine detection capability. Performance testing of the mine detection algorithm separated training and testing sensor image sets by airborne sensor depression angle and surface ground condition indigenous to site location (Countermine Alpha, Yellow Sands). Detection performance was compared in the analysis of complex versus magnitude sensor data. Performance results from independent test imagery indicated a reasonable level of clutter rejection, providing > 50% probability of detection at a false detection rate < 10 -3/m2. A description of the test scenarios applied and performance results for these scenarios are summarized in this report.

  7. A systems level characterization and tradespace evaluation of a simulated airborne Fourier transform infrared spectrometer for gas detection

    NASA Astrophysics Data System (ADS)

    Weiner, Aaron

    The remote sensing gas detection problem is one with no straightforward solution. While success has been achieved in detecting and identifying gases released from industrial stacks and other large plumes, the fugitive gas detection problem is far more complex. Fugitive gas represents a far smaller target and may be generated by leaking pipes, vents, or small scale chemical production. The nature of fugitive gas emission is such that one has no foreknowledge of the location, quantity, or transient rate of the targeted effluent which requires one to cover a broad area with high sensitivity. In such a scenario, a mobile airborne platform would be a likely candidate. Further, the spectrometer used for gas detection should be capable of rapid scan rates to prevent spatial and spectral smearing, while maintaining high resolution to aid in species identification. Often, insufficient signal to noise (SNR) prevents spectrometers from delivering useful results under such conditions. While common dispersive element spectrometers (DES) suffer from decreasing SNR with increasing spectral dispersion, Fourier Transform Spectrometers (FTS) generally do not and would seemingly be an ideal choice for such an application. FTS are ubiquitous in chemical laboratories and in use as ground based spectrometers, but have not become as pervasive in mobile applications. While FTS spectrometers would otherwise be ideal for high resolution rapid scanning in search of gaseous effluents, when conducted via a mobile platform the process of optical interferogram formation to form spectra is corrupted when the input signal is temporally unstable. This work seeks to explore the tradespace of an airborne Michelson based FTS in terms of modeling and characterizing the performance degradation over a variety of environmental and optical parameters. The major variables modeled and examined include: maximum optical path distance (resolution), scan rate, platform velocity, altitude, atmospheric and

  8. Airborne Wind Shear Detection and Warning Systems. Fourth Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Passman, Robert H. (Compiler)

    1992-01-01

    The Fourth Combined Manufacturers' and Technologists' Conference was hosted jointly by NASA Langley Research Center (LaRC) and the Federal Aviation Administration (FAA) in Williamsburg, Virginia, on April 14-16, 1992. The meeting was co-chaired by Dr. Roland Bowles of LaRC and Bob Passman of the FAA. The purpose of the meeting was to transfer significant ongoing results of the NASA/FAA Joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements. The present document has been compiled to record the essence of the technology updates and discussions which follow each.

  9. Detection of airborne severe acute respiratory syndrome (SARS) coronavirus and environmental contamination in SARS outbreak units.

    PubMed

    Booth, Timothy F; Kournikakis, Bill; Bastien, Nathalie; Ho, Jim; Kobasa, Darwyn; Stadnyk, Laurie; Li, Yan; Spence, Mel; Paton, Shirley; Henry, Bonnie; Mederski, Barbara; White, Diane; Low, Donald E; McGeer, Allison; Simor, Andrew; Vearncombe, Mary; Downey, James; Jamieson, Frances B; Tang, Patrick; Plummer, Frank

    2005-05-01

    Severe acute respiratory syndrome (SARS) is characterized by a risk of nosocomial transmission; however, the risk of airborne transmission of SARS is unknown. During the Toronto outbreaks of SARS, we investigated environmental contamination in SARS units, by employing novel air sampling and conventional surface swabbing. Two polymerase chain reaction (PCR)-positive air samples were obtained from a room occupied by a patient with SARS, indicating the presence of the virus in the air of the room. In addition, several PCR-positive swab samples were recovered from frequently touched surfaces in rooms occupied by patients with SARS (a bed table and a television remote control) and in a nurses' station used by staff (a medication refrigerator door). These data provide the first experimental confirmation of viral aerosol generation by a patient with SARS, indicating the possibility of airborne droplet transmission, which emphasizes the need for adequate respiratory protection, as well as for strict surface hygiene practices. PMID:15809906

  10. Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1990-01-01

    The Second Combined Manufacturers' and Technologists' Conference was hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) in Williamsburg, Virginia, on October 18 to 20, 1988. The meeting was co-chaired by Dr. Roland Bowles of LaRC and Herbrt Schlickenmaier of the FAA. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  11. The Tropospheric Wind Lidar Technology Experiment (TWiLiTE): An Airborne Direct Detection Doppler Lidar Instrument Development Program

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce; McGill, Matthew; Schwemmer, Geary; Hardesty, Michael; Brewer, Alan; Wilkerson, Thomas; Atlas, Robert; Sirota, Marcos; Lindemann, Scott

    2006-01-01

    Global measurement of tropospheric winds is a key measurement for understanding atmospheric dynamics and improving numerical weather prediction. Global wind profiles remain a high priority for the operational weather community and also for a variety of research applications including studies of the global hydrologic cycle and transport studies of aerosols and trace species. In addition to space based winds, a high altitude airborne system flown on UAV or other advanced platforms would be of great interest for studying mesoscale dynamics and hurricanes. The Tropospheric Wind Lidar Technology Experiment (TWiLiTE) project was selected in 2005 by the NASA Earth Sun Technology Office as part of the Instrument Incubator Program. TWiLiTE will leverage significant research and development investments in key technologies made in the past several years. The primary focus will be on integrating these sub-systems into a complete molecular direct detection Doppler wind lidar system designed for autonomous operation on a high altitude aircraft, such as the NASA WB57, so that the nadir viewing lidar will be able to profile winds through the full troposphere. TWiLiTE is a collaboration involving scientists and technologists from NASA Goddard, NOAA ESRL, Utah State University Space Dynamics Lab and industry partners Michigan Aerospace Corporation and Sigma Space Corporation. NASA Goddard and it's partners have been at the forefront in the development of key lidar technologies (lasers, telescopes, scanning systems, detectors and receivers) required to enable spaceborne global wind lidar measurement. The TWiLiTE integrated airborne Doppler lidar instrument will be the first demonstration of a airborne scanning direct detection Doppler lidar and will serve as a critical milestone on the path to a fixture spaceborne tropospheric wind system. The completed system will have the capability to profile winds in clear air from the aircraft altitude of 18 h to the surface with 250 m vertical

  12. Detection of airborne genetically modified maize pollen by real-time PCR.

    PubMed

    Folloni, Silvia; Kagkli, Dafni-Maria; Rajcevic, Bojan; Guimarães, Nilson C C; Van Droogenbroeck, Bart; Valicente, Fernando H; Van den Eede, Guy; Van den Bulcke, Marc

    2012-09-01

    The cultivation of genetically modified (GM) crops has raised numerous concerns in the European Union and other parts of the world about their environmental and economic impact. Especially outcrossing of genetically modified organisms (GMO) was from the beginning a critical issue as airborne pollen has been considered an important way of GMO dispersal. Here, we investigate the use of airborne pollen sampling combined with microscopic analysis and molecular PCR analysis as an approach to monitor GM maize cultivations in a specific area. Field trial experiments in the European Union and South America demonstrated the applicability of the approach under different climate conditions, in rural and semi-urban environment, even at very low levels of airborne pollen. The study documents in detail the sampling of GM pollen, sample DNA extraction and real-time PCR analysis. Our results suggest that this 'GM pollen monitoring by bioaerosol sampling and PCR screening' approach might represent an useful aid in the surveillance of GM-free areas, centres of origin and natural reserves. PMID:22805239

  13. Detection of tropical landslides using airborne lidar data and multi imagery: A case study in genting highland, pahang

    NASA Astrophysics Data System (ADS)

    Khamsin, I.; Zulkarnain, M.; Razak, K. A.; Rizal, S.

    2014-02-01

    The landslide geomorphological system in a tropical region is complex, and its understanding often depends on the completeness and correctness of landslide inventorization. In mountainous regions, landslides pose a significant impact and are known as an important geomorphic process in shaping major landscape in the tropics. A modern remote sensing based approach has revolutionized the landslide investigation in a forested terrain. Optical satellite imagery, aerial photographs and synthetic aperture radar images are less effective to create reliable tropical DTMs for landslide recognition, and even so in the forested equatorial regions. Airborne laser scanning (ALS) data have been used to construct the digital terrain model (DTM) under dense vegetation, but its reliability for landslide recognition in the tropics remains surprisingly unknown. The present study aims at providing better insight into the use of airborne laser scanning (ALS) data. For the bare-earth extraction, several prominent filtering algorithms and surface interpolation methods, i.e. progressive TIN densitification, morphological, and command prompt from Lastool are evaluated in a qualitative analysis, aiming at removing non-ground points while preserving important landslide features. As a result, a large landslide can be detected using OOA. Small landslides remain unrecognized. Three out of five landslides can be detected, with a 60 percent overall accuracy.

  14. Airborne Detection and Quantification of Swine Influenza A Virus in Air Samples Collected Inside, Outside and Downwind from Swine Barns

    PubMed Central

    Corzo, Cesar A.; Culhane, Marie; Dee, Scott; Morrison, Robert B.; Torremorell, Montserrat

    2013-01-01

    Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m3 of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m3 of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m3. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions. PMID:23951164

  15. Integration of airborne optical and thermal imagery for archaeological subsurface structures detection: the Arpi case study (Italy)

    NASA Astrophysics Data System (ADS)

    Bassani, C.; Cavalli, R. M.; Fasulli, L.; Palombo, A.; Pascucci, S.; Santini, F.; Pignatti, S.

    2009-04-01

    The application of Remote Sensing data for detecting subsurface structures is becoming a remarkable tool for the archaeological observations to be combined with the near surface geophysics [1, 2]. As matter of fact, different satellite and airborne sensors have been used for archaeological applications, such as the identification of spectral anomalies (i.e. marks) related to the buried remnants within archaeological sites, and the management and protection of archaeological sites [3, 5]. The dominant factors that affect the spectral detectability of marks related to manmade archaeological structures are: (1) the spectral contrast between the target and background materials, (2) the proportion of the target on the surface (relative to the background), (3) the imaging system characteristics being used (i.e. bands, instrument noise and pixel size), and (4) the conditions under which the surface is being imaged (i.e. illumination and atmospheric conditions) [4]. In this context, just few airborne hyperspectral sensors were applied for cultural heritage studies, among them the AVIRIS (Airborne Visible/Infrared Imaging Spectrometer), the CASI (Compact Airborne Spectrographic Imager), the HyMAP (Hyperspectral MAPping) and the MIVIS (Multispectral Infrared and Visible Imaging Spectrometer). Therefore, the application of high spatial/spectral resolution imagery arise the question on which is the trade off between high spectral and spatial resolution imagery for archaeological applications and which spectral region is optimal for the detection of subsurface structures. This paper points out the most suitable spectral information useful to evaluate the image capability in terms of spectral anomaly detection of subsurface archaeological structures in different land cover contexts. In this study, we assess the capability of MIVIS and CASI reflectances and of ATM and MIVIS emissivities (Table 1) for subsurface archaeological prospection in different sites of the Arpi

  16. [Building Change Detection Based on Multi-Level Rules Classification with Airborne LiDAR Data and Aerial Images].

    PubMed

    Gong, Yi-long; Yan, Li

    2015-05-01

    The present paper proposes a new building change detection method combining Lidar point cloud with aerial image, using multi-level rules classification algorithm, to solve building change detection problem between these two kinds of heterogeneous data. Then, a morphological post-processing method combined with area threshold is proposed. Thus, a complete building change detection processing flow that can be applied to actual production is proposed. Finally, the effectiveness of the building change detection method is evaluated, processing the 2010 airborne LiDAR point cloud data and 2009 high resolution aerial image of Changchun City, Jilin province, China; in addition, compared with the object-oriented building change detection method based on support vector machine (SVM) classification, more analysis and evaluation of the suggested method is given. Experiment results show that the performance of the proposed building change detection method is ideal. Its Kappa index is 0. 90, and correctness is 0. 87, which is higher than the object-oriented building change detection method based on SVM classification. PMID:26415454

  17. Cirrus cloud detection from airborne imaging spectrometer data using the 1.38 micron water vapor band

    NASA Technical Reports Server (NTRS)

    Gao, Bo-Cai; Goetz, Alexander F. H.; Wiscombe, Warren J.

    1993-01-01

    Using special images acquired by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) at 20 km altitude, we show that wavelengths close to the center of the strong 1.38 micron water vapor band are useful for detecting thin cirrus clouds. The detection makes use of the fact that cirrus clouds are located above almost all the atmospheric water vapor. Because of the strong water vapor absorption in the lower atmosphere, AVIRIS channels near 1.38 micron receive little scattered solar radiance from the surface of low level clouds. When cirrus clouds are present, however, these channels receive large amounts of scattered solar radiance from the cirrus clouds. Our ability to determine cirrus cloud cover using space-based remote sensing will be improved if channels near the center of the 1.38 micron water vapor band are added to future satellites.

  18. Performance analysis and technical assessment of coherent lidar systems for airborne wind shear detection

    NASA Technical Reports Server (NTRS)

    Huffaker, R. Milton; Targ, Russell

    1988-01-01

    Detailed computer simulations of the lidar wind-measuring process have been conducted to evaluate the use of pulsed coherent lidar for airborne windshear monitoring. NASA data fields for an actual microburst event were used in the simulation. Both CO2 and Ho:YAG laser lidar systems performed well in the microburst test case, and were able to measure wind shear in the severe weather of this wet microburst to ranges in excess of 1.4 km. The consequent warning time gained was about 15 sec.

  19. Application of infrared radiometers for airborne detection of clear air turbulence and low level wind shear, airborne infrared low level wind shear detection test

    NASA Technical Reports Server (NTRS)

    Kuhn, P. M.

    1985-01-01

    The feasibility of infrared optical techniques for the advance detection and avoidance of low level wind shear (LLWS) or low altitude wind shear hazardous to aircraft operations was investigated. A primary feasibility research effort was conducted with infrared detectors and instrumentation aboard the NASA Ames Research Center Learjet. The main field effort was flown on the NASA-Ames Dryden B57B aircraft. The original approach visualized a forward-looking, infrared transmitting (KRS-5) window through which signals would reach the detector. The present concept of a one inch diameter light pipe with a 45 deg angled mirror enables a much simpler installation virtually anywhere on the aircraft coupled with the possibility of horizontal scanning via rotation of the forward directed mirror. Present infrared detectors and filters would certainly permit ranging and horizontal scanning in a variety of methods. CRT display technology could provide a contoured picture with possible shear intensity levels from the infrared detection system on the weather radar or a small adjunct display. This procedure shoud be further developed and pilot evaluated in a light aircraft such as a Cessna 207 or equivalent.

  20. Derivation of Burn Scar Depths with Airborne Light Detection and Ranging (LIDAR) in Indonesian Peatlands

    NASA Astrophysics Data System (ADS)

    Ballhorn, U.; Siegert, F.

    2009-04-01

    more CO2 per year than the fourth-largest industrial nation, Germany, saved to achieve its Kyoto target. Since 1990, emissions from peat burning and peat decomposition have exceeded that of above ground biomass deforestation. These numbers show how important it is to have more accurate estimations for peat burn depth in the future. Until now few field measurements were made, which would require to know the fire affected area in advance or ignite peatland on purpose. Furthermore fire scars are quickly covered by regenerating vegetation. Another problem is the lack of a method without actually having to go into the field (e.g. through remote sensing techniques), due to the fact that many of the fire locations are remote and very difficult to access. We investigated if airborne light detection and ranging (LIDAR), an active laser pulse technology by which the height of objects can be precisely measured, can be used to determine the amount of peat burned during a fire event. From a LIDAR data set acquired in Central Kalimantan, Borneo, in 2007, one year after severe fires resulting from the 2006 El Niño drought, we calculated that the average depth of a burn scar was 0.30 ± 0.15 m .This was achieved through the construction of digital terrain models (DTMs) by interpolating the LIDAR ground return signals in burnt and adjacent unburned peatland. These calculated depths were compared to in situ measurements, which came to similar results. We believe that the method presented here to estimate burnt peat depth has the potential to considerably improve the accuracy of regional and global carbon emission models but would also be helpful for monitoring projects under the Kyoto Protocol like the Clean Development Mechanism (CDM) or the proposed Reducing Emissions from Deforestation and Degradation (REDD) mechanism.

  1. Toolsets for Airborne Data

    Atmospheric Science Data Center

    2015-04-02

    article title:  Toolsets for Airborne Data     View larger image The ... limit of detection values. Prior to accessing the TAD Web Application ( https://tad.larc.nasa.gov ) for the first time, users must ...

  2. SITHON: An Airborne Fire Detection System Compliant with Operational Tactical Requirements

    PubMed Central

    Kontoes, Charalabos; Keramitsoglou, Iphigenia; Sifakis, Nicolaos; Konstantinidis, Pavlos

    2009-01-01

    In response to the urging need of fire managers for timely information on fire location and extent, the SITHON system was developed. SITHON is a fully digital thermal imaging system, integrating INS/GPS and a digital camera, designed to provide timely positioned and projected thermal images and video data streams rapidly integrated in the GIS operated by Crisis Control Centres. This article presents in detail the hardware and software components of SITHON, and demonstrates the first encouraging results of test flights over the Sithonia Peninsula in Northern Greece. It is envisaged that the SITHON system will be soon operated onboard various airborne platforms including fire brigade airplanes and helicopters as well as on UAV platforms owned and operated by the Greek Air Forces. PMID:22399963

  3. Detection of airborne bacteria in a German turkey house by cultivation-based and molecular methods.

    PubMed

    Fallschissel, Kerstin; Klug, Kerstin; Kämpfer, Peter; Jäckel, Udo

    2010-11-01

    Today's large-scale poultry production with densely stocked and enclosed production buildings is often accompanied by very high concentrations of airborne microorganisms leading to a clear health hazard for employees working in such environments. Depending on the expected exposure to microorganisms, work has to be performed under occupational safety conditions. In this study, turkey houses bioaerosols were investigated by cultivation-based and molecular methods in parallel to determine the concentrations and the composition of bacterial community. Results obtained with the molecular approach showed clearly its applicability for qualitative exposure measurements. With both, cultivation-based and molecular methods species of microorganism with a potential health risk for employees (Acinetobacter johnsonii, Aerococcus viridans, Pantoea agglomerans, and Shigella flexneri) were identified. These results underline the necessity of adequate protection measures, including the recommendation to wear breathing masks during work in poultry houses. PMID:20720091

  4. Detection of hydrothermal alteration at Virginia City, Nevada using Airborne Imaging Spectrometry (AIS)

    NASA Technical Reports Server (NTRS)

    Hutsinpiller, A.; Taranik, J. V.

    1986-01-01

    Airborne Imaging Spectrometer (AIS) data were collected over Virginia City, Nevada; an area of gold and silver mineralization with extensive surface exposures of altered volcanic rocks. The data were corrected for atmospheric effects by a flat-field method, and compared to library spectra of various alteration minerals using a spectral analysis program SPAM. Areas of strong clay alteration were identified on the AIS images that were mapped as kaolinitic, illitic, and sericitic alterations zones. Kaolinitic alteration is distinguishable in the 2.1 to 2.4 and 1.2 to 1.5 micrometer wavelength regions. Montmorillonite, illite, and sericite have absorption features similar to each other at 2.2 micrometer wavelength. Montnorillonite and illite also may be present in varying proportions within one Ground Instantaneous Field of View (GIFOV). In general AIS data is useful in identifying alteration zones that are associated with or lie above precious metal mineralization at Virginia City.

  5. An upward looking airborne millimeter wave radiometer for atmospheric water vapor sounding and rain detection

    NASA Technical Reports Server (NTRS)

    Gagliano, J. A.; Platt, R. H.

    1985-01-01

    A 90/180 GHz multichannel radiometer is currently under development for NASA's 1985 Hurricane Mission onboard the Convair 990 research aircraft. The radiometer will be a fixed beam instrument with dual corrugated horns and a common lens antenna designed to operate simultaneously at 90 and 180 GHz. The all solid state front-end will contain three double side band data channels at 90 + or - 3 GHz, 180 + or - 3 GHz, and 180 + or - 7 GHz. The airborne radiometer will mount in a window port on the CV-990 and will maintain a fixed beam view approximately 14 degrees off zenith. The radiometer design is a Dicke chopper arrangement selected to achieve maximum absolute temperature accuracy and minimum brightness temperature sensitivity. Analog outputs of the three data channels will be calibrated dc voltages representing the observed radiometric brightness temperatures over the selected integration time.

  6. Airborne detection of oceanic turbidity cell structure using depth-resolved laser-induced water Raman backscatter

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.

    1983-01-01

    Airborne laser-induced, depth-resolved water Raman backscatter is useful in the detection and mapping of water optical transmission variations. This test, together with other field experiments, has identified the need for additional field experiments to resolve the degree of the contribution to the depth-resolved, Raman-backscattered signal waveform that is due to (1) sea surface height or elevation probability density; (2) off-nadir laser beam angle relative to the mean sea surface; and (3) the Gelbstoff fluorescence background, and the analytical techniques required to remove it. When converted to along-track profiles, the waveforms obtained reveal cells of a decreased Raman backscatter superimposed on an overall trend of monotonically decreasing water column optical transmission.

  7. Airborne Laser Absorption Spectrometer Measurements of CO2 Column Mixing Ratios: Source and Sink Detection in the Atmospheric Environment

    NASA Astrophysics Data System (ADS)

    Menzies, Robert T.; Spiers, Gary D.; Jacob, Joseph C.

    2016-06-01

    The JPL airborne Laser Absorption Spectrometer instrument has been flown several times in the 2007-2011 time frame for the purpose of measuring CO2 mixing ratios in the lower atmosphere. The four most recent flight campaigns were on the NASA DC-8 research aircraft, in support of the NASA ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission formulation studies. This instrument operates in the 2.05-μm spectral region. The Integrated Path Differential Absorption (IPDA) method is used to retrieve weighted CO2 column mixing ratios. We present key features of the CO2LAS signal processing, data analysis, and the calibration/validation methodology. Results from flights in various U.S. locations during the past three years include observed mid-day CO2 drawdown in the Midwest, also cases of point-source and regional plume detection that enable the calculation of emission rates.

  8. Airborne detection of magnetic anomalies associated with soils on the Oak Ridge Reservation, Tennessee

    SciTech Connect

    Doll, W.E.; Beard, L.P.; Helm, J.M.

    1995-04-01

    Reconnaissance airborne geophysical data acquired over the 35,000-acre Oak Ridge Reservation (ORR), TN, show several magnetic anomalies over undisturbed areas mapped as Copper Ridge Dolomite (CRD). The anomalies of interest are most apparent in magnetic gradient maps where they exceed 0.06 nT/m and in some cases exceed 0.5 nT/m. Anomalies as large as 25nT are seen on maps. Some of the anomalies correlate with known or suspected karst, or with apparent conductivity anomalies calculated from electromagnetic data acquired contemporaneously with the magnetic data. Some of the anomalies have a strong correlation with topographic lows or closed depressions. Surface magnetic data have been acquired over some of these sites and have confirmed the existence of the anomalies. Ground inspections in the vicinity of several of the anomalies has not led to any discoveries of manmade surface materials of sufficient size to generate the observed anomalies. One would expect an anomaly of approximately 1 nT for a pickup truck from 200 ft altitude. Typical residual magnetic anomalies have magnitudes of 5--10 nT, and some are as large as 25nT. The absence of roads or other indications of culture (past or present) near the anomalies and the modeling of anomalies in data acquired with surface instruments indicate that man-made metallic objects are unlikely to be responsible for the anomaly. The authors show that observed anomalies in the CRD can reasonably be associated with thickening of the soil layer. The occurrence of the anomalies in areas where evidences of karstification are seen would follow because sediment deposition would occur in topographic lows. Linear groups of anomalies on the maps may be associated with fracture zones which were eroded more than adjacent rocks and were subsequently covered with a thicker blanket of sediment. This study indicates that airborne magnetic data may be of use in other sites where fracture zones or buried collapse structures are of interest.

  9. Airborne Detection and Dynamic Modeling of Carbon Dioxide and Methane Plumes

    NASA Astrophysics Data System (ADS)

    Jacob, Jamey; Mitchell, Taylor; Whyte, Seabrook

    2015-11-01

    To facilitate safe storage of greenhouse gases such as CO2 and CH4, airborne monitoring is investigated. Conventional soil gas monitoring has difficulty in distinguishing gas flux signals from leakage with those associated with meteorologically driven changes. A low-cost, lightweight sensor system has been developed and implemented onboard a small unmanned aircraft that measures gas concentration and is combined with other atmospheric diagnostics, including thermodynamic data and velocity from hot-wire and multi-hole probes. To characterize the system behavior and verify its effectiveness, field tests have been conducted over controlled rangeland burns and over simulated leaks. In the former case, since fire produces carbon dioxide over a large area, this was an opportunity to test in an environment that while only vaguely similar to a carbon sequestration leak source, also exhibits interesting plume behavior. In the simulated field tests, compressed gas tanks are used to mimic leaks and generate gaseous plumes. Since the sensor response time is a function of vehicle airspeed, dynamic calibration models are required to determine accurate location of gas concentration in (x , y , z , t) . Results are compared with simulations using combined flight and atmospheric dynamic models. Supported by Department of Energy Award DE-FE0012173.

  10. Spectrum Modal Analysis for the Detection of Low-Altitude Windshear with Airborne Doppler Radar

    NASA Technical Reports Server (NTRS)

    Kunkel, Matthew W.

    1992-01-01

    A major obstacle in the estimation of windspeed patterns associated with low-altitude windshear with an airborne pulsed Doppler radar system is the presence of strong levels of ground clutter which can strongly bias a windspeed estimate. Typical solutions attempt to remove the clutter energy from the return through clutter rejection filtering. Proposed is a method whereby both the weather and clutter modes present in a return spectrum can be identified to yield an unbiased estimate of the weather mode without the need for clutter rejection filtering. An attempt will be made to show that modeling through a second order extended Prony approach is sufficient for the identification of the weather mode. A pattern recognition approach to windspeed estimation from the identified modes is derived and applied to both simulated and actual flight data. Comparisons between windspeed estimates derived from modal analysis and the pulse-pair estimator are included as well as associated hazard factors. Also included is a computationally attractive method for estimating windspeeds directly from the coefficients of a second-order autoregressive model. Extensions and recommendations for further study are included.

  11. Detection of coastal and submarine discharge on the Florida Gulf Coast with an airborne thermal-infrared mapping system

    USGS Publications Warehouse

    Raabe, Ellen; Stonehouse, David; Ebersol, Kristin; Holland, Kathryn; Robbins, Lisa

    2011-01-01

    Along the Gulf Coast of Florida north of Tampa Bay lies a region characterized by an open marsh coast, low topographic gradient, water-bearing limestone, and scattered springs. The Floridan aquifer system is at or near land surface in this region, discharging water at a consistent 70-72°F. The thermal contrast between ambient water and aquifer discharge during winter months can be distinguished using airborne thermal-infrared imagery. An airborne thermal-infrared mapping system was used to collect imagery along 126 miles of the Gulf Coast from Jefferson to Levy County, FL, in March 2009. The imagery depicts a large number of discharge locations and associated warm-water plumes in ponds, creeks, rivers, and nearshore waters. A thermal contrast of 6°F or more was set as a conservative threshold for identifying sites, statistically significant at the 99% confidence interval. Almost 900 such coastal and submarine-discharge locations were detected, averaging seven to nine per mile along this section of coast. This represents approximately one hundred times the number of previously known discharge sites in the same area. Several known coastal springs in Taylor and Levy Counties were positively identified with the imagery and were used to estimate regional discharge equivalent to one 1st-order spring, discharging 100 cubic feet per second or more, for every two miles of coastline. The number of identified discharge sites is a conservative estimate and may represent two-thirds of existing features due to low groundwater levels at time of overflight. The role of aquifer discharge in coastal and estuarine health is indisputable; however, mapping and quantifying discharge in a complex karst environment can be an elusive goal. The results of this effort illustrate the effectiveness of the instrument and underscore the influence of coastal springs along this stretch of the Florida coast.

  12. Airborne detection of natural gas leaks from transmission pipelines by using a laser system operating in visual, near-IR, and mid-IR wavelength bands

    NASA Astrophysics Data System (ADS)

    Ershov, Oleg V.; Klimov, Alexey G.; Vavilov, Vladimir P.

    2006-04-01

    An airborne gas detection IR system which includes a laser, infrared imager and video-recorder is described. The sensitivity of the system to leaks from ground pipelines by the laser channel is about 100 ppm*m at 100 m (by methane). The IR thermographic channel plays an auxiliary role and the video channel allows better coordinate positioning of detected gas leaks in conjunction with a built-in GPS device.

  13. Demonstration of radar reflector detection and ground clutter suppression using airborne weather and mapping radar

    NASA Technical Reports Server (NTRS)

    Anderson, D. J.; Bull, J. S.; Chisholm, J. P.

    1982-01-01

    A navigation system which utilizes minimum ground-based equipment is especially advantageous to helicopters, which can make off-airport landings. Research has been conducted in the use of weather and mapping radar to detect large radar reflectors overland for navigation purposes. As initial studies have not been successful, investigations were conducted regarding a new concept for the detection of ground-based radar reflectors and eliminating ground clutter, using a device called an echo processor (EP). A description is presented of the problems associated with detecting radar reflectors overland, taking into account the EP concept and the results of ground- and flight-test investigations. The echo processor concept was successfully demonstrated in detecting radar reflectors overland in a high-clutter environment. A radar reflector target size of 55 dBsm was found to be adequate for detection in an urban environment.

  14. Detection of spatio-temporal changes of Norway spruce forest stands in Ore Mountains using airborne hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Misurec, J.; Kopačková, V.; Lhotáková, Z.; Albrechtova, J.; Campbell, P. K. E.

    2015-12-01

    The Ore Mountains are an example of the region that suffered from severe environmental pollution caused by long-term coal mining and heavy industry leading to massive dieback of the local Norway spruce forests between the 1970's and 1990's. The situation became getting better at the end of 1990's after pollution loads significantly decreased. In 1998 and 2013, airborne hyperspectral data (with sensor ASAS and APEX, respectively) were used to study recovery of the originally damaged forest stands and compared them with those that have been less affected by environmental pollution. The field campaign (needle biochemical analysis, tree defoliation etc.) accompanied hyperspectral imagery acquisition. An analysis was conducted assessing a set of 16 vegetation indices providing complex information on foliage, biochemistry and canopy biophysics and structure. Five of them (NDVI, NDVI705, VOG1, MSR and TCARI/OSAVI) showing the best results were employed to study spatial gradients as well as temporal changes. The detected gradients are in accordance with ground truth data on representative trees. The obtained results indicate that the original significant differences between the damaged and undamaged stands have been generally levelled until 2013, although it is still possible to detect signs of the previous damages in several cases.

  15. Development of a tunable mid-IR difference frequency laser source for highly sensitive airborne trace gas detection

    NASA Astrophysics Data System (ADS)

    Richter, D.; Fried, A.; Wert, B. P.; Walega, J. G.; Tittel, F. K.

    The development of a compact tunable mid-IR laser system at 3.5 μm for quantitative airborne spectroscopic trace gas absorption measurements is reported. The mid-IR laser system is based on difference frequency generation (DFG) in periodically poled LiNbO3 and utilizes optical fiber amplified near-IR diode and fiber lasers as pump sources operating at 1083 nm and 1562 nm, respectively. This paper describes the optical sensor architecture, performance characteristics of individual pump lasers and DFG, as well as its application to wavelength modulation spectroscopy employing an astigmatic Herriott multi-pass gas absorption cell. This compact system permits detection of formaldehyde with a minimal detectable concentration (1σ replicate precision) of 74 parts-per-trillion by volume (pptv) for 1 min of averaging time and was achieved using calibrated gas standards, zero air background and rapid dual-beam subtraction. This corresponds to a pathlength-normalized replicate fractional absorption sensitivity of 2.5×10-10 cm-1.

  16. Development of a tunable mid-IR difference frequency laser source for highly sensitive airborne trace gas detection.

    PubMed

    Richter, D; Fried, A; Wert, B P; Walega, J G; Tittel, F K

    2002-01-01

    The development of a compact tunable mid-IR laser system at 3.5 micrometers for quantitative airborne spectroscopic trace gas absorption measurements is reported. The mid-IR laser system is based on difference frequency generation (DFG) in periodically poled LiNbO3 and utilizes optical fiber amplified near-IR diode and fiber lasers as pump sources operating at 1083 nm and 1562 nm, respectively. This paper describes the optical sensor architecture, performance characteristics of individual pump lasers and DFG, as well as its application to wavelength modulation spectroscopy employing an astigmatic Herriott multi-pass gas absorption cell. This compact system permits detection of formaldehyde with a minimal detectable concentration (1 sigma replicate precision) of 74 parts-per-trillion by volume (pptv) for 1 min of averaging time and was achieved using calibrated gas standards, zero air background and rapid dual-beam subtraction. This corresponds to a pathlength-normalized replicate fractional absorption sensitivity of 2.5 x 10-(10 )cm-1. PMID:12599397

  17. Applying six classifiers to airborne hyperspectral imagery for detecting giant reed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated and compared six different image classifiers, including minimum distance (MD), Mahalanobis distance (MAHD), maximum likelihood (ML), spectral angle mapper (SAM), mixture tuned matched filtering (MTMF) and support vector machine (SVM), for detecting and mapping giant reed (Arundo...

  18. NASA airborne radar wind shear detection algorithm and the detection of wet microbursts in the vicinity of Orlando, Florida

    NASA Technical Reports Server (NTRS)

    Britt, Charles L.; Bracalente, Emedio M.

    1992-01-01

    The algorithms used in the NASA experimental wind shear radar system for detection, characterization, and determination of windshear hazard are discussed. The performance of the algorithms in the detection of wet microbursts near Orlando is presented. Various suggested algorithms that are currently being evaluated using the flight test results from Denver and Orlando are reviewed.

