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.

High resolution mapping and classification of oyster habitats in nearshore Louisiana using sidescan sonar

USGS Publications Warehouse

Allen, Y.C.; Wilson, C.A.; Roberts, H.H.; Supan, J.

2005-01-01

Sidescan sonar holds great promise as a tool to quantitatively depict the distribution and extent of benthic habitats in Louisiana's turbid estuaries. In this study, we describe an effective protocol for acoustic sampling in this environment. We also compared three methods of classification in detail: mean-based thresholding, supervised, and unsupervised techniques to classify sidescan imagery into categories of mud and shell. Classification results were compared to ground truth results using quadrat and dredge sampling. Supervised classification gave the best overall result (kappa = 75%) when compared to quadrat results. Classification accuracy was less robust when compared to all dredge samples (kappa = 21-56%), but increased greatly (90-100%) when only dredge samples taken from acoustically homogeneous areas were considered. Sidescan sonar when combined with ground truth sampling at an appropriate scale can be effectively used to establish an accurate substrate base map for both research applications and shellfish management. The sidescan imagery presented here also provides, for the first time, a detailed presentation of oyster habitat patchiness and scale in a productive oyster growing area.

Multiple-Array Detection, Association and Location of Infrasound and Seismo-Acoustic Events - Utilization of Ground Truth Information

DTIC Science & Technology

2010-09-01

MULTIPLE-ARRAY DETECTION, ASSOCIATION AND LOCATION OF INFRASOUND AND SEISMO-ACOUSTIC EVENTS – UTILIZATION OF GROUND TRUTH INFORMATION Stephen J...and infrasound data from seismo-acoustic arrays and apply the methodology to regional networks for validation with ground truth information. In the...initial year of the project automated techniques for detecting, associating and locating infrasound signals were developed. Recently, the location

Modeling multiple time series annotations as noisy distortions of the ground truth: An Expectation-Maximization approach.

PubMed

Gupta, Rahul; Audhkhasi, Kartik; Jacokes, Zach; Rozga, Agata; Narayanan, Shrikanth

2018-01-01

Studies of time-continuous human behavioral phenomena often rely on ratings from multiple annotators. Since the ground truth of the target construct is often latent, the standard practice is to use ad-hoc metrics (such as averaging annotator ratings). Despite being easy to compute, such metrics may not provide accurate representations of the underlying construct. In this paper, we present a novel method for modeling multiple time series annotations over a continuous variable that computes the ground truth by modeling annotator specific distortions. We condition the ground truth on a set of features extracted from the data and further assume that the annotators provide their ratings as modification of the ground truth, with each annotator having specific distortion tendencies. We train the model using an Expectation-Maximization based algorithm and evaluate it on a study involving natural interaction between a child and a psychologist, to predict confidence ratings of the children's smiles. We compare and analyze the model against two baselines where: (i) the ground truth in considered to be framewise mean of ratings from various annotators and, (ii) each annotator is assumed to bear a distinct time delay in annotation and their annotations are aligned before computing the framewise mean.

An Enhanced Collaborative-Software Environment for Information Fusion at the Unit of Action

DTIC Science & Technology

2007-12-07

GRAY CONVOY RED CONVOY DISMOUNT SA-18 D O DISMOUNT W/ SURVEILANCE EQUIPDISMOUNT UNKNOWN zC-LFFRLIFEFORM < SA-18 FIXED WING CLASSIFIED INFORMATION...Ground Truth Semantic-aggregation hierarchy (evaluation-use only) BSGs GTGs BSOS GTOS Reports Figure 4: Semantic-Aggregation Hierarchy PIR/SIR CIFAR...Finally, GTOs can be aggregated into GTGs (ground-truth groups) using the provided ground-truth force structure hierarchy for GTOs. GTGs can only be

Community annotation experiment for ground truth generation for the i2b2 medication challenge

PubMed Central

Solti, Imre; Xia, Fei; Cadag, Eithon

2010-01-01

Objective Within the context of the Third i2b2 Workshop on Natural Language Processing Challenges for Clinical Records, the authors (also referred to as ‘the i2b2 medication challenge team’ or ‘the i2b2 team’ for short) organized a community annotation experiment. Design For this experiment, the authors released annotation guidelines and a small set of annotated discharge summaries. They asked the participants of the Third i2b2 Workshop to annotate 10 discharge summaries per person; each discharge summary was annotated by two annotators from two different teams, and a third annotator from a third team resolved disagreements. Measurements In order to evaluate the reliability of the annotations thus produced, the authors measured community inter-annotator agreement and compared it with the inter-annotator agreement of expert annotators when both the community and the expert annotators generated ground truth based on pooled system outputs. For this purpose, the pool consisted of the three most densely populated automatic annotations of each record. The authors also compared the community inter-annotator agreement with expert inter-annotator agreement when the experts annotated raw records without using the pool. Finally, they measured the quality of the community ground truth by comparing it with the expert ground truth. Results and conclusions The authors found that the community annotators achieved comparable inter-annotator agreement to expert annotators, regardless of whether the experts annotated from the pool. Furthermore, the ground truth generated by the community obtained F-measures above 0.90 against the ground truth of the experts, indicating the value of the community as a source of high-quality ground truth even on intricate and domain-specific annotation tasks. PMID:20819855

Microwave radiometric studies and ground truth measurements of the NASA/USGS Southern California test site

NASA Technical Reports Server (NTRS)

Edgerton, A. T.; Trexler, D. T.; Sakamoto, S.; Jenkins, J. E.

1969-01-01

The field measurement program conducted at the NASA/USGS Southern California Test Site is discussed. Ground truth data and multifrequency microwave brightness data were acquired by a mobile field laboratory operating in conjunction with airborne instruments. The ground based investigations were performed at a number of locales representing a variety of terrains including open desert, cultivated fields, barren fields, portions of the San Andreas Fault Zone, and the Salton Sea. The measurements acquired ground truth data and microwave brightness data at wavelengths of 0.8 cm, 2.2 cm, and 21 cm.

Relating ground truth collection to model sensitivity

NASA Technical Reports Server (NTRS)

Amar, Faouzi; Fung, Adrian K.; Karam, Mostafa A.; Mougin, Eric

1993-01-01

The importance of collecting high quality ground truth before a SAR mission over a forested area is two fold. First, the ground truth is used in the analysis and interpretation of the measured backscattering properties; second, it helps to justify the use of a scattering model to fit the measurements. Unfortunately, ground truth is often collected based on visual assessment of what is perceived to be important without regard to the mission itself. Sites are selected based on brief surveys of large areas, and the ground truth is collected by a process of selecting and grouping different scatterers. After the fact, it may turn out that some of the relevant parameters are missing. A three-layer canopy model based on the radiative transfer equations is used to determine, before hand, the relevant parameters to be collected. Detailed analysis of the contribution to scattering and attenuation of various forest components is carried out. The goal is to identify the forest parameters which most influence the backscattering as a function of frequency (P-, L-, and C-bands) and incident angle. The influence on backscattering and attenuation of branch diameters, lengths, angular distribution, and permittivity; trunk diameters, lengths, and permittivity; and needle sizes, their angular distribution, and permittivity are studied in order to maximize the efficiency of the ground truth collection efforts. Preliminary results indicate that while a scatterer may not contribute to the total backscattering, its contribution to attenuation may be significant depending on the frequency.

Seasonal and inter-annual variation in occurrence and biomass of rooted macrophytes and drift algae in shallow bays

NASA Astrophysics Data System (ADS)

Berglund, J.; Mattila, J.; Rönnberg, O.; Heikkilä, J.; Bonsdorff, E.

2003-04-01

Submerged rooted macrophytes and drift algae were studied in shallow (0-1 m) brackish soft-bottom bays in the Åland Islands, N Baltic Sea, in 1997-2000. The study was performed by aerial photography and ground-truth sampling and the compatibility of the methods was evaluated. The study provided quantitative results on seasonal and inter-annual variation in growth, distribution and biomass of submerged macrophytes and drift algae. On an average, 18 submerged macrophyte species occurred in the studied bays. The most common species, by weight and occurrence, were Chara aspera, Cladophora glomerata, Pilayella littoralis and Potamogeton pectinatus. Filamentous green algae constituted 45-70% of the biomass, charophytes 25-40% and vascular plants 3-18%. A seasonal pattern with a peak in biomass in July-August was found and the mean biomass was negatively correlated with exposure. There were statistically significant differences in coverage among years, and among levels of exposure. The coverage was highest when exposure was low. Both sheltered and exposed bays were influenced by drift algae (30 and 60% occurrence in July-August) and there was a positive correlation between exposure and occurrence of algal accumulations. At exposed sites, most of the algae had drifted in from other areas, while at sheltered ones they were mainly of local origin. Data obtained by aerial photography and ground-truth sampling showed a high concordance, but aerial photography gave a 9% higher estimate than the ground-truth samples. The results can be applied in planning of monitoring and management strategies for shallow soft-bottom areas under potential threat of drift algae.

Measuring Soil Moisture in Skeletal Soils Using a COSMOS Rover

NASA Astrophysics Data System (ADS)

Medina, C.; Neely, H.; Desilets, D.; Mohanty, B.; Moore, G. W.

2017-12-01

The presence of coarse fragments directly influences the volumetric water content of the soil. Current surface soil moisture sensors often do not account for the presence of coarse fragments, and little research has been done to calibrate these sensors under such conditions. The cosmic-ray soil moisture observation system (COSMOS) rover is a passive, non-invasive surface soil moisture sensor with a footprint greater than 100 m. Despite its potential, the COSMOS rover has yet to be validated in skeletal soils. The goal of this study was to validate measurements of surface soil moisture as taken by a COSMOS rover on a Texas skeletal soil. Data was collected for two soils, a Marfla clay loam and Chinati-Boracho-Berrend association, in West Texas. Three levels of data were collected: 1) COSMOS surveys at three different soil moistures, 2) electrical conductivity surveys within those COSMOS surveys, and 3) ground-truth measurements. Surveys with the COSMOS rover covered an 8000-h area and were taken both after large rain events (>2") and a long dry period. Within the COSMOS surveys, the EM38-MK2 was used to estimate the spatial distribution of coarse fragments in the soil around two COSMOS points. Ground truth measurements included coarse fragment mass and volume, bulk density, and water content at 3 locations within each EM38 survey. Ground-truth measurements were weighted using EM38 data, and COSMOS measurements were validated by their distance from the samples. There was a decrease in water content as the percent volume of coarse fragment increased. COSMOS estimations responded to both changes in coarse fragment percent volume and the ground-truth volumetric water content. Further research will focus on creating digital soil maps using landform data and water content estimations from the COSMOS rover.

A photogrammetric technique for generation of an accurate multispectral optical flow dataset

NASA Astrophysics Data System (ADS)

Kniaz, V. V.

2017-06-01

A presence of an accurate dataset is the key requirement for a successful development of an optical flow estimation algorithm. A large number of freely available optical flow datasets were developed in recent years and gave rise for many powerful algorithms. However most of the datasets include only images captured in the visible spectrum. This paper is focused on the creation of a multispectral optical flow dataset with an accurate ground truth. The generation of an accurate ground truth optical flow is a rather complex problem, as no device for error-free optical flow measurement was developed to date. Existing methods for ground truth optical flow estimation are based on hidden textures, 3D modelling or laser scanning. Such techniques are either work only with a synthetic optical flow or provide a sparse ground truth optical flow. In this paper a new photogrammetric method for generation of an accurate ground truth optical flow is proposed. The method combines the benefits of the accuracy and density of a synthetic optical flow datasets with the flexibility of laser scanning based techniques. A multispectral dataset including various image sequences was generated using the developed method. The dataset is freely available on the accompanying web site.

Design of the primary pre-TRMM and TRMM ground truth site

NASA Technical Reports Server (NTRS)

Garstang, Michael

1988-01-01

The primary objective of the Tropical Rain Measuring Mission (TRMM) were to: integrate the rain gage measurements with radar measurements of rainfall using the KSFC/Patrick digitized radar and associated rainfall network; delineate the major rain bearing systems over Florida using the Weather Service reported radar/rainfall distributions; combine the integrated measurements with the delineated rain bearing systems; use the results of the combined measurements and delineated rain bearing systems to represent patterns of rainfall which actually exist and contribute significantly to the rainfall to test sampling strategies and based on the results of these analyses decide upon the ground truth network; and complete the design begun in Phase 1 of a multi-scale (space and time) surface observing precipitation network centered upon KSFC. Work accomplished and in progress is discussed.

BLOND, a building-level office environment dataset of typical electrical appliances.

PubMed

Kriechbaumer, Thomas; Jacobsen, Hans-Arno

2018-03-27

Energy metering has gained popularity as conventional meters are replaced by electronic smart meters that promise energy savings and higher comfort levels for occupants. Achieving these goals requires a deeper understanding of consumption patterns to reduce the energy footprint: load profile forecasting, power disaggregation, appliance identification, startup event detection, etc. Publicly available datasets are used to test, verify, and benchmark possible solutions to these problems. For this purpose, we present the BLOND dataset: continuous energy measurements of a typical office environment at high sampling rates with common appliances and load profiles. We provide voltage and current readings for aggregated circuits and matching fully-labeled ground truth data (individual appliance measurements). The dataset contains 53 appliances (16 classes) in a 3-phase power grid. BLOND-50 contains 213 days of measurements sampled at 50kSps (aggregate) and 6.4kSps (individual appliances). BLOND-250 consists of the same setup: 50 days, 250kSps (aggregate), 50kSps (individual appliances). These are the longest continuous measurements at such high sampling rates and fully-labeled ground truth we are aware of.

BLOND, a building-level office environment dataset of typical electrical appliances

NASA Astrophysics Data System (ADS)

Kriechbaumer, Thomas; Jacobsen, Hans-Arno

2018-03-01

Energy metering has gained popularity as conventional meters are replaced by electronic smart meters that promise energy savings and higher comfort levels for occupants. Achieving these goals requires a deeper understanding of consumption patterns to reduce the energy footprint: load profile forecasting, power disaggregation, appliance identification, startup event detection, etc. Publicly available datasets are used to test, verify, and benchmark possible solutions to these problems. For this purpose, we present the BLOND dataset: continuous energy measurements of a typical office environment at high sampling rates with common appliances and load profiles. We provide voltage and current readings for aggregated circuits and matching fully-labeled ground truth data (individual appliance measurements). The dataset contains 53 appliances (16 classes) in a 3-phase power grid. BLOND-50 contains 213 days of measurements sampled at 50kSps (aggregate) and 6.4kSps (individual appliances). BLOND-250 consists of the same setup: 50 days, 250kSps (aggregate), 50kSps (individual appliances). These are the longest continuous measurements at such high sampling rates and fully-labeled ground truth we are aware of.

BLOND, a building-level office environment dataset of typical electrical appliances

PubMed Central

Kriechbaumer, Thomas; Jacobsen, Hans-Arno

2018-01-01

Energy metering has gained popularity as conventional meters are replaced by electronic smart meters that promise energy savings and higher comfort levels for occupants. Achieving these goals requires a deeper understanding of consumption patterns to reduce the energy footprint: load profile forecasting, power disaggregation, appliance identification, startup event detection, etc. Publicly available datasets are used to test, verify, and benchmark possible solutions to these problems. For this purpose, we present the BLOND dataset: continuous energy measurements of a typical office environment at high sampling rates with common appliances and load profiles. We provide voltage and current readings for aggregated circuits and matching fully-labeled ground truth data (individual appliance measurements). The dataset contains 53 appliances (16 classes) in a 3-phase power grid. BLOND-50 contains 213 days of measurements sampled at 50kSps (aggregate) and 6.4kSps (individual appliances). BLOND-250 consists of the same setup: 50 days, 250kSps (aggregate), 50kSps (individual appliances). These are the longest continuous measurements at such high sampling rates and fully-labeled ground truth we are aware of. PMID:29583141

NASA Ground-Truthing Capabilities Demonstrated

NASA Technical Reports Server (NTRS)

Lopez, Isaac; Seibert, Marc A.

2004-01-01

NASA Research and Education Network (NREN) ground truthing is a method of verifying the scientific validity of satellite images and clarifying irregularities in the imagery. Ground-truthed imagery can be used to locate geological compositions of interest for a given area. On Mars, astronaut scientists could ground truth satellite imagery from the planet surface and then pinpoint optimum areas to explore. These astronauts would be able to ground truth imagery, get results back, and use the results during extravehicular activity without returning to Earth to process the data from the mission. NASA's first ground-truthing experiment, performed on June 25 in the Utah desert, demonstrated the ability to extend powerful computing resources to remote locations. Designed by Dr. Richard Beck of the Department of Geography at the University of Cincinnati, who is serving as the lead field scientist, and assisted by Dr. Robert Vincent of Bowling Green State University, the demonstration also involved researchers from the NASA Glenn Research Center and the NASA Ames Research Center, who worked with the university field scientists to design, perform, and analyze results of the experiment. As shown real-time Hyperion satellite imagery (data) is sent to a mass storage facility, while scientists at a remote (Utah) site upload ground spectra (data) to a second mass storage facility. The grid pulls data from both mass storage facilities and performs up to 64 simultaneous band ratio conversions on the data. Moments later, the results from the grid are accessed by local scientists and sent directly to the remote science team. The results are used by the remote science team to locate and explore new critical compositions of interest. The process can be repeated as required to continue to validate the data set or to converge on alternate geophysical areas of interest.

Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

PubMed Central

Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

2013-01-01

Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts. PMID:24236224

Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

NASA Astrophysics Data System (ADS)

Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

2012-03-01

Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.

Geographic information system for fusion and analysis of high-resolution remote sensing and ground truth data

NASA Technical Reports Server (NTRS)

Freeman, Anthony; Dubois, Pascale; Leberl, Franz; Norikane, L.; Way, Jobea

1991-01-01

Viewgraphs on Geographic Information System for fusion and analysis of high-resolution remote sensing and ground truth data are presented. Topics covered include: scientific objectives; schedule; and Geographic Information System.

AN ASSESSMENT OF GROUND TRUTH VARIABILITY USING A "VIRTUAL FIELD REFERENCE DATABASE"

EPA Science Inventory

A "Virtual Field Reference Database (VFRDB)" was developed from field measurment data that included location and time, physical attributes, flora inventory, and digital imagery (camera) documentation foy 1,01I sites in the Neuse River basin, North Carolina. The sampling f...

A multivariate analytical method to characterize sediment attributes from high-frequency acoustic backscatter and ground-truthing data (Jade Bay, German North Sea coast)

NASA Astrophysics Data System (ADS)

Biondo, Manuela; Bartholomä, Alexander

2017-04-01

One of the burning issues on the topic of acoustic seabed classification is the lack of solid, repeatable, statistical procedures that can support the verification of acoustic variability in relation to seabed properties. Acoustic sediment classification schemes often lead to biased and subjective interpretation, as they ultimately aim at an oversimplified categorization of the seabed based on conventionally defined sediment types. However, grain size variability alone cannot be accounted for acoustic diversity, which will be ultimately affected by multiple physical processes, scale of heterogeneity, instrument settings, data quality, image processing and segmentation performances. Understanding and assessing the weight of all of these factors on backscatter is a difficult task, due to the spatially limited and fragmentary knowledge of the seabed from of direct observations (e.g. grab samples, cores, videos). In particular, large-scale mapping requires an enormous availability of ground-truthing data that is often obtained from heterogeneous and multidisciplinary sources, resulting into a further chance of misclassification. Independently from all of these limitations, acoustic segments still contain signals for seabed changes that, if appropriate procedures are established, can be translated into meaningful knowledge. In this study we design a simple, repeatable method, based on multivariate procedures, with the scope to classify a 100 km2, high-frequency (450 kHz) sidescan sonar mosaic acquired in the year 2012 in the shallow upper-mesotidal inlet of the Jade Bay (German North Sea coast). The tool used for the automated classification of the backscatter mosaic is the QTC SWATHVIEWTMsoftware. The ground-truthing database included grab sample data from multiple sources (2009-2011). The method was designed to extrapolate quantitative descriptors for acoustic backscatter and model their spatial changes in relation to grain size distribution and morphology. The modelled relationships were used to: 1) asses the automated segmentation performance, 2) obtain a ranking of most discriminant seabed attributes responsible for acoustic diversity, 3) select the best-fit ground-truthing information to characterize each acoustic class. Using a supervised Linear Discriminant Analysis (LDA), relationships between seabed parameters and acoustic classes discrimination were modelled, and acoustic classes for each data point were predicted. The model predicted a success rate of 63.5%. An unsupervised LDA was used to model relationships between acoustic variables and clustered seabed categories with the scope of identifying misrepresentative ground-truthing data points. The model prediction scored a success rate of 50.8%. Misclassified data points were disregarded for final classification. Analyses led to clearer, more accurate appreciation of relationship patterns and improved understanding of site-specific processes affecting the acoustic signal. Value to the qualitative classification output was added by comparing the latter with a more recent set of acoustic and ground-truthing information (2014). Classification resulted in the first acoustic sediment map ever produced in the area and offered valuable knowledge for detailed sediment variability. The method proved to be a simple, repeatable strategy that may be applied to similar work and environments.

Acquisition and analysis of coastal ground-truth data for correlation with ERTS-1 imagery. [surface radiance data for Santa Monica Bay and Santa Barbara Channel

NASA Technical Reports Server (NTRS)

Anikouchine, W. A. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Radiance profiles drawn along cruise tracks have been examined for use in correlating digital radiance levels with ground truth data. Preliminary examination results are encouraging. Adding weighted levels from the 4 MSS bands appears to enhance specular surface reflections while rendering sensor noise white. Comparing each band signature to the added specular signature ought to enhance non-specular effects caused by ocean turbidity. Preliminary examination of radiance profiles and ground truth turbidity measurements revealed substantial correlation.

Regolith Volatile Recovery at Simulated Lunar Environments

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie; Paulsen, Gale; Zacny, Kris; Schmidt, Sherry; Boucher, Dale

2016-01-01

Lunar Polar Volatiles: Permanently shadowed craters at the lunar poles contain water, 5 wt according to LCROSS. Interest in water for ISRU applications. Desire to ground truth water using surface prospecting e.g. Resource Prospector and RESOLVE. How to access subsurface water resources and accurately measure quantity. Excavation operations and exposure to lunar environment may affect the results. Volatile capture tests: A series a ground based dirty thermal vacuum tests are being conducted to better understand the subsurface sampling operations. Sample removal and transfer. Volatiles loss during sampling operations. Concept of operations, Instrumentation. This presentation is a progress report on volatiles capture results from these tests with lunar polar drill prototype hardware.

Remote sensing of effects of land-use practices on water quality. [environmental surveys using Landsat satellites

NASA Technical Reports Server (NTRS)

Graves, D. H.

1975-01-01

Research efforts are presented for the use of remote sensing in environmental surveys in Kentucky. Ground truth parameters were established that represent the vegetative cover of disturbed and undisturbed watersheds in the Cumberland Plateau of eastern Kentucky. Several water quality parameters were monitored of the watersheds utilized in the establishment of ground truth data. The capabilities of multistage-multispectral aerial photography and satellite imagery were evaluated in detecting various land use practices. The use of photographic signatures of known land use areas utilizing manually-operated spot densitometers was studied. The correlation of imagery signature data to water quality data was examined. Potential water quality predictions were developed from forested and nonforested watersheds based upon the above correlations. The cost effectiveness of predicting water quality values was evaluated using multistage and satellite imagery sampling techniques.

Performance evaluation of automated segmentation software on optical coherence tomography volume data

PubMed Central

Tian, Jing; Varga, Boglarka; Tatrai, Erika; Fanni, Palya; Somfai, Gabor Mark; Smiddy, William E.

2016-01-01

Over the past two decades a significant number of OCT segmentation approaches have been proposed in the literature. Each methodology has been conceived for and/or evaluated using specific datasets that do not reflect the complexities of the majority of widely available retinal features observed in clinical settings. In addition, there does not exist an appropriate OCT dataset with ground truth that reflects the realities of everyday retinal features observed in clinical settings. While the need for unbiased performance evaluation of automated segmentation algorithms is obvious, the validation process of segmentation algorithms have been usually performed by comparing with manual labelings from each study and there has been a lack of common ground truth. Therefore, a performance comparison of different algorithms using the same ground truth has never been performed. This paper reviews research-oriented tools for automated segmentation of the retinal tissue on OCT images. It also evaluates and compares the performance of these software tools with a common ground truth. PMID:27159849

Retina lesion and microaneurysm segmentation using morphological reconstruction methods with ground-truth data.

PubMed

Karnowski, Thomas P; Govindasamy, V; Tobin, Kenneth W; Chaum, Edward; Abramoff, M D

2008-01-01

In this work we report on a method for lesion segmentation based on the morphological reconstruction methods of Sbeh et. al. We adapt the method to include segmentation of dark lesions with a given vasculature segmentation. The segmentation is performed at a variety of scales determined using ground-truth data. Since the method tends to over-segment imagery, ground-truth data was used to create post-processing filters to separate nuisance blobs from true lesions. A sensitivity and specificity of 90% of classification of blobs into nuisance and actual lesion was achieved on two data sets of 86 images and 1296 images.

As-built design specification for segment map (Sgmap) program

NASA Technical Reports Server (NTRS)

Tompkins, M. A. (Principal Investigator)

1981-01-01

The segment map program (SGMAP), which is part of the CLASFYT package, is described in detail. This program is designed to output symbolic maps or numerical dumps from LANDSAT cluster/classification files or aircraft ground truth/processed ground truth files which are in 'universal' format.

Investigations using data from LANDSAT 2. [Bangladesh

NASA Technical Reports Server (NTRS)

Hossain, A. (Principal Investigator)

1978-01-01

The author has identified the following significant results. Ground truth data collected in coastal areas confirm the sedimentation base line at five fathom depth and less. Forestry ground truth at Supati in Sunderbasn was found to conform with stratifications in aerial photos and in some satellite imagery.

Satellite markers: a simple method for ground truth car pose on stereo video

NASA Astrophysics Data System (ADS)

Gil, Gustavo; Savino, Giovanni; Piantini, Simone; Pierini, Marco

2018-04-01

Artificial prediction of future location of other cars in the context of advanced safety systems is a must. The remote estimation of car pose and particularly its heading angle is key to predict its future location. Stereo vision systems allow to get the 3D information of a scene. Ground truth in this specific context is associated with referential information about the depth, shape and orientation of the objects present in the traffic scene. Creating 3D ground truth is a measurement and data fusion task associated with the combination of different kinds of sensors. The novelty of this paper is the method to generate ground truth car pose only from video data. When the method is applied to stereo video, it also provides the extrinsic camera parameters for each camera at frame level which are key to quantify the performance of a stereo vision system when it is moving because the system is subjected to undesired vibrations and/or leaning. We developed a video post-processing technique which employs a common camera calibration tool for the 3D ground truth generation. In our case study, we focus in accurate car heading angle estimation of a moving car under realistic imagery. As outcomes, our satellite marker method provides accurate car pose at frame level, and the instantaneous spatial orientation for each camera at frame level.

Assessing the intrinsic precision of 3D/3D rigid image registration results for patient setup in the absence of a ground truth.

PubMed

Wu, Jian; Murphy, Martin J

2010-06-01

To assess the precision and robustness of patient setup corrections computed from 3D/3D rigid registration methods using image intensity, when no ground truth validation is possible. Fifteen pairs of male pelvic CTs were rigidly registered using four different in-house registration methods. Registration results were compared for different resolutions and image content by varying the image down-sampling ratio and by thresholding out soft tissue to isolate bony landmarks. Intrinsic registration precision was investigated by comparing the different methods and by reversing the source and the target roles of the two images being registered. The translational reversibility errors for successful registrations ranged from 0.0 to 1.69 mm. Rotations were less than 1 degrees. Mutual information failed in most registrations that used only bony landmarks. The magnitude of the reversibility error was strongly correlated with the success/ failure of each algorithm to find the global minimum. Rigid image registrations have an intrinsic uncertainty and robustness that depends on the imaging modality, the registration algorithm, the image resolution, and the image content. In the absence of an absolute ground truth, the variation in the shifts calculated by several different methods provides a useful estimate of that uncertainty. The difference observed by reversing the source and target images can be used as an indication of robust convergence.

Searching for Organics During the Robotic Mars Analog Rio Tinto Drilling Experiment: Ground Truth and Contamination Issues

NASA Astrophysics Data System (ADS)

Bonaccorsi, R.; Stoker, C. R.; Marte Project Science Team

2007-03-01

The Mars Analog Rio Tinto Experiment (MARTE) performed a simulation of a Mars drilling experiment at the Rio Tinto (Spain). Ground-truth and contamination issues during the distribution of bulk organics and their CN isotopic composition in hematite and go

Detailed analysis of CAMS procedures for phase 3 using ground truth inventories

NASA Technical Reports Server (NTRS)

Carnes, J. G.

1979-01-01

The results of a study of Procedure 1 as used during LACIE Phase 3 are presented. The study was performed by comparing the Procedure 1 classification results with digitized ground-truth inventories. The proportion estimation accuracy, dot labeling accuracy, and clustering effectiveness are discussed.

Ground Truth Studies. Teacher Handbook. Second Edition.

ERIC Educational Resources Information Center

Boyce, Jesse; And Others

Ground Truth Studies is an interdisciplinary activity-based program that draws on the broad range of sciences that make up the study of global change and the complementary technology of remote sensing. It integrates local environmental issues with global change topics, such as the greenhouse effect, loss of biological diversity, and ozone…

Forest statistics for Arkansas counties - 1979

Treesearch

Renewable Resources Evaluation Research Work Unit

1979-01-01

This report tabulates information from a new forest survey of Arkansas completed in 1979 by the Renewable Resources Evaluation Research Unit of the Southern Forest Experiment Station. Forest area was estimated from aerial photos with an adjustment for ground truth at selected locations. Sample plots were systematically established at three-mile intervals using a grid...

Urban vacant land typology: A tool for managing urban vacant land

Treesearch

Gunwoo Kim; Patrick A. Miller; David J. Nowak

2018-01-01

A typology of urban vacant land was developed, using Roanoke, Virginia, as the study area. A comprehensive literature review, field measurements and observations, including photographs, and quantitative based approach to assessing vacant land forest structure and values (i-Tree Eco sampling) were utilized, along with aerial photo interpretation, and ground-truthing...

Automatic classification techniques for type of sediment map from multibeam sonar data

NASA Astrophysics Data System (ADS)

Zakariya, R.; Abdullah, M. A.; Che Hasan, R.; Khalil, I.

2018-02-01

Sediment map can be important information for various applications such as oil drilling, environmental and pollution study. A study on sediment mapping was conducted at a natural reef (rock) in Pulau Payar using Sound Navigation and Ranging (SONAR) technology which is Multibeam Echosounder R2-Sonic. This study aims to determine sediment type by obtaining backscatter and bathymetry data from multibeam echosounder. Ground truth data were used to verify the classification produced. The method used to analyze ground truth samples consists of particle size analysis (PSA) and dry sieving methods. Different analysis being carried out due to different sizes of sediment sample obtained. The smaller size was analyzed using PSA with the brand CILAS while bigger size sediment was analyzed using sieve. For multibeam, data acquisition includes backscatter strength and bathymetry data were processed using QINSy, Qimera, and ArcGIS. This study shows the capability of multibeam data to differentiate the four types of sediments which are i) very coarse sand, ii) coarse sand, iii) very coarse silt and coarse silt. The accuracy was reported as 92.31% overall accuracy and 0.88 kappa coefficient.

The measurement of carbon monoxide and methane in the national capital air quality control region. III - Correlation interferometer results

NASA Technical Reports Server (NTRS)

Goldstein, H. W.; Bortner, M. H.; Grenda, R. N.; Dick, R.; Lebel, P. J.; Lamontagne, R. A.

1976-01-01

Two types of experiments were performed with a correlation interferometer on-board a Bell Jet Ranger 206 Helicopter. The first consisted of simultaneous ground- and air-truth measurements as the instrumented helicopter passed over the Cheverly site. The second consisted of several measurement flights in and around the national capital air quality control region (Washington, D.C.). The correlation interferometer data, the infrared Fourier spectrometer data, and the integrated altitude sampling data showed agreement within the errors of the individual measurements. High values for CO were found from the D.C. flight data to be reproducible and concentrated in areas of stop-and-go traffic. It is concluded, that pollutants at low altitudes are detectable from an air-borne platform by remote correlation interferometry and that the correlation interferometer measurements agree with ground- and air-truth data.

A comparison of supervised classification methods for the prediction of substrate type using multibeam acoustic and legacy grain-size data.

PubMed

Stephens, David; Diesing, Markus

2014-01-01

Detailed seabed substrate maps are increasingly in demand for effective planning and management of marine ecosystems and resources. It has become common to use remotely sensed multibeam echosounder data in the form of bathymetry and acoustic backscatter in conjunction with ground-truth sampling data to inform the mapping of seabed substrates. Whilst, until recently, such data sets have typically been classified by expert interpretation, it is now obvious that more objective, faster and repeatable methods of seabed classification are required. This study compares the performances of a range of supervised classification techniques for predicting substrate type from multibeam echosounder data. The study area is located in the North Sea, off the north-east coast of England. A total of 258 ground-truth samples were classified into four substrate classes. Multibeam bathymetry and backscatter data, and a range of secondary features derived from these datasets were used in this study. Six supervised classification techniques were tested: Classification Trees, Support Vector Machines, k-Nearest Neighbour, Neural Networks, Random Forest and Naive Bayes. Each classifier was trained multiple times using different input features, including i) the two primary features of bathymetry and backscatter, ii) a subset of the features chosen by a feature selection process and iii) all of the input features. The predictive performances of the models were validated using a separate test set of ground-truth samples. The statistical significance of model performances relative to a simple baseline model (Nearest Neighbour predictions on bathymetry and backscatter) were tested to assess the benefits of using more sophisticated approaches. The best performing models were tree based methods and Naive Bayes which achieved accuracies of around 0.8 and kappa coefficients of up to 0.5 on the test set. The models that used all input features didn't generally perform well, highlighting the need for some means of feature selection.

Application of remote sensing in agriculture and forestry and ground truth documentation in resource planning

NASA Technical Reports Server (NTRS)

1974-01-01

Varied small scale imagery was used for detecting and assessing damage by the southern pine beetle. The usefulness of ERTS scanner imagery for vegetation classification and pine beetle damage detection and assessment is evaluated. Ground truth acquisition for forest identification using multispectral aerial photographs is reviewed.