  19. Portable automatic bioaerosol sampling system for rapid on-site detection of targeted airborne microorganisms.

    PubMed

    Usachev, Evgeny V; Pankova, Anna V; Rafailova, Elina A; Pyankov, Oleg V; Agranovski, Igor E

    2012-10-26

    Bioaerosols could cause various severe human and animal diseases and their opportune and qualitative precise detection and control is becoming a significant scientific and technological topic for consideration. Over the last few decades bioaerosol detection has become an important bio-defense related issue. Many types of portable and stationary bioaerosol samplers have been developed and, in some cases, integrated into automated detection systems utilizing various microbiological techniques for analysis of collected microbes. This paper describes a personal sampler used in conjunction with a portable real-time PCR technique. It was found that a single fluorescent dye could be successfully used in multiplex format for qualitative detection of numerous targeted bioaerosols in one PCR tube making the suggested technology a reliable "first alert" device. This approach has been specifically developed and successfully verified for rapid detection of targeted microorganisms by portable PCR devices, which is especially important under field conditions, where the number of microorganisms of interest usually exceeds the number of available PCR reaction tubes. The approach allows detecting targeted microorganisms and triggering some corresponding sanitary and quarantine procedures to localize possible spread of dangerous infections. Following detailed analysis of the sample under controlled laboratory conditions could be used to exactly identify which particular microorganism out of a targeted group has been rapidly detected in the field. It was also found that the personal sampler has a collection efficiency higher than 90% even for small-sized viruses (>20 nm) and stable performance over extended operating periods. In addition, it was found that for microorganisms used in this project (bacteriophages MS2 and T4) elimination of nucleic acids isolation and purification steps during sample preparation does not lead to the system sensitivity reduction, which is extremely

  20. Airborne virus detection by a sensing system using a disposable integrated impaction device.

    PubMed

    Takenaka, Kei; Togashi, Shigenori; Miyake, Ryo; Sakaguchi, Takemasa; Hide, Michihiro

    2016-01-01

    There are many respiratory infections such as influenza that cause epidemics. These respiratory infection epidemics can be effectively prevented by determining the presence or absence of infections in patients using frequent tests. We think that self-diagnosis may be possible using a system that can collect and detect biological aerosol particles in the patient's breath because breath sampling is easy work requiring no examiner. In this paper, we report a sensing system for biological aerosol particles (SSBAP) with a disposable device. Using the system and the device, someone with no medical knowledge or skills can safely, easily, and rapidly detect infectious biological aerosol particles. The disposable device, which is the core of the SSBAP, can be an impactor for biological aerosol particles, a flow-cell for reagents, and an optical window for the fluorescent detection of collected particles. Furthermore, to detect the fluorescence of very small collected particles, this disposable device is covered with a light-blocking film that lets only fluorescence of particles pass through a fluorescence detector of the SSBAP. The SSBAP using the device can automatically detect biological aerosol particles by the following process: collecting biological aerosol particles from a patient's breath in a sampling bag by the impaction method, labeling the collected biological aerosol particles with fluorescent dyes by the antigen-antibody reaction, removing free fluorescent dyes, and detecting the fluorescence of the biological aerosol particles. The collection efficiency of the device for microspheres aerosolized in the sampling bag was more than 97%, and the SSBAP with the device could detect more than 8.3  ×  10(3) particles l(-1) of aerosolized influenza virus particles within 10 min. PMID:27447200

  1. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

    Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown. PMID:23406937

  2. Functionality Based Detection of Airborne Engineered Nanoparticles in Quasi Real Time: A New Type of Detector and a New Metric

    PubMed Central

    Neubauer, Nicole

    2013-01-01

    A new type of detector which we call the Catalytic Activity Aerosol Monitor (CAAM) was investigated towards its capability to detect traces of commonly used industrial catalysts in ambient air in quasi real time. Its metric is defined as the catalytic activity concentration (CAC) expressed per volume of sampled workplace air. We thus propose a new metric which expresses the presence of nanoparticles in terms of their functionality - in this case a functionality of potential relevance for damaging effects - rather than their number, surface, or mass concentration in workplace air. The CAAM samples a few micrograms of known or anticipated airborne catalyst material onto a filter first and then initiates a chemical reaction which is specific to that catalyst. The concentration of specific gases is recorded using an IR sensor, thereby giving the desired catalytic activity. Due to a miniaturization effort, the laboratory prototype is compact and portable. Sensitivity and linearity of the CAAM response were investigated with catalytically active palladium and nickel nano-aerosols of known mass concentration and precisely adjustable primary particle size in the range of 3–30nm. With the miniature IR sensor, the smallest detectable particle mass was found to be in the range of a few micrograms, giving estimated sampling times on the order of minutes for workplace aerosol concentrations typically reported in the literature. Tests were also performed in the presence of inert background aerosols of SiO2, TiO2, and Al2O3. It was found that the active material is detectable via its catalytic activity even when the particles are attached to a non-active background aerosol. PMID:23504803

  3. Investigation of Advanced Radar Techniques for Atmospheric Hazard Detection with Airborne Weather Radar

    NASA Technical Reports Server (NTRS)

    Pazmany, Andrew L.

    2014-01-01

    In 2013 ProSensing Inc. conducted a study to investigate the hazard detection potential of aircraft weather radars with new measurement capabilities, such as multi-frequency, polarimetric and radiometric modes. Various radar designs and features were evaluated for sensitivity, measurement range and for detecting and quantifying atmospheric hazards in wide range of weather conditions. Projected size, weight, power consumption and cost of the various designs were also considered. Various cloud and precipitation conditions were modeled and used to conduct an analytic evaluation of the design options. This report provides an overview of the study and summarizes the conclusions and recommendations.

  4. Spectral angle mapper (SAM) based citrus greening disease detection using airborne hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past two decades, hyperspectral (HS) imaging has provided remarkable performance in ground object classification and disease identification, due to its high spectral resolution. In this paper, a novel method named “extended spectral angle mapping (ESAM)” is proposed to detect citrus greenin...

  5. Applying spectral unmixing and support vector machine to airborne hyperspectral imagery for detecting giant reed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated linear spectral unmixing (LSU), mixture tuned matched filtering (MTMF) and support vector machine (SVM) techniques for detecting and mapping giant reed (Arundo donax L.), an invasive weed that presents a severe threat to agroecosystems and riparian areas throughout the southern ...

  6. COMPARISON OF METHODS FOR DETECTION AND ENUMERATION OF AIRBORNE MICROORGANISMS COLLECTED BY LIQUID IMPINGEMENT

    EPA Science Inventory

    Bacterial agents and cell components can be spread as bioaerosols, producing infections and asthmatic problems. This study compares four methods for the detection and enumeration of aerosolized bacteria collected in an AGI-30 impinger. Changes in the total and viable concentratio...

  7. Data Acquisition and Processing System for Airborne Wind Profiling with a Pulsed, 2-Micron, Coherent-Detection, Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Beyon, J. Y.; Koch, G. J.; Kavaya, M. J.

    2010-01-01

    A data acquisition and signal processing system is being developed for a 2-micron airborne wind profiling coherent Doppler lidar system. This lidar, called the Doppler Aerosol Wind Lidar (DAWN), is based on a Ho:Tm:LuLiF laser transmitter and 15-cm diameter telescope. It is being packaged for flights onboard the NASA DC-8, with the first flights in the summer of 2010 in support of the NASA Genesis and Rapid Intensification Processes (GRIP) campaign for the study of hurricanes. The data acquisition and processing system is housed in a compact PCI chassis and consists of four components such as a digitizer, a digital signal processing (DSP) module, a video controller, and a serial port controller. The data acquisition and processing software (DAPS) is also being developed to control the system including real-time data analysis and display. The system detects an external 10 Hz trigger pulse and initiates the data acquisition and processing process, and displays selected wind profile parameters such as Doppler shift, power distribution, wind directions and velocities. Doppler shift created by aircraft motion is measured by an inertial navigation/GPS sensor and fed to the signal processing system for real-time removal of aircraft effects from wind measurements. A general overview of the system and the DAPS as well as the coherent Doppler lidar system is presented in this paper.

  8. Computer-based bioassay for evaluation of sensory irritation of airborne chemicals and its limit of detection.

    PubMed

    Alarie, Y

    1998-04-01

    We expanded a previously described rule-based computerized method to recognize the sensory irritating effect of airborne chemicals. Using 2-chlorobenzylchloride (CBC) as a sensory irritant, characteristic modifications of the normal breathing pattern of exposed mice were evaluated by measuring the duration of braking (TB) after inspiration and the resulting decrease in breathing frequency. From the measurement of TB, each breath was then classified as normal (N) or sensory irritation (S). Using increasing exposure concentrations, the classification S increased from < or = 2% (equivalent to sham-exposure) to 100% within a narrow exposure concentration range. The potency of CBC was then evaluated by calculating the concentration necessary to produce 50% of the breaths classified as S, i.e., S50. This approach is easier to use than obtaining RD50 (decrease in respiratory frequency by 50%) when high exposure concentrations are difficult to achieve. Detection limits were also established for this bioassay and experiments were conducted to obtain a level of response just around these limits, in order to delineate the practicality of using this bioassay at low exposure concentrations. Using this approach, sensory irritation was the only effect induced by CBC at low exposure concentrations. However, bronchoconstriction and pulmonary irritation were superimposed on this effect at higher exposure concentrations. PMID:9630013

  9. Free-surface microfluidic control of surface-enhanced Raman spectroscopy for the optimized detection of airborne molecules

    PubMed Central

    Piorek, Brian D.; Lee, Seung Joon; Santiago, Juan G.; Moskovits, Martin; Banerjee, Sanjoy; Meinhart, Carl D.

    2007-01-01

    We present a microfluidic technique for sensitive, real-time, optimized detection of airborne water-soluble molecules by surface-enhanced Raman spectroscopy (SERS). The method is based on a free-surface fluidic device in which a pressure-driven liquid microchannel flow is constrained by surface tension. A colloidal suspension of silver nanoparticles flowing through the microchannel that is open to the atmosphere absorbs gas-phase 4-aminobenzenethiol (4-ABT) from the surrounding environment. As surface ions adsorbed on the colloid nanoparticles are substituted by 4-ABT, the colloid aggregates, forming SERS “hot spots” whose concentrations vary predictably along the microchannel flow. 4-ABT confined in these hot spots produces SERS spectra of very great intensity. An aggregation model is used to account quantitatively for the extent of colloid aggregation as determined from the variation of the SERS intensity measured as a function of the streamwise position along the microchannel, which also corresponds to nanoparticle exposure time. This allows us to monitor simultaneously the nanoparticle aggregation process and to determine the location at which the SERS signal is optimized. PMID:18025462

  10. Detection of monomethylarsenic compounds originating from pesticide in airborne particulate matter sampled in an agricultural area in Japan

    NASA Astrophysics Data System (ADS)

    Mukai, Hitoshi; Ambe, Yoshinari

    Alkylarsenic species in airborne particulate matter sampled in an agricultural area in Japan were investigated. The monomethyl form of arsenic, which has not been found so far in the air, was detected in a concentration as much as 1.4 ng m -3 in a sample collected on a sunny summer day. It had a different size distribution from that of di- and tri-methyl forms of arsenic. The mean particle diameter containing monomethylarsenic compound was 2-4 μm, while those of the di- and/or tri-methyl forms of arsenic were 0.2-0.5 μm. This monomethyl form is thought to originate from the alkylarsenic pesticide spread over rice fields, based on the relation between variation in its concentration and meteorological conditions. Alkylarsenic pesticide appears to be blown up by the wind when the land surface is dry. Further, the methylation of arsenic in nature was found to be influenced by humidity and temperature.

  11. Airborne Measurements of CO2 Column Absorption and Range Using a Pulsed Direct-Detection Integrated Path Differential Absorption Lidar

    NASA Technical Reports Server (NTRS)

    Abshire, James B.; Riris, Haris; Weaver, Clark J.; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Browell, Edward V.

    2013-01-01

    We report on airborne CO2 column absorption measurements made in 2009 with a pulsed direct-detection lidar operating at 1572.33 nm and utilizing the integrated path differential absorption technique. We demonstrated these at different altitudes from an aircraft in July and August in flights over four locations in the central and eastern United States. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The lidar measurement statistics were also calculated for each flight as a function of altitude. The optical depth varied nearly linearly with altitude, consistent with calculations based on atmospheric models. The scatter in the optical depth measurements varied with aircraft altitude as expected, and the median measurement precisions for the column varied from 0.9 to 1.2 ppm. The altitude range with the lowest scatter was 810 km, and the majority of measurements for the column within it had precisions between 0.2 and 0.9 ppm.

  12. Adaptive clutter rejection filters for airborne Doppler weather radar applied to the detection of low altitude windshear

    NASA Technical Reports Server (NTRS)

    Keel, Byron M.

    1989-01-01

    An optimum adaptive clutter rejection filter for use with airborne Doppler weather radar is presented. The radar system is being designed to operate at low-altitudes for the detection of windshear in an airport terminal area where ground clutter returns may mask the weather return. The coefficients of the adaptive clutter rejection filter are obtained using a complex form of a square root normalized recursive least squares lattice estimation algorithm which models the clutter return data as an autoregressive process. The normalized lattice structure implementation of the adaptive modeling process for determining the filter coefficients assures that the resulting coefficients will yield a stable filter and offers possible fixed point implementation. A 10th order FIR clutter rejection filter indexed by geographical location is designed through autoregressive modeling of simulated clutter data. Filtered data, containing simulated dry microburst and clutter return, are analyzed using pulse-pair estimation techniques. To measure the ability of the clutter rejection filters to remove the clutter, results are compared to pulse-pair estimates of windspeed within a simulated dry microburst without clutter. In the filter evaluation process, post-filtered pulse-pair width estimates and power levels are also used to measure the effectiveness of the filters. The results support the use of an adaptive clutter rejection filter for reducing the clutter induced bias in pulse-pair estimates of windspeed.

  13. An optical radar for airborne use over natural waters. [for underwater target detection

    NASA Technical Reports Server (NTRS)

    Levis, C. A.; Swarner, W. G.; Prettyman, C.; Reinhardt, G. W.

    1975-01-01

    An optical radar for detecting targets in natural waters was built and tested in the Gulf of Mexico. The transmitter consists of a Q switched neodymium glass laser, with output amplified and doubled in KDP to 0.53 micrometer wavelength. The receiver incorporates a noval optical spatial filter to reduce the dynamic range required of the photodetector to a reasonable value. Detection of targets to a depth of 26 meters (84 feet) was achieved with a considerable sensitivity margin. The sensitivity of the radar is highly dependent on the optical attenuation coefficient. In general, measured returns fell between the values predicted on the basis of monopath and multipath attenuation. By means of simple physical arguments, a radar equation for the system was derived. To validate this theoretical model, measurements of optical attenuation and of water surface behavior were also instrumented, and some of these results are given.

  14. INNOSLAB-based single-frequency MOPA for airborne lidar detection of CO2 and methane

    NASA Astrophysics Data System (ADS)

    Löhring, Jens; Luttmann, Jörg; Kasemann, Raphael; Schlösser, Michael; Klein, Jürgen; Hoffmann, Hans-Dieter; Amediek, Axel; Büdenbender, Christian; Fix, Andreas; Wirth, Martin; Quatrevalet, Mathieu; Ehret, Gerhard

    2014-02-01

    For the CO2 and CH4 IPDA lidar CHARM-F two single frequency Nd:YAG based MOPA systems were developed. Both lasers are used for OPO/OPA-pumping in order to generate laser radiation at 1645 nm for CH4 detection and 1572 nm for CO2 detection. By the use of a Q-switched, injection seeded and actively length-stabilized oscillator and a one-stage INNOSLAB amplifier about 85 mJ pulse energy could be generated for the CH4 system. For the CO2 system the energy was boosted in second INNOSLAB-stage to about 150 mJ. Both lasers emit laser pulses of about 30 ns pulse duration at a repetition rate of 100 Hz.

  15. Detection of oil slicks at night with airborne infrared imagers. Final report, October 1993-April 1994

    SciTech Connect

    Daniels, G.M.; Hover, G.L.

    1994-12-01

    The detection of oil slicks on the ocean is a Coast Guard priority. Daytime detection in clear weather is routine; but nighttime detection requires sophisticated imaging sensors. Infrared imagers have demonstrated some capability to detect oil slicks at night in the marine environment. Infrared imagers sense the thermal radiation, and its variations, in a scene rather than the reflected radiation. Gimbal-mounted thermal imagers operating in the 8-12 micron region are currently flown on Coast Guard aircraft. This study compared the performance of these imagers with hand-held imagers operating in the 3-5 micron region. The comparison was primarily theoretical with semi-quantitative support from an uncalibrated data base of infrared images taken wit various sensors. It was found theoretically, and supported by image data, that the 8-12 micron instruments produced images with better water-oil contrast at night. This differential behavior was theoretically predicted to hold over a wide range of environmental conditions. The differential behavior was traced to the fact that the optical properties of water and oil are more different in the 8-12 than in the 3-5 micron bands. The utility of night-vision imagers or low-light level TVs was also assessed. Calculations indicated that typical water-oil contrasts would not be seen with current sensors. Image data appearing to contradict this conclusion was found to be defective in the sense that the conditions of the experiments were not representative of operational conditions. It is recommended that: the use of 8-12 micron imagers be continued for oil slick searches at night and the potential of new night-time imaging devices be assessed.

  16. Recent Developments on Airborne Forward Looking Interferometer for the Detection of Wake Vortices

    NASA Technical Reports Server (NTRS)

    Daniels, Taumi S.; Smith, William L.; Kirev, Stanislav

    2012-01-01

    A goal of these studies was development of the measurement methods and algorithms necessary to detect wake vortex hazards in real time from either an aircraft or ground-based hyperspectral Fourier Transform Spectrometer (FTS). This paper provides an update on research to model FTS detection of wake vortices. The Terminal Area Simulation System (TASS) was used to generate wake vortex fields of 3-D winds, temperature, and absolute humidity. These fields were input to the Line by Line Radiative Transfer Model (LBLRTM), a hyperspectral radiance model in the infrared, employed for the FTS numerical modeling. An initial set of cases has been analyzed to identify a wake vortex IR signature and signature sensitivities to various state variables. Results from the numerical modeling case studies will be presented. Preliminary results indicated that an imaging IR instrument sensitive to six narrow bands within the 670 to 3150 per centimeter spectral region would be sufficient for wake vortex detection. Noise floor estimates for a recommended instrument are a current research topic.

  17. Algorithms for detection of objects in image sequences captured from an airborne imaging system

    NASA Technical Reports Server (NTRS)

    Kasturi, Rangachar; Camps, Octavia; Tang, Yuan-Liang; Devadiga, Sadashiva; Gandhi, Tarak

    1995-01-01

    This research was initiated as a part of the effort at the NASA Ames Research Center to design a computer vision based system that can enhance the safety of navigation by aiding the pilots in detecting various obstacles on the runway during critical section of the flight such as a landing maneuver. The primary goal is the development of algorithms for detection of moving objects from a sequence of images obtained from an on-board video camera. Image regions corresponding to the independently moving objects are segmented from the background by applying constraint filtering on the optical flow computed from the initial few frames of the sequence. These detected regions are tracked over subsequent frames using a model based tracking algorithm. Position and velocity of the moving objects in the world coordinate is estimated using an extended Kalman filter. The algorithms are tested using the NASA line image sequence with six static trucks and a simulated moving truck and experimental results are described. Various limitations of the currently implemented version of the above algorithm are identified and possible solutions to build a practical working system are investigated.

  18. Airborne hyperspectral imaging for the detection of powdery mildew in wheat

    NASA Astrophysics Data System (ADS)

    Franke, Jonas; Mewes, Thorsten; Menz, Gunter

    2008-08-01

    Plant stresses, in particular fungal diseases, show a high variability in spatial and temporal dimension with respect to their impact on the host. Recent "Precision Agriculture"-techniques allow for a spatially and temporally adjusted pest control that might reduce the amount of cost-intensive and ecologically harmful agrochemicals. Conventional stressdetection techniques such as random monitoring do not meet demands of such optimally placed management actions. The prerequisite is an accurate sensor-based detection of stress symptoms. The present study focuses on a remotely sensed detection of the fungal disease powdery mildew (Blumeria graminis) in wheat, Europe's main crop. In a field experiment, the potential of hyperspectral data for an early detection of stress symptoms was tested. A sophisticated endmember selection procedure was used and, additionally, a linear spectral mixture model was applied to a pixel spectrum with known characteristics, in order to derive an endmember representing 100% powdery mildew-infected wheat. Regression analyses of matched fraction estimates of this endmember and in-field-observed powdery mildew severities showed promising results (r=0.82 and r2=0.67).

  19. Detection of airborne viruses using electro-aerodynamic deposition and a field-effect transistor

    PubMed Central

    Park, Kyu-Tae; Cho, Dong-Guk; Park, Ji-Woon; Hong, Seunghun; Hwang, Jungho

    2015-01-01

    We report a technique for the detection of aerosolized viruses. Conventional field-effect-transistor (FET)-based techniques use solution-based processes, thus require antibody binding to the detection region of the FET prior to the supply of the analyte. With the method described here, virus–antibody-bound particles are delivered to the FET during detection; therefore, neither a pre-treatment antibody binding step on the FET channel nor washing process for virus–antibody-binding are necessary. Our method is based on the concept that virus–antibody-bound particles are larger than the virus or antibody alone, and thus have larger charge numbers following aerosol charging. When these particles are charged by negative ions and electro-aerodynamically deposited on a substrate, there exists a location on the substrate where neither lone virus nor antibody particles land, and where only virus–antibody-bound particles are deposited. If this location coincides with the channel of the FET, the resulting variation in the current can be used to indicate the existence of a virus. By aerosolizing a mixed solution of the virus and the antibody, only the virus–antibody-bound particles were transported to the swCNT-FET, and the electric current in the swCNT-FET decreased to 30% of that measured with no deposited particles. PMID:26642822

  20. Detection of airborne viruses using electro-aerodynamic deposition and a field-effect transistor

    NASA Astrophysics Data System (ADS)

    Park, Kyu-Tae; Cho, Dong-Guk; Park, Ji-Woon; Hong, Seunghun; Hwang, Jungho

    2015-12-01

    We report a technique for the detection of aerosolized viruses. Conventional field-effect-transistor (FET)-based techniques use solution-based processes, thus require antibody binding to the detection region of the FET prior to the supply of the analyte. With the method described here, virus-antibody-bound particles are delivered to the FET during detection; therefore, neither a pre-treatment antibody binding step on the FET channel nor washing process for virus-antibody-binding are necessary. Our method is based on the concept that virus-antibody-bound particles are larger than the virus or antibody alone, and thus have larger charge numbers following aerosol charging. When these particles are charged by negative ions and electro-aerodynamically deposited on a substrate, there exists a location on the substrate where neither lone virus nor antibody particles land, and where only virus-antibody-bound particles are deposited. If this location coincides with the channel of the FET, the resulting variation in the current can be used to indicate the existence of a virus. By aerosolizing a mixed solution of the virus and the antibody, only the virus-antibody-bound particles were transported to the swCNT-FET, and the electric current in the swCNT-FET decreased to 30% of that measured with no deposited particles.

  1. Assessing the performance of methods to detect and quantify African dust in airborne particulates.

    PubMed

    Viana, Mar; Salvador, Pedro; Artíñano, Begoña; Querol, Xavier; Alastuey, Andrés; Pey, Jorge; Latz, Achim J; Cabañas, Mercè; Moreno, Teresa; García dos Santos, Saúl; Herce, María Dolores; Diez Hernández, Pablo; Romero García, Dolores; Fernández-Patier, Rosalía

    2010-12-01

    African dust (AD) contributions to particulate matter (PM) levels may be reported by Member States to the European Commission during justification of exceedances of the daily limit value (DLV). However, the detection and subsequent quantification of the AD contribution to PM levels is complex, and only two measurement-based methods are available in the literature: the Spanish-Portuguese reference method (SPR), and the Tel Aviv University method (TAU). In the present study, both methods were assessed. The SPR method was more conservative in the detection of episodes (71 days identified as AD by SPR, vs 81 by TAU), as it is less affected by interferences with local dust sources. The mean annual contribution of AD was lower with the TAU method than with SPR (2.7 vs 3.5 ± 1.5 μg/m(3)). The SPR and TAU AD time series were correlated with daily aluminum levels (a known tracer of AD), as well as with an AD source identified by the Positive Matrix Factorization (PMF) receptor model. Higher r(2) values were obtained with the SPR method than with TAU in both cases (r(2) = 0.72 vs 0.56, y = 0.05x vs y = 0.06x with aluminum levels; r(2)=0.79 vs 0.43, y = 0.8x vs y = 0.4x with the PMF source). We conclude that the SPR method is more adequate from an EU policy perspective (justification of DLV exceedances) due to the fact that it is more conservative than the TAU method. Based on our results, the TAU method requires adaptation of the thresholds in the algorithm to refine detection of low-impact episodes and avoid misclassification of local events as AD. PMID:21049991

  2. 290 and 340 nm UV LED arrays for fluorescence detection from single airborne particles

    NASA Astrophysics Data System (ADS)

    Davitt, Kristina; Song, Yoon-Kyu; Patterson, William R., III; Nurmikko, Arto V.; Gherasimova, Maria; Han, Jung; Pan, Yong-Le; Chang, Richard K.

    2005-11-01

    We demonstrate a compact system, incorporating a 32-element linear array of ultraviolet (290 nm and 340 nm) light-emitting diodes (LEDs) and a multi-anode photomultiplier tube, to the in-flight fluorescence detection of aerosolized particles, here containing the biological molecules tryptophan and NADH. This system illustrates substantial advances in the growth and fabrication of new semiconductor UV light emitting devices and an evolution in packaging details for LEDs tailored to the bio-aerosol warning problem. Optical engineering strategies are employed which take advantage of the size and versatility of light-emitting diodes to develop a truly compact fluorescence detector.

  3. 290 and 340 nm UV LED arrays for fluorescence detection from single airborne particles.

    PubMed

    Davitt, Kristina; Song, Yoon-Kyu; Patterson Iii, William; Nurmikko, Arto; Gherasimova, Maria; Han, Jung; Pan, Yong-Le; Chang, Richard

    2005-11-14

    We demonstrate a compact system, incorporating a 32-element linear array of ultraviolet (290 nm and 340 nm) light-emitting diodes (LEDs) and a multi-anode photomultiplier tube, to the in-flight fluorescence detection of aerosolized particles, here containing the biological molecules tryptophan and NADH. This system illustrates substantial advances in the growth and fabrication of new semiconductor UV light emitting devices and an evolution in packaging details for LEDs tailored to the bio-aerosol warning problem. Optical engineering strategies are employed which take advantage of the size and versatility of light-emitting diodes to develop a truly compact fluorescence detector. PMID:19503158

  4. Airborne cable detection with a W-band FMCW imaging sensor

    NASA Astrophysics Data System (ADS)

    Goshi, D. S.; Liu, Y.; Mai, K.; Bui, L.; Shih, Y.

    2010-04-01

    Numerous accidents occur each year due to wire strikes for both military and commercial helicopters leading to a significant number of fatalities. The millimeter-wave sensor presents itself as an ideal candidate for a solution because it can see the very small attributes of the typical power line/cable wire as well as operate when visual conditions worsen due to environmental issues such as fog, smoke or dust. This paper presents recent results on the development of a W-band FMCW imaging sensor with potential application to cable detection and imaging. The sensor front end is integrated with a radar signal generator, processor, and data acquisition unit for the purpose of closing the loop between prototype demonstration and system development. Real-time imaging is achieved at a 10 Hz frame rate with a field of view of 30°. A complete flight demonstration of this system was performed on a Honeywell-operated AStar helicopter to validate the flight-worthiness of the sensor under close to actual operational conditions. The development of such technology that can detect and avoid obstacles such as cables and wires especially for rotorcraft platforms will save lives, assets, and enable the execution of more complex and dangerous tactical missions.

  5. Automatic Roof Plane Detection and Analysis in Airborne Lidar Point Clouds for Solar Potential Assessment

    PubMed Central

    Jochem, Andreas; Höfle, Bernhard; Rutzinger, Martin; Pfeifer, Norbert

    2009-01-01

    A relative height threshold is defined to separate potential roof points from the point cloud, followed by a segmentation of these points into homogeneous areas fulfilling the defined constraints of roof planes. The normal vector of each laser point is an excellent feature to decompose the point cloud into segments describing planar patches. An object-based error assessment is performed to determine the accuracy of the presented classification. It results in 94.4% completeness and 88.4% correctness. Once all roof planes are detected in the 3D point cloud, solar potential analysis is performed for each point. Shadowing effects of nearby objects are taken into account by calculating the horizon of each point within the point cloud. Effects of cloud cover are also considered by using data from a nearby meteorological station. As a result the annual sum of the direct and diffuse radiation for each roof plane is derived. The presented method uses the full 3D information for both feature extraction and solar potential analysis, which offers a number of new applications in fields where natural processes are influenced by the incoming solar radiation (e.g., evapotranspiration, distribution of permafrost). The presented method detected fully automatically a subset of 809 out of 1,071 roof planes where the arithmetic mean of the annual incoming solar radiation is more than 700 kWh/m2. PMID:22346695

  6. Airborne Forward-Looking Interferometer for the Detection of Terminal-Area Hazards

    NASA Technical Reports Server (NTRS)

    West, Leanne; Gimmestad, Gary; Lane, Sarah; Smith, Bill L.; Kireev, Stanislav; Daniels, Taumi S.; Cornman, Larry; Sharman, Bob

    2014-01-01

    The Forward Looking Interferometer (FLI) program was a multi-year cooperative research effort to investigate the use of imaging radiometers with high spectral resolution, using both modeling/simulation and field experiments, along with sophisticated data analysis techniques that were originally developed for analysis of data from space-based radiometers and hyperspectral imagers. This investigation has advanced the state of knowledge in this technical area, and the FLI program developed a greatly improved understanding of the radiometric signal strength of aviation hazards in a wide range of scenarios, in addition to a much better understanding of the real-world functionality requirements for hazard detection instruments. The project conducted field experiments on three hazards (turbulence, runway conditions, and wake vortices) and analytical studies on several others including volcanic ash, reduced visibility conditions, in flight icing conditions, and volcanic ash.

  7. Low-cost lightweight airborne laser-based sensors for pipeline leak detection and reporting

    NASA Astrophysics Data System (ADS)

    Frish, Michael B.; Wainner, Richard T.; Laderer, Matthew C.; Allen, Mark G.; Rutherford, James; Wehnert, Paul; Dey, Sean; Gilchrist, John; Corbi, Ron; Picciaia, Daniele; Andreussi, Paolo; Furry, David

    2013-05-01

    Laser sensing enables aerial detection of natural gas pipeline leaks without need to fly through a hazardous gas plume. This paper describes adaptations of commercial laser-based methane sensing technology that provide relatively low-cost lightweight and battery-powered aerial leak sensors. The underlying technology is near-infrared Standoff Tunable Diode Laser Absorption Spectroscopy (sTDLAS). In one configuration, currently in commercial operation for pipeline surveillance, sTDLAS is combined with automated data reduction, alerting, navigation, and video imagery, integrated into a single-engine single-pilot light fixed-wing aircraft or helicopter platform. In a novel configuration for mapping landfill methane emissions, a miniaturized ultra-lightweight sTDLAS sensor flies aboard a small quad-rotor unmanned aerial vehicle (UAV).

  8. Flight test to determine feasibility of a proposed airborne wake vortex detection concept

    NASA Technical Reports Server (NTRS)

    Branstetter, James R.; Hastings, E. C., Jr.; Patterson, James C., Jr.

    1991-01-01

    This investigation was conducted to determine the radial extent at which aircraft mounted flow vanes or roll rate gyros can sense the circulatory flow field that exists around the lift induced vortex system generated by an aircraft in flight. The probe aircraft was equipped with wingtip sensors for measuring angle of attack and angle of sideslip, and with a fuselage mounted gyroscope for measuring roll rate. Analysis of flight test data indicated that the vortex was detectable at a lateral distance of about 105 feet (best results) using unsophisticated equipment. Measurements were made from the centerline of the probe aircraft to the center of the nearest vortex with the probe aircraft flying between one half and one and one half miles behind the vortex generating aircraft.

  9. A comparison of airborne wake vortex detection measurements with values predicted from potential theory

    NASA Technical Reports Server (NTRS)

    Stewart, Eric C.

    1991-01-01

    An analysis of flight measurements made near a wake vortex was conducted to explore the feasibility of providing a pilot with useful wake avoidance information. The measurements were made with relatively low cost flow and motion sensors on a light airplane flying near the wake vortex of a turboprop airplane weighing approximately 90000 lbs. Algorithms were developed which removed the response of the airplane to control inputs from the total airplane response and produced parameters which were due solely to the flow field of the vortex. These parameters were compared with values predicted by potential theory. The results indicated that the presence of the vortex could be detected by a combination of parameters derived from the simple sensors. However, the location and strength of the vortex cannot be determined without additional and more accurate sensors.

  10. Conditional-sampling spectrograph detection system for fluorescence measurements of individual airborne biological particles.

    PubMed

    Nachman, P; Chen, G; Pinnick, R G; Hill, S C; Chang, R K; Mayo, M W; Fernandez, G L

    1996-03-01

    We report the design and operation of a prototype conditional-sampling spectrograph detection system that can record the fluorescence spectra of individual, micrometer-sized aerosols as they traverse an intense 488-nm intracavity laser beam. The instrument's image-intensified CCD detector is gated by elastic scattering or by undispersed fluorescence from particles that enter the spectrograph's field of view. It records spectra only from particles with preselected scattering-fluorescence levels (a fiber-optic-photomultiplier subsystem provides the gating signal). This conditional-sampling procedure reduces data-handling rates and increases the signal-to-noise ratio by restricting the system's exposures to brief periods when aerosols traverse the beam. We demonstrate these advantages by reliably capturing spectra from individual fluorescent microspheres dispersed in an airstream. The conditional-sampling procedure also permits some discrimination among different types of particles, so that spectra may be recorded from the few interesting particles present in a cloud of background aerosol. We demonstrate such discrimination by measuring spectra from selected fluorescent microspheres in a mixture of two types of microspheres, and from bacterial spores in a mixture of spores and nonfluorescent kaolin particles. PMID:21085216

  11. Comparison of methods for detection and enumeration of airborne microorganisms collected by liquid impingement.

    PubMed Central

    Terzieva, S; Donnelly, J; Ulevicius, V; Grinshpun, S A; Willeke, K; Stelma, G N; Brenner, K P

    1996-01-01

    Bacterial agents and cell components can be spread as bioaerosols, producing infections and asthmatic problems. This study compares four methods for the detection and enumeration of aerosolized bacteria collected in an AGI-30 impinger. Changes in the total and viable concentrations of Pseudomonas fluorescens in the collection fluid with respect to time of impingement were determined. Two direct microscopic methods (acridine orange and BacLight) and aerodynamic aerosol-size spectrometry (Aerosizer) were employed to measure the total bacterial cell concentrations in the impinger collection fluid and the air, respectively. These data were compared with plate counts on selective (MacConkey agar) and nonselective (Trypticase soy agar) media, and the percentages of culturable cells in the collection fluid and the bacterial injury response to the impingement process were determined'. The bacterial collection rate was found to be relatively unchanged during 60 min of impingement. The aerosol measurements indicated an increased amount of cell fragments upstream of the impinger due to continuous bacterial nebulization. Some of the bacterial clusters, present in the air upstream of the impinger, deagglomerated during impingement, thus increasing the total bacterial count by both direct microscopic methods. The BacLight staining technique was also used to determine the changes in viable bacterial concentration during the impingement process. The percentage of viable bacteria, determined as a ratio of BacLight live to total counts was only 20% after 60 min of sampling. High counts on Trypticase soy agar indicated that most of the injured cells could recover. On the other hand, the counts from the MacConkey agar were very low, indicating that most of the cells were structurally damaged in the impinger. The comparison of data on the percentage of injured bacteria obtained by the traditional plate count with the data on percentage of nonviable bacteria obtained by the Bac

  12. Airborne LiDAR detection of postglacial faults and Pulju moraine in Palojärvi, Finnish Lapland

    NASA Astrophysics Data System (ADS)

    Sutinen, Raimo; Hyvönen, Eija; Middleton, Maarit; Ruskeeniemi, Timo

    2014-04-01

    Postglacial faults (PGFs) are indicative of young tectonic activity providing crucial information for nuclear repository studies. Airborne LiDAR (Light Detection And Ranging) data revealed three previously unrecognized late- or postglacial faults in northernmost Finnish Lapland. Under the canopies of mountain birch (Betula pubescens ssp. czerepanovii) we also found clusters of the Pulju moraine, typically found on the ice-divide zone of the former Fennoscandian ice sheet (FIS), to be spatially associated with the fault-scarps. Tilt derivative (TDR) filtered LiDAR data revealed the previously unknown Palojärvi fault that, by the NE-SW orientation parallels with the well documented Lainio-Suijavaara PGF in northern Sweden. This suggests that PGFs are more extensive features than previously recognized. Two inclined diamond drill holes verified the fractured system of the Palojärvi fault and revealed clear signs of postglacial reactivation. Two other previously unrecognized PGFs, the W-E trending Paatsikkajoki fault and the SE-NW trending Kultima fault, differ from the Palojärvi faulting in orientation and possibly also with regard to age. The Pulju moraine, a morphological feature showing transitions from shallow (< 2-m-high) circular/arcuate ridges to sinusoidal/anastomosing esker networks was found to be concentrated within 6 km from the Kultima fault-scarp. We advocate that some of the past seismic events took place under the retreating wet-base ice sheet and the increased pore-water pressure triggered the sediment mass flows and formation of the Pulju moraine-esker landscape.

  13. Detection of hidden mineral deposits by airborne spectral analysis of forest canopies. [Spirit Lake, Washington; Catheart Mountain, Maine; Blacktail Mountain, Montana; and Cotter Basin, Montana

    NASA Technical Reports Server (NTRS)

    Collins, W.; Chang, S. H.; Kuo, J. T.

    1984-01-01

    Data from field surveys and biogeochemical tests conducted in Maine, Montana, and Washington strongly correlate with results obtained using high resolution airborne spectroradiometer which detects an anomalous spectral waveform that appears definitely associated with sulfide mineralization. The spectral region most affected by mineral stress is between 550 nm and 750 nm. Spectral variations observed in the field occur on the wings of the red chlorophyll band centered at about 690 nm. The metal-stress-induced variations on the absorption band wing are most successfully resolved in the high spectral resolution field data using a waveform analysis technique. The development of chlorophyll pigments was retarded in greenhouse plants doped with copper and zinc in the laboratory. The lowered chlorophyll production resulted in changes on the wings of the chlorophyll bands of reflectance spectra of the plants. The airborne spectroradiometer system and waveform analysis remains the most sensitive technique for biogeochemical surveys.

  14. Airborne Remote Sensing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA imaging technology has provided the basis for a commercial agricultural reconnaissance service. AG-RECON furnishes information from airborne sensors, aerial photographs and satellite and ground databases to farmers, foresters, geologists, etc. This service produces color "maps" of Earth conditions, which enable clients to detect crop color changes or temperature changes that may indicate fire damage or pest stress problems.

  15. Detection of European Corn Borer Infestation in Iowa Corn Plots using Spectral Vegetation Indices Derived from Airborne Hyperspectral Imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing technology was used to distinguish corn infested with European corn borers, Ostrinia nubilalis, from corn that was not infested. In 2004 and 2005, eleven spectral vegetation indices that emphasize foliar plant pigments were calculated using airborne hyperspectral imagery. Manual inocu...

  16. Optimal attributes for the object based detection of giant reed in riparian habitats: A comparative study between Airborne High Spatial Resolution and WorldView-2 imagery

    NASA Astrophysics Data System (ADS)

    Fernandes, Maria Rosário; Aguiar, Francisca C.; Silva, João M. N.; Ferreira, Maria Teresa; Pereira, José M. C.

    2014-10-01

    Giant reed is an aggressive invasive plant of riparian ecosystems in many sub-tropical and warm-temperate regions, including Mediterranean Europe. In this study we tested a set of geometric, spectral and textural attributes in an object based image analysis (OBIA) approach to map giant reed invasions in riparian habitats. Bagging Classification and Regression Tree were used to select the optimal attributes and to build the classification rules sets. Mapping accuracy was performed using landscape metrics and the Kappa coefficient to compare the topographical and geometric similarity between the giant reed patches obtained with the OBIA map and with a validation map derived from on-screen digitizing. The methodology was applied in two high spatial resolution images: an airborne multispectral imagery and the newly WorldView-2 imagery. A temporal coverage of the airborne multispectral images was radiometrically calibrated with the IR-Mad transformation and used to assess the influence of the phenological variability of the invader. We found that optimal attributes for giant reed OBIA detection are a combination of spectral, geometric and textural information, with different scoring selection depending on the spectral and spatial characteristics of the imagery. WorldView-2 showed higher mapping accuracy (Kappa coefficient of 77%) and spectral attributes, including the newly yellow band, were preferentially selected, although a tendency to overestimate the total invaded area, due to the low spatial resolution (2 m of pixel size vs. 50 cm) was observed. When airborne images were used, geometric attributes were primarily selected and a higher spatial detail of the invasive patches was obtained, due to the higher spatial resolution. However, in highly heterogeneous landscapes, the low spectral resolution of the airborne images (4 bands instead of the 8 of WorldView-2) reduces the capability to detect giant reed patches. Giant reed displays peculiar spectral and geometric

  17. Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

    PubMed

    Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

    2016-04-15

    This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. PMID:26376451

  18. Detection of airborne allergen (Pla a 1) in relation to Platanus pollen in Córdoba, South Spain.

    PubMed

    Alcázar, Purificación; Galán, Carmen; Torres, Carmen; Domínguez-Vilches, Eugenio

    2015-01-01

    Córdoba is one of the Spanish cities with the highest records of plane tree pollen grains in the air. Clinical studies have identified Platanus as a major cause of pollinosis. This fact provokes an important public health problem during early spring when these trees bloom. The objective of the study is to evaluate the correlation between airborne pollen counts and Pla a 1 aeroallergen concentrations in Córdoba, to elucidate if airborne pollen can be an accurate measure that helps to explain the prevalence of allergenic symptoms. Pollen sampling was performed during 2011-2012 using a Hirst-type sampler. Daily average concentration of pollen grains (pollen grains/m 3 ) was obtained following the methodology proposed by the Spanish Aerobiology Network. A multi-vial cyclone was used for the aeroallergen quantification. Allergenic particles were measured by ELISA using specific antibodies Pla a 1. The trend of Platanus pollen was characterized by a marked seasonality, reaching high concentrations in a short period of time. Airborne pollen and aeroallergen follow similar trends. The overlapping profile between both variables during both years shows that pollen and Pla a 1 are significantly correlated. The highest significant correlation coefficients were obtained during 2011 and for the post peak. Although some studies have found notable divergence between pollen and allergen concentrations in the air, in the case of Platanus in Córdoba, similar aerobiological dynamics between pollen and Pla a 1 have been found. Allergenic activity was found only during the plane tree pollen season, showing a close relationship with daily pollen concentrations. The obtained pollen potency was similar for both years of study. The results suggest that the allergenic response in sensitive patients to plane tree pollen coincide with the presence and magnitude of airborne pollen. PMID:25780836

  19. Atmospheric CO2 measurements with a 2 μm airborne laser absorption spectrometer employing coherent detection.

    PubMed

    Spiers, Gary D; Menzies, Robert T; Jacob, Joseph; Christensen, Lance E; Phillips, Mark W; Choi, Yonghoon; Browell, Edward V

    2011-05-10

    We report airborne measurements of CO(2) column abundance conducted during two 2009 campaigns using a 2.05 μm laser absorption spectrometer. The two flight campaigns took place in the California Mojave desert and in Oklahoma. The integrated path differential absorption (IPDA) method is used for the CO(2) column mixing ratio retrievals. This instrument and the data analysis methodology provide insight into the capabilities of the IPDA method for both airborne measurements and future global-scale CO(2) measurements from low Earth orbit pertinent to the NASA Active Sensing of CO(2) Emissions over Nights, Days, and Seasons mission. The use of a favorable absorption line in the CO(2) 2 μm band allows the on-line frequency to be displaced two (surface pressure) half-widths from line center, providing high sensitivity to the lower tropospheric CO(2). The measurement repeatability and measurement precision are in good agreement with predicted estimates. We also report comparisons with airborne in situ measurements conducted during the Oklahoma campaign. PMID:21556111

  20. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  1. Airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-06-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  2. Airborne pollen in three European cities: Detection of atmospheric circulation pathways by applying three-dimensional clustering of backward trajectories

    NASA Astrophysics Data System (ADS)

    Makra, LáSzló; SáNta, TamáS.; Matyasovszky, IstváN.; Damialis, Athanasios; Karatzas, Kostas; Bergmann, Karl-Christian; Vokou, Despoina

    2010-12-01

    The long-range transport of particulates can substantially contribute to local air pollution. The importance of airborne pollen has grown due to the recent climate change; the lengthening of the pollen season and rising mean airborne pollen concentrations have increased health risks. Our aim is to identify atmospheric circulation pathways influencing pollen levels in three European cities, namely Thessaloniki, Szeged, and Hamburg. Trajectories were computed using the HYSPLIT model. The 4 day, 6 hourly three-dimensional (3-D) backward trajectories arriving at these locations at 1200 UT are produced for each day over a 5 year period. A k-means clustering algorithm using the Mahalanobis metric was applied in order to develop trajectory types. The delimitation of the clusters performed by the 3-D function "convhull" is a novel approach. The results of the cluster analysis reveal that the main pathways for Thessaloniki contributing substantially to the high mean Urticaceae pollen levels cover western Europe and the Mediterranean. The key pathway patterns for Ambrosia for Szeged are associated with backward trajectories coming from northwestern Europe, northeastern Europe, and northern Europe. A major pollen source identified is a cluster over central Europe, namely the Carpathian basin with peak values in Hungary. The principal patterns for Poaceae for Hamburg include western Europe and the mid-Atlantic region. Locations of the source areas coincide with the main habitat regions of the species in question. Critical daily pollen number exceedances conditioned on the clusters were also evaluated using two statistical indices. An attempt was made to separate medium- and long-range airborne pollen transport.

  3. A Methodology for Determining Statistical Performance Compliance for Airborne Doppler Radar with Forward-Looking Turbulence Detection Capability. Second Corrected Copy Issued May 23, 2011

    NASA Technical Reports Server (NTRS)

    Bowles, Roland L.; Buck, Bill K.

    2009-01-01

    The objective of the research developed and presented in this document was to statistically assess turbulence hazard detection performance employing airborne pulse Doppler radar systems. The FAA certification methodology for forward looking airborne turbulence radars will require estimating the probabilities of missed and false hazard indications under operational conditions. Analytical approaches must be used due to the near impossibility of obtaining sufficient statistics experimentally. This report describes an end-to-end analytical technique for estimating these probabilities for Enhanced Turbulence (E-Turb) Radar systems under noise-limited conditions, for a variety of aircraft types, as defined in FAA TSO-C134. This technique provides for one means, but not the only means, by which an applicant can demonstrate compliance to the FAA directed ATDS Working Group performance requirements. Turbulence hazard algorithms were developed that derived predictive estimates of aircraft hazards from basic radar observables. These algorithms were designed to prevent false turbulence indications while accurately predicting areas of elevated turbulence risks to aircraft, passengers, and crew; and were successfully flight tested on a NASA B757-200 and a Delta Air Lines B737-800. Application of this defined methodology for calculating the probability of missed and false hazard indications taking into account the effect of the various algorithms used, is demonstrated for representative transport aircraft and radar performance characteristics.

  4. Fault Scarp Detection Beneath Dense Vegetation Cover: Airborne Lidar Mapping of the Seattle Fault Zone, Bainbridge Island, Washington State

    NASA Technical Reports Server (NTRS)

    Harding, David J.; Berghoff, Gregory S.

    2000-01-01

    The emergence of a commercial airborne laser mapping industry is paying major dividends in an assessment of earthquake hazards in the Puget Lowland of Washington State. Geophysical observations and historical seismicity indicate the presence of active upper-crustal faults in the Puget Lowland, placing the major population centers of Seattle and Tacoma at significant risk. However, until recently the surface trace of these faults had never been identified, neither on the ground nor from remote sensing, due to cover by the dense vegetation of the Pacific Northwest temperate rainforests and extremely thick Pleistocene glacial deposits. A pilot lidar mapping project of Bainbridge Island in the Puget Sound, contracted by the Kitsap Public Utility District (KPUD) and conducted by Airborne Laser Mapping in late 1996, spectacularly revealed geomorphic features associated with fault strands within the Seattle fault zone. The features include a previously unrecognized fault scarp, an uplifted marine wave-cut platform, and tilted sedimentary strata. The United States Geologic Survey (USGS) is now conducting trenching studies across the fault scarp to establish ages, displacements, and recurrence intervals of recent earthquakes on this active fault. The success of this pilot study has inspired the formation of a consortium of federal and local organizations to extend this work to a 2350 square kilometer (580,000 acre) region of the Puget Lowland, covering nearly the entire extent (approx. 85 km) of the Seattle fault. The consortium includes NASA, the USGS, and four local groups consisting of KPUD, Kitsap County, the City of Seattle, and the Puget Sound Regional Council (PSRC). The consortium has selected Terrapoint, a commercial lidar mapping vendor, to acquire the data.

  5. Preliminary Results from the Summer 2014 ADELE (Airborne Detection of Energetic Lightning Emissions) Campaign Aboard the NOAA Hurricane Hunters' P3 Orion

    NASA Astrophysics Data System (ADS)

    Bowers, G. S.; Kelley, N. A.; Martinez-McKinney, G. F.; Smith, D. M.; Buzbee, P.; Dwyer, J. R.

    2014-12-01

    ADELE (Airborne Detection for Energetic Lightning Emissions) is an instrument designed to make observations from aircraft altitudes of high energy radiation from lightning related phenomena that include TGFs (Terrestrial Gamma-Ray Flashes), intense sub-millisecond bursts of gamma-rays with energies up to 40 MeV; gamma-ray glows, long duration continuous emissions of gamma-rays; and stepped leader enhancements, gamma-ray emissions coincident with lightning stepped leaders. The instrumentation is three energetic particle detectors each composed of a scintillating material coupled to a photomultiplier tube. The pulse heights from each PMT are discriminated into 4 to 8 energy channels, corresponding roughly to an energy range of 100 keV to 10 MeV. The time resolution for each channel is 50 microseconds. We will discuss preliminary results from the 2014 campaign aboard a NOAA "Hurricane Hunters" P3 aircraft that began on 5 July.

  6. Forest fuel treatment detection using multi-temporal airborne Lidar data and high resolution aerial imagery ---- A case study at Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Su, Y.; Guo, Q.; Collins, B.; Fry, D.; Kelly, M.

    2014-12-01

    Forest fuel treatments (FFT) are often employed in Sierra Nevada forest (located in California, US) to enhance forest health, regulate stand density, and reduce wildfire risk. However, there have been concerns that FFTs may have negative impacts on certain protected wildlife species. Due to the constraints and protection of resources (e.g., perennial streams, cultural resources, wildlife habitat, etc.), the actual FFT extents are usually different from planned extents. Identifying the actual extent of treated areas is of primary importance to understand the environmental influence of FFTs. Light detection and ranging (Lidar) is a powerful remote sensing technique that can provide accurate forest structure measurements, which provides great potential to monitor forest changes. This study used canopy height model (CHM) and canopy cover (CC) products derived from multi-temporal airborne Lidar data to detect FFTs by an approach combining a pixel-wise thresholding method and a object-of-interest segmentation method. We also investigated forest change following the implementation of landscape-scale FFT projects through the use of normalized difference vegetation index (NDVI) and standardized principle component analysis (PCA) from multi-temporal high resolution aerial imagery. The same FFT detection routine was applied on the Lidar data and aerial imagery for the purpose of comparing the capability of Lidar data and aerial imagery on FFT detection. Our results demonstrated that the FFT detection using Lidar derived CC products produced both the highest total accuracy and kappa coefficient, and was more robust at identifying areas with light FFTs. The accuracy using Lidar derived CHM products was significantly lower than that of the result using Lidar derived CC, but was still slightly higher than using aerial imagery. FFT detection results using NDVI and standardized PCA using multi-temporal aerial imagery produced almost identical total accuracy and kappa coefficient

  7. Use of spectral vegetation indices derived from airborne hyperspectral imagery for detection of European corn borer infestation in Iowa corn plots.

    PubMed

    Carroll, Matthew W; Glaser, John A; Hellmich, Richard L; Hunt, Thomas E; Sappington, Thomas W; Calvin, Dennis; Copenhaver, Ken; Fridgen, John

    2008-10-01

    Eleven spectral vegetation indices that emphasize foliar plant pigments were calculated using airborne hyperspectral imagery and evaluated in 2004 and 2005 for their ability to detect experimental plots of corn manually inoculated with Ostrinia nubilalis (Hübner) neonate larvae. Manual inoculations were timed to simulate infestation of corn, Zea mays L., by first and second flights of adult O. nubilalis. The ability of spectral vegetation indices to detect O. nubilalis-inoculated plots improved as the growing season progressed, with multiple spectral vegetation indices able to identify infested plots in late August and early September. Our findings also indicate that for detecting O. nubilalis-related plant stress in corn, spectral vegetation indices targeting carotenoid and anthocyanin pigments are not as effective as those targeting chlorophyll. Analysis of image data suggests that feeding and stem boring by O. nubilalis larvae may increase the rate of plant senescence causing detectable differences in plant biomass and vigor when compared with control plots. Further, we identified an approximate time frame of 5-6 wk postinoculation, when spectral differences of manually inoculated "second" generation O. nubilalis plots seem to peak. PMID:18950044

  8. Detection of Airborne Methicillin-Resistant Staphylococcus aureus Inside and Downwind of a Swine Building, and in Animal Feed: Potential Occupational, Animal Health, and Environmental Implications.

    PubMed

    Ferguson, Dwight D; Smith, Tara C; Hanson, Blake M; Wardyn, Shylo E; Donham, Kelley J

    2016-01-01

    Aerosolized methicillin-resistant Staphylococcus aureus (MRSA) was sampled inside and downwind of a swine facility. Animal feed was sampled before and after entry into the swine facility. Aerosolized particles were detected using an optical particle counter for real-time measurement and with an Andersen sampler to detect viable MRSA. Molecular typing and antimicrobial susceptibility testing were performed on samples collected. Viable MRSA organisms isolated inside the swine facility were primarily associated with particles >5 µm, and those isolated downwind from the swine facility were associated with particles <5 µm. MRSA isolates included spa types t008, t034, and t5706 and were resistant to methicillin, tetracycline, clindamycin, and erythromycin. Animal feed both before and after entry into the swine facility tested positive for viable MRSA. These isolates were of similar spa types as the airborne MRSA organisms. Air samples collected after power washing with a biocide inside the swine facility resulted in no viable MRSA organisms detected. This pilot study showed that the ecology of MRSA is complex. Additional studies are warranted on the maximum distance that viable MRSA can be emitted outside the facility, and the possibility that animal feed may be a source of contamination. PMID:26808288

  9. Advanced Algorithms and High-Performance Testbed for Large-Scale Site Characterization and Subsurface Target Detecting Using Airborne Ground Penetrating SAR

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Collier, James B.; Citak, Ari

    1997-01-01

    A team of US Army Corps of Engineers, Omaha District and Engineering and Support Center, Huntsville, let Propulsion Laboratory (JPL), Stanford Research Institute (SRI), and Montgomery Watson is currently in the process of planning and conducting the largest ever survey at the Former Buckley Field (60,000 acres), in Colorado, by using SRI airborne, ground penetrating, Synthetic Aperture Radar (SAR). The purpose of this survey is the detection of surface and subsurface Unexploded Ordnance (UXO) and in a broader sense the site characterization for identification of contaminated as well as clear areas. In preparation for such a large-scale survey, JPL has been developing advanced algorithms and a high-performance restbed for processing of massive amount of expected SAR data from this site. Two key requirements of this project are the accuracy (in terms of UXO detection) and speed of SAR data processing. The first key feature of this testbed is a large degree of automation and a minimum degree of the need for human perception in the processing to achieve an acceptable processing rate of several hundred acres per day. For accurate UXO detection, novel algorithms have been developed and implemented. These algorithms analyze dual polarized (HH and VV) SAR data. They are based on the correlation of HH and VV SAR data and involve a rather large set of parameters for accurate detection of UXO. For each specific site, this set of parameters can be optimized by using ground truth data (i.e., known surface and subsurface UXOs). In this paper, we discuss these algorithms and their successful application for detection of surface and subsurface anti-tank mines by using a data set from Yuma proving Ground, A7, acquired by SRI SAR.

  10. Detection of airborne bacteria in a duck production facility with two different personal air sampling devices for an exposure assessment.

    PubMed

    Martin, Elena; Dziurowitz, Nico; Jäckel, Udo; Schäfer, Jenny

    2015-01-01

    Prevalent airborne microorganisms are not well characterized in industrial animal production buildings with respect to their quantity or quality. To investigate the work-related microbial exposure, personal bioaerosol sampling during the whole working day is recommended. Therefore, bioaerosol sampling in a duck hatchery and a duck house with two personal air sampling devices, a filter-based PGP and a NIOSH particle size separator, was performed. Subsequent, quantitative and qualitative analyses were carried out with" culture independent methods. Total cell concentrations (TCC) determined via fluorescence microscopy showed no difference between the two devices. In average, 8 × 10(6) cells/m(3) were determined in the air of the duck hatchery and 5 × 10(7) cells/m(3) in the air of the duck house. A Generated Restriction Fragment Length Polymorphism (RFLP) pattern revealed deviant bacterial compositions comparing samples collected with both devices. Clone library analyses based on 16S rRNA gene sequence analysis from the hatchery's air showed 65% similarity between the two sampling devices. Detailed 16S rRNA gene sequence analyses showed the occurrence of bacterial species like Acinetobacter baumannii, Enterococcus faecalis, Escherichia sp., and Shigella sp.; and a group of Staphylococcus delphini, S. intermedius, and S. pseudintermedius that provided the evidence of potential exposure to risk group 2 bacteria at the hatchery workplace. Size fractionated sampling with the developed by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) device revealed that pathogenic bacteria would deposit in the inhalable, the thorax, and possibly alveolar dust fraction according to EN481. TCC analysis showed the deposition of bacterial cells in the third stage (< 1μm) at the NIOSH device which implies that bacteria can reach deep into the lungs and contaminate the alveolus after inhalation. Nevertheless, both personal sampling devices

  11. Airborne electromagnetic detection of shallow seafloor topographic features, including resolution of multiple sub-parallel seafloor ridges

    NASA Astrophysics Data System (ADS)

    Vrbancich, Julian; Boyd, Graham

    2014-05-01

    The HoistEM helicopter time-domain electromagnetic (TEM) system was flown over waters in Backstairs Passage, South Australia, in 2003 to test the bathymetric accuracy and hence the ability to resolve seafloor structure in shallow and deeper waters (extending to ~40 m depth) that contain interesting seafloor topography. The topography that forms a rock peak (South Page) in the form of a mini-seamount that barely rises above the water surface was accurately delineated along its ridge from the start of its base (where the seafloor is relatively flat) in ~30 m water depth to its peak at the water surface, after an empirical correction was applied to the data to account for imperfect system calibration, consistent with earlier studies using the same HoistEM system. A much smaller submerged feature (Threshold Bank) of ~9 m peak height located in waters of 35 to 40 m depth was also accurately delineated. These observations when checked against known water depths in these two regions showed that the airborne TEM system, following empirical data correction, was effectively operating correctly. The third and most important component of the survey was flown over the Yatala Shoals region that includes a series of sub-parallel seafloor ridges (resembling large sandwaves rising up to ~20 m from the seafloor) that branch out and gradually decrease in height as the ridges spread out across the seafloor. These sub-parallel ridges provide an interesting topography because the interpreted water depths obtained from 1D inversion of TEM data highlight the limitations of the EM footprint size in resolving both the separation between the ridges (which vary up to ~300 m) and the height of individual ridges (which vary up to ~20 m), and possibly also the limitations of assuming a 1D model in areas where the topography is quasi-2D/3D.

  12. Advanced algorithms and high-performance testbed for large-scale site characterization and subsurface target detection using airborne ground-penetrating SAR

    NASA Astrophysics Data System (ADS)

    Fijany, Amir; Collier, James B.; Citak, Ari

    1999-08-01

    A team of US Army Corps of Engineers, Omaha District and Engineering and Support Center, Huntsville, JPL, Stanford Research Institute (SRI), and Montgomery Watson is currently in the process of planning and conducting the largest ever survey at the Former Buckley Field, in Colorado, by using SRI airborne, ground penetrating, SAR. The purpose of this survey is the detection of surface and subsurface Unexploded Ordnance (UXO) and in a broader sense the site characterization for identification of contaminated as well as clear areas. In preparation for such a large-scale survey, JPL has been developing advanced algorithms and a high-performance testbed for processing of massive amount of expected SAR data from this site. Two key requirements of this project are the accuracy and speed of SAR data processing. The first key feature of this testbed is a large degree of automation and maximum degree of the need for human perception in the processing to achieve an acceptable processing rate of several hundred acres per day. For accuracy UXO detection, novel algorithms have been developed and implemented. These algorithms analyze dual polarized SAR data. They are based on the correlation of HH and VV SAR data and involve a rather large set of parameters for accurate detection of UXO. For each specific site, this set of parameters can be optimized by using ground truth data. In this paper, we discuss these algorithms and their successful application for detection of surface and subsurface anti-tank mines by using a data set from Yuma Proving Ground, AZ, acquired by SRI SAR.

  13. High-resolution topographic change detection of an active earthflow using airborne and terrestrial LiDAR, Mill Gulch, California

    NASA Astrophysics Data System (ADS)

    Murphy, B. P.; DeLong, S.

    2011-12-01

    In landscapes where airborne laser swath mapping (ALSM) exists, terrestrial laser scanning (TLS) can be used to update high-resolution topographic models for quantification of landscape change. At Mill Gulch in northern California, we scanned an active earthflow using TLS in 2011 that had also been imaged by ALSM in 2003 and 2007. In order to evaluate change at the sub-meter level between the ALSM and TLS data, we generated a custom, 30 cm resolution ALSM digital elevation model (DEM), employed geographic transformations to align the disparate datasets, and refined the vertical alignment using an unaltered road surface. We then conducted vegetation removal from the TLS data, gridded it to 30 cm, and produced detailed maps of topographic evolution. Previous work comparing the 2003 and 2007 ALSM data indicated that this earthflow translated blocks of material as much as 5 m/yr and that significant material was removed by the channel at the toe of the earthflow, leading to a net elevation decrease across the earthflow. Over the last four years, the earthflow has experienced overall rotational movement leading to distinct failure planes in the source area with elevations decreasing as much as 3.75 m, while the toe aggraded up to 2.5 m. Maximum translation rates in the transport zone have decreased to 3.5 m/yr and very little material was removed by the channel. Early analysis indicates a slight increase in the net volume of the earthflow and an average elevation increase of 0.05 m between 2007 and 2011. It is possible this is the result of any number of factors, including the failure of TLS to adequately measure the thalweg depth of supra-flow gullies and depths of tension fractures, higher sensitivity to grasses in TLS data, decreased material density (and concomitant volumetric increase) due to tension fracturing, the swelling of clays and increased pore water pressure in the earthflow. However, it is also reasonable that this result reflects minor systematic error

  14. Airborne radioactive contamination monitoring

    SciTech Connect

    Whitley, C.R.; Adams, J.R.; Bounds, J.A.; MacArthur, D.W.

    1996-03-01

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination.

  15. Detecting Light Hydrocarbon Microseepages and related Intra-sedimentary Structures at the São Francisco Basin, Brazil, using Airborne Geophysical Data

    NASA Astrophysics Data System (ADS)

    Curto, J. B.; Pires, A. C.; Silva, A.; Crosta, A. P.

    2011-12-01

    The use of indirect techniques for the detection of light hydrocarbons occurrences on the surface, named as microseepages, has been used to augment hydrocarbon exploration. Surveys developed for this type of application are normally targeted at mapping the effects that microseepages cause on the environment. In Brazil, most available airborne geophysical surveys were not appropriately designed for this type of application and, thus far they have been mostly used to define the main basin structural features. Existing microseepages are known in Remanso do Fogo area (Minas Gerais State, Brazil), located in São Francisco Basin, where the Quaternary sedimentary cover made the identification of new occurrences and associated controlling structures quite difficult. This study investigates the spatial distribution of hydrocarbon related structures in shallower to intra-sedimentary depths in the Remanso do Fogo area, using airborne magnetic and gamma-ray spectrometry data. These data were managed by the ANP (Brazilian Petroleum National Agency) and conducted by Lasa Engineering & Surveys in 2006. In the study area, data were acquired along north-south flight lines spaced 500 m apart and along orthogonal tie lines flown 4 Km apart at a terrain clearance of 100 m. The geophysical data were processed using techniques developed to suppress the influence of regional geological signatures. For the magnetic data, this study focuses on the enhancement of intra-sedimentary structures and possible near surface accumulations of diagenetic magnetic minerals, provided by hydrocarbon related chemical reactions. The amplitude of the analytic signal, calculated with second order derivatives, combined with the total horizontal gradient of the subtraction between the 1200 and 400 meter upward continuations, illuminated the NW and EW magnetic lineaments, which are partially related to the microseepages and the drainage of the area. The distinction of near-surface and deeper signatures also

  16. Airborne Raman lidar

    NASA Astrophysics Data System (ADS)

    Heaps, Wm. S.; Burris, J.

    1996-12-01

    We designed and tested an airborne lidar system using Raman scattering to make simultaneous measurements of methane, water vapor, and temperature in a series of flights on a NASA-operated C-130 aircraft. We present the results for methane detection, which show that the instrument has the requisite sensitivity to atmospheric trace gases. Ultimately these measurements can be used to examine the transport of chemically processed air from within the polar vortex to mid-latitudinal regions and the exchange of stratospheric air between tropical and mid-latitudinal regions.

  17. Using airborne LiDAR in geoarchaeological contexts: Assessment of an automatic tool for the detection and the morphometric analysis of grazing archaeological structures (French Massif Central).

    NASA Astrophysics Data System (ADS)

    Roussel, Erwan; Toumazet, Jean-Pierre; Florez, Marta; Vautier, Franck; Dousteyssier, Bertrand

    2014-05-01

    Airborne laser scanning (ALS) of archaeological regions of interest is nowadays a widely used and established method for accurate topographic and microtopographic survey. The penetration of the vegetation cover by the laser beam allows the reconstruction of reliable digital terrain models (DTM) of forested areas where traditional prospection methods are inefficient, time-consuming and non-exhaustive. The ALS technology provides the opportunity to discover new archaeological features hidden by vegetation and provides a comprehensive survey of cultural heritage sites within their environmental context. However, the post-processing of LiDAR points clouds produces a huge quantity of data in which relevant archaeological features are not easily detectable with common visualizing and analysing tools. Undoubtedly, there is an urgent need for automation of structures detection and morphometric extraction techniques, especially for the "archaeological desert" in densely forested areas. This presentation deals with the development of automatic detection procedures applied to archaeological structures located in the French Massif Central, in the western forested part of the Puy-de-Dôme volcano between 950 and 1100 m a.s.l.. These unknown archaeological sites were discovered by the March 2011 ALS mission and display a high density of subcircular depressions with a corridor access. The spatial organization of these depressions vary from isolated to aggregated or aligned features. Functionally, they appear to be former grazing constructions built from the medieval to the modern period. Similar grazing structures are known in other locations of the French Massif Central (Sancy, Artense, Cézallier) where the ground is vegetation-free. In order to develop a reliable process of automatic detection and mapping of these archaeological structures, a learning zone has been delineated within the ALS surveyed area. The grazing features were mapped and typical morphometric attributes

  18. Enhanced detection of 3D individual trees in forested areas using airborne full-waveform LiDAR data by combining normalized cuts with spatial density clustering

    NASA Astrophysics Data System (ADS)

    Yao, W.; Krzystek, P.; Heurich, M.

    2013-10-01

    A detailed understanding of the spatial distribution of forest understory is important but difficult. LiDAR remote sensing has been developing as a promising additional instrument to the conventional field work towards automated forest inventory. Unfortunately, understory (up to 50% of the top-tree height) in mixed and multilayered forests is often ignored due to a difficult observation scenario and limitation of the tree detection algorithm. Currently, the full-waveform (FWF) LiDAR with high penetration ability against overstory crowns can give us new hope to resolve the forest understory. Former approach based on 3D segmentation confirmed that the tree detection rates in both middle and lower forest layers are still low. Therefore, detecting sub-dominant and suppressed trees cannot be regarded as fully solved. In this work, we aim to improve the performance of the FWF laser scanner for the mapping of forest understory. The paper is to develop an enhanced methodology for detecting 3D individual trees by partitioning point clouds of airborne LiDAR. After extracting 3D coordinates of the laser beam echoes, the pulse intensity and width by waveform decomposition, the newly developed approach resolves 3D single trees are by an integrated approach, which delineates tree crowns by applying normalized cuts segmentation to the graph structure of local dense modes in point clouds constructed by mean shift clustering. In the context of our strategy, the mean shift clusters approximate primitives of (sub) single trees in LiDAR data and allow to define more significant features to reflect geometric and reflectional characteristics towards the single tree level. The developed methodology can be regarded as an object-based point cloud analysis approach for tree detection and is applied to datasets captured with the Riegl LMS-Q560 laser scanner at a point density of 25 points/m2 in the Bavarian Forest National Park, Germany, respectively under leaf-on and leaf-off conditions

  19. Use of laboratory spectrometry to predict the detection of phytoplankton luminescence by an airborne Fraunhofer line discriminator

    USGS Publications Warehouse

    Watson, Robert D.; Theisen, Arnold F.; Prezelin, Barbara B.

    1981-01-01

    Laboratory measurements of the excitation spectra of 13 species of phytoplankton (six diatoms, five dinoflagellates and two chrysophytes) were obtained with the emission wavelength held constant at 656.3 nm and the excitation wavelength scanned from 320 to 640 nm. Integrated excitation intensities were normalized to a standard concentration of rhodamine wt dye and the resulting luminescence compared to the minimum detectable FLD level of 0.12 parts per billion (p.p.b.) rhodamine wt. Results demonstrated that all 13 species would be detectable with an FLD at concentrations of 10.0 and 5.0 μg/1 of chlorophyll a and that only one would not be detectable at a chlorophyll a concentration of 1.0 μg/1.

  20. A hybrid framework for single tree detection from airborne laser scanning data: A case study in temperate mature coniferous forests in Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Zhang, Junjie; Sohn, Gunho; Brédif, Mathieu

    2014-12-01

    This study presents a hybrid framework for single tree detection from airborne laser scanning (ALS) data by integrating low-level image processing techniques into a high-level probabilistic framework. The proposed approach modeled tree crowns in a forest plot as a configuration of circular objects. We took advantage of low-level image processing techniques to generate candidate configurations from the canopy height model (CHM): the treetop positions were sampled within the over-extracted local maxima via local maxima filtering, and the crown sizes were derived from marker-controlled watershed segmentation using corresponding treetops as markers. The configuration containing the best possible set of detected tree objects was estimated by a global optimization solver. To achieve this, we introduced a Gibbs energy, which contains a data term that judges the fitness of the objects with respect to the data, and a prior term that prevents severe overlapping between tree crowns on the configuration space. The energy was then embedded into a Markov Chain Monte Carlo (MCMC) dynamics coupled with a simulated annealing to find its global minimum. In this research, we also proposed a Monte Carlo-based sampling method for parameter estimation. We tested the method on a temperate mature coniferous forest in Ontario, Canada and also on simulated coniferous forest plots with different degrees of crown overlap. The experimental results showed the effectiveness of our proposed method, which was capable of reducing the commission errors produced by local maxima filtering, thus increasing the overall detection accuracy by approximately 10% on all of the datasets.

  1. Airborne Light Detection and Ranging (lidar) Derived Deformation from the MW 6.0 24 August, 2014 South Napa Earthquake Estimated by Two and Three Dimensional Point Cloud Change Detection Techniques

    NASA Astrophysics Data System (ADS)

    Lyda, A. W.; Zhang, X.; Glennie, C. L.; Hudnut, K.; Brooks, B. A.