Merge of Five Previous Catalogues Into the Ground Truth Catalogue and Registration Based on MOLA Data with THEMIS-DIR, MDIM and MOC Data-Sets

NASA Astrophysics Data System (ADS)

Salamuniccar, G.; Loncaric, S.

2008-03-01

The Catalogue from our previous work was merged with the date of Barlow, Rodionova, Boyce, and Kuzmin. The resulting ground truth catalogue with 57,633 craters was registered, using MOLA data, with THEMIS-DIR, MDIM, and MOC data-sets.

A dataset of stereoscopic images and ground-truth disparity mimicking human fixations in peripersonal space

PubMed Central

Canessa, Andrea; Gibaldi, Agostino; Chessa, Manuela; Fato, Marco; Solari, Fabio; Sabatini, Silvio P.

2017-01-01

Binocular stereopsis is the ability of a visual system, belonging to a live being or a machine, to interpret the different visual information deriving from two eyes/cameras for depth perception. From this perspective, the ground-truth information about three-dimensional visual space, which is hardly available, is an ideal tool both for evaluating human performance and for benchmarking machine vision algorithms. In the present work, we implemented a rendering methodology in which the camera pose mimics realistic eye pose for a fixating observer, thus including convergent eye geometry and cyclotorsion. The virtual environment we developed relies on highly accurate 3D virtual models, and its full controllability allows us to obtain the stereoscopic pairs together with the ground-truth depth and camera pose information. We thus created a stereoscopic dataset: GENUA PESTO—GENoa hUman Active fixation database: PEripersonal space STereoscopic images and grOund truth disparity. The dataset aims to provide a unified framework useful for a number of problems relevant to human and computer vision, from scene exploration and eye movement studies to 3D scene reconstruction. PMID:28350382

Estimation of the sugar cane cultivated area from LANDSAT images using the two phase sampling method

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Cappelletti, C. A.; Mendonca, F. J.; Lee, D. C. L.; Shimabukuro, Y. E.

1982-01-01

A two phase sampling method and the optimal sampling segment dimensions for the estimation of sugar cane cultivated area were developed. This technique employs visual interpretations of LANDSAT images and panchromatic aerial photographs considered as the ground truth. The estimates, as a mean value of 100 simulated samples, represent 99.3% of the true value with a CV of approximately 1%; the relative efficiency of the two phase design was 157% when compared with a one phase aerial photographs sample.

Attractor learning in synchronized chaotic systems in the presence of unresolved scales

NASA Astrophysics Data System (ADS)

Wiegerinck, W.; Selten, F. M.

2017-12-01

Recently, supermodels consisting of an ensemble of interacting models, synchronizing on a common solution, have been proposed as an alternative to the common non-interactive multi-model ensembles in order to improve climate predictions. The connection terms in the interacting ensemble are to be optimized based on the data. The supermodel approach has been successfully demonstrated in a number of simulation experiments with an assumed ground truth and a set of good, but imperfect models. The supermodels were optimized with respect to their short-term prediction error. Nevertheless, they produced long-term climatological behavior that was close to the long-term behavior of the assumed ground truth, even in cases where the long-term behavior of the imperfect models was very different. In these supermodel experiments, however, a perfect model class scenario was assumed, in which the ground truth and imperfect models belong to the same model class and only differ in parameter setting. In this paper, we consider the imperfect model class scenario, in which the ground truth model class is more complex than the model class of imperfect models due to unresolved scales. We perform two supermodel experiments in two toy problems. The first one consists of a chaotically driven Lorenz 63 oscillator ground truth and two Lorenz 63 oscillators with constant forcings as imperfect models. The second one is more realistic and consists of a global atmosphere model as ground truth and imperfect models that have perturbed parameters and reduced spatial resolution. In both problems, we find that supermodel optimization with respect to short-term prediction error can lead to a long-term climatological behavior that is worse than that of the imperfect models. However, we also show that attractor learning can remedy this problem, leading to supermodels with long-term behavior superior to the imperfect models.

Accuracy assessment of percent canopy cover, cover type, and size class

Treesearch

H. T. Schreuder; S. Bain; R. C. Czaplewski

2003-01-01

Truth for vegetation cover percent and type is obtained from very large-scale photography (VLSP), stand structure as measured by size classes, and vegetation types from a combination of VLSP and ground sampling. We recommend using the Kappa statistic with bootstrap confidence intervals for overall accuracy, and similarly bootstrap confidence intervals for percent...

Forest statistics for Arkansas' delta counties

Treesearch

Richard T. Quick; Mary S. Hedlund

1979-01-01

These tables were derived from data obtained during a 1978 inventory of 21 counties comprising the North and South Delta Units of Arkansas (fig. 1). Forest area was estimated from aerial photos with an adjustment for ground truth at selected locations. Sample plots were systematically established at three-mile intervals using a grid oriented roughly N-S and E-W. At...

Forest statistics for Arkansas' Ouachita counties

Treesearch

T. Richard Quick; Marry S. Hedlund

1979-01-01

These tables were derived from data obtained during a 1978 inventory of 10 counties comprising the Quachita Unit of Arkansas (fig. 1). Forest area was estimated from aerial photos with an adjustment of ground truth at selected locations. Sample plots were systematically established at three-mile intervals using a grid orientated roughly N-S and E-W. At each locations,...

Forest statistics for Arkansas' Ozark counties

Treesearch

T. Richard Quick; Mary S. Hedlund

1979-01-01

These tables were derived from data obtained during a 1978 inventory of 24 counties comprising the Ozark Unit of Arkansas (fib. 1). Forest area was estimated from aerial photos with an adjustment of ground truth at selected locations. Sample plots were systematically established at three-mile intervals using a grid orientated roughly N-S and E-W. At each location,...

Application of LANDSAT TM images to assess circulation and dispersion in coastal lagoons

NASA Technical Reports Server (NTRS)

Kjerfve, B.; Jensen, J. R.; Magill, K. E.

1986-01-01

The main objectives are formulated around a four pronged work approach, consisting of tasks related to: image processing and analysis of LANDSAT thematic mapping; numerical modeling of circulation and dispersion; hydrographic and spectral radiation field sampling/ground truth data collection; and special efforts to focus the investigation on turbid coastal/estuarine fronts.

The Need for Careful Data Collection for Pattern Recognition in Digital Pathology.

PubMed

Marée, Raphaël

2017-01-01

Effective pattern recognition requires carefully designed ground-truth datasets. In this technical note, we first summarize potential data collection issues in digital pathology and then propose guidelines to build more realistic ground-truth datasets and to control their quality. We hope our comments will foster the effective application of pattern recognition approaches in digital pathology.

Methods for improving accuracy and extending results beyond periods covered by traditional ground-truth in remote sensing classification of a complex landscape

USDA-ARS?s Scientific Manuscript database

Successful development of approaches to quantify impacts of diverse landuse and associated agricultural management practices on ecosystem services is frequently limited by lack of historical and contemporary landuse data. We hypothesized that recent ground truth data could be used to extrapolate pre...

The use of zeolites to generate PET phantoms for the validation of quantification strategies in oncology.

PubMed

Zito, Felicia; De Bernardi, Elisabetta; Soffientini, Chiara; Canzi, Cristina; Casati, Rosangela; Gerundini, Paolo; Baselli, Giuseppe

2012-09-01

In recent years, segmentation algorithms and activity quantification methods have been proposed for oncological (18)F-fluorodeoxyglucose (FDG) PET. A full assessment of these algorithms, necessary for a clinical transfer, requires a validation on data sets provided with a reliable ground truth as to the imaged activity distribution, which must be as realistic as possible. The aim of this work is to propose a strategy to simulate lesions of uniform uptake and irregular shape in an anthropomorphic phantom, with the possibility to easily obtain a ground truth as to lesion activity and borders. Lesions were simulated with samples of clinoptilolite, a family of natural zeolites of irregular shape, able to absorb aqueous solutions of (18)F-FDG, available in a wide size range, and nontoxic. Zeolites were soaked in solutions of (18)F-FDG for increasing times up to 120 min and their absorptive properties were characterized as function of soaking duration, solution concentration, and zeolite dry weight. Saturated zeolites were wrapped in Parafilm, positioned inside an Alderson thorax-abdomen phantom and imaged with a PET-CT scanner. The ground truth for the activity distribution of each zeolite was obtained by segmenting high-resolution finely aligned CT images, on the basis of independently obtained volume measurements. The fine alignment between CT and PET was validated by comparing the CT-derived ground truth to a set of zeolites' PET threshold segmentations in terms of Dice index and volume error. The soaking time necessary to achieve saturation increases with zeolite dry weight, with a maximum of about 90 min for the largest sample. At saturation, a linear dependence of the uptake normalized to the solution concentration on zeolite dry weight (R(2) = 0.988), as well as a uniform distribution of the activity over the entire zeolite volume from PET imaging were demonstrated. These findings indicate that the (18)F-FDG solution is able to saturate the zeolite pores and that the concentration does not influence the distribution uniformity of both solution and solute, at least at the trace concentrations used for zeolite activation. An additional proof of uniformity of zeolite saturation was obtained observing a correspondence between uptake and adsorbed volume of solution, corresponding to about 27.8% of zeolite volume. As to the ground truth for zeolites positioned inside the phantom, the segmentation of finely aligned CT images provided reliable borders, as demonstrated by a mean absolute volume error of 2.8% with respect to the PET threshold segmentation corresponding to the maximum Dice. The proposed methodology allowed obtaining an experimental phantom data set that can be used as a feasible tool to test and validate quantification and segmentation algorithms for PET in oncology. The phantom is currently under consideration for being included in a benchmark designed by AAPM TG211, which will be available to the community to evaluate PET automatic segmentation methods.

Leibniz on the metaphysical foundation of physics

NASA Astrophysics Data System (ADS)

Temple, Daniel R.

This thesis examines how and why Leibniz felt that physics must be grounded in metaphysics. I argue that one of the strongest motivation Leibniz had for attempting to ground physics in metaphysics was his concern over the problem of induction. Even in his early writings, Leibniz was well aware of the problem of induction and how this problem threatened the very possibility of physics. Both his early and later theories of truth are geared towards solving this deep problem in the philosophy of science. In his early theory of truth, all truths are ultimately grounded in (but not necessarily reducible to) an identity. Hence, all truths are ultimately based in logic. Consequently, the problem of induction is seemingly solved since everything that happens, happens with the force of logical necessity. Unfortunately, this theory is incompatible with Leibniz's theory of possible worlds and hence, jeopardizes the liberty of God. In Leibniz's later theory of truth, Leibniz tries to overcome this weakness by acknowledging truths that are grounded in the free but moral necessity of God's actions. Since God's benevolence is responsible for the actualization of this world, then this world must possess rational laws. Furthermore, since God's rationality ensures that everything obeys the principle of sufficient reason, then we can use this principle to determine the fundamental laws of the universe. Leibniz himself attempts to derive these laws using this principle. Kant attempted to continue this work of securing the possibility of science, and the problems he encountered helped to shape his critical philosophy. So I conclude by a comparative analysis of Leibniz and Kant on the foundations of physics.

Sampling the Uppermost Surface of Airless Bodies

NASA Technical Reports Server (NTRS)

Noble, S. K.; Keller, L. P.; Christoffersen, R.

2011-01-01

The uppermost surface of an airless body is a critical source of ground-truth information for the various remote sensing techniques that only penetrate nanometers to micrometers into the surface. Such samples will also be vital for understanding conditions at the surface and acquiring information about how the body interacts with its environment, including solar wind interaction, grain charging and levitation [1]. Sampling the uppermost surface while preserving its structure (e.g. porosity, grain-to-grain contacts) however, is a daunting task that has not been achieved on any sample return mission to date.

Unmanned aerial vehicle-based structure from motion biomass inventory estimates

NASA Astrophysics Data System (ADS)

Bedell, Emily; Leslie, Monique; Fankhauser, Katie; Burnett, Jonathan; Wing, Michael G.; Thomas, Evan A.

2017-04-01

Riparian vegetation restoration efforts require cost-effective, accurate, and replicable impact assessments. We present a method to use an unmanned aerial vehicle (UAV) equipped with a GoPro digital camera to collect photogrammetric data of a 0.8-ha riparian restoration. A three-dimensional point cloud was created from the photos using "structure from motion" techniques. The point cloud was analyzed and compared to traditional, ground-based monitoring techniques. Ground-truth data were collected on 6.3% of the study site and averaged across the entire site to report stem heights in stems/ha in three height classes. The project site was divided into four analysis sections, one for derivation of parameters used in the UAV data analysis and the remaining three sections reserved for method validation. Comparing the ground-truth data to the UAV generated data produced an overall error of 21.6% and indicated an R2 value of 0.98. A Bland-Altman analysis indicated a 95% probability that the UAV stems/section result will be within 61 stems/section of the ground-truth data. The ground-truth data are reported with an 80% confidence interval of ±1032 stems/ha thus, the UAV was able to estimate stems well within this confidence interval.

The measurement of carbon monoxide and methane in the National Capital Air Quality Control Region. I - Measurement systems

NASA Technical Reports Server (NTRS)

Lebel, P. J.; Lamontagne, R. A.; Goldstein, H. W.

1976-01-01

The Carbon Monoxide Pollution Experiment (COPE) and the National Capital Air Quality Control Region (NCAQCR) undertook a series of measurements of atmospheric CO and CH4 to determine the accuracy of the airborne COPE Correlation Interfer4meter. The device, a modified Michelson interferometer, measures the atmospheric column density of CO and CH4 at 2.3 microns with tropospheric measurement sensitivities of 70 and 10 PPB, respectively. Data for evaluating the remote measurements included atmospheric column density measurements at a ground truth site using a van-mounted infrared Fourier spectrometer; continuous ground level gas chromatographic measurements; and chromatographic data from atmospheric grab samples collected by aircraft and at ground locations. The instruments and sampling techniques used in the experiment are described in detail.

Aeolian dunes as ground truth for atmospheric modeling on Mars

USGS Publications Warehouse

Hayward, R.K.; Titus, T.N.; Michaels, T.I.; Fenton, L.K.; Colaprete, A.; Christensen, P.R.

2009-01-01

Martian aeolian dunes preserve a record of atmosphere/surface interaction on a variety of scales, serving as ground truth for both Global Climate Models (GCMs) and mesoscale climate models, such as the Mars Regional Atmospheric Modeling System (MRAMS). We hypothesize that the location of dune fields, expressed globally by geographic distribution and locally by dune centroid azimuth (DCA), may record the long-term integration of atmospheric activity across a broad area, preserving GCM-scale atmospheric trends. In contrast, individual dune morphology, as expressed in slipface orientation (SF), may be more sensitive to localized variations in circulation, preserving topographically controlled mesoscale trends. We test this hypothesis by comparing the geographic distribution, DCA, and SF of dunes with output from the Ames Mars GCM and, at a local study site, with output from MRAMS. When compared to the GCM: 1) dunes generally lie adjacent to areas with strongest winds, 2) DCA agrees fairly well with GCM modeled wind directions in smooth-floored craters, and 3) SF does not agree well with GCM modeled wind directions. When compared to MRAMS modeled winds at our study site: 1) DCA generally coincides with the part of the crater where modeled mean winds are weak, and 2) SFs are consistent with some weak, topographically influenced modeled winds. We conclude that: 1) geographic distribution may be valuable as ground truth for GCMs, 2) DCA may be useful as ground truth for both GCM and mesoscale models, and 3) SF may be useful as ground truth for mesoscale models. Copyright 2009 by the American Geophysical Union.

A data set for evaluating the performance of multi-class multi-object video tracking

NASA Astrophysics Data System (ADS)

Chakraborty, Avishek; Stamatescu, Victor; Wong, Sebastien C.; Wigley, Grant; Kearney, David

2017-05-01

One of the challenges in evaluating multi-object video detection, tracking and classification systems is having publically available data sets with which to compare different systems. However, the measures of performance for tracking and classification are different. Data sets that are suitable for evaluating tracking systems may not be appropriate for classification. Tracking video data sets typically only have ground truth track IDs, while classification video data sets only have ground truth class-label IDs. The former identifies the same object over multiple frames, while the latter identifies the type of object in individual frames. This paper describes an advancement of the ground truth meta-data for the DARPA Neovision2 Tower data set to allow both the evaluation of tracking and classification. The ground truth data sets presented in this paper contain unique object IDs across 5 different classes of object (Car, Bus, Truck, Person, Cyclist) for 24 videos of 871 image frames each. In addition to the object IDs and class labels, the ground truth data also contains the original bounding box coordinates together with new bounding boxes in instances where un-annotated objects were present. The unique IDs are maintained during occlusions between multiple objects or when objects re-enter the field of view. This will provide: a solid foundation for evaluating the performance of multi-object tracking of different types of objects, a straightforward comparison of tracking system performance using the standard Multi Object Tracking (MOT) framework, and classification performance using the Neovision2 metrics. These data have been hosted publically.

Remote sensing-aided systems for snow qualification, evapotranspiration estimation, and their application in hydrologic models

NASA Technical Reports Server (NTRS)

Korram, S.

1977-01-01

The design of general remote sensing-aided methodologies was studied to provide the estimates of several important inputs to water yield forecast models. These input parameters are snow area extent, snow water content, and evapotranspiration. The study area is Feather River Watershed (780,000 hectares), Northern California. The general approach involved a stepwise sequence of identification of the required information, sample design, measurement/estimation, and evaluation of results. All the relevent and available information types needed in the estimation process are being defined. These include Landsat, meteorological satellite, and aircraft imagery, topographic and geologic data, ground truth data, and climatic data from ground stations. A cost-effective multistage sampling approach was employed in quantification of all the required parameters. The physical and statistical models for both snow quantification and evapotranspiration estimation was developed. These models use the information obtained by aerial and ground data through appropriate statistical sampling design.

Soil moisture ground truth: Steamboat Springs, Colorado, site and Walden, Colorado, site

NASA Technical Reports Server (NTRS)

Jones, E. B.

1976-01-01

Ground-truth data taken at Steamboat Springs and Walden, Colorado in support of the NASA missions in these areas during the period March 8, 1976 through March 11, 1976 was presented. This includes the following information: snow course data for Steamboat Springs and Walden, snow pit and snow quality data for Steamboat Springs, and soil moisture report.

Retrieval evaluation and distance learning from perceived similarity between endomicroscopy videos.

PubMed

André, Barbara; Vercauteren, Tom; Buchner, Anna M; Wallace, Michael B; Ayache, Nicholas

2011-01-01

Evaluating content-based retrieval (CBR) is challenging because it requires an adequate ground-truth. When the available groundtruth is limited to textual metadata such as pathological classes, retrieval results can only be evaluated indirectly, for example in terms of classification performance. In this study we first present a tool to generate perceived similarity ground-truth that enables direct evaluation of endomicroscopic video retrieval. This tool uses a four-points Likert scale and collects subjective pairwise similarities perceived by multiple expert observers. We then evaluate against the generated ground-truth a previously developed dense bag-of-visual-words method for endomicroscopic video retrieval. Confirming the results of previous indirect evaluation based on classification, our direct evaluation shows that this method significantly outperforms several other state-of-the-art CBR methods. In a second step, we propose to improve the CBR method by learning an adjusted similarity metric from the perceived similarity ground-truth. By minimizing a margin-based cost function that differentiates similar and dissimilar video pairs, we learn a weight vector applied to the visual word signatures of videos. Using cross-validation, we demonstrate that the learned similarity distance is significantly better correlated with the perceived similarity than the original visual-word-based distance.

ERTS-1 DCS technical support provided by Wallops Station. [ground truth stations and DCP repair depot

NASA Technical Reports Server (NTRS)

Smith, R.

1975-01-01

Wallops Station accepted the tasks of providing ground truth to several ERTS investigators, operating a DCP repair depot, designing and building an airborne DCP Data Acquisition System, and providing aircraft underflight support for several other investigators. Additionally, the data bank is generally available for use by ERTS and other investigators that have a scientific interest in data pertaining to the Chesapeake Bay area. Working with DCS has provided a means of evaluating the system as a data collection device possibly applicable to ongoing Earth Resources Program activities in the Chesapeake Bay area as well as providing useful data and services to other ERTS investigators. The two areas of technical support provided by Wallops, ground truth stations and repair for DCPs, are briefly discussed.

Collaborative Research: Ground Truth of African and Eastern Mediterranean Shallow Seismicity Using SAR Interferometry and Gibbs Sampling Inversion

DTIC Science & Technology

2006-10-05

the likely existence of a small foreshock . 2. BACKGROUND 2.1. InSAR The most well-known examples of InSAR used as a geodetic tool involve...the event. We have used the seismic waveforms in the Sultan Dag event to identify a small foreshock preceding the main shock by about 3 seconds

Truth-Telling, Ritual Culture, and Latino College Graduates in the Anthropocene

ERIC Educational Resources Information Center

Gildersleeve, Ryan Evely

2017-01-01

This article seeks to trace the cartography of truth-telling through a posthuamanist predicament of ritual culture in higher education and critical inquiry. Ritual culture in higher education such as graduation ceremony produces and reflects the realities of becoming subjects. These spaces are proliferating grounds for truth telling and practical…

Evaluation criteria for software classification inventories, accuracies, and maps

NASA Technical Reports Server (NTRS)

Jayroe, R. R., Jr.

1976-01-01

Statistical criteria are presented for modifying the contingency table used to evaluate tabular classification results obtained from remote sensing and ground truth maps. This classification technique contains information on the spatial complexity of the test site, on the relative location of classification errors, on agreement of the classification maps with ground truth maps, and reduces back to the original information normally found in a contingency table.

Severe Thunderstorm and Tornado Warnings at Raleigh, North Carolina.

NASA Astrophysics Data System (ADS)

Hoium, Debra K.; Riordan, Allen J.; Monahan, John; Keeter, Kermit K.

1997-11-01

The National Weather Service issues public warnings for severe thunderstorms and tornadoes when these storms appear imminent. A study of the warning process was conducted at the National Weather Service Forecast Office at Raleigh, North Carolina, from 1994 through 1996. The purpose of the study was to examine the decision process by documenting the types of information leading to decisions to warn or not to warn and by describing the sequence and timing of events in the development of warnings. It was found that the evolution of warnings followed a logical sequence beginning with storm monitoring and proceeding with increasingly focused activity. For simplicity, information input to the process was categorized as one of three types: ground truth, radar reflectivity, or radar velocity.Reflectivity, velocity, and ground truth were all equally likely to initiate the investigation process. This investigation took an average of 7 min, after which either a decision was made not to warn or new information triggered the warning. Decisions not to issue warnings were based more on ground truth and reflectivity than radar velocity products. Warnings with investigations of more than 2 min were more likely to be triggered by radar reflectivity, than by velocity or ground truth. Warnings with a shorter investigation time, defined here as "immediate trigger warnings," were less frequently based on velocity products and more on ground truth information. Once the decision was made to warn, it took an average of 2.1 min to prepare the warning text. In 85% of cases when warnings were issued, at least one contact was made to emergency management officials or storm spotters in the warned county. Reports of severe weather were usually received soon after the warning was transmitted-almost half of these within 30 min after issue. A total of 68% were received during the severe weather episode, but some of these storm reports later proved false according to Storm Data.Even though the WSR-88D is a sophisticated tool, ground truth information was found to be a vital part of the warning process. However, the data did not indicate that population density was statistically correlated either with the number of warnings issued or the verification rate.

Lunar Reference Suite to Support Instrument Development and Testing

NASA Technical Reports Server (NTRS)

Allen, Carlton; Sellar, Glenn; Nunez, Jorge I.; Winterhalter, Daniel; Farmer, Jack

2010-01-01

Astronauts on long-duration lunar missions will need the capability to "high-grade" their samples - to select the highest value samples for transport to Earth - and to leave others on the Moon. Instruments that may be useful for such high-grading are under development. Instruments are also being developed for possible use on future lunar robotic landers, for lunar field work, and for more sophisticated analyses at a lunar outpost. The Johnson Space Center Astromaterials acquisition and Curation Office (JSC Curation) wll support such instrument testing by providing lunar sample "ground truth".

Insights into Regolith Dynamics from the Irradiation Record Preserved in Hayabusa Samples

NASA Technical Reports Server (NTRS)

Keller, Lindsay P.; Berger, E. L.

2014-01-01

The rates of space weathering processes are poorly constrained for asteroid surfaces, with recent estimates ranging over 5 orders of magnitude. The return of the first surface samples from a space-weathered asteroid by the Hayabusa mission and their laboratory analysis provides "ground truth" to anchor the timescales for space weathering. We determine the rates of space weathering on Itokawa by measuring solar flare track densities and the widths of solar wind damaged rims on grains. These measurements are made possible through novel focused ion beam (FIB) sample preparation methods.

Sea Ice Thickness Measurement by Ground Penetrating Radar for Ground Truth of Microwave Remote Sensing Data

NASA Astrophysics Data System (ADS)

Matsumoto, M.; Yoshimura, M.; Naoki, K.; Cho, K.; Wakabayashi, H.

2018-04-01

Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR) can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately) aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

Improvements on GPS Location Cluster Analysis for the Prediction of Large Carnivore Feeding Activities: Ground-Truth Detection Probability and Inclusion of Activity Sensor Measures

PubMed Central

Blecha, Kevin A.; Alldredge, Mat W.

2015-01-01

Animal space use studies using GPS collar technology are increasingly incorporating behavior based analysis of spatio-temporal data in order to expand inferences of resource use. GPS location cluster analysis is one such technique applied to large carnivores to identify the timing and location of feeding events. For logistical and financial reasons, researchers often implement predictive models for identifying these events. We present two separate improvements for predictive models that future practitioners can implement. Thus far, feeding prediction models have incorporated a small range of covariates, usually limited to spatio-temporal characteristics of the GPS data. Using GPS collared cougar (Puma concolor) we include activity sensor data as an additional covariate to increase prediction performance of feeding presence/absence. Integral to the predictive modeling of feeding events is a ground-truthing component, in which GPS location clusters are visited by human observers to confirm the presence or absence of feeding remains. Failing to account for sources of ground-truthing false-absences can bias the number of predicted feeding events to be low. Thus we account for some ground-truthing error sources directly in the model with covariates and when applying model predictions. Accounting for these errors resulted in a 10% increase in the number of clusters predicted to be feeding events. Using a double-observer design, we show that the ground-truthing false-absence rate is relatively low (4%) using a search delay of 2–60 days. Overall, we provide two separate improvements to the GPS cluster analysis techniques that can be expanded upon and implemented in future studies interested in identifying feeding behaviors of large carnivores. PMID:26398546

Preliminary statistical studies concerning the Campos RJ sugar cane area, using LANDSAT imagery and aerial photographs

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Costa, S. R. X.; Paiao, L. B. F.; Mendonca, F. J.; Shimabukuro, Y. E.; Duarte, V.

1983-01-01

The two phase sampling technique was applied to estimate the area cultivated with sugar cane in an approximately 984 sq km pilot region of Campos. Correlation between existing aerial photography and LANDSAT data was used. The two phase sampling technique corresponded to 99.6% of the results obtained by aerial photography, taken as ground truth. This estimate has a standard deviation of 225 ha, which constitutes a coefficient of variation of 0.6%.

Verification of retail food outlet location data from a local health department using ground-truthing and remote-sensing technology: assessing differences by neighborhood characteristics.

PubMed

Rossen, Lauren M; Pollack, Keshia M; Curriero, Frank C

2012-09-01

Obtaining valid and accurate data on community food environments is critical for research evaluating associations between the food environment and health outcomes. This study utilized ground-truthing and remote-sensing technology to validate a food outlet retail list obtained from an urban local health department in Baltimore, Maryland in 2009. Ten percent of outlets (n=169) were assessed, and differences in accuracy were explored by neighborhood characteristics (96 census tracts) to determine if discrepancies were differential or non-differential. Inaccuracies were largely unrelated to a variety of neighborhood-level variables, with the exception of number of vacant housing units. Although remote-sensing technologies are a promising low-cost alternative to direct observation, this study demonstrated only moderate levels of agreement with ground-truthing. Published by Elsevier Ltd.

Social Role Discovery in Human Events (Open Access)

DTIC Science & Technology

2013-10-03

to all people in the videos. We also present a novel YouTube social roles dataset with ground truth role annota- tions, and introduce annotations on a... nursing home [13], making role identifi- cation a difficult human task. Ideally, we would like to auto- matically discover such interaction-based role...34# $% &’$( ! Figure 2. Sample frames from different events in the YouTube Social

South San Francisco Bay 2004 topographic lidar survey: Data overview and preliminary quality assessment

USGS Publications Warehouse

Foxgrover, Amy C.; Jaffe, Bruce E.

2005-01-01

This report details the collection of lidar in South Bay, the ground-truthing efforts, preliminary accuracy assessments, and known limitations of the data set. We describe the data generated from the survey and how to obtain it. In addition, we present maps and sample imagery that provides a revealing look into the intricate topographic features of South Bay.

The importance of ground truth data in remote sensing

NASA Technical Reports Server (NTRS)

Hoffer, R. M.

1972-01-01

Surface observation data is discussed as an essential part of remote sensing research. One of the most important aspects of ground truth is the collection of measurements and observations about the type, size, condition and other physical or chemical properties of importance concerning the materials on the earth's surface that are being sensed remotely. The use of a variety of sensor systems in combination at different altitudes is emphasized.

Fully automated, real-time 3D ultrasound segmentation to estimate first trimester placental volume using deep learning.

PubMed

Looney, Pádraig; Stevenson, Gordon N; Nicolaides, Kypros H; Plasencia, Walter; Molloholli, Malid; Natsis, Stavros; Collins, Sally L

2018-06-07

We present a new technique to fully automate the segmentation of an organ from 3D ultrasound (3D-US) volumes, using the placenta as the target organ. Image analysis tools to estimate organ volume do exist but are too time consuming and operator dependant. Fully automating the segmentation process would potentially allow the use of placental volume to screen for increased risk of pregnancy complications. The placenta was segmented from 2,393 first trimester 3D-US volumes using a semiautomated technique. This was quality controlled by three operators to produce the "ground-truth" data set. A fully convolutional neural network (OxNNet) was trained using this ground-truth data set to automatically segment the placenta. OxNNet delivered state-of-the-art automatic segmentation. The effect of training set size on the performance of OxNNet demonstrated the need for large data sets. The clinical utility of placental volume was tested by looking at predictions of small-for-gestational-age babies at term. The receiver-operating characteristics curves demonstrated almost identical results between OxNNet and the ground-truth). Our results demonstrated good similarity to the ground-truth and almost identical clinical results for the prediction of SGA.

Software Suite to Support In-Flight Characterization of Remote Sensing Systems

NASA Technical Reports Server (NTRS)

Stanley, Thomas; Holekamp, Kara; Gasser, Gerald; Tabor, Wes; Vaughan, Ronald; Ryan, Robert; Pagnutti, Mary; Blonski, Slawomir; Kenton, Ross

2014-01-01

A characterization software suite was developed to facilitate NASA's in-flight characterization of commercial remote sensing systems. Characterization of aerial and satellite systems requires knowledge of ground characteristics, or ground truth. This information is typically obtained with instruments taking measurements prior to or during a remote sensing system overpass. Acquired ground-truth data, which can consist of hundreds of measurements with different data formats, must be processed before it can be used in the characterization. Accurate in-flight characterization of remote sensing systems relies on multiple field data acquisitions that are efficiently processed, with minimal error. To address the need for timely, reproducible ground-truth data, a characterization software suite was developed to automate the data processing methods. The characterization software suite is engineering code, requiring some prior knowledge and expertise to run. The suite consists of component scripts for each of the three main in-flight characterization types: radiometric, geometric, and spatial. The component scripts for the radiometric characterization operate primarily by reading the raw data acquired by the field instruments, combining it with other applicable information, and then reducing it to a format that is appropriate for input into MODTRAN (MODerate resolution atmospheric TRANsmission), an Air Force Research Laboratory-developed radiative transport code used to predict at-sensor measurements. The geometric scripts operate by comparing identified target locations from the remote sensing image to known target locations, producing circular error statistics defined by the Federal Geographic Data Committee Standards. The spatial scripts analyze a target edge within the image, and produce estimates of Relative Edge Response and the value of the Modulation Transfer Function at the Nyquist frequency. The software suite enables rapid, efficient, automated processing of ground truth data, which has been used to provide reproducible characterizations on a number of commercial remote sensing systems. Overall, this characterization software suite improves the reliability of ground-truth data processing techniques that are required for remote sensing system in-flight characterizations.

The Truth, the Whole Truth, and Nothing but the Ground-Truth: Methods to Advance Environmental Justice and Researcher-Community Partnerships

ERIC Educational Resources Information Center

Sadd, James; Morello-Frosch, Rachel; Pastor, Manuel; Matsuoka, Martha; Prichard, Michele; Carter, Vanessa

2014-01-01

Environmental justice advocates often argue that environmental hazards and their health effects vary by neighborhood, income, and race. To assess these patterns and advance preventive policy, their colleagues in the research world often use complex and methodologically sophisticated statistical and geospatial techniques. One way to bridge the gap…

Truth in Testing Legislation and Private Property Concepts.

ERIC Educational Resources Information Center

Burns, Daniel J.

1981-01-01

Truth in testing laws are subject to challenge on the grounds that they invade federally protected rights and interests of the test-makers through the due process clauses of the Constitution and federal copyright protections. (Author/MLF)

GEOS-3 phase B ground truth summary

NASA Technical Reports Server (NTRS)

Parsons, C. L.; Goodman, L. R.

1975-01-01

Ground truth data collected during the experiment systems calibration and evaluation phase of the Geodynamics experimental Ocean Satellite (GEOS-3) experiment are summarized. Both National Weather Service analyses and aircraft sensor data are included. The data are structured to facilitate the use of the various data products in calibrating the GEOS-3 radar altimeter and in assessing the altimeter's sensitivity to geophysical phenomena. Brief statements are made concerning the quality and completeness of the included data.

The challenge of mapping the human connectome based on diffusion tractography.