    2016-06-01

    Remote sensing via LiDAR (Light Detection And Ranging) has proven extremely useful in both Earth science and hazard related studies. Surveys taken before and after an earthquake for example, can provide decimeter-level, 3D near-field estimates of land deformation that offer better spatial coverage of the near field rupture zone than other geodetic methods (e.g., InSAR, GNSS, or alignment array). In this study, we compare and contrast estimates of deformation obtained from different pre and post-event airborne laser scanning (ALS) data sets of the 2014 South Napa Earthquake using two change detection algorithms, Iterative Control Point (ICP) and Particle Image Velocimetry (PIV). The ICP algorithm is a closest point based registration algorithm that can iteratively acquire three dimensional deformations from airborne LiDAR data sets. By employing a newly proposed partition scheme, "moving window," to handle the large spatial scale point cloud over the earthquake rupture area, the ICP process applies a rigid registration of data sets within an overlapped window to enhance the change detection results of the local, spatially varying surface deformation near-fault. The other algorithm, PIV, is a well-established, two dimensional image co-registration and correlation technique developed in fluid mechanics research and later applied to geotechnical studies. Adapted here for an earthquake with little vertical movement, the 3D point cloud is interpolated into a 2D DTM image and horizontal deformation is determined by assessing the cross-correlation of interrogation areas within the images to find the most likely deformation between two areas. Both the PIV process and the ICP algorithm are further benefited by a presented, novel use of urban geodetic markers. Analogous to the persistent scatterer technique employed with differential radar observations, this new LiDAR application exploits a classified point cloud dataset to assist the change detection algorithms. Ground

  2. Spectral methods to detect surface mines

    NASA Astrophysics Data System (ADS)

    Winter, Edwin M.; Schatten Silvious, Miranda

    2008-04-01

    Over the past five years, advances have been made in the spectral detection of surface mines under minefield detection programs at the U. S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD). The problem of detecting surface land mines ranges from the relatively simple, the detection of large anti-vehicle mines on bare soil, to the very difficult, the detection of anti-personnel mines in thick vegetation. While spatial and spectral approaches can be applied to the detection of surface mines, spatial-only detection requires many pixels-on-target such that the mine is actually imaged and shape-based features can be exploited. This method is unreliable in vegetated areas because only part of the mine may be exposed, while spectral detection is possible without the mine being resolved. At NVESD, hyperspectral and multi-spectral sensors throughout the reflection and thermal spectral regimes have been applied to the mine detection problem. Data has been collected on mines in forest and desert regions and algorithms have been developed both to detect the mines as anomalies and to detect the mines based on their spectral signature. In addition to the detection of individual mines, algorithms have been developed to exploit the similarities of mines in a minefield to improve their detection probability. In this paper, the types of spectral data collected over the past five years will be summarized along with the advances in algorithm development.

  3. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  4. Dual-band infrared imaging applications: Locating buried minefields, mapping sea ice, and inspecting aging aircraft

    SciTech Connect

    Del Grande, N.K.; Durbin, P.F.; Perkins, D.E.

    1992-09-01

    We discuss the use of dual-band infrared (DBIR) imaging for three quantitative NDE applications: location buried surrogate mines, mapping sea ice thicknesses and inspecting subsurface flaws in aging aircraft parts. Our system of DBIR imaging offers a unique combination of thermal resolution, detectability, and interpretability. Pioneered at Lawrence Livermore Laboratory, it resolves 0.2 {degrees}C differences in surface temperatures needed to identify buried mine sites and distinguish them from surface features. It produces both surface temperature and emissivity-ratio images of sea ice, needed to accurately map ice thicknesses (e.g., by first removing clutter due to snow and surface roughness effects). The DBIR imaging technique depicts subsurface flaws in composite patches and lap joints of aircraft, thus providing a needed tool for aging aircraft inspections.

  5. Context-dependent detection of non-linearly distributed points for vegetation classification in airborne LiDAR

    NASA Astrophysics Data System (ADS)

    Horvat, Denis; Žalik, Borut; Mongus, Domen

    2016-06-01

    This paper proposes a new method for the detection of vegetation in LiDAR data. As vegetation points are characterised by non-linear distributions, they are efficiently recognised based-on large errors obtained when applying the local fitting of planar surfaces. In addition, three contextual filters are introduced capable of dealing with those exceptions that do not conform with previous interpretations. Namely, they are designed for detecting overgrowing vegetation, small objects attached to the planar surfaces (such as balconies, chimneys, and noise within the buildings) and small objects that do not belong to vegetation (vehicles, statues, fences). During the validation, the proposed method achieved over 97% correctness as well as completeness of vegetation recognition in rural areas while its average accuracy in urban settings was 90.7% in terms of F 1 -scores. The method uses only three input parameters and allows for efficient compensation between completeness and correctness, without significantly affecting the F 1 -score. Sensitivity analysis of the method also confirmed the robustness against a sub-optimal definition of the input parameters.

  6. Rapid on-site detection of airborne asbestos fibers and potentially hazardous nanomaterials using fluorescence microscopy-based biosensing.

    PubMed

    Kuroda, Akio; Alexandrov, Maxym; Nishimura, Tomoki; Ishida, Takenori

    2016-06-01

    A large number of peptides with binding affinity to various inorganic materials have been identified and used as linkers, catalysts, and building blocks in nanotechnology and nanobiotechnology. However, there have been few applications of material-binding peptides in the fluorescence microscopy-based biosensing (FM method) of environmental pollutants. A notable exception is the application of the FM method for the detection of asbestos, a dangerous industrial toxin that is still widely used in many developing countries. This review details the selection and isolation of asbestos-binding proteins and peptides with sufficient specificity to distinguish asbestos from a large variety of safer fibrous materials used as asbestos substitutes. High sensitivity to nanoscale asbestos fibers (30-35 nm in diameter) invisible under conventional phase contrast microscopy can be achieved. The FM method is the basis for developing an automated system for asbestos biosensing that can be used for on-site testing with a portable fluorescence microscope. In the future, the FM method could also become a useful tool for detecting other potentially hazardous nanomaterials in the environment. PMID:27220109

  7. Method for remote detection of trace contaminants

    DOEpatents

    Simonson, Robert J.; Hance, Bradley G.

    2003-09-09

    A method for remote detection of trace contaminants in a target area comprises applying sensor particles that preconcentrate the trace contaminant to the target area and detecting the contaminant-sensitive fluorescence from the sensor particles. The sensor particles can have contaminant-sensitive and contaminant-insensitive fluorescent compounds to enable the determination of the amount of trace contaminant present in the target are by relative comparison of the emission of the fluorescent compounds by a local or remote fluorescence detector. The method can be used to remotely detect buried minefields.

  8. PHARUS airborne SAR concept

    NASA Astrophysics Data System (ADS)

    Snoeij, Paul; Pouwels, Henk; Koomen, Peter J.; Hoogeboom, Peter

    1995-11-01

    to ingest raw data from other SARs on the input side. The combination of the airborne and the ground segment, augmented by the transfer of technological knowledge needed to operate the system, will provide for an autonomous capability of the system user/owner. The PHARUS project has so far resulted in the construction of a C-band, VV-polarized research SAR (PHARS) with a 1- look resolution of 1.5 multiplied by 5 meter (5 multiplied by 5 meter at 7 independent looks) and a swath width of 6 km. This system has been extensively used for research and application projects in Europe, for purposes of mapping, land use inventory, change detection, coastal bathymetry, ship detection and ocean wave measurement. The next system recently completed is a fully polarimetric C-band system with adjustable resolution and swath width (the latter up to 20 km); this system is expected to be operational autumn 1995. The polarimetric capability will provide for a much enhanced discerning power (discrimination between e.g. forest/cultivated, various forest types, etc.). Discrimination by polarimetric signature is an alterative approach, with different possibilities and limitations, to e.g. the use of several frequencies. This paper gives an overview of the SAR research system and the results obtained with this system. The PHARUS design and use are discussed.

  9. Real-time detection and characterization of individual flowing airborne biological particles: fluorescence spectra and elastic scattering measurements

    NASA Astrophysics Data System (ADS)

    Pan, Yongle; Holler, Stephen; Chang, Richard K.; Hill, Steven C.; Pinnick, Ronald G.; Niles, Stanley; Bottiger, Jerold R.; Bronk, Burt V.

    1999-11-01

    Real-time methods which is reagentless and could detect and partially characterize bioaerosols are of current interest. We present a technique for real-time measurement of UV-excited fluorescence spectra and two-dimensional angular optical scattering (TAOS) from individual flowing biological aerosol particles. The fluorescence spectra have been observed from more than 20 samples including Bacillus subtilis, Escherichia coli, Erwinia herbicola, allergens, dust, and smoke. The S/N and resolution of the spectra are sufficient for observing small lineshape differences among the same type of bioaerosol prepared under different conditions. The additional information from TAOS regarding particle size, shape, and granularity has the potential of aiding in distinguishing bacterial aerosols from other aerosols, such as diesel and cigarette smoke.

  10. Signal processing for airborne doppler radar detection of hazardous wind shear as applied to NASA 1991 radar flight experiment data

    NASA Technical Reports Server (NTRS)

    Baxa, Ernest G., Jr.

    1992-01-01

    Radar data collected during the 1991 NASA flight tests have been selectively analyzed to support research directed at developing both improved as well as new algorithms for detecting hazardous low-altitude windshear. Analysis of aircraft attitude data from several flights indicated that platform stability bandwidths were small compared to the data rate bandwidths which should support an assumption that radar returns can be treated as short time stationary. Various approaches at detection of weather returns in the presence of ground clutter are being investigated. Non-coventional clutter rejection through spectrum mode tracking and classification algorithms is a subject of continuing research. Based upon autoregressive modeling of the radar return time sequence, this approach may offer an alternative to overcome errors in conventional pulse-pair estimates. Adaptive filtering is being evaluated as a means of rejecting clutter with emphasis on low signal-to-clutter ratio situations, particularly in the presence of discrete clutter interference. An analysis of out-of-range clutter returns is included to illustrate effects of ground clutter interference due to range aliasing for aircraft on final approach. Data are presented to indicate how aircraft groundspeed might be corrected from the radar data as well as point to an observed problem of groundspeed estimate bias variation with radar antenna scan angle. A description of how recorded clutter return data are mixed with simulated weather returns is included. This enables the researcher to run controlled experiments to test signal processing algorithms. In the summary research efforts involving improved modelling of radar ground clutter returns and a Bayesian approach at hazard factor estimation are mentioned.

  11. Airborne multispectral and thermal remote sensing for detecting the onset of crop stress caused by multiple factors

    NASA Astrophysics Data System (ADS)

    Huang, Yanbo; Thomson, Steven J.

    2010-10-01

    Remote sensing technology has been developed and applied to provide spatiotemporal information on crop stress for precision management. A series of multispectral images over a field planted cotton, corn and soybean were obtained by a Geospatial Systems MS4100 camera mounted on an Air Tractor 402B airplane equipped with Camera Link in a Magma converter box triggered by Terraverde Dragonfly® flight navigation and imaging control software. The field crops were intentionally stressed by applying glyphosate herbicide via aircraft and allowing it to drift near-field. Aerial multispectral images in the visible and near-infrared bands were manipulated to produce vegetation indices, which were used to quantify the onset of herbicide induced crop stress. The vegetation indices normalized difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI) showed the ability to monitor crop response to herbicide-induced injury by revealing stress at different phenological stages. Two other fields were managed with irrigated versus nonirrigated treatments, and those fields were imaged with both the multispectral system and an Electrophysics PV-320T thermal imaging camera on board an Air Tractor 402B aircraft. Thermal imagery indicated water stress due to deficits in soil moisture, and a proposed method of determining crop cover percentage using thermal imagery was compared with a multispectral imaging method. Development of an image fusion scheme may be necessary to provide synergy and improve overall water stress detection ability.

  12. Evaluation of SEVIRI Thermal Infra-Red data for airborne dust detection in an arid regions: the UAE case study

    NASA Astrophysics Data System (ADS)

    Gherboudj, I.; Parajuli, S. P.; Ghedira, H.

    2011-12-01

    Our interest in the study of the dust emission cycle over arid area results from the impacts that they have on the climate and atmospheric processes. Large dust concentration emitted even naturally or anthropogenic may reduce surface insolation by extinction of solar radiation. In addition, the knowledge of its spatio-temporal distribution is essential for monitoring several applications such as solar energy potential and health effect. Satellite-based remote sensing is an efficient tool to improve our understanding of the interaction of the desert dust and surrounding climate over regional and global scales with high frequency measurements. Thermal infrared (TIR) channels (3μm -15μm) of different satellites (MVIRI, AVHRR, MODIS, ADEOS-2/POLDER, TOMS, and MSG/SERIVI) were widely used for dust detection. Several dust detection and forecasting algorithms have been proposed based on these satellite data. However, the spatial and temporal variability of the physical characteristics of dust (concentrations, particle size distribution, location in the atmosphere, and chemical composition) has limited their estimations particularly with the dependence of the dust emission on the wind, soil water content, vegetation, and sediment availability. This study focuses on the analysis of the sensitivity of the MSG/SEVIRI TIR observation to dust generation, surface wind, soil moisture, and surface emissivity over the United Arab Emirates (UAE). SEVIRI observations were acquired in 2009 with temporal and spatial resolutions of 30 minutes and about 3km respectively. While the soil moisture is extracted from the AMSR-E data (1:30 AM and 1:30 PM) at spatial resolution of 25 km, the surface emissivity and Aerosol Optical Thickness were extracted from the MODIS products at spatial resolutions of 1 km and 100 km respectively. In coincidence with the satellites acquisitions, meteorological measurements were collected from seven met stations distributed over the selected study area (wind

  13. Combination of individual tree detection and area-based approach in imputation of forest variables using airborne laser data

    NASA Astrophysics Data System (ADS)

    Vastaranta, Mikko; Kankare, Ville; Holopainen, Markus; Yu, Xiaowei; Hyyppä, Juha; Hyyppä, Hannu

    2012-01-01

    The two main approaches to deriving forest variables from laser-scanning data are the statistical area-based approach (ABA) and individual tree detection (ITD). With ITD it is feasible to acquire single tree information, as in field measurements. Here, ITD was used for measuring training data for the ABA. In addition to automatic ITD (ITD auto), we tested a combination of ITD auto and visual interpretation (ITD visual). ITD visual had two stages: in the first, ITD auto was carried out and in the second, the results of the ITD auto were visually corrected by interpreting three-dimensional laser point clouds. The field data comprised 509 circular plots ( r = 10 m) that were divided equally for testing and training. ITD-derived forest variables were used for training the ABA and the accuracies of the k-most similar neighbor ( k-MSN) imputations were evaluated and compared with the ABA trained with traditional measurements. The root-mean-squared error (RMSE) in the mean volume was 24.8%, 25.9%, and 27.2% with the ABA trained with field measurements, ITD auto, and ITD visual, respectively. When ITD methods were applied in acquiring training data, the mean volume, basal area, and basal area-weighted mean diameter were underestimated in the ABA by 2.7-9.2%. This project constituted a pilot study for using ITD measurements as training data for the ABA. Further studies are needed to reduce the bias and to determine the accuracy obtained in imputation of species-specific variables. The method could be applied in areas with sparse road networks or when the costs of fieldwork must be minimized.

  14. Revisiting a universal airborne light detection and ranging approach for tropical forest carbon mapping: scaling-up from tree to stand to landscape.

    PubMed

    Vincent, Grégoire; Sabatier, Daniel; Rutishauser, Ervan

    2014-06-01

    Airborne laser scanning provides continuous coverage mapping of forest canopy height and thereby is a powerful tool to scale-up above-ground biomass (AGB) estimates from stand to landscape. A critical first step is the selection of the plot variables which can be related to light detection and ranging (LiDAR) statistics. A universal approach was previously proposed which combines local and regional estimates of basal area (BA) and wood density with LiDAR-derived canopy height to map carbon at a regional scale (Asner et al. in Oecologia 168:1147-1160, 2012). Here we explore the contribution of stem diameter distribution, specific wood density and height-diameter (H-D) allometry to forest stand AGB and propose an alternative model. By applying the new model to a large tropical forest data set we show that an appropriate choice of input variables is essential to minimize prediction error of stand AGB which will propagate at larger scale. Stem number (N) and average stem cross-sectional area should be used instead of BA when scaling from tree to plot. Stand quadratic mean diameter above the census threshold diameter size should be preferred over stand mean diameter as it reduces the prediction error of stand AGB by a factor of ten. Wood density should be weighted by stem volume per species instead of BA. LiDAR-derived statistics should prove useful for estimating local H-D allometries as well as mapping N and the mean quadratic diameter above 10 cm at the landscape level. Prior stratification into forest types is likely to improve both estimation procedures significantly and is considered the foremost current challenge. PMID:24615493

  15. Airborne transmission of lyssaviruses.

    PubMed

    Johnson, N; Phillpotts, R; Fooks, A R

    2006-06-01

    In 2002, a Scottish bat conservationist developed a rabies-like disease and subsequently died. This was caused by infection with European bat lyssavirus 2 (EBLV-2), a virus closely related to Rabies virus (RABV). The source of this infection and the means of transmission have not yet been confirmed. In this study, the hypothesis that lyssaviruses, particularly RABV and the bat variant EBLV-2, might be transmitted via the airborne route was tested. Mice were challenged via direct introduction of lyssavirus into the nasal passages. Two hours after intranasal challenge with a mouse-adapted strain of RABV (Challenge Virus Standard), viral RNA was detectable in the tongue, lungs and stomach. All of the mice challenged by direct intranasal inoculation developed disease signs by 7 days post-infection. Two out of five mice challenged by direct intranasal inoculation of EBLV-2 developed disease between 16 and 19 days post-infection. In addition, a simple apparatus was evaluated in which mice could be exposed experimentally to infectious doses of lyssavirus from an aerosol. Using this approach, mice challenged with RABV, but not those challenged with EBLV-2, were highly susceptible to infection by inhalation. These data support the hypothesis that lyssaviruses, and RABV in particular, can be spread by airborne transmission in a dose-dependent manner. This could present a particular hazard to personnel exposed to aerosols of infectious RABV following accidental release in a laboratory environment. PMID:16687600

  16. Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

    NASA Technical Reports Server (NTRS)

    Abshire, James B.; Ramanathan, Anand; Riris, Haris; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Weaver, Clark J.; Browell, Edward V.

    2013-01-01

    We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5-6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s) matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2-3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were <1.4 ppm for flight measurement altitudes >6 km.

  17. Final report on passive and active low-frequency electromagnetic spectroscopy for airborne detection of underground facilities

    SciTech Connect

    SanFilipo, Bill

    2000-04-01

    The objective of this program is to perform research to advance the science in the application of both passive and active electromagnetic measurement techniques for the detection and spatial delineation of underground facilities. Passive techniques exploit the electromagnetic fields generated by electrical apparatus within the structure, including generators, motors, power distribution circuitry, as well as communications hardware and similar electronics equipment. Frequencies monitored are generally in the audio range (60-20,000 Hz), anticipating strong sources associated with normal AC power (i.e., 50 or 60 Hz and associated harmonics), and low frequency power from broad-band sources such as switching circuits. Measurements are made using receiver induction coils wired to electronics that digitize and record the voltage induced by the time varying magnetic fields. Active techniques employ electromagnetic field transmitters in the form of AC current carrying loops also in the audio frequency range, and receiving coils that measure the resultant time varying magnetic fields. These fields are perturbed from those expected in free space by any conductive material in the vicinity of the coils, including the ground, so that the total measured field is comprised of the primary free-space component and the secondary scattered component. The latter can be further delineated into an average background field (uniform conductive half-space earth) and anomalous field associated with heterogeneous zones in the earth, including both highly conductive objects such as metallic structures as well as highly resistive structures such as empty voids corresponding to rooms or tunnels. Work performed during Phase I included the development of the prototype GEM-2H instrumentation, collection of data at several test sites in the passive mode and a single site in the active mode, development of processing and interpretation software. The technical objectives of Phase II were to: (1

  18. Negotiating the Superwoman Minefield.

    ERIC Educational Resources Information Center

    Chambliss, Catherine

    Many women today expect themselves to be everything to everybody, simultaneously meeting the expectations of the workplace and the family. This multifaceted lifestyle usually entails trying to meet incompatible demands with the unavoidable outcome of stress. Learning better ways of managing this stress is imperative for both health and happiness.…

  19. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The characteristics of an Airborne Oceanographic Lidar (AOL) are given. The AOL system is described and its potential for various measurement applications including bathymetry and fluorosensing is discussed.

  20. Processing of GPR data from NIITEK landmine detection system

    NASA Astrophysics Data System (ADS)

    Legarsky, Justin J.; Broach, J. T.; Bishop, Steven S.

    2003-09-01

    In this paper, a signal processing approach for wide-bandwidth ground-penetrating-radar imagery from Non-Intrusive Inspection Technology, Incorporated (NIITEK) vehicle-mounted landmine detection sensor is investigated. The approach consists of a sequence of processing steps, which include signal filtering, image enhancement and detection. Filtering strategies before detection aid in image visualization by reducing ground bounce, systematic effects and redundant signals. Post-filter image processing helps by enhancing landmine signatures in the NIITEK radar imagery. Study results from applying this signal processing approach are presented for test minefield lane data, which were collected during 2002 from an Army test site.

  1. Geophex airborne unmanned survey system

    SciTech Connect

    Won, I.J.; Taylor, D.W.A.

    1995-03-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

  2. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.J.; Keiswetter, D.

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  3. Sandia Multispectral Airborne Lidar for UAV Deployment

    SciTech Connect

    Daniels, J.W.; Hargis,Jr. P.J.; Henson, T.D.; Jordan, J.D.; Lang, A.R.; Schmitt, R.L.

    1998-10-23

    Sandia National Laboratories has initiated the development of an airborne system for W laser remote sensing measurements. System applications include the detection of effluents associated with the proliferation of weapons of mass destruction and the detection of biological weapon aerosols. This paper discusses the status of the conceptual design development and plans for both the airborne payload (pointing and tracking, laser transmitter, and telescope receiver) and the Altus unmanned aerospace vehicle platform. Hardware design constraints necessary to maintain system weight, power, and volume limitations of the flight platform are identified.

  4. Adaptive Restoration of Airborne Daedalus AADS1268 ATM Thermal Data

    SciTech Connect

    D. Yuan; E. Doak; P. Guss; A. Will

    2002-01-01

    To incorporate the georegistration and restoration processes into airborne data processing in support of U.S. Department of Energy's nuclear emergency response task, we developed an adaptive restoration filter for airborne Daedalus AADS1268 ATM thermal data based on the Wiener filtering theory. Preliminary assessment shows that this filter enhances the detectability of small weak thermal anomalies in AADS1268 thermal images.

  5. Airborne microorganisms from waste containers.

    PubMed

    Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

    2012-01-01

    In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste. PMID:23047084

  6. Airborne GLM Simulator (FEGS)

    NASA Astrophysics Data System (ADS)

    Quick, M.; Blakeslee, R. J.; Christian, H. J., Jr.; Stewart, M. F.; Podgorny, S.; Corredor, D.

    2015-12-01

    Real time lightning observations have proven to be useful for advanced warning and now-casting of severe weather events. In anticipation of the launch of the Geostationary Lightning Mapper (GLM) onboard GOES-R that will provide continuous real time observations of total (both cloud and ground) lightning, the Fly's Eye GLM Simulator (FEGS) is in production. FEGS is an airborne instrument designed to provide cal/val measurements for GLM from high altitude aircraft. It consists of a 5 x 5 array of telescopes each with a narrow passband filter to isolate the 777.4 nm neutral oxygen emission triplet radiated by lightning. The telescopes will measure the optical radiance emitted by lightning that is transmitted through the cloud top with a temporal resolution of 10 μs. When integrated on the NASA ER-2 aircraft, the FEGS array with its 90° field-of-view will observe a cloud top area nearly equal to a single GLM pixel. This design will allow FEGS to determine the temporal and spatial variation of light that contributes to a GLM event detection. In addition to the primary telescope array, the instrument includes 5 supplementary optical channels that observe alternate spectral emission features and will enable the use of FEGS for interesting lightning physics applications. Here we present an up-to-date summary of the project and a description of its scientific applications.

  7. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  8. Airborne influenza virus detection with four aerosol samplers using molecular and infectivity assays: considerations for a new infectious virus aerosol sampler

    PubMed Central

    Fabian, P.; McDevitt, J. J.; Houseman, E. A.; Milton, D. K.

    2013-01-01

    As a first step in conducting studies of airborne influenza transmission, we compared the collection performance of an SKC Biosampler, a compact cascade impactor (CCI), Teflon filters, and gelatin filters by collecting aerosolized influenza virus in a one-pass aerosol chamber. Influenza virus infectivity was determined using a fluorescent focus assay and influenza virus nucleic acid (originating from viable and non-viable viruses) was measured using quantitative PCR. The results showed that the SKC Biosampler recovered and preserved influenza virus infectivity much better than the other samplers – the CCI, Teflon, and gelatin filters recovered only 7–22% of infectious viruses compared with the Biosampler. Total virus collection was not significantly different among the SKC Biosampler, the gelatin, and Teflon filters, but was significantly lower in the CCI. Results from this study show that a new sampler is needed for virus aerosol sampling, as commercially available samplers do not efficiently collect and conserve virus infectivity. Applications for a new sampler include studies of airborne disease transmission and bioterrorism monitoring. Design parameters for a new sampler include high collection efficiency for fine particles and liquid sampling media to preserve infectivity. PMID:19689447

  9. High sensitive airborne radioiodine monitor.

    PubMed

    Ogata, Yoshimune; Yamasaki, Tadashi; Hanafusa, Ryuji

    2013-11-01

    Airborne radioiodine monitoring includes a problem in that commercial radioactive gas monitors have inadequate sensitivity. To solve this problem, we designed a highly sensitive monitoring system. The higher counting efficiency and lower background made it possible to perform the low-level monitoring. The characteristics of the system were investigated using gaseous (125)I. The minimum detectable activity concentration was 1 × 10(-4)Bq cm(-3) for 1 min counting, which is one tenth of the legal limit for the radiation controlled areas in Japan. PMID:23602709

  10. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.L.; Keiswetter, D.

    1995-12-31

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

  11. The airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven; Schall, Harold; Shattuck, Paul

    2007-05-01

    The Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the current program status.

  12. Airborne simultaneous spectroscopic detection of laser-induced water Raman backscatter and fluorescence from chlorophyll a and other naturally occurring pigments.

    PubMed

    Hoge, F E; Swift, R N

    1981-09-15

    The airborne laser-induced spectral emission bands obtained simultaneously from water Raman backscatter and the fluorescence of chlorophyll and other naturally occurring waterborne pigments are reported here for the first time. The importance of this type data lies not only in its single-shot multispectral character but also in the application of the Raman line for correction or calibration of the spatial variation of the laser penetration depth without the need for in situ water attenuation measurements. The entire laser-induced fluorescence and Raman scatter emissions resulting from each separate 532-nm 10-nsec laser pulse are collected and spectrally dispersed in a diffraction grating spectrometer having forty photomultiplier tube detectors. Results from field experiments conducted in the North Sea and the Chesapeake Bay/Potomac River are presented. Difficulties involving the multispectral resolution of the induced emissions are addressed, and feasible solutions are suggested together with new instrument configurations and future research directions. PMID:20333121

  13. Airborne simultaneous spectroscopic detection of laser-induced water Raman backscatter and fluorescence from chlorophyll a and other naturally occurring pigments

    SciTech Connect

    Hoge, F.E.; Swift, R.N.

    1981-09-15

    The airborne laser-induced spectral emission bands obtained simultaneously from water Raman backscatter and the fluorescence of chlorophyll and other naturally occuring waterborne pigments are reported here for the first time. The importance of this type data lies not only in its single-shot multispectral character but also in the application of the Raman line for correction or calibration of the spatial variation of the laser penetration depth without the need for in situ water attenuation measurements. The entire laser-induced fluorescence and Raman scatter emissions resulting from each separate 532-nm 10-nsec laser pulse are collected and spectrally dispersed in a diffraction grating spectrometer having forty photomultiplier tube detectors. Results from field experiments conducted in the North Sea and the Chesapeake Bay/Potomac River are presented. Difficulties involving the multispectral resolution of the induced emissions are addressed, and feasible solutions are suggested together with new instrument configurations and future research directions.

  14. 18S rRNA Gene Variation among Common Airborne Fungi, and Development of Specific Oligonucleotide Probes for the Detection of Fungal Isolates

    PubMed Central

    Wu, Zhihong; Tsumura, Yoshihiko; Blomquist, Göran; Wang, Xiao-Ru

    2003-01-01

    In this study, we sequenced 18S rRNA genes (rDNA) from 49 fungal strains representing 31 species from 15 genera. Most of these species are common airborne fungi and pathogens that may cause various public health concerns. Sequence analysis revealed distinct divergence between Zygomycota and Ascomycota. Within Ascomycota, several strongly supported clades were identified that facilitate the taxonomic placement of several little-studied fungi. Wallemia appeared as the group most diverged from all the other Ascomycota species. Based on the 18S rDNA sequence variation, 108 oligonucleotide probes were designed for each genus and species included in this study. After homology searches and DNA hybridization evaluations, 33 probes were verified as genus or species specific. The optimal hybridization temperatures to achieve the best specificity for these 33 probes were determined. These new probes can contribute to the molecular diagnostic research for environmental monitoring. PMID:12957927

  15. Airborne simultaneous spectroscopic detection of laser-induced water Raman backscatter and fluorescence from chlorophyll a and other naturally occurring pigments

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.

    1981-01-01

    The airborne laser-induced spectral emission bands obtained simultaneously from water Raman backscatter and the fluorescence of chlorophyll and other naturally occurring waterborne pigments are reported here for the first time. The importance of this type data lies not only in its single-shot multispectral character but also in the application of the Raman line for correction or calibration of the spatial variation of the laser penetration depth without the need for in situ water attenuation measurements. The entire laser-induced fluorescence and Raman scatter emissions resulting from each separate 532-nm 10-nsec laser pulse are collected and spectrally dispersed in a diffraction grating spectrometer having forty photomultiplier tube detectors. Results from field experiments conducted in the North Sea and the Chesapeake Bay/Potomac River are presented. Difficulties involving the multispectral resolution of the induced emissions are addressed, and feasible solutions are suggested together with new instrument configurations and future research directions.

  16. Airborne Microalgae: Insights, Opportunities, and Challenges.

    PubMed

    Tesson, Sylvie V M; Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-04-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  17. Airborne pollen trends in the Iberian Peninsula.

    PubMed

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants. PMID:26803684

  18. Airborne Microalgae: Insights, Opportunities, and Challenges

    PubMed Central

    Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-01-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  19. Airborne laser communication technology and flight test

    NASA Astrophysics Data System (ADS)

    Meng, Li-xin; Zhang, Li-zhong; Li, Xiao-ming; Li, Ying-chao; Jiang, Hui-lin

    2015-11-01

    Reconnaissance aircraft is an important node of the space-air-ground integrated information network, on which equipped with a large number of high-resolution surveillance equipment, and need high speed communications equipment to transmit detected information in real time. Currently RF communication methods cannot meet the needs of communication bandwidth. Wireless laser communication has outstanding advantages high speed, high capacity, security, etc., is an important means to solve the high-speed information transmission of airborne platforms. In this paper, detailed analysis of how the system works, the system components, work processes, link power and the key technologies of airborne laser communication were discussed. On this basis, a prototype airborne laser communications was developed, and high-speed, long-distance communications tests were carried out between the two fixed-wing aircraft, and the airborne precision aiming, atmospheric laser communication impacts on laser communication were tested. The experiments ultimately realize that, the communication distance is 144km, the communication rate is 2.5Gbps. The Airborne laser communication experiments provide technical basis for the application of the conversion equipment.

  20. Simulation system of airborne FLIR searcher

    NASA Astrophysics Data System (ADS)

    Sun, Kefeng; Li, Yu; Gao, Jiaobo; Wang, Jun; Wang, Jilong; Xie, Junhu; Ding, Na; Sun, Dandan

    2014-11-01

    Airborne Forward looking infra-red (FLIR) searcher simulation system can provide multi-mode simulated test environment that almost actual field environment, and can simulate integrated performance and external interface of airborne FLIR simulation system. Furthermore, the airborne FLIR searcher simulation system can support the algorithm optimization of image processing, and support the test and evaluation of electro-optical system, and also support the line test of software and evaluate the performance of the avionics system. The detailed design structure and information cross-linking relationship of each component are given in this paper. The simulation system is composed of the simulation center, the FLIR actuator, the FLIR emulator, and the display control terminal. The simulation center can generate the simulated target and aircraft flying data in the operation state of the airborne FLIR Searcher. The FLIR actuator can provide simulation scene. It can generate the infrared target and landform based scanning scene, response to the commands from simulation center and the FLIR actuator and operation control unit. The infrared image generated by the FLIR actuator can be processed by the FLIR emulator using PowerPC hardware framework and processing software based on VxWorks system. It can detect multi-target and output the DVI video and the multi-target detection information which corresponds to the working state of the FLIR searcher. Display control terminal can display the multi-target detection information in two-dimension situation format, and realize human-computer interaction function.

  1. First airborne pathogen direct analysis system.

    PubMed

    Liu, Qi; Zhang, Yuxiao; Jing, Wenwen; Liu, Sixiu; Zhang, Dawei; Sui, Guodong

    2016-03-01

    We report a portable "sample to answer" system for the rapid detection of airborne pathogens for the first time. The system contains a key microfluidic chip which fulfills both pathogen enrichment and biological identification functions. The system realizes simple operation and less human intervention as well as minimum reagent contamination. The operation is user-friendly and suitable for field and point-of-care applications. The system is capable of handling detection of different pathogens by changing the primers. PMID:26854120

  2. The Airborne Laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-09-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  3. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Specifications and preliminary design of an Airborne Oceanographic Lidar (AOL) system, which is to be constructed for installation and used on a NASA Wallops Flight Center (WFC) C-54 research aircraft, are reported. The AOL system is to provide an airborne facility for use by various government agencies to demonstrate the utility and practicality of hardware of this type in the wide area collection of oceanographic data on an operational basis. System measurement and performance requirements are presented, followed by a description of the conceptual system approach and the considerations attendant to its development. System performance calculations are addressed, and the system specifications and preliminary design are presented and discussed.

  4. Compact Highly Sensitive Multi-species Airborne Mid-IR Spectrometer

    SciTech Connect

    Richter, Dirk; Weibring, P.; Walega, J.; Fried, Alan; Spuler, Scott M.; Taubman, Matthew S.

    2015-02-01

    We report on the development and airborne field deployment of a mid-IR laser based spectrometer. The instrument was configured for the simultaneous in-situ detection of formaldehyde (CH2O) and ethane (C2H6). Numerous mechanical, optical, electronic, and software improvements over a previous instrument design resulted in reliable highly sensitive airborne operation with long stability times yielding 90% airborne measurement coverage during the recent air quality study over the Colorado front range, FRAPPÉ 2014. Airborne detection sensitivities of ~ 15 pptv (C2H6) and ~40 pptv (CH2O) were generally obtained for 1 s of averaging for simultaneous detection.

  5. Investigation of the cross-ship comparison monitoring method of failure detection in the HIMAT RPRV. [digital control techniques using airborne microprocessors

    NASA Technical Reports Server (NTRS)

    Wolf, J. A.

    1978-01-01

    The Highly maneuverable aircraft technology (HIMAT) remotely piloted research vehicle (RPRV) uses cross-ship comparison monitoring of the actuator RAM positions to detect a failure in the aileron, canard, and elevator control surface servosystems. Some possible sources of nuisance trips for this failure detection technique are analyzed. A FORTRAN model of the simplex servosystems and the failure detection technique were utilized to provide a convenient means of changing parameters and introducing system noise. The sensitivity of the technique to differences between servosystems and operating conditions was determined. The cross-ship comparison monitoring method presently appears to be marginal in its capability to detect an actual failure and to withstand nuisance trips.