PubMed

Maier-Hein, Klaus H; Neher, Peter F; Houde, Jean-Christophe; Côté, Marc-Alexandre; Garyfallidis, Eleftherios; Zhong, Jidan; Chamberland, Maxime; Yeh, Fang-Cheng; Lin, Ying-Chia; Ji, Qing; Reddick, Wilburn E; Glass, John O; Chen, David Qixiang; Feng, Yuanjing; Gao, Chengfeng; Wu, Ye; Ma, Jieyan; Renjie, H; Li, Qiang; Westin, Carl-Fredrik; Deslauriers-Gauthier, Samuel; González, J Omar Ocegueda; Paquette, Michael; St-Jean, Samuel; Girard, Gabriel; Rheault, François; Sidhu, Jasmeen; Tax, Chantal M W; Guo, Fenghua; Mesri, Hamed Y; Dávid, Szabolcs; Froeling, Martijn; Heemskerk, Anneriet M; Leemans, Alexander; Boré, Arnaud; Pinsard, Basile; Bedetti, Christophe; Desrosiers, Matthieu; Brambati, Simona; Doyon, Julien; Sarica, Alessia; Vasta, Roberta; Cerasa, Antonio; Quattrone, Aldo; Yeatman, Jason; Khan, Ali R; Hodges, Wes; Alexander, Simon; Romascano, David; Barakovic, Muhamed; Auría, Anna; Esteban, Oscar; Lemkaddem, Alia; Thiran, Jean-Philippe; Cetingul, H Ertan; Odry, Benjamin L; Mailhe, Boris; Nadar, Mariappan S; Pizzagalli, Fabrizio; Prasad, Gautam; Villalon-Reina, Julio E; Galvis, Justin; Thompson, Paul M; Requejo, Francisco De Santiago; Laguna, Pedro Luque; Lacerda, Luis Miguel; Barrett, Rachel; Dell'Acqua, Flavio; Catani, Marco; Petit, Laurent; Caruyer, Emmanuel; Daducci, Alessandro; Dyrby, Tim B; Holland-Letz, Tim; Hilgetag, Claus C; Stieltjes, Bram; Descoteaux, Maxime

2017-11-07

Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international tractography challenge, which resulted in 96 distinct submissions from 20 research groups. Here, we report the encouraging finding that most state-of-the-art algorithms produce tractograms containing 90% of the ground truth bundles (to at least some extent). However, the same tractograms contain many more invalid than valid bundles, and half of these invalid bundles occur systematically across research groups. Taken together, our results demonstrate and confirm fundamental ambiguities inherent in tract reconstruction based on orientation information alone, which need to be considered when interpreting tractography and connectivity results. Our approach provides a novel framework for estimating reliability of tractography and encourages innovation to address its current limitations.

Interactive degraded document enhancement and ground truth generation

NASA Astrophysics Data System (ADS)

Bal, G.; Agam, G.; Frieder, O.; Frieder, G.

2008-01-01

Degraded documents are frequently obtained in various situations. Examples of degraded document collections include historical document depositories, document obtained in legal and security investigations, and legal and medical archives. Degraded document images are hard to to read and are hard to analyze using computerized techniques. There is hence a need for systems that are capable of enhancing such images. We describe a language-independent semi-automated system for enhancing degraded document images that is capable of exploiting inter- and intra-document coherence. The system is capable of processing document images with high levels of degradations and can be used for ground truthing of degraded document images. Ground truthing of degraded document images is extremely important in several aspects: it enables quantitative performance measurements of enhancement systems and facilitates model estimation that can be used to improve performance. Performance evaluation is provided using the historical Frieder diaries collection.1

The evaluation of alternate methodologies for land cover classification in an urbanizing area

NASA Technical Reports Server (NTRS)

Smekofski, R. M.

1981-01-01

The usefulness of LANDSAT in classifying land cover and in identifying and classifying land use change was investigated using an urbanizing area as the study area. The question of what was the best technique for classification was the primary focus of the study. The many computer-assisted techniques available to analyze LANDSAT data were evaluated. Techniques of statistical training (polygons from CRT, unsupervised clustering, polygons from digitizer and binary masks) were tested with minimum distance to the mean, maximum likelihood and canonical analysis with minimum distance to the mean classifiers. The twelve output images were compared to photointerpreted samples, ground verified samples and a current land use data base. Results indicate that for a reconnaissance inventory, the unsupervised training with canonical analysis-minimum distance classifier is the most efficient. If more detailed ground truth and ground verification is available, the polygons from the digitizer training with the canonical analysis minimum distance is more accurate.

Bayes classification of interferometric TOPSAR data

NASA Technical Reports Server (NTRS)

Michel, T. R.; Rodriguez, E.; Houshmand, B.; Carande, R.

1995-01-01

We report the Bayes classification of terrain types at different sites using airborne interferometric synthetic aperture radar (INSAR) data. A Gaussian maximum likelihood classifier was applied on multidimensional observations derived from the SAR intensity, the terrain elevation model, and the magnitude of the interferometric correlation. Training sets for forested, urban, agricultural, or bare areas were obtained either by selecting samples with known ground truth, or by k-means clustering of random sets of samples uniformly distributed across all sites, and subsequent assignments of these clusters using ground truth. The accuracy of the classifier was used to optimize the discriminating efficiency of the set of features that was chosen. The most important features include the SAR intensity, a canopy penetration depth model, and the terrain slope. We demonstrate the classifier's performance across sites using a unique set of training classes for the four main terrain categories. The scenes examined include San Francisco (CA) (predominantly urban and water), Mount Adams (WA) (forested with clear cuts), Pasadena (CA) (urban with mountains), and Antioch Hills (CA) (water, swamps, fields). Issues related to the effects of image calibration and the robustness of the classification to calibration errors are explored. The relative performance of single polarization Interferometric data classification is contrasted against classification schemes based on polarimetric SAR data.

The gene normalization task in BioCreative III

PubMed Central

2011-01-01

Background We report the Gene Normalization (GN) challenge in BioCreative III where participating teams were asked to return a ranked list of identifiers of the genes detected in full-text articles. For training, 32 fully and 500 partially annotated articles were prepared. A total of 507 articles were selected as the test set. Due to the high annotation cost, it was not feasible to obtain gold-standard human annotations for all test articles. Instead, we developed an Expectation Maximization (EM) algorithm approach for choosing a small number of test articles for manual annotation that were most capable of differentiating team performance. Moreover, the same algorithm was subsequently used for inferring ground truth based solely on team submissions. We report team performance on both gold standard and inferred ground truth using a newly proposed metric called Threshold Average Precision (TAP-k). Results We received a total of 37 runs from 14 different teams for the task. When evaluated using the gold-standard annotations of the 50 articles, the highest TAP-k scores were 0.3297 (k=5), 0.3538 (k=10), and 0.3535 (k=20), respectively. Higher TAP-k scores of 0.4916 (k=5, 10, 20) were observed when evaluated using the inferred ground truth over the full test set. When combining team results using machine learning, the best composite system achieved TAP-k scores of 0.3707 (k=5), 0.4311 (k=10), and 0.4477 (k=20) on the gold standard, representing improvements of 12.4%, 21.8%, and 26.6% over the best team results, respectively. Conclusions By using full text and being species non-specific, the GN task in BioCreative III has moved closer to a real literature curation task than similar tasks in the past and presents additional challenges for the text mining community, as revealed in the overall team results. By evaluating teams using the gold standard, we show that the EM algorithm allows team submissions to be differentiated while keeping the manual annotation effort feasible. Using the inferred ground truth we show measures of comparative performance between teams. Finally, by comparing team rankings on gold standard vs. inferred ground truth, we further demonstrate that the inferred ground truth is as effective as the gold standard for detecting good team performance. PMID:22151901

The gene normalization task in BioCreative III.

PubMed

Lu, Zhiyong; Kao, Hung-Yu; Wei, Chih-Hsuan; Huang, Minlie; Liu, Jingchen; Kuo, Cheng-Ju; Hsu, Chun-Nan; Tsai, Richard Tzong-Han; Dai, Hong-Jie; Okazaki, Naoaki; Cho, Han-Cheol; Gerner, Martin; Solt, Illes; Agarwal, Shashank; Liu, Feifan; Vishnyakova, Dina; Ruch, Patrick; Romacker, Martin; Rinaldi, Fabio; Bhattacharya, Sanmitra; Srinivasan, Padmini; Liu, Hongfang; Torii, Manabu; Matos, Sergio; Campos, David; Verspoor, Karin; Livingston, Kevin M; Wilbur, W John

2011-10-03

We report the Gene Normalization (GN) challenge in BioCreative III where participating teams were asked to return a ranked list of identifiers of the genes detected in full-text articles. For training, 32 fully and 500 partially annotated articles were prepared. A total of 507 articles were selected as the test set. Due to the high annotation cost, it was not feasible to obtain gold-standard human annotations for all test articles. Instead, we developed an Expectation Maximization (EM) algorithm approach for choosing a small number of test articles for manual annotation that were most capable of differentiating team performance. Moreover, the same algorithm was subsequently used for inferring ground truth based solely on team submissions. We report team performance on both gold standard and inferred ground truth using a newly proposed metric called Threshold Average Precision (TAP-k). We received a total of 37 runs from 14 different teams for the task. When evaluated using the gold-standard annotations of the 50 articles, the highest TAP-k scores were 0.3297 (k=5), 0.3538 (k=10), and 0.3535 (k=20), respectively. Higher TAP-k scores of 0.4916 (k=5, 10, 20) were observed when evaluated using the inferred ground truth over the full test set. When combining team results using machine learning, the best composite system achieved TAP-k scores of 0.3707 (k=5), 0.4311 (k=10), and 0.4477 (k=20) on the gold standard, representing improvements of 12.4%, 21.8%, and 26.6% over the best team results, respectively. By using full text and being species non-specific, the GN task in BioCreative III has moved closer to a real literature curation task than similar tasks in the past and presents additional challenges for the text mining community, as revealed in the overall team results. By evaluating teams using the gold standard, we show that the EM algorithm allows team submissions to be differentiated while keeping the manual annotation effort feasible. Using the inferred ground truth we show measures of comparative performance between teams. Finally, by comparing team rankings on gold standard vs. inferred ground truth, we further demonstrate that the inferred ground truth is as effective as the gold standard for detecting good team performance.

Is STAPLE algorithm confident to assess segmentation methods in PET imaging?

NASA Astrophysics Data System (ADS)

Dewalle-Vignion, Anne-Sophie; Betrouni, Nacim; Baillet, Clio; Vermandel, Maximilien

2015-12-01

Accurate tumor segmentation in [18F]-fluorodeoxyglucose positron emission tomography is crucial for tumor response assessment and target volume definition in radiation therapy. Evaluation of segmentation methods from clinical data without ground truth is usually based on physicians’ manual delineations. In this context, the simultaneous truth and performance level estimation (STAPLE) algorithm could be useful to manage the multi-observers variability. In this paper, we evaluated how this algorithm could accurately estimate the ground truth in PET imaging. Complete evaluation study using different criteria was performed on simulated data. The STAPLE algorithm was applied to manual and automatic segmentation results. A specific configuration of the implementation provided by the Computational Radiology Laboratory was used. Consensus obtained by the STAPLE algorithm from manual delineations appeared to be more accurate than manual delineations themselves (80% of overlap). An improvement of the accuracy was also observed when applying the STAPLE algorithm to automatic segmentations results. The STAPLE algorithm, with the configuration used in this paper, is more appropriate than manual delineations alone or automatic segmentations results alone to estimate the ground truth in PET imaging. Therefore, it might be preferred to assess the accuracy of tumor segmentation methods in PET imaging.

Is STAPLE algorithm confident to assess segmentation methods in PET imaging?

PubMed

Dewalle-Vignion, Anne-Sophie; Betrouni, Nacim; Baillet, Clio; Vermandel, Maximilien

2015-12-21

Accurate tumor segmentation in [18F]-fluorodeoxyglucose positron emission tomography is crucial for tumor response assessment and target volume definition in radiation therapy. Evaluation of segmentation methods from clinical data without ground truth is usually based on physicians' manual delineations. In this context, the simultaneous truth and performance level estimation (STAPLE) algorithm could be useful to manage the multi-observers variability. In this paper, we evaluated how this algorithm could accurately estimate the ground truth in PET imaging. Complete evaluation study using different criteria was performed on simulated data. The STAPLE algorithm was applied to manual and automatic segmentation results. A specific configuration of the implementation provided by the Computational Radiology Laboratory was used. Consensus obtained by the STAPLE algorithm from manual delineations appeared to be more accurate than manual delineations themselves (80% of overlap). An improvement of the accuracy was also observed when applying the STAPLE algorithm to automatic segmentations results. The STAPLE algorithm, with the configuration used in this paper, is more appropriate than manual delineations alone or automatic segmentations results alone to estimate the ground truth in PET imaging. Therefore, it might be preferred to assess the accuracy of tumor segmentation methods in PET imaging.

Multiple-Array Detection, Association and Location of Infrasound and Seismo-Acoustic Event-Utilization of Ground Truth Information (Postprint)

DTIC Science & Technology

2012-05-07

AFRL-RV-PS- AFRL-RV-PS- TP-2012-0017 TP-2012-0017 MULTIPLE-ARRAY DETECTION, ASSOCIATION AND LOCATION OF INFRASOUND AND SEISMO-ACOUSTIC...ASSOCIATION AND LOCATION OF 5a. CONTRACT NUMBER FA8718-08-C-0008 INFRASOUND AND SEISMO-ACOUSTIC EVENT – UTILIZATION OF GROUND-TRUTH... infrasound signals from both correlated and uncorrelated noise. Approaches to this problem are implementation of the F-detector, which employs the F

Ground-truthing electrical resistivity methods in support of submarine groundwater discharge studies: Examples from Hawaii, Washington, and California

USGS Publications Warehouse

Johnson, Cordell; Swarzenski, Peter W.; Richardson, Christina M.; Smith, Christopher G.; Kroeger, Kevin D.; Ganguli, Priya M.

2015-01-01

Rigorous ground-truthing at each field site showed that multi-channel electrcial resistivity techniques can reproduce the scales and dynamics of a seepage field when such data are correctly collected, and when the model inversions are tuned to field site characteristics. Such information can provide a unique perspective on the scales and dynamics of exchange processes within a coastal aquifer—information essential to scientists and resource managers alike.

On Evaluating Brain Tissue Classifiers without a Ground Truth

PubMed Central

Martin-Fernandez, Marcos; Ungar, Lida; Nakamura, Motoaki; Koo, Min-Seong; McCarley, Robert W.; Shenton, Martha E.

2009-01-01

In this paper, we present a set of techniques for the evaluation of brain tissue classifiers on a large data set of MR images of the head. Due to the difficulty of establishing a gold standard for this type of data, we focus our attention on methods which do not require a ground truth, but instead rely on a common agreement principle. Three different techniques are presented: the Williams’ index, a measure of common agreement; STAPLE, an Expectation Maximization algorithm which simultaneously estimates performance parameters and constructs an estimated reference standard; and Multidimensional Scaling, a visualization technique to explore similarity data. We apply these different evaluation methodologies to a set eleven different segmentation algorithms on forty MR images. We then validate our evaluation pipeline by building a ground truth based on human expert tracings. The evaluations with and without a ground truth are compared. Our findings show that comparing classifiers without a gold standard can provide a lot of interesting information. In particular, outliers can be easily detected, strongly consistent or highly variable techniques can be readily discriminated, and the overall similarity between different techniques can be assessed. On the other hand, we also find that some information present in the expert segmentations is not captured by the automatic classifiers, suggesting that common agreement alone may not be sufficient for a precise performance evaluation of brain tissue classifiers. PMID:17532646

Reanimating patients: cardio-respiratory CT and MR motion phantoms based on clinical CT patient data

NASA Astrophysics Data System (ADS)

Mayer, Johannes; Sauppe, Sebastian; Rank, Christopher M.; Sawall, Stefan; Kachelrieß, Marc

2017-03-01

Until today several algorithms have been developed that reduce or avoid artifacts caused by cardiac and respiratory motion in computed tomography (CT). The motion information is converted into so-called motion vector fields (MVFs) and used for motion compensation (MoCo) during the image reconstruction. To analyze these algorithms quantitatively there is the need for ground truth patient data displaying realistic motion. We developed a method to generate a digital ground truth displaying realistic cardiac and respiratory motion that can be used as a tool to assess MoCo algorithms. By the use of available MoCo methods we measured the motion in CT scans with high spatial and temporal resolution and transferred the motion information onto patient data with different anatomy or imaging modality, thereby reanimating the patient virtually. In addition to these images the ground truth motion information in the form of MVFs is available and can be used to benchmark the MVF estimation of MoCo algorithms. We here applied the method to generate 20 CT volumes displaying detailed cardiac motion that can be used for cone-beam CT (CBCT) simulations and a set of 8 MR volumes displaying respiratory motion. Our method is able to reanimate patient data virtually. In combination with the MVFs it serves as a digital ground truth and provides an improved framework to assess MoCo algorithms.

A ground truth based comparative study on clustering of gene expression data.

PubMed

Zhu, Yitan; Wang, Zuyi; Miller, David J; Clarke, Robert; Xuan, Jianhua; Hoffman, Eric P; Wang, Yue

2008-05-01

Given the variety of available clustering methods for gene expression data analysis, it is important to develop an appropriate and rigorous validation scheme to assess the performance and limitations of the most widely used clustering algorithms. In this paper, we present a ground truth based comparative study on the functionality, accuracy, and stability of five data clustering methods, namely hierarchical clustering, K-means clustering, self-organizing maps, standard finite normal mixture fitting, and a caBIG toolkit (VIsual Statistical Data Analyzer--VISDA), tested on sample clustering of seven published microarray gene expression datasets and one synthetic dataset. We examined the performance of these algorithms in both data-sufficient and data-insufficient cases using quantitative performance measures, including cluster number detection accuracy and mean and standard deviation of partition accuracy. The experimental results showed that VISDA, an interactive coarse-to-fine maximum likelihood fitting algorithm, is a solid performer on most of the datasets, while K-means clustering and self-organizing maps optimized by the mean squared compactness criterion generally produce more stable solutions than the other methods.

Field calibration and validation of remote-sensing surveys

USGS Publications Warehouse

Pe'eri, Shachak; McLeod, Andy; Lavoie, Paul; Ackerman, Seth D.; Gardner, James; Parrish, Christopher

2013-01-01

The Optical Collection Suite (OCS) is a ground-truth sampling system designed to perform in situ measurements that help calibrate and validate optical remote-sensing and swath-sonar surveys for mapping and monitoring coastal ecosystems and ocean planning. The OCS system enables researchers to collect underwater imagery with real-time feedback, measure the spectral response, and quantify the water clarity with simple and relatively inexpensive instruments that can be hand-deployed from a small vessel. This article reviews the design and performance of the system, based on operational and logistical considerations, as well as the data requirements to support a number of coastal science and management projects. The OCS system has been operational since 2009 and has been used in several ground-truth missions that overlapped with airborne lidar bathymetry (ALB), hyperspectral imagery (HSI), and swath-sonar bathymetric surveys in the Gulf of Maine, southwest Alaska, and the US Virgin Islands (USVI). Research projects that have used the system include a comparison of backscatter intensity derived from acoustic (multibeam/interferometric sonars) versus active optical (ALB) sensors, ALB bottom detection, and seafloor characterization using HSI and ALB.

Evaluation of Event-Based Algorithms for Optical Flow with Ground-Truth from Inertial Measurement Sensor

PubMed Central

Rueckauer, Bodo; Delbruck, Tobi

2016-01-01

In this study we compare nine optical flow algorithms that locally measure the flow normal to edges according to accuracy and computation cost. In contrast to conventional, frame-based motion flow algorithms, our open-source implementations compute optical flow based on address-events from a neuromorphic Dynamic Vision Sensor (DVS). For this benchmarking we created a dataset of two synthesized and three real samples recorded from a 240 × 180 pixel Dynamic and Active-pixel Vision Sensor (DAVIS). This dataset contains events from the DVS as well as conventional frames to support testing state-of-the-art frame-based methods. We introduce a new source for the ground truth: In the special case that the perceived motion stems solely from a rotation of the vision sensor around its three camera axes, the true optical flow can be estimated using gyro data from the inertial measurement unit integrated with the DAVIS camera. This provides a ground-truth to which we can compare algorithms that measure optical flow by means of motion cues. An analysis of error sources led to the use of a refractory period, more accurate numerical derivatives and a Savitzky-Golay filter to achieve significant improvements in accuracy. Our pure Java implementations of two recently published algorithms reduce computational cost by up to 29% compared to the original implementations. Two of the algorithms introduced in this paper further speed up processing by a factor of 10 compared with the original implementations, at equal or better accuracy. On a desktop PC, they run in real-time on dense natural input recorded by a DAVIS camera. PMID:27199639

Skepticism, truth as coherence, and constructivist epistemology: grounds for resolving the discord between science and religion?

NASA Astrophysics Data System (ADS)

Staver, John R.

2010-03-01

Science and religion exhibit multiple relationships as ways of knowing. These connections have been characterized as cousinly, mutually respectful, non-overlapping, competitive, proximate-ultimate, dominant-subordinate, and opposing-conflicting. Some of these ties create stress, and tension between science and religion represents a significant chapter in humans' cultural heritage before and since the Enlightenment. Truth, knowledge, and their relation are central to science and religion as ways of knowing, as social institutions, and to their interaction. In religion, truth is revealed through God's word. In science, truth is sought after via empirical methods. Discord can be viewed as a competition for social legitimization between two social institutions whose goals are explaining the world and how it works. Under this view, the root of the discord is truth as correspondence. In this concept of truth, knowledge corresponds to the facts of reality, and conflict is inevitable for many because humans want to ask which one—science or religion—gets the facts correct. But, the root paradox, also known as the problem of the criterion, suggests that seeking to know nature as it is represents a fruitless endeavor. The discord can be set on new ground and resolved by taking a moderately skeptical line of thought, one which employs truth as coherence and a moderate form of constructivist epistemology. Quantum mechanics and evolution as scientific theories and scientific research on human consciousness and vision provide support for this line of argument. Within a constructivist perspective, scientists would relinquish only the pursuit of knowing reality as it is. Scientists would retain everything else. Believers who hold that religion explains reality would come to understand that God never revealed His truth of nature; rather, He revealed His truth in how we are to conduct our lives.

The Role of Ground Truth in Improved Identification of Mining Explosion Signals Utilization of Calibration Explosions and Acoustic Signals

DTIC Science & Technology

2000-09-01

and the Porphyry Copper District (PCD) of east central Arizona and south west New Mexico were used in gathering ground truth ranging from mine records...previous studies of large coal cast blasting operations in Wyoming that trigger the IMS (Hedlin et al. 2000), the porphyry copper region of Arizona and...local mines producing the sources. Close cooperation has been developed with the Phelps Dodge mines in Morenci, Arizona and Tyrone, New Mexico where in

Textural Analysis and Substrate Classification in the Nearshore Region of Lake Superior Using High-Resolution Multibeam Bathymetry

NASA Astrophysics Data System (ADS)

Dennison, Andrew G.

Classification of the seafloor substrate can be done with a variety of methods. These methods include Visual (dives, drop cameras); mechanical (cores, grab samples); acoustic (statistical analysis of echosounder returns). Acoustic methods offer a more powerful and efficient means of collecting useful information about the bottom type. Due to the nature of an acoustic survey, larger areas can be sampled, and by combining the collected data with visual and mechanical survey methods provide greater confidence in the classification of a mapped region. During a multibeam sonar survey, both bathymetric and backscatter data is collected. It is well documented that the statistical characteristic of a sonar backscatter mosaic is dependent on bottom type. While classifying the bottom-type on the basis on backscatter alone can accurately predict and map bottom-type, i.e a muddy area from a rocky area, it lacks the ability to resolve and capture fine textural details, an important factor in many habitat mapping studies. Statistical processing of high-resolution multibeam data can capture the pertinent details about the bottom-type that are rich in textural information. Further multivariate statistical processing can then isolate characteristic features, and provide the basis for an accurate classification scheme. The development of a new classification method is described here. It is based upon the analysis of textural features in conjunction with ground truth sampling. The processing and classification result of two geologically distinct areas in nearshore regions of Lake Superior; off the Lester River,MN and Amnicon River, WI are presented here, using the Minnesota Supercomputer Institute's Mesabi computing cluster for initial processing. Processed data is then calibrated using ground truth samples to conduct an accuracy assessment of the surveyed areas. From analysis of high-resolution bathymetry data collected at both survey sites is was possible to successfully calculate a series of measures that describe textural information about the lake floor. Further processing suggests that the features calculated capture a significant amount of statistical information about the lake floor terrain as well. Two sources of error, an anomalous heave and refraction error significantly deteriorated the quality of the processed data and resulting validate results. Ground truth samples used to validate the classification methods utilized for both survey sites, however, resulted in accuracy values ranging from 5 -30 percent at the Amnicon River, and between 60-70 percent for the Lester River. The final results suggest that this new processing methodology does adequately capture textural information about the lake floor and does provide an acceptable classification in the absence of significant data quality issues.

Data fusion of Landsat TM and IRS images in forest classification

Treesearch

Guangxing Wang; Markus Holopainen; Eero Lukkarinen

2000-01-01

Data fusion of Landsat TM images and Indian Remote Sensing satellite panchromatic image (IRS-1C PAN) was studied and compared to the use of TM or IRS image only. The aim was to combine the high spatial resolution of IRS-1C PAN to the high spectral resolution of Landsat TM images using a data fusion algorithm. The ground truth of the study was based on a sample of 1,020...

New SHARE 2010 HSI-LiDAR dataset: re-calibration, detection assessment and delivery

NASA Astrophysics Data System (ADS)

Ientilucci, Emmett J.

2016-09-01

This paper revisits hyperspectral data collected from the SpecTIR hyperspectral airborne Rochester Experiment (SHARE) in 2010. It has been determined that there were calibration issues in the SWIR portion of the data. This calibration issue is discussed and has been rectified. Approaches for calibration to radiance and compensation to reflectance are discussed based on in-scene information and radiative transfer codes. In addition to the entire flight line, a much large target detection test and evaluation chip has been created which includes an abundance of potential false alarms. New truth masks are created along with results from target detection algorithms. Co-registered LiDAR data is also presented. Finally, all ground truth information (ground photos, metadata, MODTRAN tape5, ASD ground spectral measurements, target truth masks, etc.), in addition to the HSI flight lines and co-registered LiDAR data, has been organized, packaged and uploaded to the Center for Imaging Science / Digital Imaging and Remote Sensing Lab web server for public use.

Canny edge-based deformable image registration

NASA Astrophysics Data System (ADS)

Kearney, Vasant; Huang, Yihui; Mao, Weihua; Yuan, Baohong; Tang, Liping

2017-02-01

This work focuses on developing a 2D Canny edge-based deformable image registration (Canny DIR) algorithm to register in vivo white light images taken at various time points. This method uses a sparse interpolation deformation algorithm to sparsely register regions of the image with strong edge information. A stability criterion is enforced which removes regions of edges that do not deform in a smooth uniform manner. Using a synthetic mouse surface ground truth model, the accuracy of the Canny DIR algorithm was evaluated under axial rotation in the presence of deformation. The accuracy was also tested using fluorescent dye injections, which were then used for gamma analysis to establish a second ground truth. The results indicate that the Canny DIR algorithm performs better than rigid registration, intensity corrected Demons, and distinctive features for all evaluation matrices and ground truth scenarios. In conclusion Canny DIR performs well in the presence of the unique lighting and shading variations associated with white-light-based image registration.

First- and third-party ground truth for key frame extraction from consumer video clips

NASA Astrophysics Data System (ADS)

Costello, Kathleen; Luo, Jiebo

2007-02-01

Extracting key frames (KF) from video is of great interest in many applications, such as video summary, video organization, video compression, and prints from video. KF extraction is not a new problem. However, current literature has been focused mainly on sports or news video. In the consumer video space, the biggest challenges for key frame selection from consumer videos are the unconstrained content and lack of any preimposed structure. In this study, we conduct ground truth collection of key frames from video clips taken by digital cameras (as opposed to camcorders) using both first- and third-party judges. The goals of this study are: (1) to create a reference database of video clips reasonably representative of the consumer video space; (2) to identify associated key frames by which automated algorithms can be compared and judged for effectiveness; and (3) to uncover the criteria used by both first- and thirdparty human judges so these criteria can influence algorithm design. The findings from these ground truths will be discussed.

Bulk Growth of 2-6 Crystals in the Microgravity Environment of USML-1

NASA Technical Reports Server (NTRS)

Gillies, Donald C.; Lehoczky, Sandor L.; Szofran, Frank R.; Larson, David J.; Su, Ching-Hua; Sha, Yi-Gao; Alexander, Helga A.

1993-01-01

The first United States Microgravity Laboratory Mission (USML- 1) flew in June 1992 on the Space Shuttle Columbia. An important part of this SpaceLab mission was the debut of the Crystal Growth Furnace (CGF). Of the seven samples grown in the furnace, three were bulk grown 2-6 compounds, two of a cadmium zinc telluride alloy, and one of a mercury zinc telluride alloy. Ground based results are presented, together with the results of computer simulated growths of these experimental conditions. Preliminary characterization results for the three USML-1 growth runs are also presented and the flight sample characteristics are compared to the equivalent ground truth samples. Of particular interest are the effect of the containment vessel on surface features, and especially on the nucleation, and the effect of the gravity vector on radial and axial compositional variations and stress and defect levels.

Field size, length, and width distributions based on LACIE ground truth data. [large area crop inventory experiment

NASA Technical Reports Server (NTRS)

Pitts, D. E.; Badhwar, G.

1980-01-01

The development of agricultural remote sensing systems requires knowledge of agricultural field size distributions so that the sensors, sampling frames, image interpretation schemes, registration systems, and classification systems can be properly designed. Malila et al. (1976) studied the field size distribution for wheat and all other crops in two Kansas LACIE (Large Area Crop Inventory Experiment) intensive test sites using ground observations of the crops and measurements of their field areas based on current year rectified aerial photomaps. The field area and size distributions reported in the present investigation are derived from a representative subset of a stratified random sample of LACIE sample segments. In contrast to previous work, the obtained results indicate that most field-size distributions are not log-normally distributed. The most common field size observed in this study was 10 acres for most crops studied.

The ground truth about metadata and community detection in networks.

PubMed

Peel, Leto; Larremore, Daniel B; Clauset, Aaron

2017-05-01

Across many scientific domains, there is a common need to automatically extract a simplified view or coarse-graining of how a complex system's components interact. This general task is called community detection in networks and is analogous to searching for clusters in independent vector data. It is common to evaluate the performance of community detection algorithms by their ability to find so-called ground truth communities. This works well in synthetic networks with planted communities because these networks' links are formed explicitly based on those known communities. However, there are no planted communities in real-world networks. Instead, it is standard practice to treat some observed discrete-valued node attributes, or metadata, as ground truth. We show that metadata are not the same as ground truth and that treating them as such induces severe theoretical and practical problems. We prove that no algorithm can uniquely solve community detection, and we prove a general No Free Lunch theorem for community detection, which implies that there can be no algorithm that is optimal for all possible community detection tasks. However, community detection remains a powerful tool and node metadata still have value, so a careful exploration of their relationship with network structure can yield insights of genuine worth. We illustrate this point by introducing two statistical techniques that can quantify the relationship between metadata and community structure for a broad class of models. We demonstrate these techniques using both synthetic and real-world networks, and for multiple types of metadata and community structures.

Ground truth and benchmarks for performance evaluation

NASA Astrophysics Data System (ADS)

Takeuchi, Ayako; Shneier, Michael; Hong, Tsai Hong; Chang, Tommy; Scrapper, Christopher; Cheok, Geraldine S.

2003-09-01

Progress in algorithm development and transfer of results to practical applications such as military robotics requires the setup of standard tasks, of standard qualitative and quantitative measurements for performance evaluation and validation. Although the evaluation and validation of algorithms have been discussed for over a decade, the research community still faces a lack of well-defined and standardized methodology. The range of fundamental problems include a lack of quantifiable measures of performance, a lack of data from state-of-the-art sensors in calibrated real-world environments, and a lack of facilities for conducting realistic experiments. In this research, we propose three methods for creating ground truth databases and benchmarks using multiple sensors. The databases and benchmarks will provide researchers with high quality data from suites of sensors operating in complex environments representing real problems of great relevance to the development of autonomous driving systems. At NIST, we have prototyped a High Mobility Multi-purpose Wheeled Vehicle (HMMWV) system with a suite of sensors including a Riegl ladar, GDRS ladar, stereo CCD, several color cameras, Global Position System (GPS), Inertial Navigation System (INS), pan/tilt encoders, and odometry . All sensors are calibrated with respect to each other in space and time. This allows a database of features and terrain elevation to be built. Ground truth for each sensor can then be extracted from the database. The main goal of this research is to provide ground truth databases for researchers and engineers to evaluate algorithms for effectiveness, efficiency, reliability, and robustness, thus advancing the development of algorithms.

How Many Subjects are Needed for a Visual Field Normative Database? A Comparison of Ground Truth and Bootstrapped Statistics.

PubMed

Phu, Jack; Bui, Bang V; Kalloniatis, Michael; Khuu, Sieu K

2018-03-01

The number of subjects needed to establish the normative limits for visual field (VF) testing is not known. Using bootstrap resampling, we determined whether the ground truth mean, distribution limits, and standard deviation (SD) could be approximated using different set size ( x ) levels, in order to provide guidance for the number of healthy subjects required to obtain robust VF normative data. We analyzed the 500 Humphrey Field Analyzer (HFA) SITA-Standard results of 116 healthy subjects and 100 HFA full threshold results of 100 psychophysically experienced healthy subjects. These VFs were resampled (bootstrapped) to determine mean sensitivity, distribution limits (5th and 95th percentiles), and SD for different ' x ' and numbers of resamples. We also used the VF results of 122 glaucoma patients to determine the performance of ground truth and bootstrapped results in identifying and quantifying VF defects. An x of 150 (for SITA-Standard) and 60 (for full threshold) produced bootstrapped descriptive statistics that were no longer different to the original distribution limits and SD. Removing outliers produced similar results. Differences between original and bootstrapped limits in detecting glaucomatous defects were minimized at x = 250. Ground truth statistics of VF sensitivities could be approximated using set sizes that are significantly smaller than the original cohort. Outlier removal facilitates the use of Gaussian statistics and does not significantly affect the distribution limits. We provide guidance for choosing the cohort size for different levels of error when performing normative comparisons with glaucoma patients.

Assessing the validity of commercial and municipal food environment data sets in Vancouver, Canada.

PubMed

Daepp, Madeleine Ig; Black, Jennifer

2017-10-01

The present study assessed systematic bias and the effects of data set error on the validity of food environment measures in two municipal and two commercial secondary data sets. Sensitivity, positive predictive value (PPV) and concordance were calculated by comparing two municipal and two commercial secondary data sets with ground-truthed data collected within 800 m buffers surrounding twenty-six schools. Logistic regression examined associations of sensitivity and PPV with commercial density and neighbourhood socio-economic deprivation. Kendall's τ estimated correlations between density and proximity of food outlets near schools constructed with secondary data sets v. ground-truthed data. Vancouver, Canada. Food retailers located within 800 m of twenty-six schools RESULTS: All data sets scored relatively poorly across validity measures, although, overall, municipal data sets had higher levels of validity than did commercial data sets. Food outlets were more likely to be missing from municipal health inspections lists and commercial data sets in neighbourhoods with higher commercial density. Still, both proximity and density measures constructed from all secondary data sets were highly correlated (Kendall's τ>0·70) with measures constructed from ground-truthed data. Despite relatively low levels of validity in all secondary data sets examined, food environment measures constructed from secondary data sets remained highly correlated with ground-truthed data. Findings suggest that secondary data sets can be used to measure the food environment, although estimates should be treated with caution in areas with high commercial density.

Improving the Accuracy of Extracting Surface Water Quality Levels (SWQLs) Using Remote Sensing and Artificial Neural Network: a Case Study in the Saint John River, Canada

NASA Astrophysics Data System (ADS)

Sammartano, G.; Spanò, A.

2017-09-01

Delineating accurate surface water quality levels (SWQLs) always presents a great challenge to researchers. Existing methods of assessing surface water quality only provide individual concentrations of monitoring stations without providing the overall SWQLs. Therefore, the results of existing methods are usually difficult to be understood by decision-makers. Conversely, the water quality index (WQI) can simplify surface water quality assessment process to be accessible to decision-makers. However, in most cases, the WQI reflects inaccurate SWQLs due to the lack of representative water samples. It is very challenging to provide representative water samples because this process is costly and time consuming. To solve this problem, we introduce a cost-effective method which combines the Landsat-8 imagery and artificial intelligence to develop models to derive representative water samples by correlating concentrations of ground truth water samples to satellite spectral information. Our method was validated and the correlation between concentrations of ground truth water samples and predicted concentrations from the developed models reached a high level of coefficient of determination (R2) > 0.80, which is trustworthy. Afterwards, the predicted concentrations over each pixel of the study area were used as an input to the WQI developed by the Canadian Council of Ministers of the Environment to extract accurate SWQLs, for drinking purposes, in the Saint John River. The results indicated that SWQL was observed as 67 (Fair) and 59 (Marginal) for the lower and middle basins of the river, respectively. These findings demonstrate the potential of using our approach in surface water quality management.

Bayes estimation on parameters of the single-class classifier. [for remotely sensed crop data

NASA Technical Reports Server (NTRS)

Lin, G. C.; Minter, T. C.

1976-01-01

Normal procedures used for designing a Bayes classifier to classify wheat as the major crop of interest require not only training samples of wheat but also those of nonwheat. Therefore, ground truth must be available for the class of interest plus all confusion classes. The single-class Bayes classifier classifies data into the class of interest or the class 'other' but requires training samples only from the class of interest. This paper will present a procedure for Bayes estimation on the mean vector, covariance matrix, and a priori probability of the single-class classifier using labeled samples from the class of interest and unlabeled samples drawn from the mixture density function.

A methodology for small scale rural land use mapping in semi-arid developing countries using orbital imagery. Part 3: Review of land use surveys using orbital imagery in the USA

NASA Technical Reports Server (NTRS)

Vangenderen, J. L. (Principal Investigator); Lock, B. F.

1976-01-01

The author has identified the following significant results. Techniques of preprocessing, interpretation, classification, and ground truth sampling were studied. It has shown the need for a low cost, low level technology, viable, operational methodology to replace the emphasis given in the U.S. to machine processing, which many developing countries cannot afford, understand, nor implement.

Snowpack ground truth: Radar test site, Steamboat Springs, Colorado, 8-16 April 1976

NASA Technical Reports Server (NTRS)

Howell, S.; Jones, E. B.; Leaf, C. F.

1976-01-01

Ground-truth data taken at Steamboat Springs, Colorado is presented. Data taken during the period April 8, 1976 - April 16, 1976 included the following: (1) snow depths and densities at selected locations (using a Mount Rose snow tube); (2) snow pits for temperature, density, and liquid water determinations using the freezing calorimetry technique and vertical layer classification; (3) snow walls were also constructed of various cross sections and documented with respect to sizes and snow characteristics; (4) soil moisture at selected locations; and (5) appropriate air temperature and weather data.

Standardized UXO Technology Demonstration Site Moguls Scoring Record Number 912 (Sky Research, Inc.)

DTIC Science & Technology

2008-09-01

south from the northern end point. 8 2) A metallic pin-flag is placed over the midpoint. 3) The operator logs data along the same path...buried UXO or other metallic debris. A 5-meter-length of line is walked in eight cardinal directions (N-S, S-N, E-W, W-E, SE-NW, NW-SE, SW-NE, NE-SW...points have been rounded to protect the ground truth. The overall ground truth is composed of ferrous and nonferrous anomalies. Due to limitations

WE-AB-202-09: Feasibility and Quantitative Analysis of 4DCT-Based High Precision Lung Elastography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasse, K; Neylon, J; Low, D

2016-06-15

Purpose: The purpose of this project is to derive high precision elastography measurements from 4DCT lung scans to facilitate the implementation of elastography in a radiotherapy context. Methods: 4DCT scans of the lungs were acquired, and breathing stages were subsequently registered to each other using an optical flow DIR algorithm. The displacement of each voxel gleaned from the registration was taken to be the ground-truth deformation. These vectors, along with the 4DCT source datasets, were used to generate a GPU-based biomechanical simulation that acted as a forward model to solve the inverse elasticity problem. The lung surface displacements were appliedmore » as boundary constraints for the model-guided lung tissue elastography, while the inner voxels were allowed to deform according to the linear elastic forces within the model. A biomechanically-based anisotropic convergence magnification technique was applied to the inner voxels in order to amplify the subtleties of the interior deformation. Solving the inverse elasticity problem was accomplished by modifying the tissue elasticity and iteratively deforming the biomechanical model. Convergence occurred when each voxel was within 0.5 mm of the ground-truth deformation and 1 kPa of the ground-truth elasticity distribution. To analyze the feasibility of the model-guided approach, we present the results for regions of low ventilation, specifically, the apex. Results: The maximum apical boundary expansion was observed to be between 2 and 6 mm. Simulating this expansion within an apical lung model, it was observed that 100% of voxels converged within 0.5 mm of ground-truth deformation, while 91.8% converged within 1 kPa of the ground-truth elasticity distribution. A mean elasticity error of 0.6 kPa illustrates the high precision of our technique. Conclusion: By utilizing 4DCT lung data coupled with a biomechanical model, high precision lung elastography can be accurately performed, even in low ventilation regions of the lungs. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144087.« less

The ground truth about metadata and community detection in networks

PubMed Central

Peel, Leto; Larremore, Daniel B.; Clauset, Aaron

2017-01-01

Across many scientific domains, there is a common need to automatically extract a simplified view or coarse-graining of how a complex system’s components interact. This general task is called community detection in networks and is analogous to searching for clusters in independent vector data. It is common to evaluate the performance of community detection algorithms by their ability to find so-called ground truth communities. This works well in synthetic networks with planted communities because these networks’ links are formed explicitly based on those known communities. However, there are no planted communities in real-world networks. Instead, it is standard practice to treat some observed discrete-valued node attributes, or metadata, as ground truth. We show that metadata are not the same as ground truth and that treating them as such induces severe theoretical and practical problems. We prove that no algorithm can uniquely solve community detection, and we prove a general No Free Lunch theorem for community detection, which implies that there can be no algorithm that is optimal for all possible community detection tasks. However, community detection remains a powerful tool and node metadata still have value, so a careful exploration of their relationship with network structure can yield insights of genuine worth. We illustrate this point by introducing two statistical techniques that can quantify the relationship between metadata and community structure for a broad class of models. We demonstrate these techniques using both synthetic and real-world networks, and for multiple types of metadata and community structures. PMID:28508065

Comparing the accuracy of food outlet datasets in an urban environment.

PubMed

Wong, Michelle S; Peyton, Jennifer M; Shields, Timothy M; Curriero, Frank C; Gudzune, Kimberly A

2017-05-11

Studies that investigate the relationship between the retail food environment and health outcomes often use geospatial datasets. Prior studies have identified challenges of using the most common data sources. Retail food environment datasets created through academic-government partnership present an alternative, but their validity (retail existence, type, location) has not been assessed yet. In our study, we used ground-truth data to compare the validity of two datasets, a 2015 commercial dataset (InfoUSA) and data collected from 2012 to 2014 through the Maryland Food Systems Mapping Project (MFSMP), an academic-government partnership, on the retail food environment in two low-income, inner city neighbourhoods in Baltimore City. We compared sensitivity and positive predictive value (PPV) of the commercial and academic-government partnership data to ground-truth data for two broad categories of unhealthy food retailers: small food retailers and quick-service restaurants. Ground-truth data was collected in 2015 and analysed in 2016. Compared to the ground-truth data, MFSMP and InfoUSA generally had similar sensitivity that was greater than 85%. MFSMP had higher PPV compared to InfoUSA for both small food retailers (MFSMP: 56.3% vs InfoUSA: 40.7%) and quick-service restaurants (MFSMP: 58.6% vs InfoUSA: 36.4%). We conclude that data from academic-government partnerships like MFSMP might be an attractive alternative option and improvement to relying only on commercial data. Other research institutes or cities might consider efforts to create and maintain such an environmental dataset. Even if these datasets cannot be updated on an annual basis, they are likely more accurate than commercial data.

Strategies for cloud-top phase determination: differentiation between thin cirrus clouds and snow in manual (ground truth) analyses

NASA Astrophysics Data System (ADS)

Hutchison, Keith D.; Etherton, Brian J.; Topping, Phillip C.

1996-12-01

Quantitative assessments on the performance of automated cloud analysis algorithms require the creation of highly accurate, manual cloud, no cloud (CNC) images from multispectral meteorological satellite data. In general, the methodology to create ground truth analyses for the evaluation of cloud detection algorithms is relatively straightforward. However, when focus shifts toward quantifying the performance of automated cloud classification algorithms, the task of creating ground truth images becomes much more complicated since these CNC analyses must differentiate between water and ice cloud tops while ensuring that inaccuracies in automated cloud detection are not propagated into the results of the cloud classification algorithm. The process of creating these ground truth CNC analyses may become particularly difficult when little or no spectral signature is evident between a cloud and its background, as appears to be the case when thin cirrus is present over snow-covered surfaces. In this paper, procedures are described that enhance the researcher's ability to manually interpret and differentiate between thin cirrus clouds and snow-covered surfaces in daytime AVHRR imagery. The methodology uses data in up to six AVHRR spectral bands, including an additional band derived from the daytime 3.7 micron channel, which has proven invaluable for the manual discrimination between thin cirrus clouds and snow. It is concluded that while the 1.6 micron channel remains essential to differentiate between thin ice clouds and snow. However, this capability that may be lost if the 3.7 micron data switches to a nighttime-only transmission with the launch of future NOAA satellites.

Applications of ERTS-1 data to landscape change in eastern Tennessee

NASA Technical Reports Server (NTRS)

Rehder, J. B. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The analysis of landscape change in eastern Tennessee from ERTS-1 data is being derived from three avenues of experimentation and analysis: (1) a multi-stage sampling procedure utilizing ground and aircraft imagery for ground truth and control; (2) a densitometric and computer analytical experiment for the analysis of gray tone signatures and comparisons for landscape change detection and monitoring; and (3) an ERTS image enhancement procedure for the detection and analysis of photomorphic regions. Significant results include: maps of strip mining changes and forest inventory, watershed identification and delimitation, and agricultural regions derived from spring plowing patterns appearing on the ERTS-1 imagery.

The Conflict between Science and Religion: A Discussion on the Possibilities for Settlement

ERIC Educational Resources Information Center

Falcao, Eliane Brigida Morais

2010-01-01

In his article "Skepticism, truth as coherence, and constructivist epistemology: grounds for resolving the discord between science and religion?", John Staver identifies what he considers to be the source of the conflicts between science and religion: the establishment of the relationship between truth and knowledge, from the perspective of those…

Utilization of Airborne and in Situ Data Obtained in SGP99, SMEX02, CLASIC and SMAPVEX08 Field Campaigns for SMAP Soil Moisture Algorithm Development and Validation

NASA Technical Reports Server (NTRS)

Colliander, Andreas; Chan, Steven; Yueh, Simon; Cosh, Michael; Bindlish, Rajat; Jackson, Tom; Njoku, Eni

2010-01-01

Field experiment data sets that include coincident remote sensing measurements and in situ sampling will be valuable in the development and validation of the soil moisture algorithms of the NASA's future SMAP (Soil Moisture Active and Passive) mission. This paper presents an overview of the field experiment data collected from SGP99, SMEX02, CLASIC and SMAPVEX08 campaigns. Common in these campaigns were observations of the airborne PALS (Passive and Active L- and S-band) instrument, which was developed to acquire radar and radiometer measurements at low frequencies. The combined set of the PALS measurements and ground truth obtained from all these campaigns was under study. The investigation shows that the data set contains a range of soil moisture values collected under a limited number of conditions. The quality of both PALS and ground truth data meets the needs of the SMAP algorithm development and validation. The data set has already made significant impact on the science behind SMAP mission. The areas where complementing of the data would be most beneficial are also discussed.

First stereo video dataset with ground truth for remote car pose estimation using satellite markers

NASA Astrophysics Data System (ADS)

Gil, Gustavo; Savino, Giovanni; Pierini, Marco

2018-04-01

Leading causes of PTW (Powered Two-Wheeler) crashes and near misses in urban areas are on the part of a failure or delayed prediction of the changing trajectories of other vehicles. Regrettably, misperception from both car drivers and motorcycle riders results in fatal or serious consequences for riders. Intelligent vehicles could provide early warning about possible collisions, helping to avoid the crash. There is evidence that stereo cameras can be used for estimating the heading angle of other vehicles, which is key to anticipate their imminent location, but there is limited heading ground truth data available in the public domain. Consequently, we employed a marker-based technique for creating ground truth of car pose and create a dataset∗ for computer vision benchmarking purposes. This dataset of a moving vehicle collected from a static mounted stereo camera is a simplification of a complex and dynamic reality, which serves as a test bed for car pose estimation algorithms. The dataset contains the accurate pose of the moving obstacle, and realistic imagery including texture-less and non-lambertian surfaces (e.g. reflectance and transparency).

Design and test of an automated version of the modified Jebsen test of hand function using Microsoft Kinect.

PubMed

Simonsen, Daniel; Nielsen, Ida F; Spaich, Erika G; Andersen, Ole K

2017-05-02

The present paper describes the design and evaluation of an automated version of the Modified Jebsen Test of Hand Function (MJT) based on the Microsoft Kinect sensor. The MJT was administered twice to 11 chronic stroke subjects with varying degrees of hand function deficits. The test times of the MJT were evaluated manually by a therapist using a stopwatch, and automatically using the Microsoft Kinect sensor. The ground truth times were assessed based on inspection of the video-recordings. The agreement between the methods was evaluated along with the test-retest performance. The results from Bland-Altman analysis showed better agreement between the ground truth times and the automatic MJT time evaluations compared to the agreement between the ground truth times and the times estimated by the therapist. The results from the test-retest performance showed that the subjects significantly improved their performance in several subtests of the MJT, indicating a practice effect. The results from the test showed that the Kinect can be used for automating the MJT.

New Ground Truth Capability from InSAR Time Series Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buckley, S; Vincent, P; Yang, D

2005-07-13

We demonstrate that next-generation interferometric synthetic aperture radar (InSAR) processing techniques applied to existing data provide rich InSAR ground truth content for exploitation in seismic source identification. InSAR time series analyses utilize tens of interferograms and can be implemented in different ways. In one such approach, conventional InSAR displacement maps are inverted in a final post-processing step. Alternatively, computationally intensive data reduction can be performed with specialized InSAR processing algorithms. The typical final result of these approaches is a synthesized set of cumulative displacement maps. Examples from our recent work demonstrate that these InSAR processing techniques can provide appealing newmore » ground truth capabilities. We construct movies showing the areal and temporal evolution of deformation associated with previous nuclear tests. In other analyses, we extract time histories of centimeter-scale surface displacement associated with tunneling. The potential exists to identify millimeter per year surface movements when sufficient data exists for InSAR techniques to isolate and remove phase signatures associated with digital elevation model errors and the atmosphere.« less

AMS Ground Truth Measurements: Calibrations and Test Lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wasiolek, Piotr T.

2015-12-01

Airborne gamma spectrometry is one of the primary techniques used to define the extent of ground contamination after a radiological incident. Its usefulness was demonstrated extensively during the response to the Fukushima NPP accident in March-May 2011. To map ground contamination, a set of scintillation detectors is mounted on an airborne platform (airplane or helicopter) and flown over contaminated areas. The acquisition system collects spectral information together with the aircraft position and altitude every second. To provide useful information to decision makers, the count data, expressed in counts per second (cps), need to be converted to a terrestrial component ofmore » the exposure rate at 1 meter (m) above ground, or surface activity of the isotopes of concern. This is done using conversion coefficients derived from calibration flights. During a large-scale radiological event, multiple flights may be necessary and may require use of assets from different agencies. However, because production of a single, consistent map product depicting the ground contamination is the primary goal, it is critical to establish a common calibration line very early into the event. Such a line should be flown periodically in order to normalize data collected from different aerial acquisition systems and that are potentially flown at different flight altitudes and speeds. In order to verify and validate individual aerial systems, the calibration line needs to be characterized in terms of ground truth measurements This is especially important if the contamination is due to short-lived radionuclides. The process of establishing such a line, as well as necessary ground truth measurements, is described in this document.« less

AMS Ground Truth Measurements: Calibration and Test Lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wasiolek, P.

2013-11-01

Airborne gamma spectrometry is one of the primary techniques used to define the extent of ground contamination after a radiological incident. Its usefulness was demonstrated extensively during the response to the Fukushima nuclear power plant (NPP) accident in March-May 2011. To map ground contamination a set of scintillation detectors is mounted on an airborne platform (airplane or helicopter) and flown over contaminated areas. The acquisition system collects spectral information together with the aircraft position and altitude every second. To provide useful information to decision makers, the count rate data expressed in counts per second (cps) needs to be converted tomore » the terrestrial component of the exposure rate 1 m above ground, or surface activity of isotopes of concern. This is done using conversion coefficients derived from calibration flights. During a large scale radiological event, multiple flights may be necessary and may require use of assets from different agencies. However, as the production of a single, consistent map product depicting the ground contamination is the primary goal, it is critical to establish very early into the event a common calibration line. Such a line should be flown periodically in order to normalize data collected from different aerial acquisition systems and potentially flown at different flight altitudes and speeds. In order to verify and validate individual aerial systems, the calibration line needs to be characterized in terms of ground truth measurements. This is especially important if the contamination is due to short-lived radionuclides. The process of establishing such a line, as well as necessary ground truth measurements, is described in this document.« less

Self Occlusion and Disocclusion in Causal Video Object Segmentation

DTIC Science & Technology

2015-12-18

computation is parameter- free in contrast to [4, 32, 10]. Taylor et al . [30] perform layer segmentation in longer video sequences leveraging occlusion cues...shows that our method recovers from errors in the first frame (short of failed detection). 4413 image ground truth Lee et al . [19] Grundman et al . [14...Ochs et al . [23] Taylor et al . [30] ours Figure 7. Sample Visual Results on FBMS-59. Comparison of various state-of-the-art methods. Only a single

Surface Exposure Ages of Space-Weathered Grains from Asteroid 25143 Itokawa

NASA Technical Reports Server (NTRS)

Keller, L. P.; Berger, E. L.; Christoffersen, R.

2015-01-01

Space weathering processes such as solar wind ion irradiation and micrometeorite impacts are widely known to alter the properties of regolith materials exposed on airless bodies. The rates of space weathering processes however, are poorly constrained for asteroid regoliths, with recent estimates ranging over many orders of magnitude. The return of surface samples by JAXA's Hayabusa mission to asteroid 25143 Itokawa, and their laboratory analysis provides "ground truth" to anchor the timescales for space weathering processes on airless bodies.

Evaluation of a native vegetation masking technique

NASA Technical Reports Server (NTRS)

Kinsler, M. C.

1984-01-01

A crop masking technique based on Ashburn's vegetative index (AVI) was used to evaluate native vegetation as an indicator of crop moisture condition. A mask of the range areas (native vegetation) was generated for each of thirteen Great Plains LANDSAT MSS sample segments. These masks were compared to the digitized ground truth and accuracies were computed. An analysis of the types of errors indicates a consistency in errors among the segments. The mask represents a simple quick-look technique for evaluating vegetative cover.

Dynamic X-ray diffraction sampling for protein crystal positioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction,more » significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Furthermore, by usingin situtwo-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.« less

Dynamic X-ray diffraction sampling for protein crystal positioning

DOE PAGES

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye; ...

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction,more » significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Furthermore, by usingin situtwo-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.« less

Dynamic X-ray diffraction sampling for protein crystal positioning

PubMed Central

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye; Kissick, David J.; Zhang, Shijie; Newman, Justin A.; Sheedlo, Michael J.; Chowdhury, Azhad U.; Fischetti, Robert F.; Das, Chittaranjan; Buzzard, Gregery T.; Bouman, Charles A.; Simpson, Garth J.

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations. PMID:28009558

Dynamic X-ray diffraction sampling for protein crystal positioning.

PubMed

Scarborough, Nicole M; Godaliyadda, G M Dilshan P; Ye, Dong Hye; Kissick, David J; Zhang, Shijie; Newman, Justin A; Sheedlo, Michael J; Chowdhury, Azhad U; Fischetti, Robert F; Das, Chittaranjan; Buzzard, Gregery T; Bouman, Charles A; Simpson, Garth J

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.

Earth science research

NASA Technical Reports Server (NTRS)

Botkin, Daniel B.

1987-01-01

The analysis of ground-truth data from the boreal forest plots in the Superior National Forest, Minnesota, was completed. Development of statistical methods was completed for dimension analysis (equations to estimate the biomass of trees from measurements of diameter and height). The dimension-analysis equations were applied to the data obtained from ground-truth plots, to estimate the biomass. Classification and analyses of remote sensing images of the Superior National Forest were done as a test of the technique to determine forest biomass and ecological state by remote sensing. Data was archived on diskette and tape and transferred to UCSB to be used in subsequent research.

Machine processing of ERTS and ground truth data

NASA Technical Reports Server (NTRS)

Rogers, R. H. (Principal Investigator); Peacock, K.

1973-01-01

The author has identified the following significant results. Results achieved by ERTS-Atmospheric Experiment PR303, whose objective is to establish a radiometric calibration technique, are reported. This technique, which determines and removes solar and atmospheric parameters that degrade the radiometric fidelity of ERTS-1 data, transforms the ERTS-1 sensor radiance measurements to absolute target reflectance signatures. A radiant power measuring instrument and its use in determining atmospheric parameters needed for ground truth are discussed. The procedures used and results achieved in machine processing ERTS-1 computer -compatible tapes and atmospheric parameters to obtain target reflectance are reviewed.

Proceedings of the Annual Seismic Research Symposium on Monitoring a Comprehensive Test Ban Treaty (19th). Held in Orlando, Florida on 23-25 September 1997

DTIC Science & Technology

1997-09-05

explosions be used as sources of ground truth information? Can these sources be used as surrogates for single-fired explosions in regions where no such... sources exist? (Stump) 3. Is there a single regional discriminant that will work for all mining explosions or will it be necessary to apply a suite of...the Treaty be used to take advantage of mining sources as Ground Truth information? Is it possible to use such information to "finger print" mines

Recommended data sets, corn segments and spring wheat segments, for use in program development

NASA Technical Reports Server (NTRS)

Austin, W. W. (Principal Investigator)

1981-01-01

The sets of Large Area Crop Inventory Experiment sites, crop year 1978, which are recommended for use in the development and evaluation of classification techniques based on LANDSAT spectral data are presented. For each site, the following exists: (1) accuracy assessment digitized ground truth; (2) a minimum of 5 percent of the scene ground truth identified as corn or spring wheat; and (3) at least four acquisitions of acceptable data quality during the growing season of the crop of interest. The recommended data sets consist of 41 corn/soybean sites and 17 spring wheat sites.

Solar System Samples for Research, Education, and Public Outreach

NASA Technical Reports Server (NTRS)

Allen, J.; Luckey, M.; McInturff, B.; Kascak, A.; Tobola, K.; Galindo, C.; Allen, C.

2011-01-01

In the next two years, during the NASA Year of the Solar System, spacecraft from NASA and our international partners will; encounter a comet, orbit asteroid 4 Vesta, continue to explore Mars with rovers, and launch robotic explorers to the Moon and Mars. We have pieces of all these worlds in our laboratories, and their continued study provides incredibly valuable "ground truth" to complement space exploration missions. Extensive information about these unique materials, as well as actual lunar samples and meteorites, are available for display and education. The Johnson Space Center (JSC) has the unique responsibility to curate NASA's extraterrestrial samples from past and future missions. Curation includes documentation, preservation, preparation, and distribution of samples for research, education, and public outreach.

Explosion Source Location Study Using Collocated Acoustic and Seismic Networks in Israel

NASA Astrophysics Data System (ADS)

Pinsky, V.; Gitterman, Y.; Arrowsmith, S.; Ben-Horin, Y.

2013-12-01

We explore a joined analysis of seismic and infrasonic signals for improvement in automatic monitoring of small local/regional events, such as construction and quarry blasts, military chemical explosions, sonic booms, etc. using collocated seismic and infrasonic networks recently build in Israel (ISIN) in the frame of the project sponsored by the Bi-national USA-Israel Science Foundation (BSF). The general target is to create an automatic system, which will provide detection, location and identification of explosions in real-time or close-to-real time manner. At the moment the network comprises 15 stations hosting a microphone and seismometer (or accelerometer), operated by the Geophysical Institute of Israel (GII), plus two infrasonic arrays, operated by the National Data Center, Soreq: IOB in the South (Negev desert) and IMA in the North of Israel (Upper Galilee),collocated with the IMS seismic array MMAI. The study utilizes a ground-truth data-base of numerous Rotem phosphate quarry blasts, a number of controlled explosions for demolition of outdated ammunitions and experimental surface explosions for a structure protection research, at the Sayarim Military Range. A special event, comprising four military explosions in a neighboring country, that provided both strong seismic (up to 400 km) and infrasound waves (up to 300 km), is also analyzed. For all of these events the ground-truth coordinates and/or the results of seismic location by the Israel Seismic Network (ISN) have been provided. For automatic event detection and phase picking we tested the new recursive picker, based on Statistically optimal detector. The results were compared to the manual picks. Several location techniques have been tested using the ground-truth event recordings and the preliminary results obtained have been compared to the ground-truth locations: 1) a number of events have been located as intersection of azimuths estimated using the wide-band F-K analysis technique applied to the infrasonic phases of the two distant arrays; 2) a standard robust grid-search location procedure based on phase picks and a constant celerity for a phase (tropospheric or stratospheric) was applied; 3) a joint coordinate grid-search procedure using array waveforms and phase picks was tested, 4) the Bayesian Infrasonic Source Localization (BISL) method, incorporating semi-empirical model-based prior information, was modified for array+network configuration and applied to the ground-truth events. For this purpose we accumulated data of the former observations of the air-to-ground infrasonic phases to compute station specific ground-truth Celerity-Range Histograms (ssgtCRH) and/or model-based CRH (mbCRH), which allow to essentially improve the location results. For building the mbCRH the local meteo-data and the ray-tracing modeling in 3 available azimuth ranges, accounting seasonal variations of winds directivity (quadrants North:315-45, South: 135-225, East 45-135) have been used.

Science, Religion, and the Quest for Knowledge and Truth: An Islamic Perspective

ERIC Educational Resources Information Center

Guessoum, Nidhal

2010-01-01

This article consists of two parts. The first one is to a large extent a commentary on John R. Staver's "Skepticism, truth as coherence, and constructivist epistemology: grounds for resolving the discord between science and religion?" The second part is a related overview of Islam's philosophy of knowledge and, to a certain degree, science. In…

Development and field validation of a regional, management-scale habitat model: A koala Phascolarctos cinereus case study.

PubMed

Law, Bradley; Caccamo, Gabriele; Roe, Paul; Truskinger, Anthony; Brassil, Traecey; Gonsalves, Leroy; McConville, Anna; Stanton, Matthew

2017-09-01

Species distribution models have great potential to efficiently guide management for threatened species, especially for those that are rare or cryptic. We used MaxEnt to develop a regional-scale model for the koala Phascolarctos cinereus at a resolution (250 m) that could be used to guide management. To ensure the model was fit for purpose, we placed emphasis on validating the model using independently-collected field data. We reduced substantial spatial clustering of records in coastal urban areas using a 2-km spatial filter and by modeling separately two subregions separated by the 500-m elevational contour. A bias file was prepared that accounted for variable survey effort. Frequency of wildfire, soil type, floristics and elevation had the highest relative contribution to the model, while a number of other variables made minor contributions. The model was effective in discriminating different habitat suitability classes when compared with koala records not used in modeling. We validated the MaxEnt model at 65 ground-truth sites using independent data on koala occupancy (acoustic sampling) and habitat quality (browse tree availability). Koala bellows ( n  = 276) were analyzed in an occupancy modeling framework, while site habitat quality was indexed based on browse trees. Field validation demonstrated a linear increase in koala occupancy with higher modeled habitat suitability at ground-truth sites. Similarly, a site habitat quality index at ground-truth sites was correlated positively with modeled habitat suitability. The MaxEnt model provided a better fit to estimated koala occupancy than the site-based habitat quality index, probably because many variables were considered simultaneously by the model rather than just browse species. The positive relationship of the model with both site occupancy and habitat quality indicates that the model is fit for application at relevant management scales. Field-validated models of similar resolution would assist in guiding management of conservation-dependent species.

Evaluation of gravimetric ground truth soil moisture data collected for the agricultural soil moisture experiment, 1978 Colby, Kansas, aircraft mission

NASA Technical Reports Server (NTRS)

Arya, L. M.; Phinney, D. E. (Principal Investigator)

1980-01-01

Soil moisture data acquired to support the development of algorithms for estimating surface soil moisture from remotely sensed backscattering of microwaves from ground surfaces are presented. Aspects of field uniformity and variability of gravimetric soil moisture measurements are discussed. Moisture distribution patterns are illustrated by frequency distributions and contour plots. Standard deviations and coefficients of variation relative to degree of wetness and agronomic features of the fields are examined. Influence of sampling depth on observed moisture content an variability are indicated. For the various sets of measurements, soil moisture values that appear as outliers are flagged. The distribution and legal descriptions of the test fields are included along with examinations of soil types, agronomic features, and sampling plan. Bulk density data for experimental fields are appended, should analyses involving volumetric moisture content be of interest to the users of data in this report.

A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

NASA Astrophysics Data System (ADS)

Martin, Spencer; Brophy, Mark; Palma, David; Louie, Alexander V.; Yu, Edward; Yaremko, Brian; Ahmad, Belal; Barron, John L.; Beauchemin, Steven S.; Rodrigues, George; Gaede, Stewart

2015-02-01

This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development.

A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging.

PubMed

Martin, Spencer; Brophy, Mark; Palma, David; Louie, Alexander V; Yu, Edward; Yaremko, Brian; Ahmad, Belal; Barron, John L; Beauchemin, Steven S; Rodrigues, George; Gaede, Stewart

2015-02-21

This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development.

Reference-free ground truth metric for metal artifact evaluation in CT images.

PubMed

Kratz, Bärbel; Ens, Svitlana; Müller, Jan; Buzug, Thorsten M

2011-07-01

In computed tomography (CT), metal objects in the region of interest introduce data inconsistencies during acquisition. Reconstructing these data results in an image with star shaped artifacts induced by the metal inconsistencies. To enhance image quality, the influence of the metal objects can be reduced by different metal artifact reduction (MAR) strategies. For an adequate evaluation of new MAR approaches a ground truth reference data set is needed. In technical evaluations, where phantoms can be measured with and without metal inserts, ground truth data can easily be obtained by a second reference data acquisition. Obviously, this is not possible for clinical data. Here, an alternative evaluation method is presented without the need of an additionally acquired reference data set. The proposed metric is based on an inherent ground truth for metal artifacts as well as MAR methods comparison, where no reference information in terms of a second acquisition is needed. The method is based on the forward projection of a reconstructed image, which is compared to the actually measured projection data. The new evaluation technique is performed on phantom and on clinical CT data with and without MAR. The metric results are then compared with methods using a reference data set as well as an expert-based classification. It is shown that the new approach is an adequate quantification technique for artifact strength in reconstructed metal or MAR CT images. The presented method works solely on the original projection data itself, which yields some advantages compared to distance measures in image domain using two data sets. Beside this, no parameters have to be manually chosen. The new metric is a useful evaluation alternative when no reference data are available.