  6. NASA Airborne Lidar July 1991

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar July 1991 Data from the 1991 NASA Langley Airborne Lidar flights following the eruption of Pinatubo in July ... and Osborn [1992a, 1992b]. Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  7. NASA Airborne Lidar May 1992

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar May 1992 An airborne Nd:YAG (532 nm) lidar was operated by the NASA Langley Research Center about a year following the June 1991 eruption of ... Osborn [1992a, 1992b].  Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  8. Airborne Gravity Measurements using a Helicopter with Special Emphases on Delineating Local Gravity Anomalies Mainly for Detecting Active Seismic Faults (Invited)

    NASA Astrophysics Data System (ADS)

    Segawa, J.

    2010-12-01

    The first aerial gravity measurement in Japan started in 1998 using a Japanese airborne gravimeter ‘ Segawa-TKeiki airborne gravimeter Model FGA-1’. We lay emphasis on the measurement of detailed gravity structures at the land-to-sea border areas and mountainous areas. This is the reason why we use a helicopter and make surveys at low altitude and low speed. We have so far made measurement at twelve sites and the total flight amounts to 20,000km. The accuracy of measurement is 1.5 mgal and half-wavelength resolution is 1.5 km. The Japanese type gravimeter consists of a servo-accelerometer type gravity sensor, a horizontal platform controlled by an optical fiber gyro, GPS positioning system, and a data processing system. Helicopter movement has to be precisely monitored three-dimensionally to calculate the vehicle’s acceleration noises. The necessary accuracy of positioning of the vehicle must be better than 10 cm in positioning error. Our helicopter gravity measurement has a special target in Japan to investigate active seismic faults located across land-to-sea borderlines. In Japan, it is generally thought that gravity over most of the country has already been measured by the governmental surveys, leaving the land-sea border lines and mountainous zones unsurveyed as difficult-to-access areas. In addition the use of airplane or helicopter in Japan appeared disadvantageous because of the narrowness of the Japanese Islands. Under such situations the author thought there still remained a particular as well as unique need for aerial gravity measurement in Japan, i.e. the need for detailed and seamless knowledge of gravity structures across land-to-sea border lines to elucidate complicated crustal structures of the Japanese Islands as well as distribution of active seismic faults for disaster prevention. The results of gravity measurements we have conducted so far include those of 12 sites. In the following the brief logs of our measurements are listed. 1)April

  9. A novel approach for speciation of airborne chromium by convective-interaction media fast-monolithic chromatography with electrothermal atomic-absorption spectrometric detection.

    PubMed

    Scancar, Janez; Milacic, Radmila

    2002-05-01

    A new analytical procedure using an anion-exchange separation support based on convective-interaction media (CIM) was developed for the speciation of chromium. The separation of Cr(VI) was performed on a weak anion-exchange CIM diethylamine (DEAE) fast-monolithic chromatographic disc. Buffer A (0.005 mol dm(-3) TRIS-HCl, pH 8.0) and buffer B (buffer A plus 3 mol dm(-3) NH4NO3) were employed in the separation procedure. The separated chromium species were determined 'off-line' by ETAAS in 0.5 cm3 fractions. The applicability of the CIM DEAE-ETAAS procedure was investigated for the determination of airborne Cr(VI) at a plasma cutting workplace. Aerosols were collected on polycarbonate membrane filters of 8 and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction of filters in a heated ultrasonic bath was applied to leach chromium. Good repeatability of measurement (+/-3.0%) of the alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.30 microg m(-3) Cr(VI), when 0.25 m3 of air was collected on the filter. The validation of the procedure was performed by spiking filters with Cr(VI) and by the analysis of the standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. Good recoveries for spiked samples (101-102%) and good agreement between Cr(VI) found and the reported certified value for CRM 545 were obtained. The extracts were also analysed by the FPLC-ETAAS technique. Good agreement between two techniques (r2 = 0.9978) confirmed the reliability of the CIM DEAE-ETAAS procedure developed. The main advantage of the procedure lies in the speed of the chromatographic separation (chromatographic run completed in 15 min). PMID:12081040

  10. Joint multisensor exploitation for mine detection

    NASA Astrophysics Data System (ADS)

    Beaven, Scott G.; Stocker, Alan D.; Winter, Edwin M.

    2004-09-01

    Robust, timely, and remote detection of mines and minefields is central to both tactical and humanitarian demining efforts, yet remains elusive for single-sensor systems. Here we present an approach to jointly exploit multisensor data for detection of mines from remotely sensed imagery. LWIR, MWIR, laser, multispectral, and radar sensor have been applied individually to the mine detection and each has shown promise for supporting automated detection. However, none of these sources individually provides a full solution for automated mine detection under all expected mine, background and environmental conditions. Under support from Night Vision and Electronic Sensors Directorate (NVESD) we have developed an approach that, through joint exploitation of multiple sensors, improves detection performance over that achieved from a single sensor. In this paper we describe the joint exploitation method, which is based on fundamental detection theoretic principles, demonstrate the strength of the approach on imagery from minefields, and discuss extensions of the method to additional sensing modalities. The approach uses pre-threshold anomaly detector outputs to formulate accurate models for marginal and joint statistics across multiple detection or sensor features. This joint decision space is modeled and decision boundaries are computed from measured statistics. Since the approach adapts the decision criteria based on the measured statistics and no prior target training information is used, it provides a robust multi-algorithm or multisensor detection statistic. Results from the joint exploitation processing using two different imaging sensors over surface mines acquired by NVESD will be presented to illustrate the process. The potential of the approach to incorporate additional sensor sources, such as radar, multispectral and hyperspectral imagery is also illustrated.

  11. Airborne antenna pattern calculations

    NASA Technical Reports Server (NTRS)

    Knerr, T. J.; Schaffner, P. R.; Mielke, R. R.; Gilreath, M. C.

    1980-01-01

    A procedure for numerically calculating radiation patterns of fuselage-mounted airborne antennas using the Volumetric Pattern Analysis Program is presented. Special attention is given to aircraft modeling. An actual case study involving a large commercial aircraft is included to illustrate the analysis procedure.

  12. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

    The heating, ventilating, and air conditioning (HVAC) systems in older buildings often do not adequately handle air-borne contaminants. Outlines a three-stage Indoor Air Quality (IAQ) assessment and describes a case in point at a Pittsburgh, Pennsylvania, school. (MLF)

  13. Airborne Fraunhofer Line Discriminator

    NASA Technical Reports Server (NTRS)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  14. Apparatus and method for automated monitoring of airborne bacterial spores

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian (Inventor)

    2009-01-01

    An apparatus and method for automated monitoring of airborne bacterial spores. The apparatus is provided with an air sampler, a surface for capturing airborne spores, a thermal lysis unit to release DPA from bacterial spores, a source of lanthanide ions, and a spectrometer for excitation and detection of the characteristic fluorescence of the aromatic molecules in bacterial spores complexed with lanthanide ions. In accordance with the method: computer-programmed steps allow for automation of the apparatus for the monitoring of airborne bacterial spores.

  15. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  16. Improved Instrumentation for the Detection of Atmospheric CO2 Concentration using an Airborne IPDA LIDAR for 2014 NASA ASCENDS Science Campaign

    NASA Astrophysics Data System (ADS)

    Allan, G. R.; Riris, H.; Hasselbrack, W. E.; Rodriguez, M.; Ramanathan, A. K.; Sun, X.; Mao, J.; Abshire, J. B.

    2014-12-01

    NASA-GSFC is developing a twin-channel, Integrated-Path, Differential Absorption (IPDA) lidar to measure atmospheric CO2 from space as a candidate for NASA's ASCENDS mission (Active Sensing of CO2 Emissions over Nights, Days, and Seasons). This lidar consists of two independent, tuned, pulsed transmitters on the same optical bench using a common 8" receiver telescope. The system measures CO2 abundance and O2 surface pressure in the same column to derive the dry volume mixing ratio (vmr). The system is being tested on an airborne platform up to altitudes of 13 Km. The lidar uses a cw scanning laser, externally pulsed and a fiber amplifier in a Master Oscillator Power Amplifier (MOPA) configuration to measure lineshape, range to scattering surfaces and backscatter profiles. The CO2 operates at 1572.335 nm. The O2 channel uses similar technology but frequency doubles to the O2 A-band absorption, around 765nm. Both lasers are scanned across the absorption feature measuring at a fixed number of discrete (~30) wavelengths per scan around ~300 scans/s. Each output pulse is slightly chirped <12MHz as the laser is tuning. Removing this chirp will improve our ability to infer vertical CO2 distribution from a more accurately measured line shape. A Step Tuned Frequency Locked (STFL) DBR diode laser system has been integrated into the CO2 lidar. Tuning and locking takes a ~30μs and the laser is locked to < ±100KHz. We have the ability to position these pulses anywhere on the absorption line other than within a few MHz of line center. While the telescope and fiber coupling scheme remains unchanged the detectors have been upgraded. The O2 system now uses eight SPCMs in parallel to improve count rates and increase dynamic range. Especially useful when flying over bright surfaces. This will improve our ability to measure the O2 pressure at cloud tops and aid in the determining the vmr above clouds. An HgCdTe e-APD detector with a quantum efficient of >80%, linear over five

  17. Exposure level and distribution characteristics of airborne bacteria and fungi in Seoul metropolitan subway stations.

    PubMed

    Kim, Ki Youn; Kim, Yoon Shin; Kim, Daekeun; Kim, Hyeon Tae

    2011-01-01

    The exposure level and distribution characteristics of airborne bacteria and fungi were assessed in the workers' activity areas (station office, bedroom, ticket office and driver's seat) and passengers' activity areas (station precinct, inside the passenger carriage, and platform) of the Seoul metropolitan subway. Among investigated areas, the levels of airborne bacteria and fungi in the workers' bedroom and station precincts were relatively high. No significant difference was found in the concentration of airborne bacteria and fungi between the underground and above ground activity areas of the subway. The genera identified in all subway activity areas with a 5% or greater detection rate were Staphylococcus, Micrococcus, Bacillus and Corynebacterium for airborne bacteria and Penicillium, Cladosporium, Chrysosporium, Aspergillus for airborne fungi. Staphylococcus and Micrococcus comprised over 50% of the total airborne bacteria and Penicillium and Cladosporium comprised over 60% of the total airborne fungi, thus these four genera are the predominant genera in the subway station. PMID:21173524

  18. An examination of the application of space time adaptive processing for the detection of maritime surface targets from high altitude airborne platforms

    NASA Astrophysics Data System (ADS)

    McDonald, Michael; Cerutti-Maori, Delphine

    2013-09-01

    An examination of the application of Space Time Adaptive Processing (STAP) techniques to real, multi-channel, medium grazing angle, radar sea clutter data is undertaken and the detection performance is quantified against simulated moving maritime surface targets. The application of sub-optimal STAP approaches to the maritime radar detection problem is shown to be complicated by non-stationarity of sea clutter and rapid variations of the sea clutter spectrum due to transient wave activity. Observed performance gains from maritime STAP are much more limited than those observed for Ground Moving Target Indication (GMTI) due to the inherent spectral width of sea clutter and the slow Doppler velocities of maritime targets. Three sub-optimal STAP processing architectures are examined and PRI-Staggered Post-Doppler is shown to provide consistently superior detection performance for the data set in question.

  19. The Caltech airborne submillimeter SIS receiver

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, Jonas; Carlstrom, J.; Miller, D.; Ugras, N. G.

    1995-01-01

    We have constructed a sensitive submillimeter receiver for the NASA Kuiper Airborne Observatory (KAO) which at present operates in the 500-750 GHz band. The DSB receiver noise temperature is about 5 h nu/k(sub B) over the 500-700 GHz range. This receiver has been used to detect H2O(18)O, HCl, and CH in interstellar molecular clouds, and also to search for C(+) emission from the highly redshifted galaxy (z = 2.3) IRAS 10214.

  20. On the integration of Airborne full-waveform laser scanning and optical imagery for Site Detection and Mapping: Monteserico study case

    NASA Astrophysics Data System (ADS)

    Coluzzi, R.; Guariglia, A.; Lacovara, B.; Lasaponara, R.; Masini, N.

    2009-04-01

    This paper analyses the capability of airborne LiDAR derived data in the recognition of archaeological marks. It also evaluates the benefits to integrate them with aerial photos and very high resolution satellite imagery. The selected test site is Monteserico, a medieval village located on a pastureland hill in the North East of Basilicata (Southern Italy). The site, attested by documentary sources beginning from the 12th century, was discovered by aerial survey in 1996 [1] and investigated in 2005 by using QuickBird imagery [2]. The only architectural evidence is a castle, built on the western top of the hill; whereas on the southern side, earthenware, pottery and crumbling building materials, related to the medieval settlement, could be observed. From a geological point of view, the stratigraphic sequence is composed of Subappennine Clays, Monte Marano sands and Irsina conglomerates. Sporadic herbaceous plants grow over the investigated area. For the purpose of this study, a full-waveform laser scanning with a 240.000 Hz frequency was used. The average point density value of dataset is about 30 points/m2. The final product is a 0.30 m Digital Surface Models (DSMs) accurately modelled. To derive the DSM the point cloud of the ALS was filtered and then classified by applying appropriate algorithms. In this way surface relief and archaeological features were surveyed with great detail. The DSM was compared with other remote sensing data source such as oblique and nadiral aerial photos and QuickBird imagery, acquired in different time. In this way it was possible to evaluate, compare each other and overlay the archaeological features recorded from each data source (aerial, satellite and lidar). Lidar data showed some interesting results. In particular, they allowed for identifying and recording differences in height on the ground produced by surface and shallow archaeological remains (the so-called shadow marks). Most of these features are visible also by the optical

  1. Airborne Instruments for the In Situ Detection of ClONO2, NO2, ClO, and BrO in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Anderson, James G.

    1999-01-01

    The objective of the research supported by this grant was the development of a new instrument to both further the technology of small, lightweight instruments for robotic aircraft and to achieve the ability to detect ClONO2, NO2, ClO and BrO from the NASA ER-2 aircraft. All of these objectives were accomplished.

  2. [Air-borne disease].

    PubMed

    Lameiro Vilariño, Carmen; del Campo Pérez, Victor M; Alonso Bürger, Susana; Felpeto Nodar, Irene; Guimarey Pérez, Rosa; Pérez Alvarellos, Alberto

    2003-11-01

    Respiratory protection is a factor which worries nursing professionals who take care of patients susceptible of transmitting microorganisms through the air more as every day passes. This type of protection covers the use of surgical or hygienic masks against the transmission of infection by airborne drops to the use of highly effective masks or respirators against the transmission of airborne diseases such as tuberculosis or SARS, a recently discovered disease. The adequate choice of this protective device and its correct use are fundamental in order to have an effective protection for exposed personnel. The authors summarize the main protective respiratory devices used by health workers, their characteristics and degree of effectiveness, as well as the circumstances under which each device is indicated for use. PMID:14705591

  3. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  4. MLS airborne antenna research

    NASA Technical Reports Server (NTRS)

    Yu, C. L.; Burnside, W. D.

    1975-01-01

    The geometrical theory of diffraction was used to analyze the elevation plane pattern of on-aircraft antennas. The radiation patterns for basic elements (infinitesimal dipole, circumferential and axial slot) mounted on fuselage of various aircrafts with or without radome included were calculated and compared well with experimental results. Error phase plots were also presented. The effects of radiation patterns and error phase plots on the polarization selection for the MLS airborne antenna are discussed.

  5. Airborne field strength monitoring

    NASA Astrophysics Data System (ADS)

    Bredemeyer, J.; Kleine-Ostmann, T.; Schrader, T.; Münter, K.; Ritter, J.

    2007-06-01

    In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

  6. Mutagenicity of airborne particles.

    PubMed

    Chrisp, C E; Fisher, G L

    1980-09-01

    The physical and chemical properties of airborne particles are important for the interpretation of their potential biologic significance as genotoxic hazards. For polydisperse particle size distributions, the smallest, most respirable particles are generally the most mutagenic. Particulate collection for testing purposes should be designed to reduce artifact formation and allow condensation of mutagenic compounds. Other critical factors such as UV irradiation, wind direction, chemical reactivity, humidity, sample storage, and temperature of combustion are important. Application of chemical extraction methods and subsequent class fractionation techniques influence the observed mutagenic activity. Particles from urban air, coal fly ash, automobile and diesel exhaust, agricultural burning and welding fumes contain primarily direct-acting mutagens. Cigarette smoke condensate, smoke from charred meat and protein pyrolysates, kerosene soot and cigarette smoke condensates contain primarily mutagens which require metabolic activation. Fractionation coupled with mutagenicity testing indicates that the most potent mutagens are found in the acidic fractions of urban air, coal fly ash, and automobile diesel exhaust, whereas mutagens in rice straw smoke and cigarette smoke condensate are found primarily in the basic fractions. The interaction of the many chemical compounds in complex mixtures from airborne particles is likely to be important in determining mutagenic or comutagenic potentials. Because the mode of exposure is generally frequent and prolonged, the presence of tumor-promoting agents in complex mixtures may be a major factor in evaluation of the carcinogenic potential of airborne particles. PMID:7005667

  7. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D.; Schmitt, Michael J.; Jones, Warren F.

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  8. Airborne Instruments for the In Situ Detection of ClONO2, NO2, ClO, and BrO in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Anderson, James G.

    1999-01-01

    The objective of the research was the development of a new small, lightweight instrument for the detection of ClONO2, NO2, ClO, and BrO, carried aboard a robotic aircraft, specifically the NASA ER-2. The schematic of the instrument is shown. Some of the observations which this instrument is designed to make are discussed. The observations of the instrument during the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) mission are also reviewed.

  9. Airborne laser sensors and integrated systems

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  10. Canadian landmine detection research program

    NASA Astrophysics Data System (ADS)

    McFee, John E.; Das, Yogadhish; Faust, Anthony A.

    2003-09-01

    Defence R&D Canada (DRDC), an agency within the Department of National Defence, has been conducting research and development (R&D) on the detection of landmines for countermine operations and of unexploded ordnance (UXO) for range clearance since 1975. The Canadian Centre for Mine Action Technologies (CCMAT), located at DRDC Suffield, was formed in 1998 to carry out R&D related to humanitarian demining. The lead group responsible for formulating and executing both countermine and humanitarian R&D programs in detection is the Threat Detection Group at DRDC Suffield. This paper describes R&D for both programs under the major headings of remote minefield detection, close-in scanning detection, confirmation detection and teleoperated systems. Among DRDC's achievements in landmine and UXO detection R&D are pioneering work in electromagnetic and magnetic identification and classification; the first military-fielded multisensor, teleoperated vehicle-mounted landmine detection system; pioneering use of confirmation detectors for multisensor landmine detection systems; the first fielded thermal neutron activation landmine confirmation sensor; the first detection of landmines using a real-time hyperspectral imager; electrical impedance imaging detection of landmines and UXO and a unique neutron backscatter landmine imager.

  11. Airborne Submillimeter Spectroscopy

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    1998-01-01

    This is the final technical report for NASA-Ames grant NAG2-1068 to Caltech, entitled "Airborne Submillimeter Spectroscopy", which extended over the period May 1, 1996 through January 31, 1998. The grant was funded by the NASA airborne astronomy program, during a period of time after the Kuiper Airborne Observatory was no longer operational. Instead. this funding program was intended to help develop instrument concepts and technology for the upcoming SOFIA (Stratospheric Observatory for Infrared Astronomy) project. SOFIA, which is funded by NASA and is now being carried out by a consortium lead by USRA (Universities Space Research Association), will be a 747 aircraft carrying a 2.5 meter diameter telescope. The purpose of our grant was to fund the ongoing development of sensitive heterodyne receivers for the submillimeter band (500-1200 GHz), using sensitive superconducting (SIS) detectors. In 1997 July we submitted a proposal to USRA to construct a heterodyne instrument for SOFIA. Our proposal was successful [1], and we are now continuing our airborne astronomy effort with funding from USRA. A secondary purpose of the NAG2-1068 grant was to continue the anaIN'sis of astronomical data collected with an earlier instrument which was flown on the NASA Kuiper Airborne Observatory (KAO). The KAO instrument and the astronomical studies which were carried out with it were supported primarily under another grant, NAG2-744, which extended over October 1, 1991 through Januarv 31, 1997. For a complete description of the astronomical data and its anailysis, we refer the reader to the final technical report for NAG2-744, which was submitted to NASA on December 1. 1997. Here we report on the SIS detector development effort for SOFIA carried out under NAG2-1068. The main result of this effort has been the demonstration of SIS mixers using a new superconducting material niobium titanium nitride (NbTiN), which promises to deliver dramatic improvements in sensitivity in the 700

  12. Proteomic analysis of the differentially expressed proteins by airborne nanoparticles.

    PubMed

    Park, Seul Ki; Jeon, Yu Mi; Son, Bu Soon; Youn, Hyung Sun; Lee, Mi Young

    2011-07-01

    Airborne nanoparticles with thermodynamic diameters less than 56 nm (PM(0.056)) were collected using a Moudi cascade impactor, and the differentially expressed proteins upon exposure to the airborne nanoparticles were identified in human bronchial epithelial cells. More than 600 protein spots were detected on the two-dimensional gel, and the identified 13 of these proteins showed notable changes. Nine were up-regulated and four were down-regulated following treatment with the airborne nanoparticles. Notably, malignant transformation-associated multiple forms of keratins, epigenetic regulation-related MBD1-containing chromatin associated factor 2, epithelial malignancy-related vimentin and exocytosis-related annexin A2 were changed upon exposure to airborne nanoparticle PM(0.056). PMID:21491466

  13. Airborne Instruments for the In Situ Detection of ClONO2, NO2, ClO, and BrO in the Stratosphere

    NASA Technical Reports Server (NTRS)

    Anderson, James G.; Cohen, Ronald C.

    1996-01-01

    Design and construction of an in situ sensor for the detection of stratospheric ClONO2, ClO, BrO, and NO2, was conceived as a two-year program. The experiment has two novel components: a resistive silicon thermal dissociation heater used to fragment ClONO2 into ClO and NO2 and a laser-induced fluorescence sensor for N02. These two new components are integrated into an experiment that uses technology developed in our labs for the ER-2 ClO and ER-2 HO(X) instruments. During the first year we reconstructed our laboratory prototypes for ClONO2 and NO2 detection and made substantial improvements in the calibration apparatus. Results from these laboratory experiments have been used to refine the design of the flight instrument. During this year we began the design of all of the long-lead items required to produce a flight instrument: including the design and fabrication of the air flow system used to direct stratospheric air to our halogen sensors, design and prototyping of an aircraft-compatible thermal dissociation heater, and development and test of a new high powered laser system. Finally, we have designed and released for fabrication several subsystems.

  14. Landmine-detection rats: an evaluation of reinforcement procedures under simulated operational conditions.

    PubMed

    Mahoney, Amanda; Lalonde, Kate; Edwards, Timothy; Cox, Christophe; Weetjens, Bart; Poling, Alan

    2014-05-01

    Because the location of landmines is initially unknown, it is impossible to arrange differential reinforcement for accurate detection of landmines by pouched rats working on actual minefields. Therefore, provision must be made for maintenance of accurate responses by an alternative reinforcement strategy. The present experiment evaluated a procedure in which a plastic bag containing 2,4,6-trinitrotoluene (TNT), the active ingredient in most landmines, was placed in contact with the ground in a disturbed area, then removed, to establish opportunities for reinforcement. Each of five rats continued to accurately detect landmines when extinction was arranged for landmine-detection responses and detections of TNT-contaminated locations were reinforced under a fixed-ratio 1 schedule. The results of this translational research study suggest that the TNT-contamination procedure is a viable option for arranging reinforcement opportunities for rats engaged in actual landmine-detection activities and the viability of this procedure is currently being evaluated on minefields in Angola and Mozambique. PMID:24676627

  15. Reduction of mine suspected areas by multisensor airborne measurements: first results

    NASA Astrophysics Data System (ADS)

    Keller, Martin; Milisavljevic, Nada; Suess, Helmut; Acheroy, Marc P. J.

    2002-08-01

    Humanitarian demining is a very dangerous, cost and time intensive work, where a lot of effort is usually wasted in inspecting suspected areas that turn out to be mine-free. The main goal of the project SMART (Space and airborne Mined Area Reduction Tools) is to apply a multisensor approach towards corresponding signature data collection, developing adapted data understanding and data processing tools for improving the efficiency and reliability of level 1 minefield surveys by reducing suspected mined areas. As a result, the time for releasing mine-free areas for civilian use should be shortened. In this paper, multisensor signature data collected at four mine suspected areas in different parts of Croatia are presented, their information content is discussed, and first results are described. The multisensor system consists of a multifrequency multipolarization SAR system (DLR Experimental Synthetic Aperture Radar E-SAR), an optical scanner (Daedalus) and a camera (RMK) for color infrared aerial views. E-SAR data were acquired in X-, C-, L- and P- bands, the latter two being fully polarimetric interferometric. This provides pieces of independent information, ranging from high spatial resolution (X-band) to very good penetration abilities (P-band), together with possibilities for polarimetric and interferometric analysis. The Daedalus scanner, with 12 channels between visible and thermal infrared, has a very high spatial resolution. For each of the sensors, the applied processing, geocoding and registration is described. The information content is analyzed in sense of the capability and reliability in describing conditions inside suspected mined areas, as a first step towards identifying their mine-free parts, with special emphasis set on polarimetric and interferometric information.

  16. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The Airborne Oceanographic Lidar (AOL), a spatially scanning range-gated device installed on board a NASA C-54 aircraft, is described. The AOL system is capable of measuring topographical relief or water depth (bathymetry) with a range resolution of plus or minus 0.3 m in the vertical dimension. The system may also be used to measure fluorescent spectral signatures from 3500 to 8000 A with a resolution of 100 A. Potential applications of the AOL, including sea state measurements, water transparency assessments, oil spill identification, effluent identification and crop cover assessment are also mentioned.

  17. Traversing the Lexical Cohesion Minefield

    ERIC Educational Resources Information Center

    McGee, Iain

    2009-01-01

    When teachers hear the word "cohesion", they usually think of grammatical cohesion--an aspect of cohesion reasonably well covered in student books and teacher materials. However, occupying an area that straddles both lexis "proper" and cohesion lies "lexical cohesion". In what follows, it is argued that the teaching and learning of certain aspects…

  18. Airborne ballistic camera tracking systems

    NASA Technical Reports Server (NTRS)

    Redish, W. L.

    1976-01-01

    An operational airborne ballistic camera tracking system was tested for operational and data reduction feasibility. The acquisition and data processing requirements of the system are discussed. Suggestions for future improvements are also noted. A description of the data reduction mathematics is outlined. Results from a successful reentry test mission are tabulated. The test mission indicated that airborne ballistic camera tracking systems are feasible.

  19. BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

    SciTech Connect

    Steele, P T

    2004-07-20

    Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. A statistical model has been developed to make these decisions and the resulting performance of a hypothetical BAMS system is quantitatively predicted. The predictions indicate that a BAMS system, with reasonably attainable characteristics, can operate with a very low false alarm rate (orders of magnitude lower than some currently fielded biodetectors) while still being sensitive to small concentrations of biological particles in a large range of environments. Proof-of-concept instruments, incorporating some of the modifications described here, have already performed well in independent testing.

  20. Integration of fuzzy logic and image analysis for the detection of gullies in the Calhoun critical zone observatory using airborne LiDAR data

    NASA Astrophysics Data System (ADS)

    Bastola, S.; Noto, L. V.; Dialynas, Y. G.; Bras, R. L.

    2015-12-01

    The entire Piedmont of the Southeastern United States, where the Calhoun Critical Zone Observatory (CCZO) is located, experienced one of the most severe erosive events in the United States during last two centuries. Forested areas were cleared to cultivate cotton, tobacco and other crops during the nineteenth and early twentieth century and these land use change, together with intense rainfalls, initiated deep gullying. An accurate mapping of these landforms is important since, despite some gully stabilization and reforestation efforts, gullies are still major contributors of sediment to streams. Mapping gullies in the CCZO area is hindered by the presence of dense canopy which precludes the identification through aerial photogrammetry and other traditional remote sensing methods. Moreover, the wide spatial extent of the gullies makes detailed field surveys, for the identification and characterization of entire gullies, a very large and expensive proposition. This work aims to develop and assess an automated set of algorithms to detect and map gullies using morphological characteristics retrieved by very high resolution imagery (VHRI). A one-meter resolution LiDAR DEM is used to derive different morphometric indices whose combination, carried out using spatial analysis methods and fuzzy logic rules, are a tool to identify gullies. This spatial model has been calibrated using the reference perimeters of two gullies that we measured during a recent field survey. The entire procedure attempts to provide estimates of gully erosion patterns, which characterize the entire Calhoun CZO area and to develop and evaluate a method to measure characteristic features of gullies (i.e. depth and volume).

  1. Characterization of Airborne Bacteria at an Underground Subway Station

    PubMed Central

    Dybwad, Marius; Granum, Per Einar; Bruheim, Per

    2012-01-01

    The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization–time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

  2. Characterization of airborne bacteria at an underground subway station.

    PubMed

    Dybwad, Marius; Granum, Per Einar; Bruheim, Per; Blatny, Janet Martha

    2012-03-01

    The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization-time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

  3. Rapid System to Quantitatively Characterize the Airborne Microbial Community

    NASA Technical Reports Server (NTRS)

    Macnaughton, Sarah J.

    1998-01-01

    Bioaerosols have been linked to a wide range of different allergies and respiratory illnesses. Currently, microorganism culture is the most commonly used method for exposure assessment. Such culture techniques, however, generally fail to detect between 90-99% of the actual viable biomass. Consequently, an unbiased technique for detecting airborne microorganisms is essential. In this Phase II proposal, a portable air sampling device his been developed for the collection of airborne microbial biomass from indoor (and outdoor) environments. Methods were evaluated for extracting and identifying lipids that provide information on indoor air microbial biomass, and automation of these procedures was investigated. Also, techniques to automate the extraction of DNA were explored.

  4. The Multi-sensor Airborne Radiation Survey (MARS) Instrument

    SciTech Connect

    Fast, James E.; Aalseth, Craig E.; Asner, David M.; Bonebrake, Christopher A.; Day, Anthony R.; Dorow, Kevin E.; Fuller, Erin S.; Glasgow, Brian D.; Hossbach, Todd W.; Hyronimus, Brian J.; Jensen, Jeffrey L.; Johnson, Kenneth I.; Jordan, David V.; Morgen, Gerald P.; Morris, Scott J.; Mullen, O Dennis; Myers, Allan W.; Pitts, W. Karl; Rohrer, John S.; Runkle, Robert C.; Seifert, Allen; Shergur, Jason M.; Stave, Sean C.; Tatishvili, Gocha; Thompson, Robert C.; Todd, Lindsay C.; Warren, Glen A.; Willett, Jesse A.; Wood, Lynn S.

    2013-01-11

    The Multi-sensor Airborne Radiation Survey (MARS) project has developed a new single cryostat detector array design for high purity germanium (HPGe) gama ray spectrometers that achieves the high detection efficiency required for stand-off detection and actionable characterization of radiological threats. This approach, we found, is necessary since a high efficiency HPGe detector can only be built as an array due to limitations in growing large germanium crystals. Moreover, the system is ruggedized and shock mounted for use in a variety of field applications, including airborne and maritime operations.

  5. Improved Airborne System for Sensing Wildfires

    NASA Technical Reports Server (NTRS)

    McKeown, Donald; Richardson, Michael

    2008-01-01

    The Wildfire Airborne Sensing Program (WASP) is engaged in a continuing effort to develop an improved airborne instrumentation system for sensing wildfires. The system could also be used for other aerial-imaging applications, including mapping and military surveillance. Unlike prior airborne fire-detection instrumentation systems, the WASP system would not be based on custom-made multispectral line scanners and associated custom- made complex optomechanical servomechanisms, sensors, readout circuitry, and packaging. Instead, the WASP system would be based on commercial off-the-shelf (COTS) equipment that would include (1) three or four electronic cameras (one for each of three or four wavelength bands) instead of a multispectral line scanner; (2) all associated drive and readout electronics; (3) a camera-pointing gimbal; (4) an inertial measurement unit (IMU) and a Global Positioning System (GPS) receiver for measuring the position, velocity, and orientation of the aircraft; and (5) a data-acquisition subsystem. It would be necessary to custom-develop an integrated sensor optical-bench assembly, a sensor-management subsystem, and software. The use of mostly COTS equipment is intended to reduce development time and cost, relative to those of prior systems.

  6. MITAS: multisensor imaging technology for airborne surveillance

    NASA Astrophysics Data System (ADS)

    Thomas, John D.

    1991-08-01

    MITAS, a unique and low-cost solution to the problem of collecting and processing multisensor imaging data for airborne surveillance operations has been developed, MITAS results from integrating the established and proven real-time video processing, target tracking, and sensor management software of TAU with commercially available image exploitation and map processing software. The MITAS image analysis station (IAS) supports airborne day/night reconnaissance and surveillance missions involving low-altitude collection platforms employing a suite of sensors to perform reconnaissance functions against a variety of ground and sea targets. The system will detect, locate, and recognize threats likely to be encountered in support of counternarcotic operations and in low-intensity conflict areas. The IAS is capable of autonomous, near real-time target exploitation and has the appropriate communication links to remotely located IAS systems for more extended analysis of sensor data. The IAS supports the collection, fusion, and processing of three main imaging sensors: daylight imagery (DIS), forward looking infrared (FLIR), and infrared line scan (IRLS). The MITAS IAS provides support to all aspects of the airborne surveillance mission, including sensor control, real-time image enhancement, automatic target tracking, sensor fusion, freeze-frame capture, image exploitation, target data-base management, map processing, remote image transmission, and report generation.

  7. Optical Communications Link to Airborne Transceiver

    NASA Technical Reports Server (NTRS)

    Regehr, Martin W.; Kovalik, Joseph M.; Biswas, Abhijit

    2011-01-01

    An optical link from Earth to an aircraft demonstrates the ability to establish a link from a ground platform to a transceiver moving overhead. An airplane has a challenging disturbance environment including airframe vibrations and occasional abrupt changes in attitude during flight. These disturbances make it difficult to maintain pointing lock in an optical transceiver in an airplane. Acquisition can also be challenging. In the case of the aircraft link, the ground station initially has no precise knowledge of the aircraft s location. An airborne pointing system has been designed, built, and demonstrated using direct-drive brushless DC motors for passive isolation of pointing disturbances and for high-bandwidth control feedback. The airborne transceiver uses a GPS-INS system to determine the aircraft s position and attitude, and to then illuminate the ground station initially for acquisition. The ground transceiver participates in link-pointing acquisition by first using a wide-field camera to detect initial illumination from the airborne beacon, and to perform coarse pointing. It then transfers control to a high-precision pointing detector. Using this scheme, live video was successfully streamed from the ground to the aircraft at 270 Mb/s while simultaneously downlinking a 50 kb/s data stream from the aircraft to the ground.

  8. The Development of Airborne Data for Assessing Models (ADAM) - A central repository of airborne field campaign data archives

    NASA Astrophysics Data System (ADS)

    Chen, G.; Kleb, M. M.; Aknan, A. A.; Brown, C. C.; Mangosing, D. C.; Thornhill, A.; Rinsland, P. L.