Ground truth seismic events and location capability at Degelen mountain, Kazakhstan

NASA Astrophysics Data System (ADS)

Trabant, Chad; Thurber, Clifford; Leith, William

2002-07-01

We utilized nuclear explosions from the Degelen Mountain sub-region of the Semipalatinsk Test Site (STS), Kazakhstan, to assess seismic location capability directly. Excellent ground truth information for these events was either known or was estimated from maps of the Degelen Mountain adit complex. Origin times were refined for events for which absolute origin time information was unknown using catalog arrival times, our ground truth location estimates, and a time baseline provided by fixing known origin times during a joint hypocenter determination (JHD). Precise arrival time picks were determined using a waveform cross-correlation process applied to the available digital data. These data were used in a JHD analysis. We found that very accurate locations were possible when high precision, waveform cross-correlation arrival times were combined with JHD. Relocation with our full digital data set resulted in a mean mislocation of 2 km and a mean 95% confidence ellipse (CE) area of 6.6 km 2 (90% CE: 5.1 km 2), however, only 5 of the 18 computed error ellipses actually covered the associated ground truth location estimate. To test a more realistic nuclear test monitoring scenario, we applied our JHD analysis to a set of seven events (one fixed) using data only from seismic stations within 40° epicentral distance. Relocation with these data resulted in a mean mislocation of 7.4 km, with four of the 95% error ellipses covering less than 570 km 2 (90% CE: 438 km 2), and the other two covering 1730 and 8869 km 2 (90% CE: 1331 and 6822 km 2). Location uncertainties calculated using JHD often underestimated the true error, but a circular region with a radius equal to the mislocation covered less than 1000 km 2 for all events having more than three observations.

Consensus-Based Sorting of Neuronal Spike Waveforms.

PubMed

Fournier, Julien; Mueller, Christian M; Shein-Idelson, Mark; Hemberger, Mike; Laurent, Gilles

2016-01-01

Optimizing spike-sorting algorithms is difficult because sorted clusters can rarely be checked against independently obtained "ground truth" data. In most spike-sorting algorithms in use today, the optimality of a clustering solution is assessed relative to some assumption on the distribution of the spike shapes associated with a particular single unit (e.g., Gaussianity) and by visual inspection of the clustering solution followed by manual validation. When the spatiotemporal waveforms of spikes from different cells overlap, the decision as to whether two spikes should be assigned to the same source can be quite subjective, if it is not based on reliable quantitative measures. We propose a new approach, whereby spike clusters are identified from the most consensual partition across an ensemble of clustering solutions. Using the variability of the clustering solutions across successive iterations of the same clustering algorithm (template matching based on K-means clusters), we estimate the probability of spikes being clustered together and identify groups of spikes that are not statistically distinguishable from one another. Thus, we identify spikes that are most likely to be clustered together and therefore correspond to consistent spike clusters. This method has the potential advantage that it does not rely on any model of the spike shapes. It also provides estimates of the proportion of misclassified spikes for each of the identified clusters. We tested our algorithm on several datasets for which there exists a ground truth (simultaneous intracellular data), and show that it performs close to the optimum reached by a support vector machine trained on the ground truth. We also show that the estimated rate of misclassification matches the proportion of misclassified spikes measured from the ground truth data.

Automated wholeslide analysis of multiplex-brightfield IHC images for cancer cells and carcinoma-associated fibroblasts

NASA Astrophysics Data System (ADS)

Lorsakul, Auranuch; Andersson, Emilia; Vega Harring, Suzana; Sade, Hadassah; Grimm, Oliver; Bredno, Joerg

2017-03-01

Multiplex-brightfield immunohistochemistry (IHC) staining and quantitative measurement of multiple biomarkers can support therapeutic targeting of carcinoma-associated fibroblasts (CAF). This paper presents an automated digitalpathology solution to simultaneously analyze multiple biomarker expressions within a single tissue section stained with an IHC duplex assay. Our method was verified against ground truth provided by expert pathologists. In the first stage, the automated method quantified epithelial-carcinoma cells expressing cytokeratin (CK) using robust nucleus detection and supervised cell-by-cell classification algorithms with a combination of nucleus and contextual features. Using fibroblast activation protein (FAP) as biomarker for CAFs, the algorithm was trained, based on ground truth obtained from pathologists, to automatically identify tumor-associated stroma using a supervised-generation rule. The algorithm reported distance to nearest neighbor in the populations of tumor cells and activated-stromal fibroblasts as a wholeslide measure of spatial relationships. A total of 45 slides from six indications (breast, pancreatic, colorectal, lung, ovarian, and head-and-neck cancers) were included for training and verification. CK-positive cells detected by the algorithm were verified by a pathologist with good agreement (R2=0.98) to ground-truth count. For the area occupied by FAP-positive cells, the inter-observer agreement between two sets of ground-truth measurements was R2=0.93 whereas the algorithm reproduced the pathologists' areas with R2=0.96. The proposed methodology enables automated image analysis to measure spatial relationships of cells stained in an IHC-multiplex assay. Our proof-of-concept results show an automated algorithm can be trained to reproduce the expert assessment and provide quantitative readouts that potentially support a cutoff determination in hypothesis testing related to CAF-targeting-therapy decisions.

Predictive models of turbidity and water depth in the Doñana marshes using Landsat TM and ETM+ images.

PubMed

Bustamante, Javier; Pacios, Fernando; Díaz-Delgado, Ricardo; Aragonés, David

2009-05-01

We have used Landsat-5 TM and Landsat-7 ETM+ images together with simultaneous ground-truth data at sample points in the Doñana marshes to predict water turbidity and depth from band reflectance using Generalized Additive Models. We have point samples for 12 different dates simultaneous with 7 Landsat-5 and 5 Landsat-7 overpasses. The best model for water turbidity in the marsh explained 38% of variance in ground-truth data and included as predictors band 3 (630-690 nm), band 5 (1550-1750 nm) and the ratio between bands 1 (450-520 nm) and 4 (760-900 nm). Water turbidity is easier to predict for water bodies like the Guadalquivir River and artificial ponds that are deep and not affected by bottom soil reflectance and aquatic vegetation. For the latter, a simple model using band 3 reflectance explains 78.6% of the variance. Water depth is easier to predict than turbidity. The best model for water depth in the marsh explains 78% of the variance and includes as predictors band 1, band 5, the ratio between band 2 (520-600 nm) and band 4, and bottom soil reflectance in band 4 in September, when the marsh is dry. The water turbidity and water depth models have been developed in order to reconstruct historical changes in Doñana wetlands during the last 30 years using the Landsat satellite images time series.

Education and Public Outreach for the PICASSO-CENA Satellite-Based Research Mission: K-12 Students Use Sun Photometers to Assist Scientists in Validating Atmospheric Data

NASA Astrophysics Data System (ADS)

Robinson, D. Q.

2001-05-01

Hampton University, a historically black university, is leading the Education and Public Outreach (EPO) portion of the PICASSO-CENA satellite-based research mission. Currently scheduled for launch in 2004, PICASSO-CENA will use LIDAR (LIght Detection and Ranging), to study earth's atmosphere. The PICASSO-CENA Outreach program works with scientists, teachers, and students to better understand the effects of clouds and aerosols on earth's atmosphere. This program actively involves students nationwide in NASA research by having them obtain sun photometer measurements from their schools and homes for comparison with data collected by the PICASSO-CENA mission. Students collect data from their classroom ground observations and report the data via the Internet. Scientists will use the data from the PICASSO-CENA research and the student ground-truthing observations to improve predications about climatic change. The two-band passive remote sensing sun photometer is designed for student use as a stand alone instrument to study atmospheric turbidity or in conjunction with satellite data to provide ground-truthing. The instrument will collect measurements of column optical depth from the ground level. These measurements will not only give the students an appreciation for atmospheric turbidity, but will also provide quantitative correlative information to the PICASSO-CENA mission on ground-level optical depth. Student data obtained in this manner will be sufficiently accurate for scientists to use as ground truthing. Thus, students will have the opportunity to be involved with a NASA satellite-based research mission.

Beyond illusion: Psychoanalysis and the question of religious truth.

PubMed

Blass, Rachel B

2004-06-01

In this paper the author critically examines the nature of the positive, reconciliatory attitude towards religion that has become increasingly prevalent within psychoanalytic thinking and writing over the past 20 years. She shows how this positive attitude rests on a change in the nature of the prototype of religion and its reassignment to the realm of illusion, thus making irrelevant an issue most central both to psychoanalysis and to traditional Judeo-Christian belief--the passionate search for truth. The author demonstrates how the concern with truth, and specifically with the truth of religious claims, lies at the basis of the opposition between psychoanalysis and religion but, paradoxically, also provides the common ground for dialogue between the two. She argues that, as Freud developed his ideas regarding the origin of conviction in religious claims in his Moses and monotheism (1939), the nature of this common ground was expanded and the dialogue became potentially more meaningful. The author concludes that meaningful dialogue emerges through recognition of fundamental differences rather than through harmonisation within a realm of illusion. In this light, the present study may also be seen as an attempt to recognise fundamental differences that have been evolving within psychoanalysis itself.

Ground-Based Remote Sensing of Water-Stressed Crops: Thermal and Multispectral Imaging

USDA-ARS?s Scientific Manuscript database

Ground-based methods of remote sensing can be used as ground-truthing for satellite-based remote sensing, and in some cases may be a more affordable means of obtaining such data. Plant canopy temperature has been used to indicate and quantify plant water stress. A field research study was conducted ...

Ground-based thermal and multispectral imaging of limited irrigation crops

USDA-ARS?s Scientific Manuscript database

Ground-based methods of remote sensing can be used as ground-truth for satellite-based remote sensing, and in some cases may be a more affordable means of obtaining such data. Plant canopy temperature has been used to indicate and quantify plant water stress. A field research study was conducted in ...

Automatic breast density classification using a convolutional neural network architecture search procedure

NASA Astrophysics Data System (ADS)

Fonseca, Pablo; Mendoza, Julio; Wainer, Jacques; Ferrer, Jose; Pinto, Joseph; Guerrero, Jorge; Castaneda, Benjamin

2015-03-01

Breast parenchymal density is considered a strong indicator of breast cancer risk and therefore useful for preventive tasks. Measurement of breast density is often qualitative and requires the subjective judgment of radiologists. Here we explore an automatic breast composition classification workflow based on convolutional neural networks for feature extraction in combination with a support vector machines classifier. This is compared to the assessments of seven experienced radiologists. The experiments yielded an average kappa value of 0.58 when using the mode of the radiologists' classifications as ground truth. Individual radiologist performance against this ground truth yielded kappa values between 0.56 and 0.79.

LANDSAT landcover information applied to regional planning decisions. [Prince Edward County, Virginia

NASA Technical Reports Server (NTRS)

Dixon, C. M.

1981-01-01

Land cover information derived from LANDSAT is being utilized by Piedmont Planning District Commission located in the State of Virginia. Progress to date is reported on a level one land cover classification map being produced with nine categories. The nine categories of classification are defined. The computer compatible tape selection is presented. Two unsupervised classifications were done, with 50 and 70 classes respectively. Twenty-eight spectral classes were developed using the supervised technique, employing actual ground truth training sites. The accuracy of the unsupervised classifications are estimated through comparison with local county statistics and with an actual pixel count of LANDSAT information compared to ground truth.

Limits of Risk Predictability in a Cascading Alternating Renewal Process Model.

PubMed

Lin, Xin; Moussawi, Alaa; Korniss, Gyorgy; Bakdash, Jonathan Z; Szymanski, Boleslaw K

2017-07-27

Most risk analysis models systematically underestimate the probability and impact of catastrophic events (e.g., economic crises, natural disasters, and terrorism) by not taking into account interconnectivity and interdependence of risks. To address this weakness, we propose the Cascading Alternating Renewal Process (CARP) to forecast interconnected global risks. However, assessments of the model's prediction precision are limited by lack of sufficient ground truth data. Here, we establish prediction precision as a function of input data size by using alternative long ground truth data generated by simulations of the CARP model with known parameters. We illustrate the approach on a model of fires in artificial cities assembled from basic city blocks with diverse housing. The results confirm that parameter recovery variance exhibits power law decay as a function of the length of available ground truth data. Using CARP, we also demonstrate estimation using a disparate dataset that also has dependencies: real-world prediction precision for the global risk model based on the World Economic Forum Global Risk Report. We conclude that the CARP model is an efficient method for predicting catastrophic cascading events with potential applications to emerging local and global interconnected risks.

Sweet-spot training for early esophageal cancer detection

NASA Astrophysics Data System (ADS)

van der Sommen, Fons; Zinger, Svitlana; Schoon, Erik J.; de With, Peter H. N.

2016-03-01

Over the past decade, the imaging tools for endoscopists have improved drastically. This has enabled physicians to visually inspect the intestinal tissue for early signs of malignant lesions. Besides this, recent studies show the feasibility of supportive image analysis for endoscopists, but the analysis problem is typically approached as a segmentation task where binary ground truth is employed. In this study, we show that the detection of early cancerous tissue in the gastrointestinal tract cannot be approached as a binary segmentation problem and it is crucial and clinically relevant to involve multiple experts for annotating early lesions. By employing the so-called sweet spot for training purposes as a metric, a much better detection performance can be achieved. Furthermore, a multi-expert-based ground truth, i.e. a golden standard, enables an improved validation of the resulting delineations. For this purpose, besides the sweet spot we also propose another novel metric, the Jaccard Golden Standard (JIGS) that can handle multiple ground-truth annotations. Our experiments involving these new metrics and based on the golden standard show that the performance of a detection algorithm of early neoplastic lesions in Barrett's esophagus can be increased significantly, demonstrating a 10 percent point increase in the resulting F1 detection score.

Development of a Scalable Testbed for Mobile Olfaction Verification.

PubMed

Zakaria, Syed Muhammad Mamduh Syed; Visvanathan, Retnam; Kamarudin, Kamarulzaman; Yeon, Ahmad Shakaff Ali; Md Shakaff, Ali Yeon; Zakaria, Ammar; Kamarudin, Latifah Munirah

2015-12-09

The lack of information on ground truth gas dispersion and experiment verification information has impeded the development of mobile olfaction systems, especially for real-world conditions. In this paper, an integrated testbed for mobile gas sensing experiments is presented. The integrated 3 m × 6 m testbed was built to provide real-time ground truth information for mobile olfaction system development. The testbed consists of a 72-gas-sensor array, namely Large Gas Sensor Array (LGSA), a localization system based on cameras and a wireless communication backbone for robot communication and integration into the testbed system. Furthermore, the data collected from the testbed may be streamed into a simulation environment to expedite development. Calibration results using ethanol have shown that using a large number of gas sensor in the LGSA is feasible and can produce coherent signals when exposed to the same concentrations. The results have shown that the testbed was able to capture the time varying characteristics and the variability of gas plume in a 2 h experiment thus providing time dependent ground truth concentration maps. The authors have demonstrated the ability of the mobile olfaction testbed to monitor, verify and thus, provide insight to gas distribution mapping experiment.

Development of a Scalable Testbed for Mobile Olfaction Verification

PubMed Central

Syed Zakaria, Syed Muhammad Mamduh; Visvanathan, Retnam; Kamarudin, Kamarulzaman; Ali Yeon, Ahmad Shakaff; Md. Shakaff, Ali Yeon; Zakaria, Ammar; Kamarudin, Latifah Munirah

2015-01-01

The lack of information on ground truth gas dispersion and experiment verification information has impeded the development of mobile olfaction systems, especially for real-world conditions. In this paper, an integrated testbed for mobile gas sensing experiments is presented. The integrated 3 m × 6 m testbed was built to provide real-time ground truth information for mobile olfaction system development. The testbed consists of a 72-gas-sensor array, namely Large Gas Sensor Array (LGSA), a localization system based on cameras and a wireless communication backbone for robot communication and integration into the testbed system. Furthermore, the data collected from the testbed may be streamed into a simulation environment to expedite development. Calibration results using ethanol have shown that using a large number of gas sensor in the LGSA is feasible and can produce coherent signals when exposed to the same concentrations. The results have shown that the testbed was able to capture the time varying characteristics and the variability of gas plume in a 2 h experiment thus providing time dependent ground truth concentration maps. The authors have demonstrated the ability of the mobile olfaction testbed to monitor, verify and thus, provide insight to gas distribution mapping experiment. PMID:26690175

WE-G-BRD-06: Volumetric Cine MRI (VC-MRI) Estimated Based On Prior Knowledge for On-Board Target Localization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, W; Yin, F; Cai, J

Purpose: To develop a technique to generate on-board VC-MRI using patient prior 4D-MRI, motion modeling and on-board 2D-cine MRI for real-time 3D target verification of liver and lung radiotherapy. Methods: The end-expiration phase images of a 4D-MRI acquired during patient simulation are used as patient prior images. Principal component analysis (PCA) is used to extract 3 major respiratory deformation patterns from the Deformation Field Maps (DFMs) generated between end-expiration phase and all other phases. On-board 2D-cine MRI images are acquired in the axial view. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI atmore » the end-expiration phase. The DFM is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by matching the corresponding 2D slice of the estimated VC-MRI with the acquired single 2D-cine MRI. The method was evaluated using both XCAT (a computerized patient model) simulation of lung cancer patients and MRI data from a real liver cancer patient. The 3D-MRI at every phase except end-expiration phase was used to simulate the ground-truth on-board VC-MRI at different instances, and the center-tumor slice was selected to simulate the on-board 2D-cine images. Results: Image subtraction of ground truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground truth with prior image. Excellent agreement between profiles was achieved. The normalized cross correlation coefficients between the estimated and ground-truth in the axial, coronal and sagittal views for each time step were >= 0.982, 0.905, 0.961 for XCAT data and >= 0.998, 0.911, 0.9541 for patient data. For XCAT data, the maximum-Volume-Percent-Difference between ground-truth and estimated tumor volumes was 1.6% and the maximum-Center-of-Mass-Shift was 0.9 mm. Conclusion: Preliminary studies demonstrated the feasibility to estimate real-time VC-MRI for on-board target localization before or during radiotherapy treatments. National Institutes of Health Grant No. R01-CA184173; Varian Medical System.« less

TU-AB-BRA-09: A Novel Method of Generating Ultrafast Volumetric Cine MRI (VC-MRI) Using Prior 4D-MRI and On-Board Phase-Skipped Encoding Acquisition for Radiotherapy Target Localization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, C; Yin, F; Harris, W

Purpose: To develop a technique generating ultrafast on-board VC-MRI using prior 4D-MRI and on-board phase-skipped encoding k-space acquisition for real-time 3D target tracking of liver and lung radiotherapy. Methods: The end-of-expiration (EOE) volume in 4D-MRI acquired during the simulation was selected as the prior volume. 3 major respiratory deformation patterns were extracted through the principal component analysis of the deformation field maps (DFMs) generated between EOE and all other phases. The on-board VC-MRI at each instant was considered as a deformation of the prior volume, and the deformation was modeled as a linear combination of the extracted 3 major deformationmore » patterns. To solve the weighting coefficients of the 3 major patterns, a 2D slice was extracted from VC-MRI volume to match with the 2D on-board sampling data, which was generated by 8-fold phase skipped-encoding k-space acquisition (i.e., sample 1 phase-encoding line out of every 8 lines) to achieve an ultrafast 16–24 volumes/s frame rate. The method was evaluated using XCAT digital phantom to simulate lung cancer patients. The 3D volume of end-ofinhalation (EOI) phase at the treatment day was used as ground-truth onboard VC-MRI with simulated changes in 1) breathing amplitude and 2) breathing amplitude/phase change from the simulation day. A liver cancer patient case was evaluated for in-vivo feasibility demonstration. Results: The comparison between ground truth and estimated on-board VC-MRI shows good agreements. In XCAT study with changed breathing amplitude, the volume-percent-difference(VPD) between ground-truth and estimated tumor volumes at EOI was 6.28% and the Center-of-Mass-Shift(COMS) was 0.82mm; with changed breathing amplitude and phase, the VPD was 8.50% and the COMS was 0.54mm. The study of liver patient case also demonstrated a promising in vivo feasibility of the proposed method Conclusion: Preliminary results suggest the feasibility to estimate ultrafast VC-MRI for on-board target localization with phase skipped-encoding k-space acquisition. Research grant from NIH R01-184173.« less

Collaboration and Conflict Resolution in Education.

ERIC Educational Resources Information Center

Melamed, James C.; Reiman, John W.

2000-01-01

Presents guidelines for resolving conflicts between educators and parents. Participants should seek different perspectives, not "truths," consider the common ground, define an effective problem-solving procedure, adopt ground rules for discussion, address issues, identify interests and positive intentions, develop options, select arrangements, and…

Photographs of the Sea Floor of Western Massachusetts Bay, Offshore of Boston, Massachusett, July 1999

USGS Publications Warehouse

Gutierrez, Benjamin T.; Butman, Bradford; Blackwood, Dann S.

2001-01-01

This CD-ROM contains photographs and sediment sample analyses of the sea floor obtained at 142 sites in western Massachusetts Bay (Figure 1) during a research cruise (USGS cruise ISBL99024) aboard the Fishing Vessel (FV) Isabel S. (Figure 2) conducted July 18-21, 1999. These photographs and samples provide critical ground truth information for the interpretation of shaded relief and backscatter intensity maps created using data collected with a multibeam echo sounder system (Butman and others, in press, a, b, c; Valentine and others, in press, a, b, c). Collection of these photographs and samples was undertaken in support of a large project whose overall objective is to map and describe the sea floor of Massachusetts Bay.

Assessment of infrasound signals recorded on seismic stations and infrasound arrays in the western United States using ground truth sources

NASA Astrophysics Data System (ADS)

Park, Junghyun; Hayward, Chris; Stump, Brian W.

2018-06-01

Ground truth sources in Utah during 2003-2013 are used to assess the contribution of temporal atmospheric conditions to infrasound detection and the predictive capabilities of atmospheric models. Ground truth sources consist of 28 long duration static rocket motor burn tests and 28 impulsive rocket body demolitions. Automated infrasound detections from a hybrid of regional seismometers and infrasound arrays use a combination of short-term time average/long-term time average ratios and spectral analyses. These detections are grouped into station triads using a Delaunay triangulation network and then associated to estimate phase velocity and azimuth to filter signals associated with a particular source location. The resulting range and azimuth distribution from sources to detecting stations varies seasonally and is consistent with predictions based on seasonal atmospheric models. Impulsive signals from rocket body detonations are observed at greater distances (>700 km) than the extended duration signals generated by the rocket burn test (up to 600 km). Infrasound energy attenuation associated with the two source types is quantified as a function of range and azimuth from infrasound amplitude measurements. Ray-tracing results using Ground-to-Space atmospheric specifications are compared to these observations and illustrate the degree to which the time variations in characteristics of the observations can be predicted over a multiple year time period.

Field Ground Truthing Data Collector - a Mobile Toolkit for Image Analysis and Processing

NASA Astrophysics Data System (ADS)

Meng, X.

2012-07-01

Field Ground Truthing Data Collector is one of the four key components of the NASA funded ICCaRS project, being developed in Southeast Michigan. The ICCaRS ground truthing toolkit entertains comprehensive functions: 1) Field functions, including determining locations through GPS, gathering and geo-referencing visual data, laying out ground control points for AEROKAT flights, measuring the flight distance and height, and entering observations of land cover (and use) and health conditions of ecosystems and environments in the vicinity of the flight field; 2) Server synchronization functions, such as, downloading study-area maps, aerial photos and satellite images, uploading and synchronizing field-collected data with the distributed databases, calling the geospatial web services on the server side to conduct spatial querying, image analysis and processing, and receiving the processed results in field for near-real-time validation; and 3) Social network communication functions for direct technical assistance and pedagogical support, e.g., having video-conference calls in field with the supporting educators, scientists, and technologists, participating in Webinars, or engaging discussions with other-learning portals. This customized software package is being built on Apple iPhone/iPad and Google Maps/Earth. The technical infrastructures, data models, coupling methods between distributed geospatial data processing and field data collector tools, remote communication interfaces, coding schema, and functional flow charts will be illustrated and explained at the presentation. A pilot case study will be also demonstrated.

Scientific investigations in the Gulf of Mexico and Caribbean Sea during the 1974-1975 Calypso cruise, parts 1 and 2

NASA Technical Reports Server (NTRS)

Elsayed, S. Z.; Reheim, H. A.; Fryxell, G. A.; Harlan, J. C.; Hill, J. M.; Babai, P.; Whitney, P.

1975-01-01

The distribution and concentrations of the standing crop of phytoplankton and nutrient salts in the Gulf of Mexico and the Caribbean Sea were investigated to provide ground truth for correlating temperature and chlorophyll-a measurements with observations from NASA U-2 aircraft equipped with specially designed sensors for measuring ocean color phenomena. The physical, chemical, and biological data obtained is summarized. Sampling procedures and methods used for determining plant pigments, species composition of phytoplankton, nutrient salt analysis, and the euphotic zones are described.

Sensor-independent approach to the vicarious calibration of satellite ocean color radiometry.

PubMed

Franz, Bryan A; Bailey, Sean W; Werdell, P Jeremy; McClain, Charles R

2007-08-01

The retrieval of ocean color radiometry from space-based sensors requires on-orbit vicarious calibration to achieve the level of accuracy desired for quantitative oceanographic applications. The approach developed by the NASA Ocean Biology Processing Group (OBPG) adjusts the integrated instrument and atmospheric correction system to retrieve normalized water-leaving radiances that are in agreement with ground truth measurements. The method is independent of the satellite sensor or the source of the ground truth data, but it is specific to the atmospheric correction algorithm. The OBPG vicarious calibration approach is described in detail, and results are presented for the operational calibration of SeaWiFS using data from the Marine Optical Buoy (MOBY) and observations of clear-water sites in the South Pacific and southern Indian Ocean. It is shown that the vicarious calibration allows SeaWiFS to reproduce the MOBY radiances and achieve good agreement with radiometric and chlorophyll a measurements from independent in situ sources. We also find that the derived vicarious gains show no significant temporal or geometric dependencies, and that the mission-average calibration reaches stability after approximately 20-40 high-quality calibration samples. Finally, we demonstrate that the performance of the vicariously calibrated retrieval system is relatively insensitive to the assumptions inherent in our approach.

Analytic Perturbation Method for Estimating Ground Flash Fraction from Satellite Lightning Observations

NASA Technical Reports Server (NTRS)

Koshak, William; Solakiewicz, Richard

2013-01-01

An analytic perturbation method is introduced for estimating the lightning ground flash fraction in a set of N lightning flashes observed by a satellite lightning mapper. The value of N is large, typically in the thousands, and the observations consist of the maximum optical group area produced by each flash. The method is tested using simulated observations that are based on Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) data. National Lightning Detection NetworkTM (NLDN) data is used to determine the flash-type (ground or cloud) of the satellite-observed flashes, and provides the ground flash fraction truth for the simulation runs. It is found that the mean ground flash fraction retrieval errors are below 0.04 across the full range 0-1 under certain simulation conditions. In general, it is demonstrated that the retrieval errors depend on many factors (i.e., the number, N, of satellite observations, the magnitude of random and systematic measurement errors, and the number of samples used to form certain climate distributions employed in the model).

Sediment mineralogy based on visible and near-infrared reflectance spectroscopy

USGS Publications Warehouse

Jarrard, R.D.; Vanden Berg, M.D.; ,

2006-01-01

Visible and near-infrared spectroscopy (VNIS) can be used to measure reflectance spectra (wavelength 350-2500 nm) for sediment cores and samples. A local ground-truth calibration of spectral features to mineral percentages is calculated by measuring reflectance spectra for a suite of samples of known mineralogy. This approach has been tested on powders, core plugs and split cores, and we conclude that it works well on all three, unless pore water is present. Initial VNIS studies have concentrated on determination of relative proportions of carbonate, opal, smectite and illite in equatorial Pacific sediments. Shipboard VNIS-based determination of these four components was demonstrated on Ocean Drilling Program Leg 199. ?? The Geological Society of London 2006.

Pest measurement and management

USDA-ARS?s Scientific Manuscript database

Pest scouting, whether it is done only with ground scouting methods or using remote sensing with some ground-truthing, is an important tool to aid site-specific crop management. Different pests may be monitored at different times and using different methods. Remote sensing has the potential to provi...

Ground Truth Studies - A hands-on environmental science program for students, grades K-12

NASA Technical Reports Server (NTRS)

Katzenberger, John; Chappell, Charles R.

1992-01-01

The paper discusses the background and the objectives of the Ground Truth Studies (GTSs), an activity-based teaching program which integrates local environmental studies with global change topics, utilizing remotely sensed earth imagery. Special attention is given to the five key concepts around which the GTS programs are organized, the pilot program, the initial pilot study evaluation, and the GTS Handbook. The GTS Handbook contains a primer on global change and remote sensing, aerial and satellite images, student activities, glossary, and an appendix of reference material. Also described is a K-12 teacher training model. International participation in the program is to be initiated during the 1992-1993 school year.

Land use and land cover mapping: City of Palm Bay, Florida

NASA Technical Reports Server (NTRS)

Barile, D. D.; Pierce, R.

1977-01-01

Two different computer systems were compared for use in making land use and land cover maps. The Honeywell 635 with the LANDSAT signature development program (LSDP) produced a map depicting general patterns, but themes were difficult to classify as specific land use. Urban areas were unclassified. The General Electric Image 100 produced a map depicting eight land cover categories classifying 68 percent of the total area. Ground truth, LSDP, and Image 100 maps were all made to the same scale for comparison. LSDP agreed with the ground truth 60 percent and 64 percent within the two test areas compared and Image 100 was in agreement 70 percent and 80 percent.

Erosional and depositional history of central Chryse Planitia

NASA Technical Reports Server (NTRS)

Crumpler, L. S.

1992-01-01

This map uses high resolution image data to assess the detailed depositional and erosional history of part of Chryse Planitia. This area is significant to the study of the global geology of Mars because it represents one of only two areas on the martian surface where planetary geologic mapping is assisted with 'ground truth.' In this case the ground truth was provided by Viking Lander 1. Additional questions addressed in this study are concerned with the following: the geologic context of the regional plains surface and the local surface of the Viking Lander 1 site; and the relative influence of volcanic, sedimentary, impact, aeolian, and tectonic processes at the regional and local scales.

Estimating Number of People Using Calibrated Monocular Camera Based on Geometrical Analysis of Surface Area

NASA Astrophysics Data System (ADS)

Arai, Hiroyuki; Miyagawa, Isao; Koike, Hideki; Haseyama, Miki

We propose a novel technique for estimating the number of people in a video sequence; it has the advantages of being stable even in crowded situations and needing no ground-truth data. By analyzing the geometrical relationships between image pixels and their intersection volumes in the real world quantitatively, a foreground image directly indicates the number of people. Because foreground detection is possible even in crowded situations, the proposed method can be applied in such situations. Moreover, it can estimate the number of people in an a priori manner, so it needs no ground-truth data unlike existing feature-based estimation techniques. Experiments show the validity of the proposed method.

Within-field variability of plant and soil parameters

NASA Technical Reports Server (NTRS)

Ulaby, F. T. (Principal Investigator); Brisco, B.; Dobson, C.

1981-01-01

The variability of ground truth data collected for vegetation experiments was investigated. Two fields of wheat and one field of corn were sampled on two different dates. The variability of crop and soil parameters within a field, between two fields of the same type, and within a field over time were compared statistically. The number of samples from each test site required in order to be able to determine with confidence the mean and standard deviations for a given variable was determined. Eight samples were found to be adequate for plant height determinations, while twenty samples were required for plant moisture and soil moisture characterization. Eighteen samples were necessary for detecting within field variability over time and for between field variability for the same crop. The necessary sample sites vary according to the physiological growth stage of the crop and recent weather events that affect the moisture and/or height characteristics of the field in question.

The Kenya rangeland ecological monitoring unit

NASA Technical Reports Server (NTRS)

Stevens, W. E. (Principal Investigator)

1978-01-01

The author has identified the following significant results. Methodology for aerial surveys and ground truth studies was developed, tested, and revised several times to produce reasonably firm methods of procedure. Computer programs were adapted or developed to analyze, store, and recall data from the ground and air monitoring surveys.

Defining biological assemblages (biotopes) of conservation interest in the submarine canyons of the South West Approaches (offshore United Kingdom) for use in marine habitat mapping

NASA Astrophysics Data System (ADS)

Davies, Jaime S.; Howell, Kerry L.; Stewart, Heather A.; Guinan, Janine; Golding, Neil

2014-06-01

In 2007, the upper part of a submarine canyon system located in water depths between 138 and 1165 m in the South West (SW) Approaches (North East Atlantic Ocean) was surveyed over a 2 week period. High-resolution multibeam echosounder data covering 1106 km2, and 44 ground-truthing video and image transects were acquired to characterise the biological assemblages of the canyons. The SW Approaches is an area of complex terrain, and intensive ground-truthing revealed the canyons to be dominated by soft sediment assemblages. A combination of multivariate analysis of seabed photographs (184-1059 m) and visual assessment of video ground-truthing identified 12 megabenthic assemblages (biotopes) at an appropriate scale to act as mapping units. Of these biotopes, 5 adhered to current definitions of habitats of conservation concern, 4 of which were classed as Vulnerable Marine Ecosystems. Some of the biotopes correspond to descriptions of communities from other megahabitat features (for example the continental shelf and seamounts), although it appears that the canyons host modified versions, possibly due to the inferred high rates of sedimentation in the canyons. Other biotopes described appear to be unique to canyon features, particularly the sea pen biotope consisting of Kophobelemnon stelliferum and cerianthids.

Spatio-temporal evaluation of plant height in corn via unmanned aerial systems

NASA Astrophysics Data System (ADS)

Varela, Sebastian; Assefa, Yared; Vara Prasad, P. V.; Peralta, Nahuel R.; Griffin, Terry W.; Sharda, Ajay; Ferguson, Allison; Ciampitti, Ignacio A.

2017-07-01

Detailed spatial and temporal data on plant growth are critical to guide crop management. Conventional methods to determine field plant traits are intensive, time-consuming, expensive, and limited to small areas. The objective of this study was to examine the integration of data collected via unmanned aerial systems (UAS) at critical corn (Zea mays L.) developmental stages for plant height and its relation to plant biomass. The main steps followed in this research were (1) workflow development for an ultrahigh resolution crop surface model (CSM) with the goal of determining plant height (CSM-estimated plant height) using data gathered from the UAS missions; (2) validation of CSM-estimated plant height with ground-truthing plant height (measured plant height); and (3) final estimation of plant biomass via integration of CSM-estimated plant height with ground-truthing stem diameter data. Results indicated a correlation between CSM-estimated plant height and ground-truthing plant height data at two weeks prior to flowering and at flowering stage, but high predictability at the later growth stage. Log-log analysis on the temporal data confirmed that these relationships are stable, presenting equal slopes for both crop stages evaluated. Concluding, data collected from low-altitude and with a low-cost sensor could be useful in estimating plant height.

Sea-surface circulation, sediment transport, and marine mammal distribution, Alaska continental shelf

NASA Technical Reports Server (NTRS)

Wright, F. F. (Principal Investigator); Sharma, G. D.; Burns, J. J.

1973-01-01

The author has identified the following significant results. Even though nonsynchronous, the ERTS-1 imagery of November 4, 1972, showed a striking similarity to the ground truth data obtained in late August and September, 1972. The comparison of the images with ground truth data revealed that the general water circulation pattern in Lower Cook Inlet is consistent through the Fall season and that ERTS-1 images in MSS bands 4 and 5 are capable of delineating water masses with a suspended load as low as 1 mg/liter. The ERTS-1 data and the ground truth data demonstrate clearly that the coriolis effect dominates circulation in Lower Cook Inlet. The configuration of plumes in Nushagak and Kuskokwim bays further indicates the influence of the coriolis effect on the movement of sea water at high latitudes. Comparison of MSS bands 4, 5, 6, and 7 suggest MSS-1 penetration of several meters into the water column. Sea ice analysis of available imagery was exceptionally rewarding. The imagery provided a rapid method to delineate and describe the ice types apparent in the photos. The ice types ranged from newly formed grease ice to heavy flows of disintegrating shore-fast ice. Sea ice maps showing the extent of different ice zones in the Chukchi Sea are being compiled.

Rice Crop Monitoring Using Microwave and Optical Remotely Sensed Image Data

NASA Astrophysics Data System (ADS)

Suga, Y.; Konishi, T.; Takeuchi, S.; Kitano, Y.; Ito, S.

Hiroshima Institute of Technology HIT is operating the direct down-links of microwave and optical satellite data in Japan This study focuses on the validation for rice crop monitoring using microwave and optical remotely sensed image data acquired by satellites referring to ground truth data such as height of crop ratio of crop vegetation cover and leaf area index in the test sites of Japan ENVISAT-1 ASAR data has a capability to capture regularly and to monitor during the rice growing cycle by alternating cross polarization mode images However ASAR data is influenced by several parameters such as landcover structure direction and alignment of rice crop fields in the test sites In this study the validation was carried out combined with microwave and optical satellite image data and ground truth data regarding rice crop fields to investigate the above parameters Multi-temporal multi-direction descending and ascending and multi-angle ASAR alternating cross polarization mode images were used to investigate rice crop growing cycle LANDSAT data were used to detect landcover structure direction and alignment of rice crop fields corresponding to the backscatter of ASAR As the result of this study it was indicated that rice crop growth can be precisely monitored using multiple remotely sensed data and ground truth data considering with spatial spectral temporal and radiometric resolutions

Metric Evaluation Pipeline for 3d Modeling of Urban Scenes

NASA Astrophysics Data System (ADS)

Bosch, M.; Leichtman, A.; Chilcott, D.; Goldberg, H.; Brown, M.

2017-05-01

Publicly available benchmark data and metric evaluation approaches have been instrumental in enabling research to advance state of the art methods for remote sensing applications in urban 3D modeling. Most publicly available benchmark datasets have consisted of high resolution airborne imagery and lidar suitable for 3D modeling on a relatively modest scale. To enable research in larger scale 3D mapping, we have recently released a public benchmark dataset with multi-view commercial satellite imagery and metrics to compare 3D point clouds with lidar ground truth. We now define a more complete metric evaluation pipeline developed as publicly available open source software to assess semantically labeled 3D models of complex urban scenes derived from multi-view commercial satellite imagery. Evaluation metrics in our pipeline include horizontal and vertical accuracy and completeness, volumetric completeness and correctness, perceptual quality, and model simplicity. Sources of ground truth include airborne lidar and overhead imagery, and we demonstrate a semi-automated process for producing accurate ground truth shape files to characterize building footprints. We validate our current metric evaluation pipeline using 3D models produced using open source multi-view stereo methods. Data and software is made publicly available to enable further research and planned benchmarking activities.

Calibration of Smartphone-Based Weather Measurements Using Pairwise Gossip.

PubMed

Zamora, Jane Louie Fresco; Kashihara, Shigeru; Yamaguchi, Suguru

2015-01-01

Accurate and reliable daily global weather reports are necessary for weather forecasting and climate analysis. However, the availability of these reports continues to decline due to the lack of economic support and policies in maintaining ground weather measurement systems from where these reports are obtained. Thus, to mitigate data scarcity, it is required to utilize weather information from existing sensors and built-in smartphone sensors. However, as smartphone usage often varies according to human activity, it is difficult to obtain accurate measurement data. In this paper, we present a heuristic-based pairwise gossip algorithm that will calibrate smartphone-based pressure sensors with respect to fixed weather stations as our referential ground truth. Based on actual measurements, we have verified that smartphone-based readings are unstable when observed during movement. Using our calibration algorithm on actual smartphone-based pressure readings, the updated values were significantly closer to the ground truth values.

Calibration of Smartphone-Based Weather Measurements Using Pairwise Gossip

PubMed Central

Yamaguchi, Suguru

2015-01-01

Accurate and reliable daily global weather reports are necessary for weather forecasting and climate analysis. However, the availability of these reports continues to decline due to the lack of economic support and policies in maintaining ground weather measurement systems from where these reports are obtained. Thus, to mitigate data scarcity, it is required to utilize weather information from existing sensors and built-in smartphone sensors. However, as smartphone usage often varies according to human activity, it is difficult to obtain accurate measurement data. In this paper, we present a heuristic-based pairwise gossip algorithm that will calibrate smartphone-based pressure sensors with respect to fixed weather stations as our referential ground truth. Based on actual measurements, we have verified that smartphone-based readings are unstable when observed during movement. Using our calibration algorithm on actual smartphone-based pressure readings, the updated values were significantly closer to the ground truth values. PMID:26421312

Developing a methodology for the inverse estimation of root architectural parameters from field based sampling schemes

NASA Astrophysics Data System (ADS)

Morandage, Shehan; Schnepf, Andrea; Vanderborght, Jan; Javaux, Mathieu; Leitner, Daniel; Laloy, Eric; Vereecken, Harry

2017-04-01

Root traits are increasingly important in breading of new crop varieties. E.g., longer and fewer lateral roots are suggested to improve drought resistance of wheat. Thus, detailed root architectural parameters are important. However, classical field sampling of roots only provides more aggregated information such as root length density (coring), root counts per area (trenches) or root arrival curves at certain depths (rhizotubes). We investigate the possibility of obtaining the information about root system architecture of plants using field based classical root sampling schemes, based on sensitivity analysis and inverse parameter estimation. This methodology was developed based on a virtual experiment where a root architectural model was used to simulate root system development in a field, parameterized for winter wheat. This information provided the ground truth which is normally unknown in a real field experiment. The three sampling schemes coring, trenching, and rhizotubes where virtually applied to and aggregated information computed. Morris OAT global sensitivity analysis method was then performed to determine the most sensitive parameters of root architecture model for the three different sampling methods. The estimated means and the standard deviation of elementary effects of a total number of 37 parameters were evaluated. Upper and lower bounds of the parameters were obtained based on literature and published data of winter wheat root architectural parameters. Root length density profiles of coring, arrival curve characteristics observed in rhizotubes, and root counts in grids of trench profile method were evaluated statistically to investigate the influence of each parameter using five different error functions. Number of branches, insertion angle inter-nodal distance, and elongation rates are the most sensitive parameters and the parameter sensitivity varies slightly with the depth. Most parameters and their interaction with the other parameters show highly nonlinear effect to the model output. The most sensitive parameters will be subject to inverse estimation from the virtual field sampling data using DREAMzs algorithm. The estimated parameters can then be compared with the ground truth in order to determine the suitability of the sampling schemes to identify specific traits or parameters of the root growth model.

Ground truth seismic events and location capability at Degelen mountain, Kazakhstan

USGS Publications Warehouse

Trabant, C.; Thurber, C.; Leith, W.

2002-01-01

We utilized nuclear explosions from the Degelen Mountain sub-region of the Semipalatinsk Test Site (STS), Kazakhstan, to assess seismic location capability directly. Excellent ground truth information for these events was either known or was estimated from maps of the Degelen Mountain adit complex. Origin times were refined for events for which absolute origin time information was unknown using catalog arrival times, our ground truth location estimates, and a time baseline provided by fixing known origin times during a joint hypocenter determination (JHD). Precise arrival time picks were determined using a waveform cross-correlation process applied to the available digital data. These data were used in a JHD analysis. We found that very accurate locations were possible when high precision, waveform cross-correlation arrival times were combined with JHD. Relocation with our full digital data set resulted in a mean mislocation of 2 km and a mean 95% confidence ellipse (CE) area of 6.6 km2 (90% CE: 5.1 km2), however, only 5 of the 18 computed error ellipses actually covered the associated ground truth location estimate. To test a more realistic nuclear test monitoring scenario, we applied our JHD analysis to a set of seven events (one fixed) using data only from seismic stations within 40?? epicentral distance. Relocation with these data resulted in a mean mislocation of 7.4 km, with four of the 95% error ellipses covering less than 570 km2 (90% CE: 438 km2), and the other two covering 1730 and 8869 km2 (90% CE: 1331 and 6822 km2). Location uncertainties calculated using JHD often underestimated the true error, but a circular region with a radius equal to the mislocation covered less than 1000 km2 for all events having more than three observations. ?? 2002 Elsevier Science B.V. All rights reserved.

Relationship of land use to water quality in the Chesapeake Bay region. [water sampling and photomapping river basins

NASA Technical Reports Server (NTRS)

Correll, D. L.

1978-01-01

Both the proportions of the various land use categories present on each watershed and the specific management practices in use in each category affect the quality of runoff waters, and the water quality of the Bay. Several permanent and portable stations on various Maryland Rivers collect volume-integrated water samples. All samples are analyzed for a series of nutrient, particulate, bacterial, herbicide, and heavy metal parameters. Each basin is mapped with respect to land use by the analysis of low-elevation aerial photos. Analyses are verified and adjusted by ground truth surveys. Data are processed and stored in the Smithsonian Institution data bank. Land use categories being investigated include forests/old fields, pastureland, row crops, residential areas, upland swamps, and tidal marshes.

Automated labelling of cancer textures in colorectal histopathology slides using quasi-supervised learning.

PubMed

Onder, Devrim; Sarioglu, Sulen; Karacali, Bilge

2013-04-01

Quasi-supervised learning is a statistical learning algorithm that contrasts two datasets by computing estimate for the posterior probability of each sample in either dataset. This method has not been applied to histopathological images before. The purpose of this study is to evaluate the performance of the method to identify colorectal tissues with or without adenocarcinoma. Light microscopic digital images from histopathological sections were obtained from 30 colorectal radical surgery materials including adenocarcinoma and non-neoplastic regions. The texture features were extracted by using local histograms and co-occurrence matrices. The quasi-supervised learning algorithm operates on two datasets, one containing samples of normal tissues labelled only indirectly, and the other containing an unlabeled collection of samples of both normal and cancer tissues. As such, the algorithm eliminates the need for manually labelled samples of normal and cancer tissues for conventional supervised learning and significantly reduces the expert intervention. Several texture feature vector datasets corresponding to different extraction parameters were tested within the proposed framework. The Independent Component Analysis dimensionality reduction approach was also identified as the one improving the labelling performance evaluated in this series. In this series, the proposed method was applied to the dataset of 22,080 vectors with reduced dimensionality 119 from 132. Regions containing cancer tissue could be identified accurately having false and true positive rates up to 19% and 88% respectively without using manually labelled ground-truth datasets in a quasi-supervised strategy. The resulting labelling performances were compared to that of a conventional powerful supervised classifier using manually labelled ground-truth data. The supervised classifier results were calculated as 3.5% and 95% for the same case. The results in this series in comparison with the benchmark classifier, suggest that quasi-supervised image texture labelling may be a useful method in the analysis and classification of pathological slides but further study is required to improve the results. Copyright © 2013 Elsevier Ltd. All rights reserved.

The NRL 2011 Airborne Sea-Ice Thickness Campaign

NASA Astrophysics Data System (ADS)

Brozena, J. M.; Gardner, J. M.; Liang, R.; Ball, D.; Richter-Menge, J.

2011-12-01

In March of 2011, the US Naval Research Laboratory (NRL) performed a study focused on the estimation of sea-ice thickness from airborne radar, laser and photogrammetric sensors. The study was funded by ONR to take advantage of the Navy's ICEX2011 ice-camp /submarine exercise, and to serve as a lead-in year for NRL's five year basic research program on the measurement and modeling of sea-ice scheduled to take place from 2012-2017. Researchers from the Army Cold Regions Research and Engineering Laboratory (CRREL) and NRL worked with the Navy Arctic Submarine Lab (ASL) to emplace a 9 km-long ground-truth line near the ice-camp (see Richter-Menge et al., this session) along which ice and snow thickness were directly measured. Additionally, US Navy submarines collected ice draft measurements under the groundtruth line. Repeat passes directly over the ground-truth line were flown and a grid surrounding the line was also flown to collect altimeter, LiDAR and Photogrammetry data. Five CRYOSAT-2 satellite tracks were underflown, as well, coincident with satellite passage. Estimates of sea ice thickness are calculated assuming local hydrostatic balance, and require the densities of water, ice and snow, snow depth, and freeboard (defined as the elevation of sea ice, plus accumulated snow, above local sea level). Snow thickness is estimated from the difference between LiDAR and radar altimeter profiles, the latter of which is assumed to penetrate any snow cover. The concepts we used to estimate ice thickness are similar to those employed in NASA ICEBRIDGE sea-ice thickness estimation. Airborne sensors used for our experiment were a Reigl Q-560 scanning topographic LiDAR, a pulse-limited (2 nS), 10 GHz radar altimeter and an Applanix DSS-439 digital photogrammetric camera (for lead identification). Flights were conducted on a Twin Otter aircraft from Pt. Barrow, AK, and averaged ~ 5 hours in duration. It is challenging to directly compare results from the swath LiDAR with the pulse-limited radar altimeter that has a footprint that varies from a few meters to a few tens of meters depending on altitude and roughness of the reflective surface. Intercalibration of the two instruments was accomplished at leads in the ice and by multiple over-flights of four radar corner-cubes set ~ 2 m above the snow along the ground-truth line. Direct comparison of successive flights of the ground-truth line to flights done in a grid pattern over and adjacent to the line was complicated by the ~ 20-30 m drift of the ice-floe between successive flight-lines. This rapid ice movement required the laser and radar data be translated into an ice-fixed, rather than a geographic reference frame. This was facilitated by geodetic GPS receiver measurements at the ice-camp and Pt. Barrow. The NRL data set, in combination with the ground-truth line and submarine upward-looking sonar data, will aid in understanding the error budgets of our systems, the ICEBRIDGE airborne measurements (also flown over the ground-truth line), and the CRYOSAT-2 data over a wide range of ice types.

Geographic applications of ERTS-1 data to landscape change

NASA Technical Reports Server (NTRS)

Rehder, J. B.

1973-01-01

The analysis of landscape change requires large area coverage on a periodic basis in order to analyze aggregate changes over an extended period of time. To date, only the ERTS program can provide this capability. Three avenues of experimentation and analysis are being used in the investigation: (1) a multi-scale sampling procedure utilizing aircraft imagery for ground truth and control; (2) a densitometric and computer analytical experiment for the analysis of gray tone signatures, comparisons and ultimately for landscape change detection and monitoring; and (3) an ERTS image enhancement procedure for the detection and analysis of photomorphic regions.

Passive Wake Acoustics Measurements at Denver International Airport

NASA Technical Reports Server (NTRS)

Wang, Frank Y.; Wassaf, Hadi; Dougherty, Robert P.; Clark, Kevin; Gulsrud, Andrew; Fenichel, Neil; Bryant, Wayne H.

2004-01-01

From August to September 2003, NASA conducted an extensive measurement campaign to characterize the acoustic signal of wake vortices. A large, both spatially as well as in number of elements, phased microphone array was deployed at Denver International Airport for this effort. This paper will briefly describe the program background, the microphone array, as well as the supporting ground-truth and meteorological sensor suite. Sample results to date are then presented and discussed. It is seen that, in the frequency range processed so far, wake noise is generated predominantly from a very confined area around the cores.

Distribution and concentration of suspended matter in Delaware Bay

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Philpot, W.

1977-01-01

The author has identified the following significant results. The problem of remote sensing of suspended matter in water was analyzed in terms of the single-scattering albedo, and a semiempirical relationship between satellite radiance measurements and the concentration of suspended matter in the water was developed. The relationship was tested using data from the 7 July 1973 LANDSAT overpass of Delaware Bay with good results. Suspended sediment concentration maps for the entire Delaware Bay were prepared using radiance values extracted from LANDSAT MSS imagery and correlating them with ground truth samples collected from boats and helicopter.

Evaluating segmentation error without ground truth.

PubMed

Kohlberger, Timo; Singh, Vivek; Alvino, Chris; Bahlmann, Claus; Grady, Leo

2012-01-01

The automatic delineation of the boundaries of organs and other anatomical structures is a key component of many medical image processing systems. In this paper we present a generic learning approach based on a novel space of segmentation features, which can be trained to predict the overlap error and Dice coefficient of an arbitrary organ segmentation without knowing the ground truth delineation. We show the regressor to be much stronger a predictor of these error metrics than the responses of probabilistic boosting classifiers trained on the segmentation boundary. The presented approach not only allows us to build reliable confidence measures and fidelity checks, but also to rank several segmentation hypotheses against each other during online usage of the segmentation algorithm in clinical practice.

Generating high precision ionospheric ground-truth measurements

NASA Technical Reports Server (NTRS)

Komjathy, Attila (Inventor); Sparks, Lawrence (Inventor); Mannucci, Anthony J. (Inventor)

2007-01-01

A method, apparatus and article of manufacture provide ionospheric ground-truth measurements for use in a wide-area augmentation system (WAAS). Ionospheric pseudorange/code and carrier phase data as primary observables is received by a WAAS receiver. A polynomial fit is performed on the phase data that is examined to identify any cycle slips in the phase data. The phase data is then leveled. Satellite and receiver biases are obtained and applied to the leveled phase data to obtain unbiased phase-leveled ionospheric measurements that are used in a WAAS system. In addition, one of several measurements may be selected and data is output that provides information on the quality of the measurements that are used to determine corrective messages as part of the WAAS system.

Exploring the "what if?" in geology through a RESTful open-source framework for cloud-based simulation and analysis

NASA Astrophysics Data System (ADS)

Klump, Jens; Robertson, Jess

2016-04-01

The spatial and temporal extent of geological phenomena makes experiments in geology difficult to conduct, if not entirely impossible and collection of data is laborious and expensive - so expensive that most of the time we cannot test a hypothesis. The aim, in many cases, is to gather enough data to build a predictive geological model. Even in a mine, where data are abundant, a model remains incomplete because the information at the level of a blasting block is two orders of magnitude larger than the sample from a drill core, and we have to take measurement errors into account. So, what confidence can we have in a model based on sparse data, uncertainties and measurement error? Our framework consist of two layers: (a) a ground-truth layer that contains geological models, which can be statistically based on historical operations data, and (b) a network of RESTful synthetic sensor microservices which can query the ground-truth for underlying properties and produce a simulated measurement to a control layer, which could be a database or LIMS, a machine learner or a companies' existing data infrastructure. Ground truth data are generated by an implicit geological model which serves as a host for nested models of geological processes as smaller scales. Our two layers are implemented using Flask and Gunicorn, which are open source Python web application framework and server, the PyData stack (numpy, scipy etc) and Rabbit MQ (an open-source queuing library). Sensor data is encoded using a JSON-LD version of the SensorML and Observations and Measurements standards. Containerisation of the synthetic sensors using Docker and CoreOS allows rapid and scalable deployment of large numbers of sensors, as well as sensor discovery to form a self-organized dynamic network of sensors. Real-time simulation of data sources can be used to investigate crucial questions such as the potential information gain from future sensing capabilities, or from new sampling strategies, or the combination of both, and it enables us to test many "what if?" questions, both in geology and in data engineering. What would we be able to see if we could obtain data at higher resolution? How would real-time data analysis change sampling strategies? Does our data infrastructure handle many new real-time data streams? What feature engineering can be deducted for machine learning approaches? By providing a 'data sandbox' able to scale to realistic geological scenarios we hope to start answering some of these questions. Faults happen in real world networks. Future work will investigate the effect of failure on dynamic sensor networks and the impact on the predictive capability of machine learning algorithms.

Circular tomosynthesis for neuro perfusion imaging on an interventional C-arm

NASA Astrophysics Data System (ADS)

Claus, Bernhard E.; Langan, David A.; Al Assad, Omar; Wang, Xin

2015-03-01

There is a clinical need to improve cerebral perfusion assessment during the treatment of ischemic stroke in the interventional suite. The clinician is able to determine whether the arterial blockage was successfully opened but is unable to sufficiently assess blood flow through the parenchyma. C-arm spin acquisitions can image the cerebral blood volume (CBV) but are challenged to capture the temporal dynamics of the iodinated contrast bolus, which is required to derive, e.g., cerebral blood flow (CBF) and mean transit time (MTT). Here we propose to utilize a circular tomosynthesis acquisition on the C-arm to achieve the necessary temporal sampling of the volume at the cost of incomplete data. We address the incomplete data problem by using tools from compressed sensing and incorporate temporal interpolation to improve our temporal resolution. A CT neuro perfusion data set is utilized for generating a dynamic (4D) volumetric model from which simulated tomo projections are generated. The 4D model is also used as a ground truth reference for performance evaluation. The performance that may be achieved with the tomo acquisition and 4D reconstruction (under simulation conditions, i.e., without considering data fidelity limitations due to imaging physics and imaging chain) is evaluated. In the considered scenario, good agreement between the ground truth and the tomo reconstruction in the parenchyma was achieved.

JOVE Program

NASA Technical Reports Server (NTRS)

Hardy, John T.

1997-01-01

Coastal reef degradation and widespread bleaching of corals, i.e. loss of pigments and/or symbiotic zooxanthellae, is increasing globally. Remote sensing has great potential for assessing the extent of reef change. However, measuring reef change from remote platforms (boats, aircraft or satellites), requires ground-truth spectral algorithms characteristic of healthy and degraded reef populations. Our laboratory experiments demonstrated, for the first time, that healthy coral colonies emit characteristic fluorescence spectra in response to excitation with short wavelength (blue or ultraviolet) light. Furthermore, following stress, e.g. increased temperature, corals lose symbiotic algae and their health is compromised. We measured changes in coral fluorescence spectra along with pigment loss in response to temperature-induced stress. Following laboratory demonstration, we tested this approach in the field. The NASA P3 aircraft with the airborne oceanographic LIDAR system was used to map transects of coral reef in Hawaii. Ground truth samples of coral; were collected and analyzed for pigment density (pigments/surface area). Fluorescence spectra along transects showed consistent chlorophyll fluorescence peaks at 685 nm from the chlorophyll of the zooxanthellae and peaks between 400 and 570 nm believed to emanate from the coral tissue. Our results suggest that remote sensing of laser-induced fluorescence represents an efficient and effective approach to monitoring the health of coral reefs. Lists of papers, conferences, proposals awarded and a summary of student involvement is included in the appendices.

Severe storm electricity

NASA Technical Reports Server (NTRS)

Rust, W. D.; Macgorman, D. R.; Taylor, W.; Arnold, R. T.

1984-01-01

Severe storms and lightning were measured with a NASA U2 and ground based facilities, both fixed base and mobile. Aspects of this program are reported. The following results are presented: (1) ground truth measurements of lightning for comparison with those obtained by the U2. These measurements include flash type identification, electric field changes, optical waveforms, and ground strike location; (2) simultaneous extremely low frequency (ELF) waveforms for cloud to ground (CG) flashes; (3) the CG strike location system (LLP) using a combination of mobile laboratory and television video data are assessed; (4) continued development of analog-to-digital conversion techniques for processing lightning data from the U2, mobile laboratory, and NSSL sensors; (5) completion of an all azimuth TV system for CG ground truth; (6) a preliminary analysis of both IC and CG lightning in a mesocyclone; and (7) the finding of a bimodal peak in altitude lightning activity in some storms in the Great Plains and on the east coast. In the forms on the Great Plains, there was a distinct class of flash what forms the upper mode of the distribution. These flashes are smaller horizontal extent, but occur more frequently than flashes in the lower mode of the distribution.

UAS-Borne Photogrammetry for Surface Topographic Characterization: A Ground-Truth Baseline for Future Change Detection and Refinement of Scaled Remotely-Sensed Datasets

NASA Astrophysics Data System (ADS)

Coppersmith, R.; Schultz-Fellenz, E. S.; Sussman, A. J.; Vigil, S.; Dzur, R.; Norskog, K.; Kelley, R.; Miller, L.

2015-12-01

While long-term objectives of monitoring and verification regimes include remote characterization and discrimination of surficial geologic and topographic features at sites of interest, ground truth data is required to advance development of remote sensing techniques. Increasingly, it is desirable for these ground-based or ground-proximal characterization methodologies to be as nimble, efficient, non-invasive, and non-destructive as their higher-altitude airborne counterparts while ideally providing superior resolution. For this study, the area of interest is an alluvial site at the Nevada National Security Site intended for use in the Source Physics Experiment's (Snelson et al., 2013) second phase. Ground-truth surface topographic characterization was performed using a DJI Inspire 1 unmanned aerial system (UAS), at very low altitude (< 5-30m AGL). 2D photographs captured by the standard UAS camera payload were imported into Agisoft Photoscan to create three-dimensional point clouds. Within the area of interest, careful installation of surveyed ground control fiducial markers supplied necessary targets for field collection, and information for model georectification. The resulting model includes a Digital Elevation Model derived from 2D imagery. It is anticipated that this flexible and versatile characterization process will provide point cloud data resolution equivalent to a purely ground-based LiDAR scanning deployment (e.g., 1-2cm horizontal and vertical resolution; e.g., Sussman et al., 2012; Schultz-Fellenz et al., 2013). In addition to drastically increasing time efficiency in the field, the UAS method also allows for more complete coverage of the study area when compared to ground-based LiDAR. Comparison and integration of these data with conventionally-acquired airborne LiDAR data from a higher-altitude (~ 450m) platform will aid significantly in the refinement of technologies and detection capabilities of remote optical systems to identify and detect surface geologic and topographic signatures of interest. This work includes a preliminary comparison of surface signatures detected from varying standoff distances to assess current sensor performance and benefits.

Using mixture tuned match filtering to measure changes in subpixel vegetation area in Las Vegas, Nevada

NASA Astrophysics Data System (ADS)

Brelsford, Christa; Shepherd, Doug

2013-09-01

In desert cities, securing sufficient water supply to meet the needs of both existing population and future growth is a complex problem with few easy solutions. Grass lawns are a major driver of water consumption and accurate measurements of vegetation area are necessary to understand drivers of changes in household water consumption. Measuring vegetation change in a heterogeneous urban environment requires sub-pixel estimation of vegetation area. Mixture Tuned Match Filtering has been successfully applied to target detection for materials that only cover small portions of a satellite image pixel. There have been few successful applications of MTMF to fractional area estimation, despite theory that suggests feasibility. We use a ground truth dataset over ten times larger than that available for any previous MTMF application to estimate the bias between ground truth data and matched filter results. We find that the MTMF algorithm underestimates the fractional area of vegetation by 5-10%, and calculate that averaging over 20 to 30 pixels is necessary to correct this bias. We conclude that with a large ground truth dataset, using MTMF for fractional area estimation is possible when results can be estimated at a lower spatial resolution than the base image. When this method is applied to estimating vegetation area in Las Vegas, NV spatial and temporal trends are consistent with expectations from known population growth and policy goals.

Evaluating Continuous-Time Slam Using a Predefined Trajectory Provided by a Robotic Arm

NASA Astrophysics Data System (ADS)

Koch, B.; Leblebici, R.; Martell, A.; Jörissen, S.; Schilling, K.; Nüchter, A.

2017-09-01

Recently published approaches to SLAM algorithms process laser sensor measurements and output a map as a point cloud of the environment. Often the actual precision of the map remains unclear, since SLAMalgorithms apply local improvements to the resulting map. Unfortunately, it is not trivial to compare the performance of SLAMalgorithms objectively, especially without an accurate ground truth. This paper presents a novel benchmarking technique that allows to compare a precise map generated with an accurate ground truth trajectory to a map with a manipulated trajectory which was distorted by different forms of noise. The accurate ground truth is acquired by mounting a laser scanner on an industrial robotic arm. The robotic arm is moved on a predefined path while the position and orientation of the end-effector tool are monitored. During this process the 2D profile measurements of the laser scanner are recorded in six degrees of freedom and afterwards used to generate a precise point cloud of the test environment. For benchmarking, an offline continuous-time SLAM algorithm is subsequently applied to remove the inserted distortions. Finally, it is shown that the manipulated point cloud is reversible to its previous state and is slightly improved compared to the original version, since small errors that came into account by imprecise assumptions, sensor noise and calibration errors are removed as well.

Evaluating the state of the art in coreference resolution for electronic medical records

PubMed Central

Bodnari, Andreea; Shen, Shuying; Forbush, Tyler; Pestian, John; South, Brett R

2012-01-01

Background The fifth i2b2/VA Workshop on Natural Language Processing Challenges for Clinical Records conducted a systematic review on resolution of noun phrase coreference in medical records. Informatics for Integrating Biology and the Bedside (i2b2) and the Veterans Affair (VA) Consortium for Healthcare Informatics Research (CHIR) partnered to organize the coreference challenge. They provided the research community with two corpora of medical records for the development and evaluation of the coreference resolution systems. These corpora contained various record types (ie, discharge summaries, pathology reports) from multiple institutions. Methods The coreference challenge provided the community with two annotated ground truth corpora and evaluated systems on coreference resolution in two ways: first, it evaluated systems for their ability to identify mentions of concepts and to link together those mentions. Second, it evaluated the ability of the systems to link together ground truth mentions that refer to the same entity. Twenty teams representing 29 organizations and nine countries participated in the coreference challenge. Results The teams' system submissions showed that machine-learning and rule-based approaches worked best when augmented with external knowledge sources and coreference clues extracted from document structure. The systems performed better in coreference resolution when provided with ground truth mentions. Overall, the systems struggled in solving coreference resolution for cases that required domain knowledge. PMID:22366294

SAGE to examine Earth's stratosphere

NASA Technical Reports Server (NTRS)

1979-01-01

The SAGE mission is discussed along with the role of the Nimbus 7 experiment. Other topics discussed include: ground truth measurements, data collection and processing, SAGE instrumentation, and launch sequence.

A Wide-Angle Camera for the Mobile Asteroid Surface Scout (MASCOT) on Hayabusa-2

NASA Astrophysics Data System (ADS)

Schmitz, N.; Koncz, A.; Jaumann, R.; Hoffmann, H.; Jobs, D.; Kachlicki, J.; Michaelis, H.; Mottola, S.; Pforte, B.; Schroeder, S.; Terzer, R.; Trauthan, F.; Tschentscher, M.; Weisse, S.; Ho, T.-M.; Biele, J.; Ulamec, S.; Broll, B.; Kruselburger, A.; Perez-Prieto, L.

2014-04-01

JAXA's Hayabusa-2 mission, an asteroid sample return mission, is scheduled for launch in December 2014, for a rendezvous with the C-type asteroid 1999 JU3 in 2018. MASCOT, the Mobile Asteroid Surface Scout [1], is a small lander, designed to deliver ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context for the returned samples.MASCOT's main objective is to investigate the landing site's geomorphology, the internal structure, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the surface. MASCOT comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyper-spectral microscope. The camera (MASCOT CAM) was designed and built by DLR's Institute of Planetary Research, together with Airbus DS Germany.

Classification of microscopy images of Langerhans islets

NASA Astrophysics Data System (ADS)

Å vihlík, Jan; Kybic, Jan; Habart, David; Berková, Zuzana; Girman, Peter; Kříž, Jan; Zacharovová, Klára

2014-03-01

Evaluation of images of Langerhans islets is a crucial procedure for planning an islet transplantation, which is a promising diabetes treatment. This paper deals with segmentation of microscopy images of Langerhans islets and evaluation of islet parameters such as area, diameter, or volume (IE). For all the available images, the ground truth and the islet parameters were independently evaluated by four medical experts. We use a pixelwise linear classifier (perceptron algorithm) and SVM (support vector machine) for image segmentation. The volume is estimated based on circle or ellipse fitting to individual islets. The segmentations were compared with the corresponding ground truth. Quantitative islet parameters were also evaluated and compared with parameters given by medical experts. We can conclude that accuracy of the presented fully automatic algorithm is fully comparable with medical experts.

Late diagenetic indicators of buried oil and gas. 2: Direct detection experiment at Cement and Garza fields, Oklahoma and Texas, using enhanced LANDSAT 1 and 2 images

NASA Technical Reports Server (NTRS)

Donovan, T. J.; Termain, P. A.; Henry, M. E. (Principal Investigator)

1979-01-01

The author has identified the following significant results. The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite were the major alteration phenomena at Cement. The bedrock alterations were partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters, biased by detailed ground truth, were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation.

PSNet: prostate segmentation on MRI based on a convolutional neural network.

PubMed

Tian, Zhiqiang; Liu, Lizhi; Zhang, Zhenfeng; Fei, Baowei

2018-04-01

Automatic segmentation of the prostate on magnetic resonance images (MRI) has many applications in prostate cancer diagnosis and therapy. We proposed a deep fully convolutional neural network (CNN) to segment the prostate automatically. Our deep CNN model is trained end-to-end in a single learning stage, which uses prostate MRI and the corresponding ground truths as inputs. The learned CNN model can be used to make an inference for pixel-wise segmentation. Experiments were performed on three data sets, which contain prostate MRI of 140 patients. The proposed CNN model of prostate segmentation (PSNet) obtained a mean Dice similarity coefficient of [Formula: see text] as compared to the manually labeled ground truth. Experimental results show that the proposed model could yield satisfactory segmentation of the prostate on MRI.

Mapping Arctic plant functional type distributions in the Barrow Environmental Observatory using WorldView-2 and LiDAR datasets

DOE PAGES

Langford, Zachary; Kumar, Jitendra; Hoffman, Forrest; ...