    2010-12-01

    NASA, NOAA, and NSF have conducted over 30 airborne campaigns during the past three decades aimed at gaining an understanding of the tropospheric chemical and physical processes related to climate change and air-quality issues. In recent years, the scientific value of this accumulated airborne data has been increasingly recognized for use in satellite validation and model assessment and evaluation activities. In addition to the high spatial-temporal resolutions, the airborne data, especially from the more recent studies, offers a comprehensive view of the atmosphere through a large suite of the simultaneously observed atmospheric species/parameters, ranging from photochemical precursors to products as well as particle chemical, microphysical, and optical properties. To better facilitate the model assessment and evaluation activities, we are actively engaged in the development of a web-based central airborne data archive: ADAM (Airborne Data for Assessing Models). This effort is sponsored by the NASA MEaSUREs program and is intended to archive data from tropospheric chemistry airborne field campaign since the 1980s. The principal design philosophy of the ADAM web site is to provide an intuitive user interface that allows users to browse, visualize, subset (both spatially and temporally), merge, and download the airborne data, as well as providing adequate metadata associated with the data archive. A working version of the web site which shows the ADAM user interface and functionalities will be presented. Also presented are conventions to establish common names for the atmospheric variables which are often observed during airborne campaigns as well as the approaches to handle missing data and limit of detections. This presentation is intended to serve the purpose of getting feedback from the broad atmospheric community, including both modelers and measurement experts.

  9. Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE)

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.

    1998-01-01

    Scanning holographic lidar receivers are currently in use in two operational lidar systems, PHASERS (Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing) and now HARLIE (Holographic Airborne Rotating Lidar Instrument Experiment). These systems are based on volume phase holograms made in dichromated gelatin (DCG) sandwiched between 2 layers of high quality float glass. They have demonstrated the practical application of this technology to compact scanning lidar systems at 532 and 1064 nm wavelengths, the ability to withstand moderately high laser power and energy loading, sufficient optical quality for most direct detection systems, overall efficiencies rivaling conventional receivers, and the stability to last several years under typical lidar system environments. Their size and weight are approximately half of similar performing scanning systems using reflective optics. The cost of holographic systems will eventually be lower than the reflective optical systems depending on their degree of commercialization. There are a number of applications that require or can greatly benefit from a scanning capability. Several of these are airborne systems, which either use focal plane scanning, as in the Laser Vegetation Imaging System or use primary aperture scanning, as in the Airborne Oceanographic Lidar or the Large Aperture Scanning Airborne Lidar. The latter class requires a large clear aperture opening or window in the aircraft. This type of system can greatly benefit from the use of scanning transmission holograms of the HARLIE type because the clear aperture required is only about 25% larger than the collecting aperture as opposed to 200-300% larger for scan angles of 45 degrees off nadir.

  10. Analysis of remote sensing data collected for detection and mapping of oil spills: Reduction and analysis of multi-sensor airborne data of the NASA Wallops oil spill exercise of November 1978

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Airborne, remotely sensed data of the NASA Wallops controlled oil spill were corrected, reduced and analysed. Sensor performance comparisons were made by registering data sets from different sensors, which were near-coincident in time and location. Multispectral scanner images were, in turn, overlayed with profiles of correlation between airborne and laboratory-acquired fluorosensor spectra of oil; oil-thickness contours derived (by NASA) from a scanning fluorosensor and also from a two-channel scanning microwave radiometer; and synthetic aperture radar X-HH images. Microwave scatterometer data were correlated with dual-channel (UV and TIR) line scanner images of the oil slick.

  11. Processor architecture for airborne SAR systems

    NASA Technical Reports Server (NTRS)

    Glass, C. M.

    1983-01-01

    Digital processors for spaceborne imaging radars and application of the technology developed for airborne SAR systems are considered. Transferring algorithms and implementation techniques from airborne to spaceborne SAR processors offers obvious advantages. The following topics are discussed: (1) a quantification of the differences in processing algorithms for airborne and spaceborne SARs; and (2) an overview of three processors for airborne SAR systems.

  12. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  13. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  14. Airborne Wind Turbine

    SciTech Connect

    2010-09-01

    Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.

  15. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  16. Real-time detection of airborne chemicals

    NASA Astrophysics Data System (ADS)

    Hartenstein, Steven D.; Tremblay, Paul L. A.; Fryer, Michael O.; Kaser, Timothy

    1999-02-01

    Accurate, real time air quality measurements are difficult to make, because real time sensors for some gas species are not specific to a single gas. For example, some carbon dioxide sensors react to hydrogen sulfide. By combining the response of several types of real time gas sensors the Real-time Air Quality Monitoring System (RAQMS) accurately measures many different gases. The sensor suite for the INEEL's Real-time Air Quality Monitoring System (RAQMS) incudes seven, inexpensive, commercially-available chemical sensors for gases associated with air quality. These chemical sensors are marketed as devices to measure carbon dioxide, hydrogen sulfide, carbon monoxide, sulfur dioxide, nitrogen dioxide, water vapor and volatile organic compounds (VOC's). However, these chemical sensors respond to more than a single compound, e.g. both the VOC and the carbon dioxide sensors respond strongly to methane. This multiple sensor response to a given chemical is used to advantage in the RAQMS system, as patterns of responses by the sensors were found to be unique and distinguishable for several chemicals. Therefore, there is the potential that the seven sensors combined output can: (1) provide more accurate measurements of the advertized gases and (2) estimate the presence and quantity of additional gases. The patterns of sensor response can be thought of as clusters of data points in a seven dimensional space. One dimension for each sensor's output. For all of the gases tested, these clusters were separated enough that good quantitative results were obtained. As an example, the prototype RAQMS is able to distinguish methane from butane and predict accurate concentrations of both gases. A mathematical technique for estimating probability density functions from random samples is used to distinguish the data clusters from each other and to make gas concentration estimates. Bayes optimal estimates of gas concentration are calculated using the probability density function. The Bayes optimal estimates are analogous to least square error curve fits or regression analysis. A computer program was used to find the best parameters for the Bayes optimal estimating functions. The program implemented a probabilistic neural net.

  17. PROGRAM ASPECT - FOR REMOTE SENSING OF AIRBORNE PLUMES

    EPA Science Inventory

    The SAFEGUARD program is a multi-sensor program for the detection and imaging of chemical plumes and vapors. The system is composed of an airborne sensor suite including an infrared line scanner and a high-speed fourier transform infrared spectrometer. Both systems are integrat...

  18. Upgraded airborne scanner for commercial remote sensing

    NASA Astrophysics Data System (ADS)

    Chang, Sheng-Huei; Rubin, Tod D.

    1994-06-01

    Traditional commercial remote sensing has focused on the geologic market, with primary focus on mineral identification and mapping in the visible through short-wave infrared spectral regions (0.4 to 2.4 microns). Commercial remote sensing users now demand airborne scanning capabilities spanning the entire wavelength range from ultraviolet through thermal infrared (0.3 to 12 microns). This spectral range enables detection, identification, and mapping of objects and liquids on the earth's surface and gases in the air. Applications requiring this range of wavelengths include detection and mapping of oil spills, soil and water contamination, stressed vegetation, and renewable and non-renewable natural resources, and also change detection, natural hazard mitigation, emergency response, agricultural management, and urban planning. GER has designed and built a configurable scanner that acquires high resolution images in 63 selected wave bands in this broad wavelength range.

  19. Wavelet periodicity detection algorithms

    NASA Astrophysics Data System (ADS)

    Benedetto, John J.; Pfander, Goetz E.

    1998-10-01

    This paper deals with the analysis of time series with respect to certain known periodicities. In particular, we shall present a fast method aimed at detecting periodic behavior inherent in noise data. The method is composed of three steps: (1) Non-noisy data are analyzed through spectral and wavelet methods to extract specific periodic patterns of interest. (2) Using these patterns, we construct an optimal piecewise constant wavelet designed to detect the underlying periodicities. (3) We introduce a fast discretized version of the continuous wavelet transform, as well as waveletgram averaging techniques, to detect occurrence and period of these periodicities. The algorithm is formulated to provide real time implementation. Our procedure is generally applicable to detect locally periodic components in signals s which can be modeled as s(t) equals A(t)F(h(t)) + N(t) for t in I, where F is a periodic signal, A is a non-negative slowly varying function, and h is strictly increasing with h' slowly varying, N denotes background activity. For example, the method can be applied in the context of epileptic seizure detection. In this case, we try to detect seizure periodics in EEG and ECoG data. In the case of ECoG data, N is essentially 1/f noise. In the case of EEG data and for t in I,N includes noise due to cranial geometry and densities. In both cases N also includes standard low frequency rhythms. Periodicity detection has other applications including ocean wave prediction, cockpit motion sickness prediction, and minefield detection.

  20. Bioreporter bacteria for landmine detection

    SciTech Connect

    Burlage, R.S.; Youngblood, T.; Lamothe, D.

    1998-04-01

    Landmines (and other UXO) gradually leak explosive chemicals into the soil at significant concentrations. Bacteria, which have adapted to scavenge low concentrations of nutrients, can detect these explosive chemicals. Uptake of these chemicals results in the triggering of specific bacterial genes. The authors have created genetically recombinant bioreporter bacteria that detect small concentrations of energetic chemicals. These bacteria are genetically engineered to produce a bioluminescent signal when they contact specific explosives. A gene for a brightly fluorescent compound can be substituted for increased sensitivity. By finding the fluorescent bacteria, you find the landmine. Detection might be accomplished using stand-off illumination of the minefield and GPS technology, which would result in greatly reduced risk to the deminers. Bioreporter technology has been proven at the laboratory scale, and will be tested under field conditions in the near future. They have created a bacterial strain that detects sub-micromolar concentrations of o- and p-nitrotoluene. Related bacterial strains were produced using standard laboratory protocols, and bioreporters of dinitrotoluene and trinitrotoluene were produced, screening for activity with the explosive compounds. Response time is dependent on the growth rate of the bacteria. Although frill signal production may require several hours, the bacteria can be applied over vast areas and scanned quickly, producing an equivalent detection speed that is very fast. This technology may be applicable to other needs, such as locating buried explosives at military and ordnance/explosive manufacturing facilities.

  1. Airborne rescue system

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1991-01-01

    The airborne rescue system includes a boom with telescoping members for extending a line and collar to a rescue victim. The boom extends beyond the tip of the helicopter rotor so that the victim may avoid the rotor downwash. The rescue line is played out and reeled in by winch. The line is temporarily retained under the boom. When the boom is extended, the rescue line passes through clips. When the victim dons the collar and the tension in the line reaches a predetermined level, the clips open and release the line from the boom. Then the rescue line can form a straight line between the victim and the winch, and the victim can be lifted to the helicopter. A translator is utilized to push out or pull in the telescoping members. The translator comprises a tape and a rope. Inside the telescoping members the tape is curled around the rope and the tape has a tube-like configuration. The tape and rope are provided from supply spools.

  2. Real-time airborne hyperspectral imaging of land mines

    NASA Astrophysics Data System (ADS)

    Ivanco, Tyler; Achal, Steve; McFee, John E.; Anger, Cliff; Young, Jane

    2007-04-01

    DRDC Suffeld and Itres Research have jointly investigated the use of visible and infrared hyperspectral imaging (HSI) for surface and buried land mine detection since 1989. These studies have demonstrated reliable passive HSI detection of surface-laid mines, based on their reflectance spectra, from airborne and ground-based platforms. Commercial HSI instruments collect and store image data at aircraft speeds, but the data are analysed off- line. This is useful for humanitarian demining, but unacceptable for military countermine operations. We have developed a hardware and software system with algorithms that can process the raw hyperspectral data in real time to detect mines. The custom algorithms perform radiometric correction of the raw data, then classify pixels of the corrected data, referencing a spectral signature library. The classification results are stored and displayed in real time, that is, within a few frame times of the data acquisition. Such real-time mine detection was demonstrated for the first time from a slowly moving land vehicle in March 2000. This paper describes an improved system which can achieve real-time detection of mines from an airborne platform, with its commensurately higher data rates. The system is presently compatible with the Itres family of visible/near infrared, short wave infrared and thermal infrared pushbroom hyperspectral imagers and its broadband thermal infrared pushbroom imager. Experiments to detect mines from an airborne platform in real time were conducted at DRDC Suffield in November 2006. Surface-laid land mines were detected in real time from a slowly moving helicopter with generally good detection rates and low false alarm rates. To the authors' knowledge, this is the first time that land mines have been detected from an airborne platform in real time using hyperspectral imaging.

  3. Airborne signals of communication in sagebrush: a pharmacological approach

    PubMed Central

    Shiojiri, Kaori; Ishizaki, Satomi; Ozawa, Rika; Karban, Richard

    2015-01-01

    When plants receive volatiles from a damaged plant, the receivers become more resistant to herbivory. This phenomenon has been reported in many plant species and called plant-plant communication. Lab experiments have suggested that several compounds may be functioning as airborne signals. The objective of this study is to identify potential airborne signals used in communication between sagebrush (Artemisia tridentata) individuals in the field. We collected volatiles of one branch from each of 99 sagebrush individual plants. Eighteen different volatiles were detected by GC-MS analysis. Among these, 4 compounds; 1.8-cineol, β-caryophyllene, α-pinene and borneol, were investigated as signals of communication under natural conditions. The branches which received either 1,8-cineol or β-caryophyllene tended to get less damage than controls. These results suggested that 1,8-cineol and β-caryophyllene should be considered further as possible candidates for generalized airborne signals in sagebrush. PMID:26418970

  4. Instrument Would Detect and Collect Biological Aerosols

    NASA Technical Reports Server (NTRS)

    Savoy, Steve; Mayo, Mike

    2006-01-01

    A proposed compact, portable instrument would sample micron-sized airborne particles, would discriminate between biological ones (e.g., bacteria) and nonbiological ones (e.g., dust particles), and would collect the detected biological particles for further analysis. The instrument is intended to satisfy a growing need for means of rapid, inexpensive collection of bioaerosols in a variety of indoor and outdoor settings. Purposes that could be served by such collection include detecting airborne pathogens inside buildings and their ventilation systems, measuring concentrations of airborne biological contaminants around municipal waste-processing facilities, monitoring airborne effluents from suspected biowarfare facilities, and warning of the presence of airborne biowarfare agents

  5. Remote Mine Detection Technologies for Land and Water Environments

    SciTech Connect

    Hoover, Eddie R.

    1999-05-11

    The detection of mines, both during and after hostilities, is a growing international problem. It limits military operations during wartime and unrecovered mines create tragic consequences for civilians. From a purely humanitarian standpoint an estimated 100 million or more unrecovered mines are located in over 60 countries worldwide. This paper presents an overview of some of the technologies currently being investigated by Sandia National Laboratories for the detection and monitoring of minefields in land and water environments. The three technical areas described in this paper are: 1) the development of new mathematical techniques for combining or fusing the data from multiple sources for enhanced decision-making; 2) an environmental fate and transport (EF&T) analysis approach that is central to improving trace chemical sensing technique; and 3) the investigation of an underwater range imaging device to aid in locating and characterizing mines and other obstacles in coastal waters.

  6. Airborne Laser Polar Nephelometer

    NASA Technical Reports Server (NTRS)

    Grams, Gerald W.

    1973-01-01

    A polar nephelometer has been developed at NCAR to measure the angular variation of the intensity of light scattered by air molecules and particles. The system has been designed for airborne measurements using outside air ducted through a 5-cm diameter airflow tube; the sample volume is that which is common to the intersection of a collimated source beam and the detector field of view within the airflow tube. The source is a linearly polarized helium-neon laser beam. The optical system defines a collimated field-of-view (0.5deg half-angle) through a series of diaphragms located behind a I72-mm focal length objective lens. A photomultiplier tube is located immediately behind an aperture in the focal plane of the objective lens. The laser beam is mechanically chopped (on-off) at a rate of 5 Hz; a two-channel pulse counter, synchronized to the laser output, measures the photomultiplier pulse rate with the light beam both on and off. The difference in these measured pulse rates is directly proportional to the intensity of the scattered light from the volume common to the intersection of the laser beam and the detector field-of-view. Measurements can be made at scattering angles from 15deg to 165deg with reference to the direction of propagation of the light beam. Intermediate angles are obtained by selecting the angular increments desired between these extreme angles (any multiple of 0.1deg can be selected for the angular increment; 5deg is used in normal operation). Pulses provided by digital circuits control a stepping motor which sequentially rotates the detector by pre-selected angular increments. The synchronous photon-counting system automatically begins measurement of the scattered-light intensity immediately after the rotation to a new angle has been completed. The instrument has been flown on the NASA Convair 990 airborne laboratory to obtain data on the complex index of refraction of atmospheric aerosols. A particle impaction device is operated simultaneously

  7. Algorithms used in the Airborne Lidar Processing System (ALPS)

    USGS Publications Warehouse

    Nagle, David B.; Wright, C. Wayne

    2016-01-01

    The Airborne Lidar Processing System (ALPS) analyzes Experimental Advanced Airborne Research Lidar (EAARL) data—digitized laser-return waveforms, position, and attitude data—to derive point clouds of target surfaces. A full-waveform airborne lidar system, the EAARL seamlessly and simultaneously collects mixed environment data, including submerged, sub-aerial bare earth, and vegetation-covered topographies.ALPS uses three waveform target-detection algorithms to determine target positions within a given waveform: centroid analysis, leading edge detection, and bottom detection using water-column backscatter modeling. The centroid analysis algorithm detects opaque hard surfaces. The leading edge algorithm detects topography beneath vegetation and shallow, submerged topography. The bottom detection algorithm uses water-column backscatter modeling for deeper submerged topography in turbid water.The report describes slant range calculations and explains how ALPS uses laser range and orientation measurements to project measurement points into the Universal Transverse Mercator coordinate system. Parameters used for coordinate transformations in ALPS are described, as are Interactive Data Language-based methods for gridding EAARL point cloud data to derive digital elevation models. Noise reduction in point clouds through use of a random consensus filter is explained, and detailed pseudocode, mathematical equations, and Yorick source code accompany the report.

  8. Airborne chemistry coupled to Raman spectroscopy.

    PubMed

    Santesson, Sabina; Johansson, Jonas; Taylor, Lynne S; Levander, Ia; Fox, Shannon; Sepaniak, Michael; Nilsson, Staffan

    2003-05-01

    In this paper, the use of airborne chemistry (acoustically levitated drops) in combination with Raman spectroscopy is explored. We report herein the first Raman studies of crystallization processes in levitated drops and the first demonstration of surface-enhanced Raman scattering (SERS) detection in this medium. Crystallization studies on the model compounds benzamide and indomethacin resulted in the formation of two crystal modifications for each compound, suggesting that this methodology may be useful for investigation of polymorphs. SERS detection resulted in a signal enhancement of 27 000 for benzoic acid and 11 000 for rhodamine 6-G. The preliminary results presented here clearly indicate that several important applications of the combination between Raman spectroscopy and acoustic drop levitation can be expected in the future. PMID:12720359

  9. An airborne isothermal haze chamber

    NASA Technical Reports Server (NTRS)

    Hindman, E. E.

    1981-01-01

    Thermal gradient diffusion cloud chambers (TGDCC) are used to determine the concentrations of cloud condensation nuclei (CCN) with critical supersaturations greater than or equal to about 0.2%. The CCN concentrations measured with the airborne IHC were lower than theoretically predicted by factors ranging between 7.9 and 9.0. The CCN concentrations measured with the airborne IHC were lower than the concentrations measured with the larger laboratory IHC's by factors ranging between 3.9 and 7.5. The bounds of the supersaturation ranges of the airborne IHC and the CSU-Mee TGDCC do not overlap. Nevertheless, the slopes of the interpolated data between the bounds agree favorably with the theoretical slopes.

  10. Airborne laser topographic mapping results

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Collins, J. G.; Link, L. E.; Swift, R. N.; Butler, M. L.

    1984-01-01

    The results of terrain mapping experiments utilizing the National Aeronautics and Space Administration (NASA) Airborne Oceanographic Lidar (AOL) over forested areas are presented. The flight tests were conducted as part of a joint NASA/U.S. Army Corps of Engineers (CE) investigation aimed at evaluating the potential of an airborne laser ranging system to provide cross-sectional topographic data on flood plains that are difficult and expensive to survey using conventional techniques. The data described in this paper were obtained in the Wolf River Basin located near Memphis, TN. Results from surveys conducted under winter 'leaves off' and summer 'leaves on' conditions, aspects of day and night operation, and data obtained from decidous and coniferous tree types are compared. Data processing techniques are reviewed. Conclusions relative to accuracy and present limitations of the AOL, and airborne lidar systems in general, to terrain mapping over forested areas are discussed.

  11. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT RESEARCH PLAN

    EPA Science Inventory

    The goal of the Western Airborne Contaminants Assessment Project (WACAP) is to assess the deposition of airborne contaminants in Western National Parks, providing regional and local information on exposure, accumulation, impacts, and probable sources. This project is being desig...

  12. NASA Airborne Lidar 1982-1984 Flights

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar 1982-1984 Flights Data from the 1982 NASA Langley Airborne Lidar flights following the eruption of El Chichon ... continuing to January 1984. Transcribed from the following NASA Tech Reports: McCormick, M. P., and M. T. Osborn, Airborne lidar ...

  13. A comparison of real and simulated airborne multisensor imagery

    NASA Astrophysics Data System (ADS)

    Bloechl, Kevin; De Angelis, Chris; Gartley, Michael; Kerekes, John; Nance, C. Eric

    2014-06-01

    This paper presents a methodology and results for the comparison of simulated imagery to real imagery acquired with multiple sensors hosted on an airborne platform. The dataset includes aerial multi- and hyperspectral imagery with spatial resolutions of one meter or less. The multispectral imagery includes data from an airborne sensor with three-band visible color and calibrated radiance imagery in the long-, mid-, and short-wave infrared. The airborne hyperspectral imagery includes 360 bands of calibrated radiance and reflectance data spanning 400 to 2450 nm in wavelength. Collected in September 2012, the imagery is of a park in Avon, NY, and includes a dirt track and areas of grass, gravel, forest, and agricultural fields. A number of artificial targets were deployed in the scene prior to collection for purposes of target detection, subpixel detection, spectral unmixing, and 3D object recognition. A synthetic reconstruction of the collection site was created in DIRSIG, an image generation and modeling tool developed by the Rochester Institute of Technology, based on ground-measured reflectance data, ground photography, and previous airborne imagery. Simulated airborne images were generated using the scene model, time of observation, estimates of the atmospheric conditions, and approximations of the sensor characteristics. The paper provides a comparison between the empirical and simulated images, including a comparison of achieved performance for classification, detection and unmixing applications. It was found that several differences exist due to the way the image is generated, including finite sampling and incomplete knowledge of the scene, atmospheric conditions and sensor characteristics. The lessons learned from this effort can be used in constructing future simulated scenes and further comparisons between real and simulated imagery.

  14. Column CO2 Measurement From an Airborne Solid-State Double-Pulsed 2-Micron Integrated Path Differential Absorption Lidar

    NASA Technical Reports Server (NTRS)

    Singh, U. N.; Yu, J.; Petros, M.; Refaat, T. F.; Remus, R.; Fay, J.; Reithmaier, K.

    2014-01-01

    NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micrometers IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

  15. Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

    NASA Astrophysics Data System (ADS)

    Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

    2010-05-01

    . These results encouraged us to apply these methods to airborne geophysical data sets from the United Mexican States. One survey was targeted to provide additional data for advanced groundwater modeling in remote areas of the karstic plateau of Yucatan. Within the other project a sustainable source of water supply for a small settlement on the isolated island of Socorro, 700 km off the Mexican main coast had to be detected. At both survey areas no accurate elevation models or area-wide information about vegetation heights where available before the airborne geophysical survey. The results of these investigations will be presented. From an evaluation of the results it can be concluded that the use of laser altimetry not only provides essential information about the ground clearance of the geophysical instruments but also increases the benefit of the airborne survey for the client by delivering additional information about the survey area. It is clear that the accuracy of the resulting data cannot compete with a high resolution laser scanning survey. However in areas where such information is not available an obvious additional benefit can be achieved without the need to spend money for additional survey campaigns. Currently further studies are launched to investigate the possibility to increase the accuracy of the altitude data by determining roll and pitch of the helicopter by the use of differentially corrected multiple L1/L2 band GPS receiver mounted at fixed positions on the helicopter platform. The above study was partly financed by the Austrian Science Fund, Xplore (L524-N10) project.

  16. Software Development for an Airborne Wind LIDAR

    NASA Astrophysics Data System (ADS)

    Zhu, Jishan; Li, Zhigang; Chen, Zhen; Liu, Zhishen

    2014-11-01

    Currently, Wind lidar offers an important way to obtain clear air wind field [1]. The principle of the wind lidar is based on the Doppler frequency shift in the air of the laser. The received signal of the lidar is scattered by the air molecular and particles [2]. They are Rayleigh scattering and Mie scattering. Coherent detection technique is an effective method to get the Doppler shift from the scattering in the air. From the Doppler shift we can get the radial wind speed. Generally, the horizontal wind field is that people concerned about. Based on the radial wind speed of more than 3 directions, we can use the VAD technique to retrieve the horizontal wind field. For an airborne lidar, some corrections such as the air plane posture, the air plane velocity must be performed. We developed a set of software for an airborne wind lidar using the MFC visual C++ Programming technology. Functions of the software are raw data decoding, radial wind speed inversion, horizontal wind field retrieve by VAD technique, air plane posture correction, air plane velocity correction, and so on. It also has functions for data display and saves. The results can be saved as picture or numerical values.

  17. Handling Trajectory Uncertainties for Airborne Conflict Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Doble, Nathan A.; Karr, David; Palmer, Michael T.

    2005-01-01

    Airborne conflict management is an enabling capability for NASA's Distributed Air-Ground Traffic Management (DAG-TM) concept. DAGTM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, autonomous aircraft maintain separation from each other and from managed aircraft unequipped for autonomous flight. NASA Langley Research Center has developed the Autonomous Operations Planner (AOP), an onboard decision support system that provides airborne conflict management (ACM) and strategic flight planning support for autonomous aircraft pilots. The AOP performs conflict detection, prevention, and resolution from nearby traffic aircraft and area hazards. Traffic trajectory information is assumed to be provided by Automatic Dependent Surveillance Broadcast (ADS-B). Reliable trajectory prediction is a key capability for providing effective ACM functions. Trajectory uncertainties due to environmental effects, differences in aircraft systems and performance, and unknown intent information lead to prediction errors that can adversely affect AOP performance. To accommodate these uncertainties, the AOP has been enhanced to create cross-track, vertical, and along-track buffers along the predicted trajectories of both ownship and traffic aircraft. These buffers will be structured based on prediction errors noted from previous simulations such as a recent Joint Experiment between NASA Ames and Langley Research Centers and from other outside studies. Currently defined ADS-B parameters related to navigation capability, trajectory type, and path conformance will be used to support the algorithms that generate the buffers.

  18. Airborne Imagery Collections Barrow 2013

    DOE Data Explorer

    Cherry, Jessica; Crowder, Kerri

    2015-07-20

    The data here are orthomosaics, digital surface models (DSMs), and individual frames captured during low altitude airborne flights in 2013 at the Barrow Environmental Observatory. The orthomosaics, thermal IR mosaics, and DSMs were generated from the individual frames using Structure from Motion techniques.

  19. Airborne fungi--a resurvey

    SciTech Connect

    Meyer, G.H.; Prince, H.E.; Raymer, W.J.

    1983-07-01

    A 15-month survey of airborne fungi at 14 geographical stations was conducted to determine the incidence of different fungal genera. Five of these stations were surveyed 25 years earlier. A comparison between previous studies and present surveys revealed similar organisms at each station with slight shifts in frequency of dominant genera.

  20. Tropospheric and Airborne Emission Spectrometers

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas; Beer, Reinhard

    1996-01-01

    X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

  1. AARD - Autonomous Airborne Refueling Demonstration

    NASA Technical Reports Server (NTRS)

    Ewers, Dick

    2007-01-01

    This viewgraph document reviews the Autonomous Airborne Refueling Demonstration program, and NASA Dryden's work in the program. The primary goal of the program is to make one fully automatic probe-to-drogue engagement using the AARD system. There are pictures of the aircraft approaching to the docking.

  2. Airborne asbestos in public buildings

    SciTech Connect

    Chesson, J.; Hatfield, J.; Schultz, B.; Dutrow, E.; Blake, J. )

    1990-02-01

    The U.S. Environmental Protection Agency sampled air in 49 government-owned buildings (six buildings with no asbestos-containing material, six buildings with asbestos-containing material in generally good condition, and 37 buildings with damaged asbestos-containing material). This is the most comprehensive study to date of airborne asbestos levels in U.S. public buildings during normal building activities. The air outside each building was also sampled. Air samples were analyzed by transmission electron microscopy using a direct transfer preparation technique. The results show an increasing trend in average airborne asbestos levels; outdoor levels are lowest and levels in buildings with damaged asbestos-containing material are highest. However, the measured levels and the differences between indoors and outdoors and between building categories are small in absolute magnitude. Comparable studies from Canada and the UK, although differing in their estimated concentrations, also conclude that while airborne asbestos levels may be elevated in buildings that contain asbestos, levels are generally low. This conclusion does not eliminate the possibility of higher airborne asbestos levels during maintenance or renovation that disturbs the asbestos-containing material.

  3. Calibration of airborne SAR interferograms using multisquint-processed image pairs

    NASA Astrophysics Data System (ADS)

    Prats, Pau; Mallorqui, Jordi J.; Reigber, Andreas; Broquetas, Antoni

    2004-01-01

    This paper presents two different approaches to detect and correct phase errors appearing in interferometric airborne SAR sensors due to the lack of precision in the navigation system. The first one is intended for interferometric pairs with high coherence, and the second one for low coherent ones. Both techniques are based on a multisquint processing approach, i.e., by processing the same image pairs with different squint angles we can combine the information of different interferograms to obtain the desired phase correction. Airborne single- and repeat-pass interferometric data from the Deutsches Zentrum fur Luft- und Raumfahrt (DLR) Experimental airborne SAR is used to validate the method.

  4. Airborne particulate discriminator

    DOEpatents

    Creek, Kathryn Louise; Castro, Alonso; Gray, Perry Clayton

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  5. Monitoring human and vehicle activities using airborne video

    NASA Astrophysics Data System (ADS)

    Cutler, Ross; Shekhar, Chandra S.; Burns, B.; Chellappa, Rama; Bolles, Robert C.; Davis, Larry S.

    2000-05-01

    Ongoing work in Activity Monitoring (AM) for the Airborne Video Surveillance (AVS) project is described. The goal for AM is to recognize activities of interest involving humans and vehicles using airborne video. AM consists of three major components: (1) moving object detection, tracking, and classification; (2) image to site-model registration; (3) activity recognition. Detecting and tracking humans and vehicles form airborne video is a challenging problem due to image noise, low GSD, poor contrast, motion parallax, motion blur, and camera blur, and camera jitter. We use frame-to- frame affine-warping stabilization and temporally integrated intensity differences to detect independent motion. Moving objects are initially tracked using nearest-neighbor correspondence, followed by a greedy method that favors long track lengths and assumes locally constant velocity. Object classification is based on object size, velocity, and periodicity of motion. Site-model registration uses GPS information and camera/airplane orientations to provide an initial geolocation with +/- 100m accuracy at an elevation of 1000m. A semi-automatic procedure is utilized to improve the accuracy to +/- 5m. The activity recognition component uses the geolocated tracked objects and the site-model to detect pre-specified activities, such as people entering a forbidden area and a group of vehicles leaving a staging area.

  6. Terrestrial Method for Airborne Lidar Quality Control and Assessment

    NASA Astrophysics Data System (ADS)

    Alsubaie, N. M.; Badawy, H. M.; Elhabiby, M. M.; El-Sheimy, N.

    2014-11-01

    Most of LiDAR systems do not provide the end user with the calibration and acquisition procedures that can use to validate the quality of the data acquired by the airborne system. Therefore, this system needs data Quality Control (QC) and assessment procedures to verify the accuracy of the laser footprints and mainly at building edges. This research paper introduces an efficient method for validating the quality of the airborne LiDAR point clouds data using terrestrial laser scanning data integrated with edge detection techniques. This method will be based on detecting the edge of buildings from these two independent systems. Hence, the building edges are extracted from the airborne data using an algorithm that is based on the standard deviation of neighbour point's height from certain threshold with respect to centre points using radius threshold. The algorithm is adaptive to different point densities. The approach is combined with another innovative edge detection technique from terrestrial laser scanning point clouds that is based on the height and point density constraints. Finally, statistical analysis and assessment will be applied to compare these two systems in term of edge detection extraction precision, which will be a priori step for 3D city modelling generated from heterogeneous LiDAR systems

  7. Airborne infrared low level wind shear predictor

    NASA Technical Reports Server (NTRS)

    Kuhn, P. M.; Kurkowski, R. L.

    1984-01-01

    The operating principles and test performance of an airborne IR (13-16 micron) temperature-sensing detection and warning system for low-level wind shear (LLWS) are presented. The physics of LLWS phenomena and of the IR radiometer are introduced. The cold density-current outflow or gust front related to LLWS is observed in the IR spectrum of CO2 by a radiometer with + or - 0.5-C accuracy at 0.5-Hz sampling rate; LLWS alerts are given on the basis of specific criteria. Test results from the JAWS experiments conducted at Denver in July 1982, are presented graphically and discussed. The feasibility of the passive IR system is demonstrated, with an average warning time of 51 sec, corresponding to a distance from touchdown of about 2 miles.

  8. Location of the Rhine plume front by airborne remote sensing

    NASA Astrophysics Data System (ADS)

    Ruddick, K. G.; Lahousse, L.; Donnay, E.

    1994-04-01

    The aim of this study was to determine the feasibility of using airborne remote sensing to locate the Rhine plume front. Interest in fronts arises from the desire to predict the fate of pollutants and biological nutrients discharged from rivers into the open sea. Observations were made during flights over the Dutch coastal waters using a vertically-mounted video camera and a side-looking airborne radar (SLAR) designed for oil slick detection. Comparison of radar images with visual observations of the sea colour discontinuity and foam line establish that fronts can indeed be detected by SLAR because of high radar backscatter along the convergence line, where the fresh water jet impinges on saltier water. This provides a sound basis for future investigations using Synthetic Aperture Radar as mounted on ERS-1. An estimation of errors is given, identifying priorities for improvement of the technique. The accuracy achieved is considered sufficient for the validation of hydrodynamic models.

  9. Airborne ultrasound enters the ear through the eyes

    NASA Astrophysics Data System (ADS)

    Lenhardt, Martin

    2005-09-01

    Musical spectrum above 20000 Hz has been demonstrated to influence human judgments and physiology. Moreover airborne ultrasonic noise has been implicated in hearing loss, tinnitus, and other subjective effects such as headaches and fullness in the ear. Contact ultrasound, i.e., with a transducer affixed to the skin of the head/neck, is audible; assumed by bone conduction. However, lightly touching the soft tissues of the head, avoiding bone, can also produce audibility. When contact ultrasound is applied to the head, energy from 25 to ~60 kHz can be recorded from the closed eyelid, with care to avoid sensor contact with the orbit. If the same frequency band of noise is passed through a transducer in from of the eye, with just air coupling, the same response is again recordable on the head. An acrylic barrier between the eye and the transducer eliminates the response. Once airborne ultrasound exceeds the impedance mismatch of the eye it readily propagates through the soft tissues of the eye and brain via one of the fluid windows (end lymphatic, perilymphatic or vascular) to the cochlea. The eye fenestration explains how people can detect airborne ultrasonic components in music and develop ear effects from airborne ultrasonic noise.

  10. Satellite and airborne IR sensor validation by an airborne interferometer

    SciTech Connect

    Gumley, L.E.; Delst, P.F. van; Moeller, C.C.