2016-09-06

Multi-scale modeling of Arctic tundra vegetation requires characterization of the heterogeneous tundra landscape, which includes representation of distinct plant functional types (PFTs). We combined high-resolution multi-spectral remote sensing imagery from the WorldView-2 satellite with light detecting and ranging (LiDAR)-derived digital elevation models (DEM) to characterize the tundra landscape in and around the Barrow Environmental Observatory (BEO), a 3021-hectare research reserve located at the northern edge of the Alaskan Arctic Coastal Plain. Vegetation surveys were conducted during the growing season (June August) of 2012 from 48 1 m 1 m plots in the study region for estimating the percent cover ofmore » PFTs (i.e., sedges, grasses, forbs, shrubs, lichens and mosses). Statistical relationships were developed between spectral and topographic remote sensing characteristics and PFT fractions at the vegetation plots from field surveys. These derived relationships were employed to statistically upscale PFT fractions for our study region of 586 hectares at 0.25-m resolution around the sampling areas within the BEO, which was bounded by the LiDAR footprint. We employed an unsupervised clustering for stratification of this polygonal tundra landscape and used the clusters for segregating the field data for our upscaling algorithm over our study region, which was an inverse distance weighted (IDW) interpolation. We describe two versions of PFT distribution maps upscaled by IDW from WorldView-2 imagery and LiDAR: (1) a version computed from a single image in the middle of the growing season; and (2) a version computed from multiple images through the growing season. This approach allowed us to quantify the value of phenology for improving PFT distribution estimates. We also evaluated the representativeness of the field surveys by measuring the Euclidean distance between every pixel. This guided the ground-truthing campaign in late July of 2014 for addressing uncertainty based on representativeness analysis by selecting 24 1 m 1 m plots that were well and poorly represented. Ground-truthing indicated that including phenology had a better accuracy (R 2=0.75, RMSE=9.94) than the single image upscaling (R 2=0.63 , RMSE=12.05) predicted from IDW. We also updated our upscaling approach to include the 24 ground-truthing plots, and a second ground-truthing campaign in late August of 2014 indicated a better accuracy for the phenology model (R 2=0.61 , RMSE=13.78 ) than only using the original 48 plots for the phenology model (R 2=0.23 , RMSE=17.49). After all, we believe that the cluster-based IDW upscaling approach and the representativeness analysis offer new insights for upscaling high-resolution data in fragmented landscapes. This analysis and approach provides PFT maps needed to inform land surface models in Arctic ecosystems.« less

UTILIZING RESULTS FROM INSAR TO DEVELOP SEISMIC LOCATION BENCHMARKS AND IMPLICATIONS FOR SEISMIC SOURCE STUDIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. BEGNAUD; ET AL

2000-09-01

Obtaining accurate seismic event locations is one of the most important goals for monitoring detonations of underground nuclear teats. This is a particular challenge at small magnitudes where the number of recording stations may be less than 20. Although many different procedures are being developed to improve seismic location, most procedures suffer from inadequate testing against accurate information about a seismic event. Events with well-defined attributes, such as latitude, longitude, depth and origin time, are commonly referred to as ground truth (GT). Ground truth comes in many forms and with many different levels of accuracy. Interferometric Synthetic Aperture Radar (InSAR)more » can provide independent and accurate information (ground truth) regarding ground surface deformation and/or rupture. Relating surface deformation to seismic events is trivial when events are large and create a significant surface rupture, such as for the M{sub w} = 7.5 event that occurred in the remote northern region of the Tibetan plateau in 1997. The event, which was a vertical strike slip even appeared anomalous in nature due to the lack of large aftershocks and had an associated surface rupture of over 180 km that was identified and modeled using InSAR. The east-west orientation of the fault rupture provides excellent ground truth for latitude, but is of limited use for longitude. However, a secondary rupture occurred 50 km south of the main shock rupture trace that can provide ground truth with accuracy within 5 km. The smaller, 5-km-long secondary rupture presents a challenge for relating the deformation to a seismic event. The rupture is believed to have a thrust mechanism; the dip of the fimdt allows for some separation between the secondary rupture trace and its associated event epicenter, although not as much as is currently observed from catalog locations. Few events within the time period of the InSAR analysis are candidates for the secondary rupture. Of these, we have identified six possible secondary rupture events (mb range = 3.7-4.8, with two magnitudes not reported), based on synthetic tests and residual analysis. All of the candidate events are scattered about the main and secondary rupture. A Joint Hypocenter Determination (JHD) approach applied to the aftershocks using global picks was not able to identify the secondary event. We added regional data and used propagation path corrections to reduce scatter and remove the 20-km bias seen in the main shock location. A&r preliminary analysis using several different velocity models, none of the candidate events proved to relocate on the surface trace of the secondary rupture. However, one event (mb = not reported) moved from a starting distance of {approximately}106 km to a relocated distance of {approximately}28 km from the secondary rupture, the only candidate event to relocate in relative proximity to the secondary rupture.« less

Assessment of atmospheric models for tele-infrasonic propagation

NASA Astrophysics Data System (ADS)

McKenna, Mihan; Hayek, Sylvia

2005-04-01

Iron mines in Minnesota are ideally located to assess the accuracy of available atmospheric profiles used in infrasound modeling. These mines are located approximately 400 km away to the southeast (142) of the Lac-Du-Bonnet infrasound station, IS-10. Infrasound data from June 1999 to March 2004 was analyzed to assess the effects of explosion size and atmospheric conditions on observations. IS-10 recorded a suite of events from this time period resulting in well constrained ground truth. This ground truth allows for the comparison of ray trace and PE (Parabolic Equation) modeling to the observed arrivals. The tele-infrasonic distance (greater than 250 km) produces ray paths that turn in the upper atmosphere, the thermosphere, at approximately 120 km to 140 km. Modeling based upon MSIS/HWM (Mass Spectrometer Incoherent Scatter/Horizontal Wind Model) and the NOGAPS (Navy Operational Global Atmospheric Prediction System) and NRL-GS2 (Naval Research Laboratory Ground to Space) augmented profiles are used to interpret the observed arrivals.

A procedure used for a ground truth study of a land use map of North Alabama generated from LANDSAT data

NASA Technical Reports Server (NTRS)

Downs, S. W., Jr.; Sharma, G. C.; Bagwell, C.

1977-01-01

A land use map of a five county area in North Alabama was generated from LANDSAT data using a supervised classification algorithm. There was good overall agreement between the land use designated and known conditions, but there were also obvious discrepancies. In ground checking the map, two types of errors were encountered - shift and misclassification - and a method was developed to eliminate or greatly reduce the errors. Randomly selected study areas containing 2,525 pixels were analyzed. Overall, 76.3 percent of the pixels were correctly classified. A contingency coefficient of correlation was calculated to be 0.7 which is significant at the alpha = 0.01 level. The land use maps generated by computers from LANDSAT data are useful for overall land use by regional agencies. However, care must be used when making detailed analysis of small areas. The procedure used for conducting the ground truth study together with data from representative study areas is presented.

A Mobile Asteroid Surface Scout (MASCOT) on board the Hayabusa 2 Mission to the near Earth asteroid (162173) Ryugu

NASA Astrophysics Data System (ADS)

Jaumann, R.; Bibring, J. P.; Glassmeier, K. H.; Grott, M.; Ho, T. M.; Ulamec, S.; Schmitz, N.; Auster, H. U.; Biele, J.; Kuninaka, H.; Okada, T.; Yoshikawa, M.; Watanabe, S.; Spohn, T.; Koncz, A.; Hercik, D.; Michaelis, H.; Fujimoto, M.

2016-12-01

MASCOT is part of JAXA's Hayabusa 2 asteroid sample return mission that has been launched to asteroid (162173) Ryugu (1,2,3) on Dec 3rd, 2014. It is scheduled to arrive at Ryugu in 2018, and return samples to Earth in 2020. The German Aerospace Center (DLR) developed the lander MASCOT with contributions from CNES (France) (2,3). Ryugu has been classified as a Cg-type (4), believed to be a primitive volatile-rich remnant from the early solar system. Its visible geometric albedo is 0.07±0.01with a diameter of 0.87±0.03 km (5). The thermal inertia indicates thick dust with a cm-sized, gravel-dominated surface layer (5,6). Ryugu shows a retrograde rotation with a period of 7.63±0.01h. Spectral observations indicate iron-bearing phyllosilicates (1) on parts of the surface, suggesting compositional heterogeneity. MASCOT will enable to in-situ map the asteroid's geomorphology, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and its thermal, mechanical, and magnetic properties in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples (2,3). MASCOT comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyperspectral microscope (2,3). Characterizing the properties of asteroid regolith in-situ will deliver important ground truth for further understanding telescopic and orbital observations as well as samples of asteroids. MASCOT will descend and land on the asteroid and will change its position by hopping (3). (1) Vilas, F., Astro. J. 1101-1105, 2008; (2) Jaumann, R., et al., SSR, DOI 10.1007/s11214-016-0263-2, 2016; (3) Ho, T.-M. et al., SSR, DOI 10.1007/s11214-016-0251-6, 2016; (4) Bus, S.J., Binzel, R.P. Icarus 158, 2002; (5) Hasegawa, T.G., et al., Astron. Soc. Japan 60, 2008; (6) T.G. Müller, T.G., et al., doi 10.1051/0004-6361/201015599, 2011.

A Mobile Asteroid Surface Scout (MASCOT) for the Hayabusa 2 Mission to 1999 JU3: The Scientific Approach

NASA Astrophysics Data System (ADS)

Jaumann, Ralf; Bibring, Jean-Pierre; Glassmeier, Karl-Heinz; Grott, Matthias; Ho, Tra-Mi; Ulamec, Stepahn; Schmitz, Nicole; Auster, Ulrich; Biele, Jens; Kuninaka, Hitoshi; Okada, Tatsuaki; Yoshikawa, Makoto; Watanabe, Sei-ichhiro; Fujimoto, Masaki; Spohn, Tilman; Koncz, Alexander; Michaelis, Harald

2014-05-01

MASCOT, a Mobile Asteroid Surface Scout, will support JAXA's Hayabusa 2 mission to investigate the C-type asteroid 1999 JU3 (1). The German Aer-ospace Center (DLR) develops MASCOT with contributions from CNES (France) (2,3). Main objective is to in-situ map the asteroid's geomorpholo-gy, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the sur-face in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples. MASCOT comprises a payload of four scientific in-struments: camera, radiometer, magnetometer and hyperspectral microscope. C- and D-type asteroids hold clues to the origin of the solar system, the for-mation of planets, the origins of water and life on Earth, the protection of Earth from impacts, and resources for future human exploration. C- and D-types are dark and difficult to study from Earth, and have only been glimpsed by spacecraft. While results from recent missions (e.g., Hayabusa, NEAR (4, 5, 6)) have dramatically increased our understanding of asteroids, important questions remain. For example, characterizing the properties of asteroid regolith in-situ would deliver important ground truth for further understanding telescopic and orbital observations and samples of such aster-oids. MASCOT will descend and land on the asteroid and will change its position two times by hopping. This enables measurements during descent, at the landing and hopping positions #1-3, and during hopping. References: (1) Vilas, F., Astronomical J. 1101-1105, 2008; (2) Ulamec, S., et al., Acta Astronautica, Vol. 93, pp. 460-466; (3) Jaumann et al., 45th LPSC, Houston; (4) Special Issue, Science, Vol. 312 no. 5778, 2006; (5) Special Issue Science, Vol. 333 no. 6046, 2011. (6) Bell, L., Mitton, J-., Cambridge Univ. Press, 2002.

A Mobile Asteroid Surface Scout (MASCOT) for the Hayabusa 2 Mission to 1999 JU3: The Scientific Approach

NASA Astrophysics Data System (ADS)

Jaumann, Ralf; Bibring, Jean-Pierre; Glassmeier, Karl-Heinz; Grott, Matthias; Ho, Tra-Mie; Ulamec, Stephan; Schmitz, Nicole; Auster, Hans-Ulrich; Biele, Jens; Kuninaka, Hitoshi; Okada, Tatsuaki; Yoshikawa, Makoto; Watanabe, Sei-ichhiro; Fujimoto, Masaki; Spohn, Tilman

2013-04-01

Mascot, a Mobile Asteroid Surface Scout, will support JAXA's Hayabusa 2 mission to investigate the C-type asteroid 1999 JU3 (1). The German Aero-space Center (DLR) develops Mascot with contributions from CNES (France) (2). Main objective is to in-situ map the asteroid's geomorphology, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the surface in order to provide ground truth for the orbiter remote measurements, sup-port the selection of sampling sites, and provide context information for the returned samples. Mascot comprises a payload of four scientific instruments: camera, radiometer, magnetometer and hyperspectral microscope. C- and D-type asteroids hold clues to the origin of the solar system, the formation of planets, the origins of water and life on Earth, the protection of Earth from impacts, and resources for future human exploration. C- and D-types are dark and difficult to study from Earth, and have only been glimpsed by spacecraft. While results from recent missions (e.g., Hayabusa, NEAR (3, 4, 5)) have dramatically increased our understanding of asteroids, important questions remain. For example, characterizing the properties of asteroid reg-olith in-situ would deliver important ground truth for further understanding telescopic and orbital observations and samples of such asteroids. Mascot will descend and land on the asteroid and will change its position two times by hopping. This enables measurements during descent, at the landing and hopping positions #1-3, and during hopping. References: (1) Vilas, F., Astronomical J. 1101-1105, 2008; (2) Ulamec, S., et al., COSPAR, General Assembly, Mysore/India, 2012; (3) Special Issue, Science, Vol. 312 no. 5778, 2006; (4) Special Issue Science, Vol. 333 no. 6046, 2011; (5) Bell, L., Mitton, J-., Cambridge Univ. Press, 2002.

Spatial Heterogeneity of Habitat Suitability for Rift Valley Fever Occurrence in Tanzania: An Ecological Niche Modelling Approach

PubMed Central

Sindato, Calvin; Stevens, Kim B.; Karimuribo, Esron D.; Mboera, Leonard E. G.; Paweska, Janusz T.; Pfeiffer, Dirk U.

2016-01-01

Background Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Materials and Methods Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Principal Findings Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). Conclusion/Significance The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics. PMID:27654268

TU-F-18C-05: Evaluation of a Method to Calculate Patient-Oriented MGD Coefficients Using Estimates of Glandular Tissue Distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porras-Chaverri, M; University of Costa Rica, San Jose; Galavis, P

Purpose: Evaluate mammographic mean glandular dose (MGD) coefficients for particular known tissue distributions using a novel formalism that incorporates the effect of the heterogeneous glandular tissue distribution, by comparing them with MGD coefficients derived from the corresponding anthropomorphic computer breast phantom. Methods: MGD coefficients were obtained using MCNP5 simulations with the currently used homogeneous assumption and the heterogeneously-layered breast (HLB) geometry and compared against those from the computer phantom (ground truth). The tissue distribution for the HLB geometry was estimated using glandularity map image pairs corrected for the presence of non-glandular fibrous tissue. Heterogeneity of tissue distribution was quantified usingmore » the glandular tissue distribution index, Idist. The phantom had 5 cm compressed breast thickness (MLO and CC views) and 29% whole breast glandular percentage. Results: Differences as high as 116% were found between the MGD coefficients with the homogeneous breast core assumption and those from the corresponding ground truth. Higher differences were found for cases with more heterogeneous distribution of glandular tissue. The Idist for all cases was in the [−0.8{sup −}+0.3] range. The use of the methods presented in this work results in better agreement with ground truth with an improvement as high as 105 pp. The decrease in difference across all phantom cases was in the [9{sup −}105] pp range, dependent on the distribution of glandular tissue and was larger for the cases with the highest Idist values. Conclusion: Our results suggest that the use of corrected glandularity image pairs, as well as the HLB geometry, improves the estimates of MGD conversion coefficients by accounting for the distribution of glandular tissue within the breast. The accuracy of this approach with respect to ground truth is highly dependent on the particular glandular tissue distribution studied. Predrag Bakic discloses current funding from NIH, NSF, and DoD, former funding from Real Time Tomography, LLC and a current research collaboration with Barco and Hologic.« less

MO-AB-BRA-09: Temporally Realistic Manipulation a 4D Biomechanical Lung Phantom for Evaluation of Simultaneous Registration and Segmentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markel, D; Levesque, I R.; Larkin, J

Purpose: To produce multi-modality compatible, realistic datasets for the joint evaluation of segmentation and registration with a reliable ground truth using a 4D biomechanical lung phantom. The further development of a computer controlled air flow system for recreation of real patient breathing patterns is incorporated for additional evaluation of motion prediction algorithms. Methods: A pair of preserved porcine lungs was pneumatically manipulated using an in-house computer controlled respirator. The respirator consisted of a set of bellows actuated by a 186 W computer controlled industrial motor. Patient breathing traces were recorded using a respiratory bellows belt during CT simulation and inputmore » into a control program incorporating a proportional-integral-derivative (PID) feedback controller in LabVIEW. Mock tumors were created using dual compartment vacuum sealed sea sponges. 65% iohexol,a gadolinium-based contrast agent and 18F-FDG were used to produce contrast and thus determine a segmentation ground truth. The intensity distributions of the compartments were then digitally matched for the final dataset. A bifurcation tracking pipeline provided a registration ground truth using the bronchi of the lung. The lungs were scanned using a GE Discovery-ST PET/CT scanner and a Phillips Panorama 0.23T MRI using a T1 weighted 3D fast field echo (FFE) protocol. Results: The standard deviation of the error between the patient breathing trace and the encoder feedback from the respirator was found to be ±4.2%. Bifurcation tracking error using CT (0.97×0.97×3.27 mm{sup 3} resolution) was found to be sub-voxel up to 7.8 cm displacement for human lungs and less than 1.32 voxel widths in any axis up to 2.3 cm for the porcine lungs. Conclusion: An MRI/PET/CT compatible anatomically and temporally realistic swine lung phantom was developed for the evaluation of simultaneous registration and segmentation algorithms. With the addition of custom software and mock tumors, the entire package offers ground truths for benchmarking performance with high fidelity.« less

SU-F-R-36: Validating Quantitative Radiomic Texture Features for Oncologic PET: A Digital Phantom Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, F; Yang, Y; Young, L

Purpose: Radiomic texture features derived from the oncologic PET have recently been brought under intense investigation within the context of patient stratification and treatment outcome prediction in a variety of cancer types; however, their validity has not yet been examined. This work is aimed to validate radiomic PET texture metrics through the use of realistic simulations in the ground truth setting. Methods: Simulation of FDG-PET was conducted by applying the Zubal phantom as an attenuation map to the SimSET software package that employs Monte Carlo techniques to model the physical process of emission imaging. A total of 15 irregularly-shaped lesionsmore » featuring heterogeneous activity distribution were simulated. For each simulated lesion, 28 texture features in relation to the intensity histograms (GLIH), grey-level co-occurrence matrices (GLCOM), neighborhood difference matrices (GLNDM), and zone size matrices (GLZSM) were evaluated and compared with their respective values extracted from the ground truth activity map. Results: In reference to the values from the ground truth images, texture parameters appearing on the simulated data varied with a range of 0.73–3026.2% for GLIH-based, 0.02–100.1% for GLCOM-based, 1.11–173.8% for GLNDM-based, and 0.35–66.3% for GLZSM-based. For majority of the examined texture metrics (16/28), their values on the simulated data differed significantly from those from the ground truth images (P-value ranges from <0.0001 to 0.04). Features not exhibiting significant difference comprised of GLIH-based standard deviation, GLCO-based energy and entropy, GLND-based coarseness and contrast, and GLZS-based low gray-level zone emphasis, high gray-level zone emphasis, short zone low gray-level emphasis, long zone low gray-level emphasis, long zone high gray-level emphasis, and zone size nonuniformity. Conclusion: The extent to which PET imaging disturbs texture appearance is feature-dependent and could be substantial. It is thus advised that use of PET texture parameters for predictive and prognostic measurements in oncologic setting awaits further systematic and critical evaluation.« less

Geographic applications of ERTS-1 imagery to rural landscape change in eastern Tennessee

NASA Technical Reports Server (NTRS)

Rehder, J. B. (Principal Investigator); Omalley, J. R.

1973-01-01

There are no author-identified significant results in this report. A multistage sampling experiment was conducted using low (10,000') and high (60,000') altitude aircraft imagery in comparison with orbital (560 miles) ERTS imagery. Although the aircraft data provide detailed landscape observations similar to ground truth data, they cover relatively small areas per image frame for irregular static slices of time. By comparison, ERTS provides repetitive observations in a regional perspective for broad areal coverage. Microdensitometric and computer techniques are being used to analyze the ERTS imagery for gray tone signatures, comparisons, and ultimately for landscape change detection.

A methodology for small scale rural land use mapping in semi-arid developing countries using orbital imagery. Part 4: Review of land use surveys using orbital imagery outside of the USA

NASA Technical Reports Server (NTRS)

Vangenderen, J. L. (Principal Investigator); Lock, B. F.

1976-01-01

The author has identified the following significant results. Outside the U.S., various attempts were made to investigate the feasibility of utilizing orbital MSS imagery in the production of small scale land use maps. Overall, these studies are not as elaborate or extensive in their scope as the U.S. ones, and generally the non-U.S. investigators have employed nonsophisticated and less expensive techniques. A representative range of studies is presented to demonstrate the approaches and trends dealing with reprocessing, interpretation, classification, sampling, and ground truth procedures.

Application of selected methods of remote sensing for detecting carbonaceous water pollution

NASA Technical Reports Server (NTRS)

Davis, E. M.; Fosbury, W. J.

1972-01-01

The use of aerial photography to determine the nature and extent of water pollution from carbonaceous materials is discussed. Flights were conducted over the Galveston Bay estuarine complex. Ground truth data were developed from field sampling of the waters in a region near the Houston Ship Channel. Tests conducted in the field were those for the following physical and chemical factors: (1) ph, (2) dissolved oxygen, (3) temperature, and (4) light penetration. Laboratory analyses to determine various properties of the water are described and the types of instruments used are identified. Results of the analyses are presented as charts and graphs.

Stardust Interstellar Preliminary Examination II: Curating the Interstellar Dust Collector, Picokeystones, and Sources of Impact Tracks

NASA Technical Reports Server (NTRS)

Frank, David R.; Westphal, Andrew J.; Zolensky, Michael E.; Gainsforth, Zack; Butterworth, Anna L.; Bastien, Ronald K.; Allen, Carlton; Anderson, David; Bechtel, Hans A.; Sandford, Scott A.

2013-01-01

We discuss the inherent difficulties that arise during "ground truth" characterization of the Stardust interstellar dust collector. The challenge of identifying contemporary interstellar dust impact tracks in aerogel is described within the context of background spacecraft secondaries and possible interplanetary dust particles and beta-meteoroids. In addition, the extraction of microscopic dust embedded in aerogel is technically challenging. Specifically, we provide a detailed description of the sample preparation techniques developed to address the unique goals and restrictions of the Interstellar Preliminary Exam. These sample preparation requirements and the scarcity of candidate interstellar impact tracks exacerbate the difficulties. We also illustrate the role of initial optical imaging with critically important examples, and summarize the overall processing of the collection to date.

The use of the truth and deception in dementia care amongst general hospital staff.

PubMed

Turner, Alex; Eccles, Fiona; Keady, John; Simpson, Jane; Elvish, Ruth

2017-08-01

Deceptive practice has been shown to be endemic in long-term care settings. However, little is known about the use of deception in dementia care within general hospitals and staff attitudes towards this practice. This study aimed to develop understanding of the experiences of general hospital staff and explore their decision-making processes when choosing whether to tell the truth or deceive a patient with dementia. This qualitative study drew upon a constructivist grounded theory approach to analyse data gathered from semi-structured interviews with a range of hospital staff. A model, grounded in participant experiences, was developed to describe their decision-making processes. Participants identified particular triggers that set in motion the need for a response. Various mediating factors influenced how staff chose to respond to these triggers. Overall, hospital staff were reluctant to either tell the truth or to lie to patients. Instead, 'distracting' or 'passing the buck' to another member of staff were preferred strategies. The issue of how truth and deception are defined was identified. The study adds to the growing research regarding the use of lies in dementia care by considering the decision-making processes for staff in general hospitals. Various factors influence how staff choose to respond to patients with dementia and whether deception is used. Similarities and differences with long-term dementia care settings are discussed. Clinical and research implications include: opening up the topic for further debate, implementing staff training about communication and evaluating the impact of these processes.

Status of the undisturbed mangroves at Brunei Bay, East Malaysia: a preliminary assessment based on remote sensing and ground-truth observations

PubMed Central

Izzaty Horsali, Nurul Amira; Mat Zauki, Nurul Ashikin; Otero, Viviana; Nadzri, Muhammad Izuan; Ibrahim, Sulong; Husain, Mohd-Lokman; Dahdouh-Guebas, Farid

2018-01-01

Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite—ALOS) and ground-truth (Point-Centred Quarter Method—PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such as Nypa fruticans, Rhizophora apiculata, Sonneratia caseolaris, S. alba and Xylocarpus granatum in the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok—suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution of Sonneratia spp. as pioneer vegetation at shallow river mouths, N. fruticans in the areas of strong freshwater discharge, R. apiculata in the areas of strong neritic incursion and X. granatum at interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present. PMID:29479500

Consensus-Based Sorting of Neuronal Spike Waveforms

PubMed Central

Fournier, Julien; Mueller, Christian M.; Shein-Idelson, Mark; Hemberger, Mike

2016-01-01

Optimizing spike-sorting algorithms is difficult because sorted clusters can rarely be checked against independently obtained “ground truth” data. In most spike-sorting algorithms in use today, the optimality of a clustering solution is assessed relative to some assumption on the distribution of the spike shapes associated with a particular single unit (e.g., Gaussianity) and by visual inspection of the clustering solution followed by manual validation. When the spatiotemporal waveforms of spikes from different cells overlap, the decision as to whether two spikes should be assigned to the same source can be quite subjective, if it is not based on reliable quantitative measures. We propose a new approach, whereby spike clusters are identified from the most consensual partition across an ensemble of clustering solutions. Using the variability of the clustering solutions across successive iterations of the same clustering algorithm (template matching based on K-means clusters), we estimate the probability of spikes being clustered together and identify groups of spikes that are not statistically distinguishable from one another. Thus, we identify spikes that are most likely to be clustered together and therefore correspond to consistent spike clusters. This method has the potential advantage that it does not rely on any model of the spike shapes. It also provides estimates of the proportion of misclassified spikes for each of the identified clusters. We tested our algorithm on several datasets for which there exists a ground truth (simultaneous intracellular data), and show that it performs close to the optimum reached by a support vector machine trained on the ground truth. We also show that the estimated rate of misclassification matches the proportion of misclassified spikes measured from the ground truth data. PMID:27536990

As-built design specification for MISMAP

NASA Technical Reports Server (NTRS)

Brown, P. M.; Cheng, D. E.; Tompkins, M. A. (Principal Investigator)

1981-01-01

The MISMAP program, which is part of the CLASFYT package, is described. The program is designed to compare classification values with ground truth values for a segment and produce a comparison map and summary table.

Ground truth report 1975 Phoenix microwave experiment. [Joint Soil Moisture Experiment

NASA Technical Reports Server (NTRS)

Blanchard, B. J.

1975-01-01

Direct measurements of soil moisture obtained in conjunction with aircraft data flights near Phoenix, Arizona in March, 1975 are summarized. The data were collected for the Joint Soil Moisture Experiment.

A statistical evaluation and comparison of VISSR Atmospheric Sounder (VAS) data and corresponding rawinsonde measurements

NASA Technical Reports Server (NTRS)

1984-01-01

Three mesoscale sounding data sets from the VISSR Atmospheric Sounder (VAS) produced using different retrieval techniques were evaluated of corresponding ground truth rawinsonde data for 6-7 March 1982. Mean, standard deviations, and RMS differences between the satellite and rawinsonde parameters were calculated over gridded fields in central Texas and Oklahoma. Large differences exist between each satellite data set and the ground truth data. Biases in the satellite temperature and moisture profiles seem extremely dependent upon the three dimensional structure of the atmosphere and range from 1 deg to 3 deg C for temperature and 3 deg to 6 deg C for dewpoint temperature. Atmospheric gradients of basic and derived parameters determined from the VAS data sets produced an adequate representation of the mesoscale environment but their magnitudes were often reduced by 30 to 50%.

A three-part geometric model to predict the radar backscatter from wheat, corn, and sorghum

NASA Technical Reports Server (NTRS)

Ulaby, F. T. (Principal Investigator); Eger, G. W., III; Kanemasu, E. T.

1982-01-01

A model to predict the radar backscattering coefficient from crops must include the geometry of the canopy. Radar and ground-truth data taken on wheat in 1979 indicate that the model must include contributions from the leaves, from the wheat head, and from the soil moisture. For sorghum and corn, radar and ground-truth data obtained in 1979 and 1980 support the necessity of a soil moisture term and a leaf water term. The Leaf Area Index (LAI) is an appropriate input for the leaf contribution to the radar response for wheat and sorghum, however the LAI generates less accurate values for the backscattering coefficient for corn. Also, the data for corn and sorghum illustrate the importance of the water contained in the stalks in estimating the radar response.

Using virtual environment for autonomous vehicle algorithm validation

NASA Astrophysics Data System (ADS)

Levinskis, Aleksandrs

2018-04-01

This paper describes possible use of modern game engine for validating and proving the concept of algorithm design. As the result simple visual odometry algorithm will be provided to show the concept and go over all workflow stages. Some of stages will involve using of Kalman filter in such a way that it will estimate optical flow velocity as well as position of moving camera located at vehicle body. In particular Unreal Engine 4 game engine will be used for generating optical flow patterns and ground truth path. For optical flow determination Horn and Schunck method will be applied. As the result, it will be shown that such method can estimate position of the camera attached to vehicle with certain displacement error respect to ground truth depending on optical flow pattern. For displacement rate RMS error is calculating between estimated and actual position.

Using Seismic and Infrasonic Data to Identify Persistent Sources

NASA Astrophysics Data System (ADS)

Nava, S.; Brogan, R.

2014-12-01

Data from seismic and infrasound sensors were combined to aid in the identification of persistent sources such as mining-related explosions. It is of interest to operators of seismic networks to identify these signals in their event catalogs. Acoustic signals below the threshold of human hearing, in the frequency range of ~0.01 to 20 Hz are classified as infrasound. Persistent signal sources are useful as ground truth data for the study of atmospheric infrasound signal propagation, identification of manmade versus naturally occurring seismic sources, and other studies. By using signals emanating from the same location, propagation studies, for example, can be conducted using a variety of atmospheric conditions, leading to improvements to the modeling process for eventual use where the source is not known. We present results from several studies to identify ground truth sources using both seismic and infrasound data.

SAGE ground truth plan: Correlative measurements for the Stratospheric Aerosol and Gas Experiment (SAGE) on the AEM-B satellite

NASA Technical Reports Server (NTRS)

Russell, P. B. (Editor); Cunnold, D. M.; Grams, G. W.; Laver, J.; Mccormick, M. P.; Mcmaster, L. R.; Murcray, D. G.; Pepin, T. J.; Perry, T. W.; Planet, W. G.

1979-01-01

The ground truth plan is outlined for correlative measurements to validate the Stratospheric Aerosol and Gas Experiment (SAGE) sensor data. SAGE will fly aboard the Applications Explorer Mission-B satellite scheduled for launch in early 1979 and measure stratospheric vertical profiles of aerosol, ozone, nitrogen dioxide, and molecular extinction between 79 N and 79 S. latitude. The plan gives details of the location and times for the simultaneous satellite/correlative measurements for the nominal launch time, the rationale and choice of the correlative sensors, their characteristics and expected accuracies, and the conversion of their data to extinction profiles. In addition, an overview of the SAGE expected instrument performance and data inversion results are presented. Various atmospheric models representative of stratospheric aerosols and ozone are used in the SAGE and correlative sensor analyses.

Comparing Eyewitness-Derived Trajectories of Bright Meteors to Ground Truth Data

NASA Technical Reports Server (NTRS)

Moser, D. E.

2016-01-01

The NASA Meteoroid Environment Office is a US government agency tasked with analyzing meteors of public interest. When queried about a meteor observed over the United States, the MEO must respond with a characterization of the trajectory, orbit, and size within a few hours. If the event is outside meteor network coverage and there is no imagery recorded by the public, a timely assessment can be difficult if not impossible. In this situation, visual reports made by eyewitnesses may be the only resource available. This has led to the development of a tool to quickly calculate crude meteor trajectories from eyewitness reports made to the American Meteor Society. A description of the tool, example case studies, and a comparison to ground truth data observed by the NASA All Sky Fireball Network are presented.

A real-time freehand ultrasound calibration system with automatic accuracy feedback and control.