    1996-11-01

    The validation of in-orbit longwave IR radiances from the GOES-8 Sounder and inflight longwave IR radiances from the MODIS Airborne Simulator (MAS) is described. The reference used is the airborne University of Wisconsin High Resolution Interferometer Sounder (HIS). The calibration of each sensor is described. Data collected during the Ocean Temperature Interferometric Survey (OTIS) experiment in January 1995 is used in the comparison between sensors. Detailed forward calculations of at-sensor radiance are used to account for the difference in GOES-8 and HIS altitude and viewing geometry. MAS radiances and spectrally averaged HIS radiances are compared directly. Differences between GOES-8 and HIS brightness temperatures, and GOES-8 and MAS brightness temperatures, are found to be with 1.0 K for the majority of longwave channels examined. The same validation approach will be used for future sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS). 11 refs., 2 figs., 4 tabs.

  11. Identifying Airborne Pathogens in Time to Respond

    SciTech Connect

    Hazi, A

    2006-01-25

    Among the possible terrorist activities that might threaten national security is the release of an airborne pathogen such as anthrax. Because the potential damage to human health could be severe, experts consider 1 minute to be an operationally useful time limit for identifying the pathogen and taking action. Many commercial systems can identify airborne pathogenic microbes, but they take days or, at best, hours to produce results. The Department of Homeland Security (DHS) and other U.S. government agencies are interested in finding a faster approach. To answer this national need, a Livermore team, led by scientist Eric Gard, has developed the bioaerosol mass spectrometry (BAMS) system--the only instrument that can detect and identify spores at low concentrations in less than 1 minute. BAMS can successfully distinguish between two related but different spore species. It can also sort out a single spore from thousands of other particles--biological and nonbiological--with no false positives. The BAMS team won a 2005 R&D 100 Award for developing the system. Livermore's Laboratory Directed Research and Development (LDRD) Program funded the biomedical aspects of the BAMS project, and the Department of Defense's Technical Support Working Group and Defense Advanced Research Project Agency funded the biodefense efforts. Developing a detection system that can analyze small samples so quickly has been challenging. Livermore engineer Vincent Riot, who worked on the BAMS project, explains, ''A typical spore weighs approximately one-trillionth of a gram and is dispersed in the atmosphere, which contains naturally occurring particles that could be present at concentrations thousands of times higher. Previous systems also had difficulty separating benign organisms from those that are pathogenic but very similar, which has resulted in false alarms''.

  12. Simultaneous gas-phase and total water detection for airborne applications with a multi-channel TDL spectrometer at 1.4 μm and 2.6 μm

    NASA Astrophysics Data System (ADS)

    Buchholz, Bernhard; Afchine, Armin; Klein, Alexander; Barthel, Jochen; Kallweit, Sören; Klostermann, Tim; Krämer, Martina; Schiller, Cornelius; Ebert, Volker

    2013-04-01

    Water vapor measurements especially within clouds are difficult, in particular due to numerous instrument-specific limitations in precision, time resolution and accuracy. Notably the quantification of the ice and gas-phase water content in cirrus clouds, which play an important role in the global climate system, require new high-speed hygrometers concepts which are capable of resolving large water vapor gradients. Previously we demonstrated a stationary concept of a Tunable Diode Laser Absorption Spectroscopy (TDLAS)-based quantification of the ice/liquid water by independent, but simultaneous measurements of A) the gas-phase water in an open-path configuration (optical-path 125 m) and B) the total water in an extractive version with a closed cell (30 m path) after evaporating the condensed water [1]. In this case we used laboratory TDLAS instrumentation in combination with a long absorption paths and applied those to the AIDA cloud camber [2]. Recently we developed an advanced, miniature version of the concept, suitable for mobile field applications and in particular for use on aircrafts. First tests of our new, fiber-coupled open-path TDLAS cell [3] for airborne applications were combined with the experiences of our extractive SEALDH instruments [4] and led to a new, multi-channel, "multi-phase TDL-hygrometer" called "HAI" ("Hygrometer for Atmospheric Investigations"). HAI, which is explicitly designed for the new German HALO (High Altitude and Long Range Research Aircraft) airplane, provides a similar, but improved functionality like the stationary, multi-phase TDLAS developed for AIDA. However HAI comes in a much more compact, six height units, 30 kg, electronics rack for the main unit and with a new, completely fiber-coupled, compact, 21 kg, dual-wavelength open-path TDL-cell which is placed in the aircraft's skin. HAI is much more complex and versatile than the AIDA precursor and can be seen as comprised of four TDL-spectrometers, as it simultaneously

  13. Initial results of detected methane emissions from landfills in the Los Angeles Basin during the COMEX campaign by the Methane Airborne MAPper (MAMAP) instrument and a greenhouse gas in-situ analyser

    NASA Astrophysics Data System (ADS)

    Krautwurst, Sven; Gerilowski, Konstantin; Kolyer, Richard; Jonsson, Haflidi; Krings, Thomas; Horstjann, Markus; Leifer, Ira; Vigil, Sam; Buchwitz, Michael; Schüttemeyer, Dirk; Fladeland, Matthew M.; Burrows, John P.; Bovensmann, Heinrich

    2015-04-01

    Methane (CH4) is the second most important anthropogenic greenhouse gas beside carbon dioxide (CO2). Significant contributors to the global methane budget are fugitive emissions from landfills. Due to the growing world population, it is expected that the amount of waste and, therefore, waste disposal sites will increase in number and size in parts of the world, often adjacent growing megacities. Besides bottom-up modelling, a variety of ground based methods (e.g., flux chambers, trace gases, radial plume mapping, etc.) have been used to estimate (top-down) these fugitive emissions. Because landfills usually are large, sometimes with significant topographic relief, vary temporally, and leak/emit heterogeneously across their surface area, assessing total emission strength by ground-based techniques is often difficult. In this work, we show how airborne based remote sensing measurements of the column-averaged dry air mole fraction of CH4 can be utilized to estimate fugitive emissions from landfills in an urban environment by a mass balance approach. Subsequently, these emission rates are compared to airborne in-situ horizontal cross section measurements of CH4 taken within the planetary boundary layer (PBL) upwind and downwind of the landfill at different altitudes immediately after the remote sensing measurements were finished. Additional necessary parameters (e.g., wind direction, wind speed, aerosols, dew point temperature, etc.) for the data inversion are provided by a standard instrumentation suite for atmospheric measurements aboard the aircraft, and nearby ground-based weather stations. These measurements were part of the CO2 and Methane EXperiment (COMEX), which was executed during the summer 2014 in California and was co-funded by the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA). The remote sensing measurements were taken by the Methane Airborne MAPper (MAMAP) developed and operated by the University of Bremen and

  14. Ground and Airborne Methane Measurements with an Optical Parametric Amplifier

    NASA Technical Reports Server (NTRS)

    Numata, Kenji

    2012-01-01

    We report on ground and airborne atmospheric methane measurements with a differential absorption lidar using an optical parametric amplifier (OPA). Methane is a strong greenhouse gas on Earth and its accurate global mapping is urgently needed to understand climate change. We are developing a nanosecond-pulsed OPA for remote measurements of methane from an Earth-orbiting satellite. We have successfully demonstrated the detection of methane on the ground and from an airplane at approximately 11-km altitude.

  15. Airborne-biogeochemical survey test-case results

    USGS Publications Warehouse

    Collins, William E.; Chang, Sheng-Huei; Raines, Gary L.; Canney, Frank C.; Ashley, Roger

    1980-01-01

    Airborne spectroradiometer surveys over several forest-covered sulfide bodies indicate that mineralization has affected the overlying vegetation; anomalous spectral reflectivity properties can be detected in the vegetation using appropriate remote-sensing interments and data-reduction techniques. Mineralization induces subtle changes in the shape of the chlorophyll a and b absorption spectrum between 550 and 750 nm. The observed spectral variations appear specifically to be on the wings of the broad red chlorophyll bars, centered at about 680 nm.

  16. Airborne infrared mineral mapping survey of Marysvale, Utah

    NASA Technical Reports Server (NTRS)

    Collins, W.; Chang, S. H.

    1982-01-01

    Infrared spectroradiometer survey results from flights over the Marysvale, Utah district show that hydrothermal alteration mineralogy can be mapped using very rapid and effective airborne techniques. The system detects alteration mineral absorption band intensities in the infrared spectral region with high sensitivity. The higher resolution spectral features and high spectral differences characteristic of the various clay and carbonate minerals are also readily identified by the instrument allowing the mineralogy to be mapped as well as the mineralization intensity.

  17. Covariance analysis of the airborne laser ranging system

    NASA Technical Reports Server (NTRS)

    Englar, T. S., Jr.; Hammond, C. L.; Gibbs, B. P.

    1981-01-01

    The requirements and limitations of employing an airborne laser ranging system for detecting crustal shifts of the Earth within centimeters over a region of approximately 200 by 400 km are presented. The system consists of an aircraft which flies over a grid of ground deployed retroreflectors, making six passes over the grid at two different altitudes. The retroreflector baseline errors are assumed to result from measurement noise, a priori errors on the aircraft and retroreflector positions, tropospheric refraction, and sensor biases.

  18. Large aperture scanning airborne lidar

    NASA Technical Reports Server (NTRS)

    Smith, J.; Bindschadler, R.; Boers, R.; Bufton, J. L.; Clem, D.; Garvin, J.; Melfi, S. H.

    1988-01-01

    A large aperture scanning airborne lidar facility is being developed to provide important new capabilities for airborne lidar sensor systems. The proposed scanning mechanism allows for a large aperture telescope (25 in. diameter) in front of an elliptical flat (25 x 36 in.) turning mirror positioned at a 45 degree angle with respect to the telescope optical axis. The lidar scanning capability will provide opportunities for acquiring new data sets for atmospheric, earth resources, and oceans communities. This completed facility will also make available the opportunity to acquire simulated EOS lidar data on a near global basis. The design and construction of this unique scanning mechanism presents exciting technological challenges of maintaining the turning mirror optical flatness during scanning while exposed to extreme temperatures, ambient pressures, aircraft vibrations, etc.

  19. Magnetic airborne survey - geophysical flight

    NASA Astrophysics Data System (ADS)

    de Barros Camara, Erick; Nei Pereira Guimarães, Suze

    2016-06-01

    This paper provides a technical review process in the area of airborne acquisition of geophysical data, with emphasis for magnetometry. In summary, it addresses the calibration processes of geophysical equipment as well as the aircraft to minimize possible errors in measurements. The corrections used in data processing and filtering are demonstrated with the same results as well as the evolution of these techniques in Brazil and worldwide.

  20. Airborne lidar global positioning investigations

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.

    1988-01-01

    The Global Positioning System (GPS) network of satellites shows high promise of revolutionizing methods for conducting surveying, navigation, and positioning. This is especially true in the case of airborne or satellite positioning. A single GPS receiver (suitably adapted for aircraft deployment) can yield positioning accuracies (world-wide) in the order of 30 to 50 m vertically, as well as horizontally. This accuracy is dramatically improved when a second GPS receiver is positioned at a known horizontal and vertical reference. Absolute horizontal and vertical positioning of 1 to 2 m are easily achieved over areas of separation of tens of km. If four common satellites remain in lock in both receivers, then differential phase pseudo-ranges on the GPS L-band carrier can be utilized to achieve accuracies of + or - 10 cm and perhaps as good as + or - 2 cm. The initial proof of concept investigation for airborne positioning using the phase difference between the airborne and stationary GPS receivers was conducted and is examined.

  1. NASA Student Airborne Research Program

    NASA Astrophysics Data System (ADS)

    Schaller, E. L.; Shetter, R. E.

    2012-12-01

    The NASA Student Airborne Research Program (SARP) is a unique summer internship program for advanced undergraduates and early graduate students majoring in the STEM disciplines. SARP participants acquire hands-on research experience in all aspects of an airborne research campaign, including flying onboard an major NASA resource used for studying Earth system processes. In summer 2012, thirty-two participants worked in four interdisciplinary teams to study surface, atmospheric, and oceanographic processes. Participants assisted in the operation of instruments onboard the NASA P-3B aircraft where they sampled and measured atmospheric gases and imaged land and water surfaces in multiple spectral bands. Along with airborne data collection, students participated in taking measurements at field sites. Mission faculty and research mentors helped to guide participants through instrument operation, sample analysis, and data reduction. Over the eight-week program, each student developed an individual research project from the data collected and delivered a conference-style final presentation on his/her results. We will discuss the results and effectiveness of the program from the first four summers and discuss plans for the future.

  2. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  3. Domestic Mite Antigens in Floor and Airborne Dust at Workplaces in Comparison to Living Areas: A New Immunoassay to Assess Personal Airborne Allergen Exposure

    PubMed Central

    Sander, Ingrid; Zahradnik, Eva; Kraus, Gerhard; Mayer, Stefan; Neumann, Heinz-Dieter; Fleischer, Christina; Brüning, Thomas; Raulf-Heimsoth, Monika

    2012-01-01

    Objectives Allergens produced by domestic mites (DM) are among the most common allergic sensitizers and risk factors for asthma. To compare exposure levels between workplaces and living areas a new assay able to measure airborne DM antigen concentrations was developed. Methods At workplaces and in living areas, 213 floor dust samples and 92 personal inhalable dust samples were collected. For sensitive quantification of DM antigens, a new enzyme immunoassay (EIA) based on polyclonal antibodies to Dermatophagoides farinae extract was developed. Reactivity of five house dust mite and four storage mite species was tested. All dust samples were tested with the new EIA and with the Der f 1 and Der p 1-EIAs (Indoor Biotechnologies, UK) which detect major allergens from D. farinae and D. pteronyssinus by monoclonal antibodies. Samples below the detection limit in the DM-EIA were retested in an assay variant with a fluorogenic substrate (DM-FEIA). Results The newly developed DM-EIA detects antigens from all nine tested domestic mite species. It has a lower detection limit of 200 pg/ml of D.farinae protein, compared to 50 pg/ml for the DM-FEIA. DM antigens were detected by DM-EIA/FEIA in all floor dust and 80 (87%) of airborne samples. Der f 1 was found in 133 (62%) floor dust and in only 6 airborne samples, Der p 1 was found in 70 (33%) of floor samples and in one airborne sample. Der f 1 and DM concentrations were highly correlated. DM-antigens were significantly higher in inhalable airborne samples from textile recycling, bed feather filling, feed production, grain storage and cattle stables in comparison to living areas. Conclusions A new sensitive EIA directed at DM antigens was developed. DM antigen quantities were well correlated to Der f 1 values and were measurable in the majority (87%) of airborne dust samples. Some workplaces had significantly higher DM antigen concentrations than living areas. PMID:23285240

  4. Survival rate of airborne Mycobacterium bovis.

    PubMed

    Gannon, B W; Hayes, C M; Roe, J M

    2007-04-01

    Despite years of study the principle transmission route of bovine tuberculosis to cattle remains unresolved. The distribution of pathological lesions, which are concentrated in the respiratory system, and the very low dose of Mycobacterium bovis needed to initiate infection from a respiratory tract challenge suggest that the disease is spread by airborne transmission. Critical to the airborne transmission of a pathogenic microorganism is its ability to survive the stresses incurred whilst airborne. This study demonstrates that M. bovis is resistant to the stresses imposed immediately after becoming airborne, 94% surviving the first 10 min after aerosolisation. Once airborne the organism is robust, its viability decreasing with a half-life of approximately 1.5 hours. These findings support the hypothesis that airborne transmission is the principle route of infection for bovine tuberculosis. PMID:17045316

  5. The NCAR Airborne Infrared Lidar System (NAILS)

    NASA Technical Reports Server (NTRS)

    Schwiesow, R. L.; Lightsey, P. A.

    1986-01-01

    A planned airborne lidar system is presented which is intended to provide a remote sensing facility for a variety of applications. The eventual goal of the system development is a Doppler wind measurement capability for boundary layer dynamics and cloud physics applications. The first stage of development is focused initially on a direct detection lidar to measure aerosol profiles and depolarization from cloud backscatter. Because of the Doppler goal, interest in larger particles to define the top of the mixed layer, and eye safety, the first stage of the system is based on a pulsed CO2 laser. A compact, relatively simple and inexpensive system that achieves flexibility to meet the data requirements of a variety of investigators by being easily modified rather than having many different capabilities built in is the goal. Although the direct detection sensitivity is less than that for heterodyne detection, the simpler system allows the achievement of useful scientific results and operating experience towards more complex lidars while staying within budget and time constraints.

  6. Airborne chemistry: acoustic levitation in chemical analysis.

    PubMed

    Santesson, Sabina; Nilsson, Staffan

    2004-04-01

    This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals. PMID:14762640

  7. Airborne cell analysis.

    PubMed

    Santesson, S; Andersson, M; Degerman, E; Johansson, T; Nilsson, J; Nilsson, S

    2000-08-01

    A miniaturized analysis system for the study of living cells and biochemical reactions in microdroplets was developed. The technique utilizes an in-house-developed piezoelectric flow-through droplet dispenser for precise reagent supply and an ultrasonic levitator for contactless sample handling. A few-cell study was performed with living primary adipocytes. Droplets (500 nL) containing 3-15 individual cells were acoustically levitated. The addition of beta-adrenergic agonists into the levitated droplet using the droplet dispenser stimulated adipocyte lipolysis, leading to free fatty acid release and a consequent pH decrease of the surrounding buffer. The addition of insulin antagonized lipolysis and hence also the decrease in pH. The changes in pH, i.e., the cell response in the droplet, were followed using a pH-dependent fluorophore continuously monitored by fluorescence imaging detection. An image analysis computer program was employed to calculate the droplet intensities. To counteract droplet evaporation, found to affect the fluorescence intensities, a separate dispenser was used to continually add water, thus keeping the droplet volume constant. PMID:10952520

  8. An intercomparison of airborne nitric acid measurements

    NASA Astrophysics Data System (ADS)

    Gregory, G. L.; Hoell, J. M.; Huebert, B. J.; van Bramer, S. E.; Lebel, P. J.; Vay, S. A.; Marinaro, R. M.; Schiff, H. I.; Hastie, D. R.; Mackay, G. I.; Karecki, D. R.

    1990-06-01

    Results from an airborne intercomparison of techniques to measure tropospheric levels of nitric acid are discussed. The intercomparison was part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and was conducted during the summer of 1986. Instruments intercompared included a denuder tube collection system (DENUDER) with chemiluminescent detection, a niylon filter collection system (FILTER) with ion chromatography detection, and a tunable diode laser (TDLAS) multipath absorption system. Intercomparison of investigators' calibration standards were also performed as part of the test protocol. While results were somewhat "soft" and data sparse, these tests suggested that the TDLAS measurements might be high compared to the other techniques. Airborne intercomparisons were conducted predominately in the free troposphere and included encounters with marine and continental air masses. While the intercomparisons included mixing ratios to 1000 parts per trillion by volume (pptv), the majority of the results were for mixing ratios of <300 pptv. The TDLAS participated in an intercomparison of NO2 instruments (major focus) that was also conducted during the same flights. As a result the TDLAS data set is limited. Further, a significant fraction of the nitric acid measurements were below the TDLAS detection limit (75 pptv as configured for these tests). While the lack of simultaneous measurements from the three instruments limits the conclusions that can be drawn, it is clear that there can be substantial disagreement among the three techniques, even at mixing ratios above their respective detection limits. Equally clear is that at mixing ratios below 150 pptv there is very little correlation between their results. Based on these observations, an overall conclusion from the intercomparison is that none of the HNO3 techniques can be identified to unambiguously (e.g., 20% accuracy) provide measurements of HNO3 at levels often encountered in the

  9. Locating spilled oil with airborne laser fluorosensors

    NASA Astrophysics Data System (ADS)

    Brown, Carl E.; Fingas, Mervin F.; Nelson, Robert D.; Mullin, Joseph V.

    1999-02-01

    Locating oil in marine and terrestrial environments is a daunting task. There are commercially available off the shelf (COTS) sensors with a wide field-of-view (FOV) which can be used to map the overall extent of the spill. These generic sensors, however, lack the specificity required to positively identify oil and related products. The problem is exacerbated along beach and shoreline environments where a variety of organic and inorganic substrates are present. One sensor that can detect and classify oil in these environments is the laser fluorosensor. Laser fluorosensors have been under development by several agencies around the world for the past two decades. Environment Canada has been involved with laser fluorosensor development since the early 1990s. The prototype system was known as the Laser Environmental Airborne Fluorosensor (LEAF). The LEAF has recently been modified to provide real-time oil spill detection and classification. Fluorescence spectra are collected and analyzed at the rate of 100 Hz. Geo-referenced maps showing the locations of oil contamination are produced in real-time onboard the aircraft. While the LEAF has proven to be an excellent prototype sensor and a good operational tool, it has some deficiencies when it comes to oil spill response operations. A consortium including Environment Canada and the Minerals Management Service has recently funded the development of a new fluorosensor, called the Scanning Laser Environmental Airborne Fluorosensor (SLEAF). The SLEAF was designed to detect and map oil in shoreline environments where other non-specific sensors experience difficulty. Oil tends to pile up in narrow bands along the high tide line on beaches. A nadir-looking, small footprint sensor such as the LEAF would have difficulty locating oil in this situation. The SLEAF employs a pair of conical scanning mirrors to direct the laser beam in a circular pattern below the aircraft. With a sampling rate of 400 Hz and real-time spectral analysis

  10. CARABAS - an airborne VHF SAR system

    SciTech Connect

    Larsson, B.; Frolined, P.O.; Gustavsson, A.

    1996-11-01

    There is an increasing interest in imaging radar systems operating at low frequencies, Examples of civilian and military applications are detection of stealth-designed man-made objects, targets hidden under foliage, biomass estimation, and penetration into glaciers or ground. CARABAS (Coherent All Radio Band Sensing) is a new airborne SAR system developed by FOA. It is designed for operation in the lowest part of the VHF band (20-90 NHz), using horizontal polarisation. This frequency region gives the system a good ability to penetrate vegetation and to some extent ground. CARABAS is the first known SAR sensor with a capability of diffraction limited imaging, i.e. a resolution in magnitude of the adopted wavelengths. A Sabreliner business jet aircraft is used as the airborne platform. Critical parts in the development have been the antenna system, the receiver and the processing algorithms. Based upon the experiences gained with CARABAS I a major system upgrade is now taking place. The new CARABAS II system is scheduled to fly in May 1996. This system is designed to give operational performance while CARABAS I was used to verify the feasibility. The first major field campaigns are planned for the second half of 1996. CARABAS II is jointly developed by FOA and Ericsson Microwave Systems AB in Sweden. This paper will give an overview of the system design and data collected with the current radar system, including some results for forested regions. The achieved system performance will be discussed, with a presentation of the major modifications made in the new CARABAS 11 system. 12 refs., 7 figs., 2 tabs.

  11. Airborne Oceanographic Lidar (AOL) flight mission participation

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.

    1988-01-01

    From February 1986 to the present, the AOL participated in six interagency flight missions. (1) Shelf Edge Exchange Processes (SEEP II) (Department of Energy). The SEEP experiments are designed to assess the assimilative capacity of the Continental Shelf to absorb the energy by-products introduced into the near-shore ocean environment from coastal communities and marine activities such as energy production plants and offshore oil operations. (2) BIOWATT II (Office of Naval Research). The major objective of this study was to provide a better understanding of the relationships between ocean physics, biology, bioluminescence, and optics in oligotrophic portions of the Atlantic Ocean. (3) Fall Experiment (FLEX) (Department of Energy). The FLEX studies were designed to determine the fate of low salinity water in the coastal boundary zone that is advected south towards the Florida coast during autumn. (4) Greenland Sea and Icelandic Marine Biological Experiments (NASA). The investigations were designed to evaluate the distribution of surface layer chlorophyll in the Greeland Sea and in the coastal waters in the vicinity of Iceland. (5) Submerged Oceanic Scattering Layer Experiment (Naval Ocean Systems Center). This flight experiment demonstrated for the first time the feasibility of detecting and metrically measuring the depth to submerged layers of particulate matter in the shelf break region and in the inner coastal zone. (6) Microbial Exchanges and Coupling in Coastal Atlantic Systems (National Science Foundation). This investigation was designed to study the transportation and fate of particulates in coastal waters and in particular the Chesapeake Bay/coastal Atlantic Ocean. Shortly after the conduct of the flight experiments, airborne laser-induced chlorophyll a and phycoerythrin fluorescence data, as well as sea surface temperature and airborne expendable bathythermograph water column temperature profiles are supplied to cooperating institutions.

  12. Exposure to airborne asbestos in buildings

    SciTech Connect

    Lee, R.J.; Van Orden, D.R.; Corn, M.; Crump, K.S. )

    1992-08-01

    The concentration of airborne asbestos in buildings and its implication for the health of building occupants is a major public health issue. A total of 2892 air samples from 315 public, commercial, residential, school, and university buildings has been analyzed by transmission electron microscopy. The buildings that were surveyed were the subject of litigation related to suits alleging the general building occupants were exposed to a potential health hazard as a result of exposure to the presence of asbestos containing materials (ACM). The average concentration of all asbestos structures was 0.02 structures/ml (s/ml) and the average concentration of asbestos greater than or equal to 5 microns long was 0.00013 fibers/ml (f/ml). The concentration of asbestos was higher in schools than in other buildings. In 48% of indoor samples and 75% of outdoor samples, no asbestos fibers were detected. The observed airborne concentration in 74% of the indoor samples and 96% of the outdoor samples is below the Asbestos Hazard Emergency Response Act clearance level of 0.01 s/ml. Finally, using those fibers which could be seen optically, all indoor samples and all outdoor samples are below the Occupational Safety and Health Administration permissible exposure level of 0.1 f/ml for fibers greater than or equal to 5 microns in length. These results provide substantive verification of the findings of the U.S. Environmental Protection Agency public building study which found very low ambient concentrations of asbestos fibers in buildings with ACM, irrespective of the condition of the material in the buildings.

  13. Airborne Oceanographic Lidar (AOL) flight mission participation

    NASA Astrophysics Data System (ADS)

    Hoge, F. E.

    From February 1986 to the present, the AOL participated in six interagency flight missions. (1) Shelf Edge Exchange Processes (SEEP II) (Department of Energy). The SEEP experiments are designed to assess the assimilative capacity of the Continental Shelf to absorb the energy by-products introduced into the near-shore ocean environment from coastal communities and marine activities such as energy production plants and offshore oil operations. (2) BIOWATT II (Office of Naval Research). The major objective of this study was to provide a better understanding of the relationships between ocean physics, biology, bioluminescence, and optics in oligotrophic portions of the Atlantic Ocean. (3) Fall Experiment (FLEX) (Department of Energy). The FLEX studies were designed to determine the fate of low salinity water in the coastal boundary zone that is advected south towards the Florida coast during autumn. (4) Greenland Sea and Icelandic Marine Biological Experiments (NASA). The investigations were designed to evaluate the distribution of surface layer chlorophyll in the Greeland Sea and in the coastal waters in the vicinity of Iceland. (5) Submerged Oceanic Scattering Layer Experiment (Naval Ocean Systems Center). This flight experiment demonstrated for the first time the feasibility of detecting and metrically measuring the depth to submerged layers of particulate matter in the shelf break region and in the inner coastal zone. (6) Microbial Exchanges and Coupling in Coastal Atlantic Systems (National Science Foundation). This investigation was designed to study the transportation and fate of particulates in coastal waters and in particular the Chesapeake Bay/coastal Atlantic Ocean. Shortly after the conduct of the flight experiments, airborne laser-induced chlorophyll a and phycoerythrin fluorescence data, as well as sea surface temperature and airborne expendable bathythermograph water column temperature profiles are supplied to cooperating institutions.

  14. Monitoring Groundwater Contaminant Plumes Using Airborne Geophysical Data

    NASA Astrophysics Data System (ADS)

    Robinson, Martin; Oftendinger, Ulrich; Ruffell, Alastair; Cowan, Marie; Cassidy, Rachel; Comte, Jean-Christophe; Wilson, Christopher; Desissa, Mohammednur

    2013-04-01

    airborne data for the detection of groundwater contaminant plumes. This will provide a basis for assessing the influence that drift and bedrock geology exert on the feasibility of using Tellus airborne data as a plume monitoring tool. This research will facilitate a conjunctive approach for the detection and monitoring of pollution sources adversely affecting water bodies, as well as improve the targeting of costly intrusive monitoring and restoration efforts.

  15. Airborne Trailblazer: Two decades with NASA Langley's 737 flying laboratory

    NASA Technical Reports Server (NTRS)

    Wallace, Lane E.

    1994-01-01

    This book is the story of a very unique aircraft and the contributions it has made to the air transportation industry. NASA's Boeing 737-100 Transport Systems Research Vehicle started life as the prototype for Boeing's 737 series of aircraft. The airplane was acquired by LaRC in 1974 to conduct research into advanced transport aircraft technologies. In the twenty years that followed, the airplane participated in more than twenty different research projects, evolving from a research tool for a specific NASA program into a national airborne research facility. It played a critical role in developing and gaining acceptance for numerous significant transport technologies including 'glass cockpits,' airborne windshear detection systems, data links for air traffic control communications, the microwave landing system, and the satellite-based global positioning system (GPS).

  16. Identification of human motion signature using airborne radar data

    NASA Astrophysics Data System (ADS)

    McDonald, Michael; Damini, Anthony

    2013-09-01

    Data containing the radar signature of amoving person on the groundwere collected at ranges of up to 30 kmfroma moving airborne platform using the DRDC Ottawa X-bandWideband Experimental Airborne Radar (XWEAR). The human target radar echo returns were found to possess a characteristic amplitude modulated (AM) and frequency modulated (FM) signature which could be usefully characterized in terms of conventional AM and FM modulation parameters. Human detection performance after space time adaptive processing is frequently limited by false alarms arising from incomplete cancellation of large radar cross-section discretes during the whitening step. However, the clutter discretes possess different modulation characteristics from the human targets discussed above. The ability of pattern classification techniques to use this parameter measurement space to distinguish between human targets and clutter discretes is explored and preliminary results presented.

  17. Laser Imaging of Airborne Acoustic Emission by Nonlinear Defects

    NASA Astrophysics Data System (ADS)

    Solodov, Igor; Döring, Daniel; Busse, Gerd

    2008-06-01

    Strongly nonlinear vibrations of near-surface fractured defects driven by an elastic wave radiate acoustic energy into adjacent air in a wide frequency range. The variations of pressure in the emitted airborne waves change the refractive index of air thus providing an acoustooptic interaction with a collimated laser beam. Such an air-coupled vibrometry (ACV) is proposed for detecting and imaging of acoustic radiation of nonlinear spectral components by cracked defects. The photoelastic relation in air is used to derive induced phase modulation of laser light in the heterodyne interferometer setup. The sensitivity of the scanning ACV to different spatial components of the acoustic radiation is analyzed. The animated airborne emission patterns are visualized for the higher harmonic and frequency mixing fields radiated by planar defects. The results confirm a high localization of the nonlinear acoustic emission around the defects and complicated directivity patterns appreciably different from those observed for fundamental frequencies.

  18. Geoscience Applications of Airborne and Spaceborne Lidar Altimetry

    NASA Technical Reports Server (NTRS)

    Harding David J.

    1999-01-01

    Recent advances in lidar altimetry technology have enabled new methods to describe the vertical structure of the Earth's surface with great accuracy. Application of these methods in several geoscience disciplines will be described. Airborne characterization of vegetation canopy structure will be illustrated, including a validation of lidar-derived Canopy Height Profiles for closed-canopy, broadleaf forests. Airborne detection of tectonic landforms beneath dense canopy will also be illustrated, with an application mapping active fault traces in the Puget Lowland of Washington state for earthquake hazard assessment purposes. Application of data from the first and second flights of the Shuttle Laser Altimeter will also be discussed in an assessment of global digital elevation model accuracy and error characteristics. Two upcoming space flight missions will be described, the Vegetation Canopy Lidar (VCL) and the Ice, Cloud and Land Elevation Mission (ICESat), which will provide comprehensive lidar altimeter observations of the Earth's topography and vegetation cover.

  19. Off-axis measurements of atmospheric trace gases by use of an airborne ultraviolet-visible spectrometer.

    PubMed

    Petritoli, Andrea; Ravegnani, Fabrizio; Giovanelli, Giorgio; Bortoli, Daniele; Bonafè, Ubaldo; Kostadinov, Ivan; Oulanovsky, Alexey

    2002-09-20

    An airborne UV-visible spectrometer, the Gas Analyzer Spectrometer Correlating Optical Differences, airborne version (GASCOD/A4pi) was successfully operated during the Airborne Polar Experiment, Geophysica Aircraft in Antarctica airborne campaign from Ushuaia (54 degrees 49' S, 68 degrees 18' W), Argentina in southern spring 1999. The instrument measured scattered solar radiation through three optical windows with a narrow field of view (FOV), one from the zenith, two from the horizontal, as well as actinic fluxes through 2pi FOV radiometric heads. Only a few airborne measurements of scattered solar radiation at different angles from the zenith are available in the literature. With our configuration we attempted to obtain the average line-of-sight concentrations of detectable trace gases. The retrieval method, based on differential optical absorption spectroscopy, is described and results for ozone are shown and compared with measurements from an in situ instrument as the first method of validation. PMID:12269557

  20. Off-axis measurements of atmospheric trace gases by use of an airborne ultraviolet-visible spectrometer

    NASA Astrophysics Data System (ADS)

    Petritoli, Andrea; Ravegnani, Fabrizio; Giovanelli, Giorgio; Bortoli, Daniele; Bonafè, Ubaldo; Kostadinov, Ivan; Oulanovsky, Alexey

    2002-09-01

    An airborne UV-visible spectrometer, the Gas Analyzer Spectrometer Correlating Optical Differences, airborne version (GASCOD/A4π) was successfully operated during the Airborne Polar Experiment, Geophysica Aircraft in Antarctica airborne campaign from Ushuaia (54°49'S, 68°18'W), Argentina in southern spring 1999. The instrument measured scattered solar radiation through three optical windows with a narrow field of view (FOV), one from the zenith, two from the horizontal, as well as actinic fluxes through 2π FOV radiometric heads. Only a few airborne measurements of scattered solar radiation at different angles from the zenith are available in the literature. With our configuration we attempted to obtain the average line-of-sight concentrations of detectable trace gases. The retrieval method, based on differential optical absorption spectroscopy, is described and results for ozone are shown and compared with measurements from an in situ instrument as the first method of validation.

  1. Airborne wavemeter validation and calibration

    NASA Technical Reports Server (NTRS)

    Goad, Joseph H., Jr.; Rinsland, Pamela L.; Kist, Edward H., Jr.; Geier, Erika B.; Banziger, Curtis G.

    1992-01-01

    This manuscript outlines a continuing effort to validate and verify the performance of an airborne autonomous wavemeter for tuning solid state lasers to a desired wavelength. The application is measuring the vertical profiles of atmospheric water vapor using a differential absorption lidar (DIAL) technique. Improved wavemeter performance data for varying ambient temperatures are presented. This resulted when the electronic grounding and shielding were improved. The results with short pulse duration lasers are also included. These lasers show that similar performance could be obtained with lasers operating in the continuous and the pulsed domains.

  2. Cyberinfrastructure for Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.

    2009-01-01

    Since 2004 the NASA Airborne Science Program has been prototyping and using infrastructure that enables researchers to interact with each other and with their instruments via network communications. This infrastructure uses satellite links and an evolving suite of applications and services that leverage open-source software. The use of these tools has increased near-real-time situational awareness during field operations, resulting in productivity improvements and the collection of better data. This paper describes the high-level system architecture and major components, with example highlights from the use of the infrastructure. The paper concludes with a discussion of ongoing efforts to transition to operational status.

  3. Biological monitoring of airborne pollution

    SciTech Connect

    Ditz, D.W. )

    1990-01-01

    Common plants such as grasses, mosses, and even goldenrod may turn out to have a new high-tech role as monitors of airborne pollution from solid waste incinerators. Certain plants that respond to specific pollutants can provide continuous surveillance of air quality over long periods of time: they are bio-indicators. Other species accumulate pollutants and can serve as sensitive indicators of pollutants and of food-chain contamination: they are bio-accumulators. Through creative use of these properties, biological monitoring can provide information that cannot be obtained by current methods such as stack testing.

  4. Airborne Research Experience for Educators

    NASA Astrophysics Data System (ADS)

    Costa, V. B.; Albertson, R.; Smith, S.; Stockman, S. A.

    2009-12-01

    The Airborne Research Experience for Educators (AREE) Program, conducted by the NASA Dryden Flight Research Center Office of Education in partnership with the AERO Institute, NASA Teaching From Space Program, and California State University Fullerton, is a complete end-to-end residential research experience in airborne remote sensing and atmospheric science. The 2009 program engaged ten secondary educators who specialize in science, technology, engineering or mathematics in a 6-week Student Airborne Research Program (SARP) offered through NSERC. Educators participated in collection of in-flight remote sensor data during flights aboard the NASA DC-8 as well as in-situ research on atmospheric chemistry (bovine emissions of methane); algal blooms (remote sensing to determine location and degree of blooms for further in-situ analysis); and crop classification (exploration of how drought conditions in Central California have impacted almond and cotton crops). AREE represents a unique model of the STEM teacher-as-researcher professional development experience because it asks educators to participate in a research experience and then translate their experiences into classroom practice through the design, implementation, and evaluation of instructional materials that emphasize the scientific research process, inquiry-based investigations, and manipulation of real data. Each AREE Master Educator drafted a Curriculum Brief, Teachers Guide, and accompanying resources for a topic in their teaching assignment Currently, most professional development programs offer either a research experience OR a curriculum development experience. The dual nature of the AREE model engaged educators in both experiences. Educators’ content and pedagogical knowledge of STEM was increased through the review of pertinent research articles during the first week, attendance at lectures and workshops during the second week, and participation in the airborne and in-situ research studies, data

  5. Diversity and seasonal dynamics of airborne archaea

    NASA Astrophysics Data System (ADS)

    Fröhlich-Nowoisky, J.; Ruzene Nespoli, C.; Pickersgill, D. A.; Galand, P. E.; Müller-Germann, I.; Nunes, T.; Gomes Cardoso, J.; Almeida, S. M.; Pio, C.; Andreae, M. O.; Conrad, R.; Pöschl, U.; Després, V. R.

    2014-11-01

    Archaea are widespread and abundant in many terrestrial and aquatic environments, and are thus outside extreme environments, accounting for up to ~10% of the prokaryotes. Compared to bacteria and other microorganisms, however, very little is known about the abundance, diversity, and dispersal of archaea in the atmosphere. By means of DNA analysis and Sanger sequencing targeting the 16S rRNA (435 sequences) and amoA genes in samples of air particulate matter collected over 1 year at a continental sampling site in Germany, we obtained first insights into the seasonal dynamics of airborne archaea. The detected archaea were identified as Thaumarchaeota or Euryarchaeota, with soil Thaumarchaeota (group I.1b) being present in all samples. The normalized species richness of Thaumarchaeota correlated positively with relative humidity and negatively with temperature. This together with an increase in bare agricultural soil surfaces may explain the diversity peaks observed in fall and winter. The detected Euryarchaeota were mainly predicted methanogens with a low relative frequency of occurrence. A slight increase in their frequency during spring may be linked to fertilization processes in the surrounding agricultural fields. Comparison with samples from the Cape Verde islands (72 sequences) and from other coastal and continental sites indicates that the proportions of Euryarchaeota are enhanced in coastal air, which is consistent with their suggested abundance in marine surface waters. We conclude that air transport may play an important role in the dispersal of archaea, including assumed ammonia-oxidizing Thaumarchaeota and methanogens.

  6. Diversity and seasonal dynamics of airborne Archaea

    NASA Astrophysics Data System (ADS)

    Fröhlich-Nowoisky, J.; Ruzene Nespoli, C.; Pickersgill, D. A.; Galand, P. E.; Müller-Germann, I.; Nunes, T.; Gomes Cardoso, J.; Marta Almeida, S.; Pio, C.; Andreae, M. O.; Conrad, R.; Pöschl, U.; Després, V. R.

    2014-05-01

    Archaea are widespread and abundant in many terrestrial and aquatic environments, accounting for up to ∼10% of the prokaryotes. Compared to Bacteria and other microorganisms, however, very little is known about the abundance, diversity, and dispersal of Archaea in the atmosphere. By DNA analysis targeting the 16S rRNA and amoA genes in samples of air particulate matter collected over one year at a continental sampling site in Germany, we obtained first insights into the seasonal dynamics of airborne Archaea. The detected Archaea were identified as Thaumarchaeota or Euryarchaeota, with soil Thaumarchaeota (group I.1b) being present in all samples. The normalized species richness of Thaumarchaeota correlated positively with relative humidity and negatively with temperature. This together with an increase of bare agricultural soil surfaces may explain the diversity peaks observed in fall and winter. The detected Euryarchaeota were mainly methanogens with a low relative frequency of occurrence. A slight increase in their frequency during spring may be linked to fertilization processes in the surrounding agricultural fields. Comparison with samples from the Cape Verde islands and from other coastal and continental sites indicates that the proportions of Euryarchaeota are enhanced in coastal air, which is consistent with their suggested abundance in marine surface waters. We conclude that air transport may play an important role for the dispersal of Archaea, including ammonia-oxidizing Thaumarchaeota and methanogens. Also, anthropogenic activities might influence the atmospheric abundance and diversity of Archaea.

  7. Airborne Visible Laser Optical Communications Program (AVLOC)

    NASA Technical Reports Server (NTRS)

    Ward, J. H.

    1975-01-01

    The design, development, and operation of airborne and ground-based laser communications and laser radar hardware is described in support of the Airborne Visible Laser Optical Communication program. The major emphasis is placed on the development of a highly flexible test bed for the evaluation of laser communications systems techniques and components in an operational environment.

  8. Global Test Range: Toward Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Mace, Thomas H.; Freudinger, Larry; DelFrate John H.

    2008-01-01

    This viewgraph presentation reviews the planned global sensor network that will monitor the Earth's climate, and resources using airborne sensor systems. The vision is an intelligent, affordable Earth Observation System. Global Test Range is a lab developing trustworthy services for airborne instruments - a specialized Internet Service Provider. There is discussion of several current and planned missions.

  9. Airborne Relay-Based Regional Positioning System

    PubMed Central

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-01-01

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations. PMID:26029953

  10. The Continuous wavelet in airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Liang, X.; Liu, L.

    2013-12-01

    Airborne gravimetry is an efficient method to recover medium and high frequency band of earth gravity over any region, especially inaccessible areas, which can measure gravity data with high accuracy,high resolution and broad range in a rapidly and economical way, and It will play an important role for geoid and geophysical exploration. Filtering methods for reducing high-frequency errors is critical to the success of airborne gravimetry due to Aircraft acceleration determination based on GPS.Tradiontal filters used in airborne gravimetry are FIR,IIR filer and so on. This study recommends an improved continuous wavelet to process airborne gravity data. Here we focus on how to construct the continuous wavelet filters and show their working principle. Particularly the technical parameters (window width parameter and scale parameter) of the filters are tested. Then the raw airborne gravity data from the first Chinese airborne gravimetry campaign are filtered using FIR-low pass filter and continuous wavelet filters to remove the noise. The comparison to reference data is performed to determinate external accuracy, which shows that continuous wavelet filters applied to airborne gravity in this thesis have good performances. The advantages of the continuous wavelet filters over digital filters are also introduced. The effectiveness of the continuous wavelet filters for airborne gravimetry is demonstrated through real data computation.

  11. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  12. Airborne Oceanographic Lidar (AOL) (Global Carbon Cycle)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This bimonthly contractor progress report covers the operation, maintenance and data management of the Airborne Oceanographic Lidar and the Airborne Topographic Mapper. Monthly activities included: mission planning, sensor operation and calibration, data processing, data analysis, network development and maintenance and instrument maintenance engineering and fabrication.

  13. Meeting Review: Airborne Aerosol Inlet Workshop

    NASA Technical Reports Server (NTRS)

    Baumgardner, Darrel; Huebert, Barry; Wilson, Chuck

    1991-01-01

    Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

  14. Laser Communications Airborne Testbed: Potential For An Air-To-Satellite Laser Communications Link

    NASA Astrophysics Data System (ADS)

    Feldmann, Robert J.

    1988-05-01

    The Laser Communications Airborne Testbed (LCAT) offers an excellent opportunity for testing of an air-to-satellite laser communications link with the NASA Advanced Communications Technology Satellite (ACTS). The direct detection laser portion of the ACTS is suitable for examining the feasibility of an airborne terminal. Development of an airborne laser communications terminal is not currently part of the ACTS program; however, an air-to-satellite link is of interest. The Air Force performs airborne laser communications experiments to examine the potential usefulness of this technology to future aircraft. Lasers could be used, for example, by future airborne command posts and reconnaissance aircraft to communicate via satellite over long distances and transmit large quantities of data in the fastest way possible from one aircraft to another or to ground sites. Lasers are potentially secure, jam resistant and hard to detect and in this regard increase the survivability of the users. Under a contract awarded by Aeronautical Systems Division's Avionics Laboratory, a C-135E testbed aircraft belonging to ASD's 4950th Test Wing will be modified to create a Laser Communications Airborne Testbed. The contract is for development and fabrication of laser testbed equipment and support of the aircraft modification effort by the Test Wing. The plane to be modified is already in use as a testbed for other satellite communications projects and the LCAT effort will expand those capabilities. This analysis examines the characteristics of an LCAT to ACTS direct detection communications link. The link analysis provides a measure of the feasibility of developing an airborne laser terminal which will interface directly to the LCAT. Through the existence of the LCAT, the potential for development of an air-to-satellite laser communications terminal for the experimentation with the ACTS system is greatly enhanced.

  15. A theoretical model for airborne radars

    NASA Astrophysics Data System (ADS)

    Faubert, D.

    1989-11-01

    This work describes a general theory for the simulation of airborne (or spaceborne) radars. It can simulate many types of systems including Airborne Intercept and Airborne Early Warning radars, airborne missile approach warning systems etc. It computes the average Signal-to-Noise ratio at the output of the signal processor. In this manner, one obtains the average performance of the radar without having to use Monte Carlo techniques. The model has provision for a waveform without frequency modulation and one with linear frequency modulation. The waveform may also have frequency hopping for Electronic Counter Measures or for clutter suppression. The model can accommodate any type of encounter including air-to-air, air-to-ground (look-down) and rear attacks. It can simulate systems with multiple phase centers on receive for studying advanced clutter or jamming interference suppression techniques. An Airborne Intercept radar is investigated to demonstrate the validity and the capability of the model.

  16. Topography and Vegetation Characterization using Dual-Wavelength Airborne Lidar

    NASA Astrophysics Data System (ADS)

    Neuenschwander, A. L.; Bradford, B.; Magruder, L. A.

    2014-12-01

    Monitoring Earth surface dynamics at an ever increasing resolution has helped to support the characterization of local topography, including vegetated and urban environments. Airborne remote sensing using light detection and ranging (LIDAR) is naturally suited to characterize vegetation and landscapes as it provides detailed three-dimensional spatial data with multiple elevation recordings for each laser pulse. The full waveform LIDAR receiver is unique in this aspect as it can capture and record the complete temporal history of the reflected signal, which contains detailed information about the structure of the objects and ground surfaces illuminated by the beam. This study examines the utility of co-collected, dual-wavelength, full waveform LIDAR data to characterize vegetation and landscapes through the extraction of waveform features, including total waveform energy, canopy energy distribution, and foliage penetration metrics. Assessments are performed using data collected in May 2014 over Monterey, CA, including the Naval Postgraduate School campus area as well as the Point Lobos State Natural Reserve situated on the Monterey coast. The surveys were performed with the Chiroptera dual-laser LIDAR mapping system from Airborne Hydrography AB (AHAB), which can collect both green (515nm) and near infrared (1064nm) waveforms simultaneously. Making use of the dual waveforms allows for detailed characterization of the vegetation and landscape not previously possible with airborne LIDAR.

  17. High Resolution Airborne Digital Imagery for Precision Agriculture

    NASA Technical Reports Server (NTRS)

    Herwitz, Stanley R.

    1998-01-01

    The Environmental Research Aircraft and Sensor Technology (ERAST) program is a NASA initiative that seeks to demonstrate the application of cost-effective aircraft and sensor technology to private commercial ventures. In 1997-98, a series of flight-demonstrations and image acquisition efforts were conducted over the Hawaiian Islands using a remotely-piloted solar- powered platform (Pathfinder) and a fixed-wing piloted aircraft (Navajo) equipped with a Kodak DCS450 CIR (color infrared) digital camera. As an ERAST Science Team Member, I defined a set of flight lines over the largest coffee plantation in Hawaii: the Kauai Coffee Company's 4,000 acre Koloa Estate. Past studies have demonstrated the applications of airborne digital imaging to agricultural management. Few studies have examined the usefulness of high resolution airborne multispectral imagery with 10 cm pixel sizes. The Kodak digital camera integrated with ERAST's Airborne Real Time Imaging System (ARTIS) which generated multiband CCD images consisting of 6 x 106 pixel elements. At the designated flight altitude of 1,000 feet over the coffee plantation, pixel size was 10 cm. The study involved the analysis of imagery acquired on 5 March 1998 for the detection of anomalous reflectance values and for the definition of spectral signatures as indicators of tree vigor and treatment effectiveness (e.g., drip irrigation; fertilizer application).

  18. Airborne trace contaminants of possible interest in CELSS

    NASA Technical Reports Server (NTRS)

    Garavelli, J. S.

    1986-01-01

    One design goal of Closed Ecological Life Support Systems (CELSS) for long duration space missions is to maintain an atmosphere which is healthy for all the desirable biological species and not deleterious to any of the mechanical components in that atmosphere. CELESS design must take into account the interactions of at least six major components; (1) humans and animals, (2) higher plants, (3) microalgae, (4) bacteria and fungi, (5) the waste processing system, and (6) other mechanical systems. Each of these major components can be both a source and a target of airborne trace contaminants in a CELSS. A range of possible airborne trace contaminants is discussed within a chemical classification scheme. These contaminants are analyzed with respect to their probable sources among the six major components and their potential effects on those components. Data on airborne chemical contaminants detected in shuttle missions is presented along with this analysis. The observed concentrations of several classes of compounds, including hydrocarbons, halocarbons, halosilanes, amines and nitrogen oxides, are considered with respect to the problems which they present to CELSS.

  19. Airborne endotoxin in fine particulate matter in Beijing

    NASA Astrophysics Data System (ADS)

    Guan, Tianjia; Yao, Maosheng; Wang, Junxia; Fang, Yanhua; Hu, Songhe; Wang, Yan; Dutta, Anindita; Yang, Junnan; Wu, Yusheng; Hu, Min; Zhu, Tong

    2014-11-01

    Endotoxin is an important biological component of particulate matter (PM) which, upon inhalation, can induce adverse health effects, and also possibly complicate the diseases in combination with other pollutants. From 1 March 2012 to 27 February 2013 we collected air samples using quartz filters daily for the quantification of airborne endotoxin and also fine PM (PM2.5) in Beijing, China. The geometric means for endotoxin concentration and the fraction of endotoxin in PM were 0.65 EU/m3 (range: 0.10-75.02) and 10.25 EU/mg PM2.5 (range: 0.38-1627.29), respectively. The endotoxin concentrations were shown to vary greatly with seasons, typically with high values in the spring and winter seasons. Temperature and relative humidity, as well as concentrations of sulfur dioxide and nitrogen oxides were found to be significantly correlated with airborne endotoxin concentrations (p < 0.05). Additionally, positive correlations were also detected between endotoxin concentrations and natural sources of Na+, K+, Mg2+, and F-, while negative correlations were observed between endotoxin concentrations and anthropogenic sources of P, Co, Zn, As, and Tl. Oxidative potential analysis revealed that endotoxin concentrations were positively correlated with reactive oxygen species (ROS), but not dithiothreitol (DTT) of PM. This study provided the first continuous time series of airborne endotoxin concentrations in Beijing, and identifies its potential associations with atmospheric factors. The information developed here can assist in the assessment of health effects of air pollution in Beijing.

  20. Multispectral Airborne Laser Scanning for Automated Map Updating

    NASA Astrophysics Data System (ADS)

    Matikainen, Leena; Hyyppä, Juha; Litkey, Paula

    2016-06-01

    During the last 20 years, airborne laser scanning (ALS), often combined with multispectral information from aerial images, has shown its high feasibility for automated mapping processes. Recently, the first multispectral airborne laser scanners have been launched, and multispectral information is for the first time directly available for 3D ALS point clouds. This article discusses the potential of this new single-sensor technology in map updating, especially in automated object detection and change detection. For our study, Optech Titan multispectral ALS data over a suburban area in Finland were acquired. Results from a random forests analysis suggest that the multispectral intensity information is useful for land cover classification, also when considering ground surface objects and classes, such as roads. An out-of-bag estimate for classification error was about 3% for separating classes asphalt, gravel, rocky areas and low vegetation from each other. For buildings and trees, it was under 1%. According to feature importance analyses, multispectral features based on several channels were more useful that those based on one channel. Automatic change detection utilizing the new multispectral ALS data, an old digital surface model (DSM) and old building vectors was also demonstrated. Overall, our first analyses suggest that the new data are very promising for further increasing the automation level in mapping. The multispectral ALS technology is independent of external illumination conditions, and intensity images produced from the data do not include shadows. These are significant advantages when the development of automated classification and change detection procedures is considered.

  1. An intercomparison of airborne nitric acid measurements

    SciTech Connect

    Gregory, G.L.; Hoell, J.M. Jr.; LeBel, P.J.; Vay, S.A. ); Huebert, B.J. ); Van Bramer, S.E. ); Marinaro, R.M. ); Schiff, H.I.; Hastie, D.R. ); Mackay, G.I.; Karecki, D.R. )

    1990-06-20

    Instruments intercompared included a denuder tube collection system (DENUDER) with chemiluminescent detection, a nylon filter collection system (FILTER) with ion chromatography detection, and a tunable diode laser (TDLAS) multipath absorption system. While results were somewhat soft and data sparse, these tests suggested that the TDLAS measurements might be high compared to the other techniques. Airborne intercomparisons were conducted predominantly in the free troposphere and included encounters with marine and continental air masses. While the intercomparisons included mixing ratios to 1,000 parts per trillion by volume (pptv), the majority of the results were for mixing ratios of <300 pptv. While the lack of simultaneous measurements from the three instruments limits the conclusions that can be drawn, it is clear that there can be substantial disagreement among the three techniques, even at mixing ratios above their respective detection limits. Equally clear is that at mixing ratios below 150 pptv there is very little correlation between their results. Based on these observations, an overall conclusion from the intercomparison is that none of the HNO{sub 3} techniques can be identified to unambiguously (e.g., 20% accuracy) provide measurements of HNO{sub 3} at levels often encountered in the free troposphere (e.g., 100 pptv). However, at the more elevated levels of HNO{sub 3} (e.g., >150 pptv), both the FILTER and DENUDER techniques reported the same levels of nitric acid, while as suggested by the results from the standards intercomparison, the TDLAS reported higher nitric acid values than the other two techniques.

  2. Comprehensive analysis of airborne contaminants from recent Spacelab missions

    NASA Technical Reports Server (NTRS)

    Matney, M. L.; Boyd, J. F.; Covington, P. A.; Leano, H. J.; Pierson, D. L.; Limero, T. F.; James, J. T.

    1993-01-01

    The Shuttle experiences unique air contamination problems because of microgravity and the closed environment. Contaminant build-up in the closed atmosphere and the lack of a gravitational settling mechanism have produced some concern in previous missions about the amount of solid and volatile airborne contaminants in the Orbiter and Spacelab. Degradation of air quality in the Orbiter/Spacelab environment, through processes such as chemical contamination, high solid-particulate levels, and high microbial levels, may affect crew performance and health. A comprehensive assessment of the Shuttle air quality was undertaken during STS-40 and STS-42 missions, in which a variety of air sampling and monitoring techniques were employed to determine the contaminant load by characterizing and quantitating airborne contaminants. Data were collected on the airborne concentrations of volatile organic compounds, microorganisms, and particulate matter collected on Orbiter/Spacelab air filters. The results showed that STS-40/42 Orbiter/Spacelab air was toxicologically safe to breathe, except during STS-40 when the Orbiter Refrigerator/Freezer unit was releasing noxious gases in the middeck. On STS-40, the levels of airborne bacteria appeared to increase as the mission progressed; however, this trend was not observed for the STS-42 mission. Particulate matter in the Orbiter/Spacelab air filters was chemically analyzed in order to determine the source of particles. Only small amounts of rat hair and food bar (STS-40) and traces of soiless medium (STS-42) were detected in the Spacelab air filters, indicating that containment for Spacelab experiments was effective.

  3. Presence of airborne fibers in tungsten refining and manufacturing processes: preliminary characterization.

    PubMed

    McKernan, John L; Toraason, Mark A; Fernback, Joseph E

    2008-07-01

    In tungsten refining and manufacturing processes, a series of tungsten oxides (WO(X)) are typically formed as intermediates in the production of tungsten powder. Studies in the Swedish tungsten refining and manufacturing industry have shown that intermediate tungsten refining processes can create WO(X) fibers. The purpose of the present study was to identify and provide a preliminary characterization of airborne tungsten-containing fiber dimensions, elemental composition, and concentrations in the U.S. tungsten refining and manufacturing industry. To provide the preliminary characterization, 10 static air samples were collected during the course of normal employee work activities and analyzed using standard fiber sampling and counting methods. Results from transmission electron microscopy analyses conducted indicate that airborne fibers with length > 0.5 microm, diameter > 0.01 microm, and aspect ratio > or = 3:1, with a geometric mean (GM) length of approximately 2.0 microm and GM diameter of approximately 0.25 microm, were present on 9 of the 10 air samples collected. Energy dispersive X-ray spectrometry results indicate that airborne fibers prior to the carburization process consisted primarily of tungsten and oxygen, with other elements being detected in trace quantities. Results from an air sample collected at the carburization process indicated the presence of fibers composed primarily of tungsten with oxygen and carbon, and traces of other elements. Based on National Institute for Occupational Safety and Health standard fiber counting rules, airborne fiber concentrations ranged from below the limit of detection to 0.14 f/cm(3). The calcining process was associated with the highest airborne fiber concentrations. More than 99% (574/578) of the airborne fibers identified had an aerodynamic diameter

  4. Modis-N airborne simulator

    NASA Technical Reports Server (NTRS)

    Cech, Steven D.

    1992-01-01

    All required work associated with the above referenced contract has been successfully completed at this time. The Modis-N Airborne Simulator has been developed from existing AB184 Wildfire spectrometer parts as well as new detector arrays, optical components, and associated mechanical and electrical hardware. The various instrument components have been integrated into an operational system which has undergone extensive laboratory calibration and testing. The instrument has been delivered to NASA Ames where it will be installed on the NASA ER-2. The following paragraphs detail the specific tasks performed during the contract effort, the results obtained during the integration and testing of the instrument, and the conclusions which can be drawn from this effort.

  5. Airborne imaging spectrometer development tasks

    NASA Astrophysics Data System (ADS)

    Bolten, John

    The tasks that must be completed to design and build an airborne imaging spectrometer are listed. The manpower and resources required to do these tasks must be estimated by the people responsible for that work. The tasks are broken down by instrument subsystem or discipline. The instrument performance can be assessed at various stages during the development. The initial assessment should be done with the preliminary computer model. The instrument calibration facilities should be designed, but no calibration facilities are needed. The intermediate assessment can be done when the front end has been assembled. The preliminary instrument calibration facility should be available at this stage. The final assessment can only be done when the instrument is complete and ready for flight. For this, the final instrument calibration facility and the flight qualification facilities must be ready. The final assessment is discussed in each discipline under the section on integration and test.

  6. Research on MLS airborne antenna

    NASA Technical Reports Server (NTRS)

    Yu, C. L.; Burnside, W. D.

    1976-01-01

    Numerical solutions for the radiation patterns of antennas mounted on aircraft are developed. The airborne antenna problems associated with the Microwave Landing System (MLS) are emphasized. Based on the requirements of the MLS, volumetric pattern solutions are essential. Previous attempts at solving for the volumetric patterns were found to be far too complex and very inefficient. However as a result of previous efforts, it is possible to combine the elevation and roll plane pattern solutions to give the complete volumetric pattern. This combination is described as well as the aircraft simulation models used in the analysis. A numerical technique is presented to aid in the simulation of the aircraft studied. Finally, a description of the input data used in the computer code is given.

  7. Global deposition of airborne dioxin.

    PubMed

    Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

    2013-10-15

    We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others. PMID:23962732

  8. Development of an airborne laser bathymeter

    NASA Technical Reports Server (NTRS)

    Kim, H., H.; Cervenka, P. O.; Lankford, C. B.

    1975-01-01

    An airborne laser depth sounding system was built and taken through a complete series of field tests. Two green laser sources were tried: a pulsed neon laser at 540 nm and a frequency-doubled Nd:YAG transmitter at 532 nm. To obtain a depth resolution of better than 20 cm, the pulses had a duration of 5 to 7 nanoseconds and could be fired up to at rates of 50 pulses per second. In the receiver, the signal was detected by a photomultiplier tube connected to a 28 cm diameter Cassegrainian telescope that was aimed vertically downward. Oscilloscopic traces of the signal reflected from the sea surface and the ocean floor could either be recorded by a movie camera on 35 mm film or digitized into 500 discrete channels of information and stored on magnetic tape, from which depth information could be extracted. An aerial color movie camera recorded the geographic footprint while a boat crew of oceanographers measured depth and other relevant water parameters. About two hundred hours of flight time on the NASA C-54 airplane in the area of Chincoteague, Virginia, the Chesapeake Bay, and in Key West, Florida, have yielded information on the actual operating conditions of such a system and helped to optimize the design. One can predict the maximum depth attainable in a mission by measuring the effective attenuation coefficient in flight. This quantity is four times smaller than the usual narrow beam attenuation coefficient. Several square miles of a varied underwater landscape were also mapped.

  9. On-site airborne pheromone sensing.

    PubMed

    Wehrenfennig, Christoph; Schott, Matthias; Gasch, Tina; Düring, Rolf Alexander; Vilcinskas, Andreas; Kohl, Claus-Dieter

    2013-08-01

    Pheromones and other semiochemicals play an important role in the natural world by influencing the behavior of plants, mammals, and insects. In the latter case, species-dependent pheromone communication has numerous applications, including the detection, trapping, monitoring and guiding of insects, as well as pest management in agriculture. On-site sensors are desirable when volatile organic compounds (VOCs) are used as semiochemicals. Insects have evolved highly selective sensors for such compounds, so biosensors comprising complete insects, isolated organs or individual proteins can be highly effective. However, isolated insect organs have a limited lifetime as biosensor, so biomimetic approaches are needed for prolonged monitoring, novel applications, or measurements in challenging environments. We discuss the development of on-site biosensors and biomimetic approaches for airborne-pheromone sensing, together with biomimetic VOC sensor systems. Furthermore, the infochemical effect describing the anthropogenic contamination of the ecosystem through semiochemicals, will be considered in the context of novel on-site pheromone sensing-systems. PMID:23842897

  10. ARM Airborne Continuous carbon dioxide measurements

    DOE Data Explorer

    Biraud, Sebastien

    2013-03-26

    The heart of the AOS CO2 Airborne Rack Mounted Analyzer System is the AOS Manifold. The AOS Manifold is a nickel coated aluminum analyzer and gas processor designed around two identical nickel-plated gas cells, one for reference gas and one for sample gas. The sample and reference cells are uniquely designed to provide optimal flushing efficiency. These cells are situated between a black-body radiation source and a photo-diode detection system. The AOS manifold also houses flow meters, pressure sensors and control valves. The exhaust from the analyzer flows into a buffer volume which allows for precise pressure control of the analyzer. The final piece of the analyzer is the demodulator board which is used to convert the DC signal generated by the analyzer into an AC response. The resulting output from the demodulator board is an averaged count of CO2 over a specified hertz cycle reported in volts and a corresponding temperature reading. The system computer is responsible for the input of commands and therefore works to control the unit functions such as flow rate, pressure, and valve control.The remainder of the system consists of compressors, reference gases, air drier, electrical cables, and the necessary connecting plumbing to provide a dry sample air stream and reference air streams to the AOS manifold.

  11. Airborne remote sensing of forest biomes

    NASA Technical Reports Server (NTRS)

    Sader, Steven A.

    1987-01-01

    Airborne sensor data of forest biomes obtained using an SAR, a laser profiler, an IR MSS, and a TM simulator are presented and examined. The SAR was utilized to investigate forest canopy structures in Mississippi and Costa Rica; the IR MSS measured forest canopy temperatures in Oregon and Puerto Rico; the TM simulator was employed in a tropical forest in Puerto Rico; and the laser profiler studied forest canopy characteristics in Costa Rica. The advantages and disadvantages of airborne systems are discussed. It is noted that the airborne sensors provide measurements applicable to forest monitoring programs.

  12. Passive IR polarization sensors: a new technology for mine detection

    NASA Astrophysics Data System (ADS)

    Barbour, Blair A.; Jones, Michael W.; Barnes, Howard B.; Lewis, Charles P.

    1998-09-01

    The problem of mine and minefield detection continues to provide a significant challenge to sensor systems. Although the various sensor technologies (infrared, ground penetrating radar, etc.) may excel in certain situations there does not exist a single sensor technology that can adequately detect mines in all conditions such as time of day, weather, buried or surface laid, etc. A truly robust mine detection system will likely require the fusion of data from multiple sensor technologies. The performance of these systems, however, will ultimately depend on the performance of the individual sensors. Infrared (IR) polarimetry is a new and innovative sensor technology that adds substantial capabilities to the detection of mines. IR polarimetry improves on basic IR imaging by providing improved spatial resolution of the target, an inherent ability to suppress clutter, and the capability for zero (Delta) T imaging. Nichols Research Corporation (Nichols) is currently evaluating the effectiveness of IR polarization for mine detection. This study is partially funded by the U.S. Army Night Vision & Electronic Sensors Directorate (NVESD). The goal of the study is to demonstrate, through phenomenology studies and limited field trials, that IR polarizaton outperforms conventional IR imaging in the mine detection arena.

  13. Test of IR arrays on the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Russell, R. W.; Rossano, G. S.; Lynch, D. K.; Colon-Bonet, G. T.; Hackwell, J. A.

    1986-01-01

    NASA's Kuiper Airborne Observatory, which is a C-141 transport aircraft equipped with a 90-cm, all-reflective altazimuth telescope, has been engaged in the Kuiper Infrared Technology Experiment. Attention is presently given to the Experiment's flight series for state-of-the-art two-dimensional, 500-element arrays that use either blocked impurity band or bulk silicon devices. The switched FET readout scheme used on the three arrays flown thus far yields exceptionally low crosstalk. System sensitivities are found to be sufficient for the detection of both pointlike and extended sources; several of each type have been used in staring and scanning experiments.

  14. An automated data exploitation system for airborne sensors

    NASA Astrophysics Data System (ADS)

    Chen, Hai-Wen; McGurr, Mike

    2014-06-01

    Advanced wide area persistent surveillance (WAPS) sensor systems on manned or unmanned airborne vehicles are essential for wide-area urban security monitoring in order to protect our people and our warfighter from terrorist attacks. Currently, human (imagery) analysts process huge data collections from full motion video (FMV) for data exploitation and analysis (real-time and forensic), providing slow and inaccurate results. An Automated Data Exploitation System (ADES) is urgently needed. In this paper, we present a recently developed ADES for airborne vehicles under heavy urban background clutter conditions. This system includes four processes: (1) fast image registration, stabilization, and mosaicking; (2) advanced non-linear morphological moving target detection; (3) robust multiple target (vehicles, dismounts, and human) tracking (up to 100 target tracks); and (4) moving or static target/object recognition (super-resolution). Test results with real FMV data indicate that our ADES can reliably detect, track, and recognize multiple vehicles under heavy urban background clutters. Furthermore, our example shows that ADES as a baseline platform can provide capability for vehicle abnormal behavior detection to help imagery analysts quickly trace down potential threats and crimes.

  15. Airborne infrared hyperspectral imager for intelligence, surveillance and reconnaissance applications

    NASA Astrophysics Data System (ADS)

    Lagueux, Philippe; Puckrin, Eldon; Turcotte, Caroline S.; Gagnon, Marc-André; Bastedo, John; Farley, Vincent; Chamberland, Martin

    2012-09-01

    Persistent surveillance and collection of airborne intelligence, surveillance and reconnaissance information is critical in today's warfare against terrorism. High resolution imagery in visible and infrared bands provides valuable detection capabilities based on target shapes and temperatures. However, the spectral resolution provided by a hyperspectral imager adds a spectral dimension to the measurements, leading to additional tools for detection and identification of targets, based on their spectral signature. The Telops Hyper-Cam sensor is an interferometer-based imaging system that enables the spatial and spectral analysis of targets using a single sensor. It is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides datacubes of up to 320×256 pixels at spectral resolutions as fine as 0.25 cm-1. The LWIR version covers the 8.0 to 11.8 μm spectral range. The Hyper-Cam has been recently used for the first time in two compact airborne platforms: a bellymounted gyro-stabilized platform and a gyro-stabilized gimbal ball. Both platforms are described in this paper, and successful results of high-altitude detection and identification of targets, including industrial plumes, and chemical spills are presented.

  16. Airborne infrared hyperspectral imager for intelligence, surveillance, and reconnaissance applications

    NASA Astrophysics Data System (ADS)

    Puckrin, Eldon; Turcotte, Caroline S.; Gagnon, Marc-André; Bastedo, John; Farley, Vincent; Chamberland, Martin

    2012-06-01

    Persistent surveillance and collection of airborne intelligence, surveillance and reconnaissance information is critical in today's warfare against terrorism. High resolution imagery in visible and infrared bands provides valuable detection capabilities based on target shapes and temperatures. However, the spectral resolution provided by a hyperspectral imager adds a spectral dimension to the measurements, leading to additional tools for detection and identification of targets, based on their spectral signature. The Telops Hyper-Cam sensor is an interferometer-based imaging system that enables the spatial and spectral analysis of targets using a single sensor. It is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides datacubes of up to 320×256 pixels at spectral resolutions as fine as 0.25 cm-1. The LWIR version covers the 8.0 to 11.8 μm spectral range. The Hyper-Cam has been recently used for the first time in two compact airborne platforms: a belly-mounted gyro-stabilized platform and a gyro-stabilized gimbal ball. Both platforms are described in this paper, and successful results of high-altitude detection and identification of targets, including industrial plumes, and chemical spills are presented.

  17. Airborne Gamma-Spectrometry in Switzerland

    SciTech Connect

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-07

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of {sup 137}Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  18. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect

    Glissmeyer, John A.

    2010-10-18

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  19. SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH

    EPA Science Inventory

    Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (<_ 1....

  20. Mapping of airborne Doppler radar data

    SciTech Connect

    Lee, W.; Dodge, P.; Marks, F.D. Jr.; Hildebrand, P.H. NOAA, Miami, FL )

    1994-04-01

    Two sets of equations are derived to (1) map airborne Doppler radar data from an aircraft-relative coordinate system to an earth-relative coordinate system, and (2) remove the platform motion from the observed Doppler velocities. These equations can be applied to data collected by the National Oceanic and Atmospheric Administration WP-3D system, the National Center for Atmospheric Research Electra Doppler Radar (ELDORA) system, and other airborne radar systems.