PubMed

Chen, Thomas Kuiran; Thurston, Adrian D; Ellis, Randy E; Abolmaesumi, Purang

2009-01-01

This article describes a fully automatic, real-time, freehand ultrasound calibration system. The system was designed to be simple and sterilizable, intended for operating-room usage. The calibration system employed an automatic-error-retrieval and accuracy-control mechanism based on a set of ground-truth data. Extensive validations were conducted on a data set of 10,000 images in 50 independent calibration trials to thoroughly investigate the accuracy, robustness, and performance of the calibration system. On average, the calibration accuracy (measured in three-dimensional reconstruction error against a known ground truth) of all 50 trials was 0.66 mm. In addition, the calibration errors converged to submillimeter in 98% of all trials within 12.5 s on average. Overall, the calibration system was able to consistently, efficiently and robustly achieve high calibration accuracy with real-time performance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markel, D; Levesque, I R; Research Institute of the McGill University Health Centre, Montreal, QC

Segmentation and registration of medical imaging data are two processes that can be integrated (a process termed regmentation) to iteratively reinforce each other, potentially improving efficiency and overall accuracy. A significant challenge is presented when attempting to validate the joint process particularly with regards to minimizing geometric uncertainties associated with the ground truth while maintaining anatomical realism. This work demonstrates a 4D MRI, PET, and CT compatible tissue phantom with a known ground truth for evaluating registration and segmentation accuracy. The phantom consists of a preserved swine lung connected to an air pump via a PVC tube for inflation. Mockmore » tumors were constructed from sea sponges contained within two vacuum-sealed compartments with catheters running into each one for injection of radiotracer solution. The phantom was scanned using a GE Discovery-ST PET/CT scanner and a 0.23T Phillips MRI, and resulted in anatomically realistic images. A bifurcation tracking algorithm was implemented to provide a ground truth for evaluating registration accuracy. This algorithm was validated using known deformations of up to 7.8 cm using a separate CT scan of a human thorax. Using the known deformation vectors to compare against, 76 bifurcation points were selected. The tracking accuracy was found to have maximum mean errors of −0.94, 0.79 and −0.57 voxels in the left-right, anterior-posterior and inferior-superior directions, respectively. A pneumatic control system is under development to match the respiratory profile of the lungs to a breathing trace from an individual patient.« less

The verification of lightning location accuracy in Finland deduced from lightning strikes to trees

NASA Astrophysics Data System (ADS)

Mäkelä, Antti; Mäkelä, Jakke; Haapalainen, Jussi; Porjo, Niko

2016-05-01

We present a new method to determine the ground truth and accuracy of lightning location systems (LLS), using natural lightning strikes to trees. Observations of strikes to trees are being collected with a Web-based survey tool at the Finnish Meteorological Institute. Since the Finnish thunderstorms tend to have on average a low flash rate, it is often possible to identify from the LLS data unambiguously the stroke that caused damage to a given tree. The coordinates of the tree are then the ground truth for that stroke. The technique has clear advantages over other methods used to determine the ground truth. Instrumented towers and rocket launches measure upward-propagating lightning. Video and audio records, even with triangulation, are rarely capable of high accuracy. We present data for 36 quality-controlled tree strikes in the years 2007-2008. We show that the average inaccuracy of the lightning location network for that period was 600 m. In addition, we show that the 50% confidence ellipse calculated by the lightning location network and used operationally for describing the location accuracy is physically meaningful: half of all the strikes were located within the uncertainty ellipse of the nearest recorded stroke. Using tree strike data thus allows not only the accuracy of the LLS to be estimated but also the reliability of the uncertainty ellipse. To our knowledge, this method has not been attempted before for natural lightning.

Evaluation metrics for bone segmentation in ultrasound

NASA Astrophysics Data System (ADS)

Lougheed, Matthew; Fichtinger, Gabor; Ungi, Tamas

2015-03-01

Tracked ultrasound is a safe alternative to X-ray for imaging bones. The interpretation of bony structures is challenging as ultrasound has no specific intensity characteristic of bones. Several image segmentation algorithms have been devised to identify bony structures. We propose an open-source framework that would aid in the development and comparison of such algorithms by quantitatively measuring segmentation performance in the ultrasound images. True-positive and false-negative metrics used in the framework quantify algorithm performance based on correctly segmented bone and correctly segmented boneless regions. Ground-truth for these metrics are defined manually and along with the corresponding automatically segmented image are used for the performance analysis. Manually created ground truth tests were generated to verify the accuracy of the analysis. Further evaluation metrics for determining average performance per slide and standard deviation are considered. The metrics provide a means of evaluating accuracy of frames along the length of a volume. This would aid in assessing the accuracy of the volume itself and the approach to image acquisition (positioning and frequency of frame). The framework was implemented as an open-source module of the 3D Slicer platform. The ground truth tests verified that the framework correctly calculates the implemented metrics. The developed framework provides a convenient way to evaluate bone segmentation algorithms. The implementation fits in a widely used application for segmentation algorithm prototyping. Future algorithm development will benefit by monitoring the effects of adjustments to an algorithm in a standard evaluation framework.

Validation of neural spike sorting algorithms without ground-truth information.

PubMed

Barnett, Alex H; Magland, Jeremy F; Greengard, Leslie F

2016-05-01

The throughput of electrophysiological recording is growing rapidly, allowing thousands of simultaneous channels, and there is a growing variety of spike sorting algorithms designed to extract neural firing events from such data. This creates an urgent need for standardized, automatic evaluation of the quality of neural units output by such algorithms. We introduce a suite of validation metrics that assess the credibility of a given automatic spike sorting algorithm applied to a given dataset. By rerunning the spike sorter two or more times, the metrics measure stability under various perturbations consistent with variations in the data itself, making no assumptions about the internal workings of the algorithm, and minimal assumptions about the noise. We illustrate the new metrics on standard sorting algorithms applied to both in vivo and ex vivo recordings, including a time series with overlapping spikes. We compare the metrics to existing quality measures, and to ground-truth accuracy in simulated time series. We provide a software implementation. Metrics have until now relied on ground-truth, simulated data, internal algorithm variables (e.g. cluster separation), or refractory violations. By contrast, by standardizing the interface, our metrics assess the reliability of any automatic algorithm without reference to internal variables (e.g. feature space) or physiological criteria. Stability is a prerequisite for reproducibility of results. Such metrics could reduce the significant human labor currently spent on validation, and should form an essential part of large-scale automated spike sorting and systematic benchmarking of algorithms. Copyright © 2016 Elsevier B.V. All rights reserved.

Simulation of bright-field microscopy images depicting pap-smear specimen

PubMed Central

Malm, Patrik; Brun, Anders; Bengtsson, Ewert

2015-01-01

As digital imaging is becoming a fundamental part of medical and biomedical research, the demand for computer-based evaluation using advanced image analysis is becoming an integral part of many research projects. A common problem when developing new image analysis algorithms is the need of large datasets with ground truth on which the algorithms can be tested and optimized. Generating such datasets is often tedious and introduces subjectivity and interindividual and intraindividual variations. An alternative to manually created ground-truth data is to generate synthetic images where the ground truth is known. The challenge then is to make the images sufficiently similar to the real ones to be useful in algorithm development. One of the first and most widely studied medical image analysis tasks is to automate screening for cervical cancer through Pap-smear analysis. As part of an effort to develop a new generation cervical cancer screening system, we have developed a framework for the creation of realistic synthetic bright-field microscopy images that can be used for algorithm development and benchmarking. The resulting framework has been assessed through a visual evaluation by experts with extensive experience of Pap-smear images. The results show that images produced using our described methods are realistic enough to be mistaken for real microscopy images. The developed simulation framework is very flexible and can be modified to mimic many other types of bright-field microscopy images. © 2015 The Authors. Published by Wiley Periodicals, Inc. on behalf of ISAC PMID:25573002

Technical Note: A new zeolite PET phantom to test segmentation algorithms on heterogeneous activity distributions featured with ground-truth contours.

PubMed

Soffientini, Chiara D; De Bernardi, Elisabetta; Casati, Rosangela; Baselli, Giuseppe; Zito, Felicia

2017-01-01

Design, realization, scan, and characterization of a phantom for PET Automatic Segmentation (PET-AS) assessment are presented. Radioactive zeolites immersed in a radioactive heterogeneous background simulate realistic wall-less lesions with known irregular shape and known homogeneous or heterogeneous internal activity. Three different zeolite families were evaluated in terms of radioactive uptake homogeneity, necessary to define activity and contour ground truth. Heterogeneous lesions were simulated by the perfect matching of two portions of a broken zeolite, soaked in two different 18 F-FDG radioactive solutions. Heterogeneous backgrounds were obtained with tissue paper balls and sponge pieces immersed into radioactive solutions. Natural clinoptilolite proved to be the most suitable zeolite for the construction of artificial objects mimicking homogeneous and heterogeneous uptakes in 18 F-FDG PET lesions. Heterogeneous backgrounds showed a coefficient of variation equal to 269% and 443% of a uniform radioactive solution. Assembled phantom included eight lesions with volumes ranging from 1.86 to 7.24 ml and lesion to background contrasts ranging from 4.8:1 to 21.7:1. A novel phantom for the evaluation of PET-AS algorithms was developed. It is provided with both reference contours and activity ground truth, and it covers a wide range of volumes and lesion to background contrasts. The dataset is open to the community of PET-AS developers and utilizers. © 2016 American Association of Physicists in Medicine.

Comparing brain graphs in which nodes are regions of interest or independent components: A simulation study.

PubMed

Yu, Qingbao; Du, Yuhui; Chen, Jiayu; He, Hao; Sui, Jing; Pearlson, Godfrey; Calhoun, Vince D

2017-11-01

A key challenge in building a brain graph using fMRI data is how to define the nodes. Spatial brain components estimated by independent components analysis (ICA) and regions of interest (ROIs) determined by brain atlas are two popular methods to define nodes in brain graphs. It is difficult to evaluate which method is better in real fMRI data. Here we perform a simulation study and evaluate the accuracies of a few graph metrics in graphs with nodes of ICA components, ROIs, or modified ROIs in four simulation scenarios. Graph measures with ICA nodes are more accurate than graphs with ROI nodes in all cases. Graph measures with modified ROI nodes are modulated by artifacts. The correlations of graph metrics across subjects between graphs with ICA nodes and ground truth are higher than the correlations between graphs with ROI nodes and ground truth in scenarios with large overlapped spatial sources. Moreover, moving the location of ROIs would largely decrease the correlations in all scenarios. Evaluating graphs with different nodes is promising in simulated data rather than real data because different scenarios can be simulated and measures of different graphs can be compared with a known ground truth. Since ROIs defined using brain atlas may not correspond well to real functional boundaries, overall findings of this work suggest that it is more appropriate to define nodes using data-driven ICA than ROI approaches in real fMRI data. Copyright © 2017 Elsevier B.V. All rights reserved.

An Efficient and Examinable Illegal Fallow Fields Detecting Method with Spatio-Temporal Information Integration

NASA Astrophysics Data System (ADS)

Chang, Chia-Hao; Chu, Tzu-How

2017-04-01

To control the rice production and farm usage in Taiwan, Agriculture and Food Agency (AFA) has published a series of policies to subsidize farmers to plant different crops or to practice fallow science 1983. Because of no efficient and examinable mechanism to verify the fallow fields surveyed by township office, illegal fallow fields were still repeated each year. In this research, we used remote sensing images, GIS data of Fields, and application records of fallow fields to establish an illegal fallow fields detecting method in Yulin County in central Taiwan. This method included: 1. collected multi-temporal images from FS-2 or SPOT series with 4 time periods; 2. combined the application records and GIS data of fields to verify the location of fallow fields; 3. conducted ground truth survey and classified images with ISODATA and Maximum Likelihood Classification (MLC); 4. defined the land cover type of fallow fields by zonal statistic; 5. verified accuracy with ground truth; 6. developed potential illegal fallow fields survey method and benefit estimation. We use 190 fallow fields with 127 legal and 63 illegal as ground truth and accuracies of illegal fallow field interpretation in producer and user are 71.43% and 38.46%. If township office surveyed 117 classified illegal fallow fields, 45 of 63 illegal fallow fields will be detected. By using our method, township office can save 38.42% of the manpower to detect illegal fallow fields and receive an examinable 71.43% producer accuracy.

Isolated effect of geometry on mitral valve function for in silico model development.

PubMed

Siefert, Andrew William; Rabbah, Jean-Pierre Michel; Saikrishnan, Neelakantan; Kunzelman, Karyn Susanne; Yoganathan, Ajit Prithivaraj

2015-01-01

Computational models for the heart's mitral valve (MV) exhibit several uncertainties that may be reduced by further developing these models using ground-truth data-sets. This study generated a ground-truth data-set by quantifying the effects of isolated mitral annular flattening, symmetric annular dilatation, symmetric papillary muscle (PM) displacement and asymmetric PM displacement on leaflet coaptation, mitral regurgitation (MR) and anterior leaflet strain. MVs were mounted in an in vitro left heart simulator and tested under pulsatile haemodynamics. Mitral leaflet coaptation length, coaptation depth, tenting area, MR volume, MR jet direction and anterior leaflet strain in the radial and circumferential directions were successfully quantified at increasing levels of geometric distortion. From these data, increase in the levels of isolated PM displacement resulted in the greatest mean change in coaptation depth (70% increase), tenting area (150% increase) and radial leaflet strain (37% increase) while annular dilatation resulted in the largest mean change in coaptation length (50% decrease) and regurgitation volume (134% increase). Regurgitant jets were centrally located for symmetric annular dilatation and symmetric PM displacement. Asymmetric PM displacement resulted in asymmetrically directed jets. Peak changes in anterior leaflet strain in the circumferential direction were smaller and exhibited non-significant differences across the tested conditions. When used together, this ground-truth data-set may be used to parametrically evaluate and develop modelling assumptions for both the MV leaflets and subvalvular apparatus. This novel data may improve MV computational models and provide a platform for the development of future surgical planning tools.

Local involvement in measuring and governing carbon stocks in China, Vietnam, Indonesia and Laos

Treesearch

Michael Køie Poulsen

2013-01-01

An important element of MRV is to ensure accurate measurements of carbon stocks. Measuring trees on the ground may be needed for ground truthing of remote sensing results. It can also provide more accurate carbon stock monitoring than remote sensing alone. Local involvement in measuring trees for monitoring of carbon stocks may be advantageous in several ways....

Methodology for Calculating Latency of GPS Probe Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhongxiang; Hamedi, Masoud; Young, Stanley

Crowdsourced GPS probe data, such as travel time on changeable-message signs and incident detection, have been gaining popularity in recent years as a source for real-time traffic information to driver operations and transportation systems management and operations. Efforts have been made to evaluate the quality of such data from different perspectives. Although such crowdsourced data are already in widespread use in many states, particularly the high traffic areas on the Eastern seaboard, concerns about latency - the time between traffic being perturbed as a result of an incident and reflection of the disturbance in the outsourced data feed - havemore » escalated in importance. Latency is critical for the accuracy of real-time operations, emergency response, and traveler information systems. This paper offers a methodology for measuring probe data latency regarding a selected reference source. Although Bluetooth reidentification data are used as the reference source, the methodology can be applied to any other ground truth data source of choice. The core of the methodology is an algorithm for maximum pattern matching that works with three fitness objectives. To test the methodology, sample field reference data were collected on multiple freeway segments for a 2-week period by using portable Bluetooth sensors as ground truth. Equivalent GPS probe data were obtained from a private vendor, and their latency was evaluated. Latency at different times of the day, impact of road segmentation scheme on latency, and sensitivity of the latency to both speed-slowdown and recovery-from-slowdown episodes are also discussed.« less

Automatic segmentation of Leishmania parasite in microscopic images using a modified CV level set method

NASA Astrophysics Data System (ADS)

Farahi, Maria; Rabbani, Hossein; Talebi, Ardeshir; Sarrafzadeh, Omid; Ensafi, Shahab

2015-12-01

Visceral Leishmaniasis is a parasitic disease that affects liver, spleen and bone marrow. According to World Health Organization report, definitive diagnosis is possible just by direct observation of the Leishman body in the microscopic image taken from bone marrow samples. We utilize morphological and CV level set method to segment Leishman bodies in digital color microscopic images captured from bone marrow samples. Linear contrast stretching method is used for image enhancement and morphological method is applied to determine the parasite regions and wipe up unwanted objects. Modified global and local CV level set methods are proposed for segmentation and a shape based stopping factor is used to hasten the algorithm. Manual segmentation is considered as ground truth to evaluate the proposed method. This method is tested on 28 samples and achieved 10.90% mean of segmentation error for global model and 9.76% for local model.

Subsurface Organics in Aseptic Cores From the MARTE Robotic Drilling Experiment: Ground truth and Contamination Issues

NASA Astrophysics Data System (ADS)

Bonaccorsi, R.; Stoker, C. R.

2006-12-01

The subsurface is the key environment for searching for life on planets lacking surface life. This includes the search for past/present life on Mars where possible subsurface life could exist [1]. The Mars-Analog-Rio-Tinto-Experiment (MARTE) performed a simulation of a Mars robotic drilling at the RT Borehole#7 Site ~6.07m, atop a massive-pyrite deposit from the Iberian Pyritic Belt. The RT site is considered an important analog of Sinus Meridiani on Mars, an ideal model analog for a subsurface Martian setting [2], and a relevant example of deep subsurface microbial community including aerobic and anaerobic chemoautotrophs [4-5]. Searching for microbes or bulk organics of biological origin in a subsurface sample from a planet is a key scientific objective of Robotic drilling missions. During the 2005 Field experiment 28 minicores were robotically handled and subsampled for life detection experiments under anti-contamination protocols. Ground truth included visual observation of cores and lab based Elemental and Isotope Ratios Mass Spectrometry analysis (EA-IRMS) of bulk organics in Hematite and Gohetite-rich gossanized tuffs, gossan and clay layers within 0-6m-depth. C-org and N-tot vary up to four orders of magnitude among the litter (~11Wt%, 0-1cm) and the mineralized (~3Wt%, 1-3cm) layers, and the first 6 m-depth (C-org=0.02-0.38Wt%). Overall, the distribution/ preservation of plant and soil-derived organics (d13C-org = 26 per mil to 24 per mil) is ten times higher (C-org=0.33Wt%) that in hematite-poor clays, or where rootlets are present, than in hematite- rich samples (C-org=<0.01Wt%). This is consistent with ATP assay (Lightning-MVP, Biocontrol) for total biomass in subsurface (Borehole#7 ~6.07m, ~avg. 153RLU) vs. surface soil samples (~1,500-81,449RLU) [5]. However, the in-situ ATP assay failed in detecting presence of roots during the in-situ life detection experiment. Furthermore, cm-sized roots were overlooked during remote observations. Finally, ATP Luminometry provided insights for potential contamination from core-handling and environmental dust loadings on cleaned/sterilized control surfaces (e.g., 6,782-36,243RLU/cm2). Cleanliness/sterility can be maintained by applying a simple sterile protocol under field conditions. Science results from this research will support future Astrobiology driven drilling mission planned on Mars. Specifically, ground truth offers relevant insights to assess strengths and limits of in-situ/remote observations vs. laboratory measurements. Results from this experiment will also aid the debate on advantages/ disadvantages of manned vs. robotic drilling missions on Mars or other planets. [1] Boston et al., 1997; [2] http://marte.arc.nasa.gov; [3] Stoker, C., et al., 2006 AbSciCon, [4] Stoker et al., submitted; [5] Bonaccorsi., et al., 2006 AbSciCon.

A 868MHz-based wireless sensor network for ground truthing of soil moisture for a hyperspectral remote sensing campaign - design and preliminary results

NASA Astrophysics Data System (ADS)

Näthe, Paul; Becker, Rolf

2014-05-01

Soil moisture and plant available water are important environmental parameters that affect plant growth and crop yield. Hence, they are significant parameters for vegetation monitoring and precision agriculture. However, validation through ground-based soil moisture measurements is necessary for accessing soil moisture, plant canopy temperature, soil temperature and soil roughness with airborne hyperspectral imaging systems in a corresponding hyperspectral imaging campaign as a part of the INTERREG IV A-Project SMART INSPECTORS. At this point, commercially available sensors for matric potential, plant available water and volumetric water content are utilized for automated measurements with smart sensor nodes which are developed on the basis of open-source 868MHz radio modules, featuring a full-scale microcontroller unit that allows an autarkic operation of the sensor nodes on batteries in the field. The generated data from each of these sensor nodes is transferred wirelessly with an open-source protocol to a central node, the so-called "gateway". This gateway collects, interprets and buffers the sensor readings and, eventually, pushes the data-time series onto a server-based database. The entire data processing chain from the sensor reading to the final storage of data-time series on a server is realized with open-source hardware and software in such a way that the recorded data can be accessed from anywhere through the internet. It will be presented how this open-source based wireless sensor network is developed and specified for the application of ground truthing. In addition, the system's perspectives and potentials with respect to usability and applicability for vegetation monitoring and precision agriculture shall be pointed out. Regarding the corresponding hyperspectral imaging campaign, results from ground measurements will be discussed in terms of their contributing aspects to the remote sensing system. Finally, the significance of the wireless sensor network for the application of ground truthing shall be determined.

Comparison of manual and automatic segmentation methods for brain structures in the presence of space-occupying lesions: a multi-expert study

PubMed Central

Deeley, M A; Chen, A; Datteri, R; Noble, J; Cmelak, A; Donnelly, E; Malcolm, A; Moretti, L; Jaboin, J; Niermann, K; Yang, Eddy S; Yu, David S; Yei, F; Koyama, T; Ding, G X; Dawant, B M

2011-01-01

The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, of 20 patients who underwent therapy for large space-occupying tumors. Performance variability was assessed through three geometric measures: volume, Dice similarity coefficient, and Euclidean distance. In addition, two simulated ground truth segmentations were calculated via the simultaneous truth and performance level estimation (STAPLE) algorithm and a novel application of probability maps. The experts and automatic system were found to generate structures of similar volume, though the experts exhibited higher variation with respect to tubular structures. No difference was found between the mean Dice coefficient (DSC) of the automatic and expert delineations as a group at a 5% significance level over all cases and organs. The larger structures of the brainstem and eyes exhibited mean DSC of approximately 0.8–0.9, whereas the tubular chiasm and nerves were lower, approximately 0.4–0.5. Similarly low DSC have been reported previously without the context of several experts and patient volumes. This study, however, provides evidence that experts are similarly challenged. The average maximum distances (maximum inside, maximum outside) from a simulated ground truth ranged from (−4.3, +5.4) mm for the automatic system to (−3.9, +7.5) mm for the experts considered as a group. Over all the structures in a rank of true positive rates at a 2 mm threshold from the simulated ground truth, the automatic system ranked second of the nine raters. This work underscores the need for large scale studies utilizing statistically robust numbers of patients and experts in evaluating quality of automatic algorithms. PMID:21725140

Comparison of manual and automatic segmentation methods for brain structures in the presence of space-occupying lesions: a multi-expert study

NASA Astrophysics Data System (ADS)

Deeley, M. A.; Chen, A.; Datteri, R.; Noble, J. H.; Cmelak, A. J.; Donnelly, E. F.; Malcolm, A. W.; Moretti, L.; Jaboin, J.; Niermann, K.; Yang, Eddy S.; Yu, David S.; Yei, F.; Koyama, T.; Ding, G. X.; Dawant, B. M.

2011-07-01

The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, of 20 patients who underwent therapy for large space-occupying tumors. Performance variability was assessed through three geometric measures: volume, Dice similarity coefficient, and Euclidean distance. In addition, two simulated ground truth segmentations were calculated via the simultaneous truth and performance level estimation algorithm and a novel application of probability maps. The experts and automatic system were found to generate structures of similar volume, though the experts exhibited higher variation with respect to tubular structures. No difference was found between the mean Dice similarity coefficient (DSC) of the automatic and expert delineations as a group at a 5% significance level over all cases and organs. The larger structures of the brainstem and eyes exhibited mean DSC of approximately 0.8-0.9, whereas the tubular chiasm and nerves were lower, approximately 0.4-0.5. Similarly low DSCs have been reported previously without the context of several experts and patient volumes. This study, however, provides evidence that experts are similarly challenged. The average maximum distances (maximum inside, maximum outside) from a simulated ground truth ranged from (-4.3, +5.4) mm for the automatic system to (-3.9, +7.5) mm for the experts considered as a group. Over all the structures in a rank of true positive rates at a 2 mm threshold from the simulated ground truth, the automatic system ranked second of the nine raters. This work underscores the need for large scale studies utilizing statistically robust numbers of patients and experts in evaluating quality of automatic algorithms.

Automated quantification of renal interstitial fibrosis for computer-aided diagnosis: A comprehensive tissue structure segmentation method.

PubMed

Tey, Wei Keat; Kuang, Ye Chow; Ooi, Melanie Po-Leen; Khoo, Joon Joon

2018-03-01

Interstitial fibrosis in renal biopsy samples is a scarring tissue structure that may be visually quantified by pathologists as an indicator to the presence and extent of chronic kidney disease. The standard method of quantification by visual evaluation presents reproducibility issues in the diagnoses. This study proposes an automated quantification system for measuring the amount of interstitial fibrosis in renal biopsy images as a consistent basis of comparison among pathologists. The system extracts and segments the renal tissue structures based on colour information and structural assumptions of the tissue structures. The regions in the biopsy representing the interstitial fibrosis are deduced through the elimination of non-interstitial fibrosis structures from the biopsy area and quantified as a percentage of the total area of the biopsy sample. A ground truth image dataset has been manually prepared by consulting an experienced pathologist for the validation of the segmentation algorithms. The results from experiments involving experienced pathologists have demonstrated a good correlation in quantification result between the automated system and the pathologists' visual evaluation. Experiments investigating the variability in pathologists also proved the automated quantification error rate to be on par with the average intra-observer variability in pathologists' quantification. Interstitial fibrosis in renal biopsy samples is a scarring tissue structure that may be visually quantified by pathologists as an indicator to the presence and extent of chronic kidney disease. The standard method of quantification by visual evaluation presents reproducibility issues in the diagnoses due to the uncertainties in human judgement. An automated quantification system for accurately measuring the amount of interstitial fibrosis in renal biopsy images is presented as a consistent basis of comparison among pathologists. The system identifies the renal tissue structures through knowledge-based rules employing colour space transformations and structural features extraction from the images. In particular, the renal glomerulus identification is based on a multiscale textural feature analysis and a support vector machine. The regions in the biopsy representing interstitial fibrosis are deduced through the elimination of non-interstitial fibrosis structures from the biopsy area. The experiments conducted evaluate the system in terms of quantification accuracy, intra- and inter-observer variability in visual quantification by pathologists, and the effect introduced by the automated quantification system on the pathologists' diagnosis. A 40-image ground truth dataset has been manually prepared by consulting an experienced pathologist for the validation of the segmentation algorithms. The results from experiments involving experienced pathologists have demonstrated an average error of 9 percentage points in quantification result between the automated system and the pathologists' visual evaluation. Experiments investigating the variability in pathologists involving samples from 70 kidney patients also proved the automated quantification error rate to be on par with the average intra-observer variability in pathologists' quantification. The accuracy of the proposed quantification system has been validated with the ground truth dataset and compared against the pathologists' quantification results. It has been shown that the correlation between different pathologists' estimation of interstitial fibrosis area has significantly improved, demonstrating the effectiveness of the quantification system as a diagnostic aide. Copyright © 2017 Elsevier B.V. All rights reserved.

A Mobile Asteroid Surface Scout (MASCOT) for the Hayabusa 2 Mission to 1999 JU3: The Scientific Approach

NASA Astrophysics Data System (ADS)

Jaumann, Ralf; Bibring, Jean-Piere; Glassmeier, Karl-Heiz; Grott, Mathias; Ho, Tra-Mi; Ulamec, Stefan; Schmitz, Nicole; Auster, Ulrich; Biele, Jens; Kuninaka, Hitoshi; Okada, Tatsuaki; Yoshikawa, Makoto; Watanabe, Sei-ichiro; Fujimoto, Masaki; Spohn, Tilman; Koncz, Aalexander; Hercik, Davis; Michaelis, Harald

2015-04-01

MASCOT, a Mobile Asteroid Surface Scout, will support JAXA's Hayabusa 2 mission to investigate the C-type asteroid 1999 JU3 (1). The German Aer-ospace Center (DLR) develops MASCOT with contributions from CNES (France) (2,3,4). Main objective is to in-situ map the asteroid's geomorphol-ogy, the intimate mixture, texture and composition of the regolith (dust, soil and rocks), and the thermal, mechanical, and magnetic properties of the sur-face in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples. MASCOT comprises a payload of four scientific in-struments: camera, radiometer, magnetometer and hyperspectral microscope. C- and D-type asteroids hold clues to the origin of the solar system, the for-mation of planets, the origins of water and life on Earth, the protection of Earth from impacts, and resources for future human exploration. C- and D-types are dark and difficult to study from Earth, and have only been glimpsed by spacecraft. While results from recent missions (e.g., Hayabusa, NEAR (5, 6, 7)) have dramatically increased our understanding of asteroids, important questions remain open. For example, characterizing the properties of asteroid regolith in-situ would deliver important ground truth for further understanding telescopic and orbital observations and samples of such asteroids. MASCOT will descend and land on the asteroid and will change its own position up to two times by hopping. This enables measurements during descent, at the landing and hopping positions #1-3, and during hopping. Hayabusa 2 together with MASCOT launched December 3rd 2014, will arrive at 1999JU3 in 2018 and return samples back to Earth in 2020. References: (1) Vilas, F., Astronomical J. 1101-1105, 2008; (2) Ulamec, S., et al., Acta Astronautica, Vol. 93, pp. 460-466; (3) Jaumann et al., 45th LPSC, #1812, Houston; (4) Ho et al., 45th LPSC, #2535, Houston; (5) Spe-cial Issue, Science, Vol. 312 no. 5778, 2006; (6) Special Issue Science, Vol. 333 no. 6046, 2011. (7) Bell, L., Mitton, J-., Cambridge Univ. Press, 2002.

Value Orientation of Singapore Adolescents Towards Truthfulness, Justice and Compassion.

ERIC Educational Resources Information Center

Seng, SeokHoon; Siang, Low Meow; Wei, Tan Tai

This study examined the value orientation of Singapore adolescents toward the three fundamental values of truthfulness, justice, and compassion. A random sample of 315 secondary school students from 4 schools in Singapore (135 males and 180 females) completed a questionnaire, and a select sample of 19 students completed interviews about their…

Estimation of old field ecosystem biomass using low altitude imagery

NASA Technical Reports Server (NTRS)

Nor, S. M.; Safir, G.; Burton, T. M.; Hook, J. E.; Schultink, G.

1977-01-01

Color-infrared photography was used to evaluate the biomass of experimental plots in an old-field ecosystem that was treated with different levels of waste water from a sewage treatment facility. Cibachrome prints at a scale of approximately 1:1,600 produced from 35 mm color infrared slides were used to analyze density patterns using prepared tonal density scales and multicell grids registered to ground panels shown on the photograph. Correlation analyses between tonal density and vegetation biomass obtained from ground samples and harvests were carried out. Correlations between mean tonal density and harvest biomass data gave consistently high coefficients ranging from 0.530 to 0.896 at the 0.001 significance level. Corresponding multiple regression analysis resulted in higher correlation coefficients. The results of this study indicate that aerial infrared photography can be used to estimate standing crop biomass on waste water irrigated old field ecosystems. Combined with minimal ground truth data, this technique could enable managers of wastewater irrigation projects to precisely time harvest of such systems for maximal removal of nutrients in harvested biomass.

As-built design specification for PARCLS

NASA Technical Reports Server (NTRS)

Tompkins, M. A. (Principal Investigator)

1981-01-01

The PARCLS program, part of the CLASFYG package, reads a parameter file created by the CLASFYG program and a pure pixel ground truth file in order to create to classification file of three separate crop categories in universal format.

The use of Skylab data to study the early detection of insect infestations and density and distribution of host plants

NASA Technical Reports Server (NTRS)

Hart, W. G.; Ingle, S. J.; Davis, M. R.

1975-01-01

The detection of insect infestations and the density and distribution of host plants were studied using Skylab data, aerial photography and ground truth simultaneously. Additional ground truth and aerial photography were acquired between Skylab passes. Three test areas were selected: area 1, of high density citrus, was located northwest of Mission, Texas; area 2, 20 miles north of Weslaco, Texas, irrigated pastures and brush-covered land; area 3 covered the entire Lower Rio Grande Valley and adjacent areas of Mexico. A color composite picture of S-190A data showed patterns of vegetation on both sides of the Rio Grande River clearly delineating the possible avenues of entry of pest insects from Mexico into the United States or from the United States into Mexico. Vegetation that could be identified with conventional color and color IR film included: citrus, brush, sugarcane, alfalfa, irrigated and unimproved pastures.

Modeling Being "Lost": Imperfect Situation Awareness

NASA Technical Reports Server (NTRS)

Middleton, Victor E.

2011-01-01

Being "lost" is an exemplar of imperfect Situation Awareness/Situation Understanding (SA/SU) -- information/knowledge that is uncertain, incomplete, and/or just wrong. Being "lost" may be a geo-spatial condition - not knowing/being wrong about where to go or how to get there. More broadly, being "lost" can serve as a metaphor for uncertainty and/or inaccuracy - not knowing/being wrong about how one fits into a larger world view, what one wants to do, or how to do it. This paper discusses using agent based modeling (ABM) to explore imperfect SA/SU, simulating geo-spatially "lost" intelligent agents trying to navigate in a virtual world. Each agent has a unique "mental map" -- its idiosyncratic view of its geo-spatial environment. Its decisions are based on this idiosyncratic view, but behavior outcomes are based on ground truth. Consequently, the rate and degree to which an agent's expectations diverge from ground truth provide measures of that agent's SA/SU.

A system for verifying models and classification maps by extraction of information from a variety of data sources

NASA Technical Reports Server (NTRS)

Norikane, L.; Freeman, A.; Way, J.; Okonek, S.; Casey, R.

1992-01-01

Recent updates to a geographical information system (GIS) called VICAR (Video Image Communication and Retrieval)/IBIS are described. The system is designed to handle data from many different formats (vector, raster, tabular) and many different sources (models, radar images, ground truth surveys, optical images). All the data are referenced to a single georeference plane, and average or typical values for parameters defined within a polygonal region are stored in a tabular file, called an info file. The info file format allows tracking of data in time, maintenance of links between component data sets and the georeference image, conversion of pixel values to `actual' values (e.g., radar cross-section, luminance, temperature), graph plotting, data manipulation, generation of training vectors for classification algorithms, and comparison between actual measurements and model predictions (with ground truth data as input).

Estimation of vegetation cover at subpixel resolution using LANDSAT data

NASA Technical Reports Server (NTRS)

Jasinski, Michael F.; Eagleson, Peter S.

1986-01-01

The present report summarizes the various approaches relevant to estimating canopy cover at subpixel resolution. The approaches are based on physical models of radiative transfer in non-homogeneous canopies and on empirical methods. The effects of vegetation shadows and topography are examined. Simple versions of the model are tested, using the Taos, New Mexico Study Area database. Emphasis has been placed on using relatively simple models requiring only one or two bands. Although most methods require some degree of ground truth, a two-band method is investigated whereby the percent cover can be estimated without ground truth by examining the limits of the data space. Future work is proposed which will incorporate additional surface parameters into the canopy cover algorithm, such as topography, leaf area, or shadows. The method involves deriving a probability density function for the percent canopy cover based on the joint probability density function of the observed radiances.

Operation of agricultural test fields for study of stressed crops by remote sensing

NASA Technical Reports Server (NTRS)

Toler, R. W.

1974-01-01

A test site for the study of winter wheat development and collection of ERTS data was established in September of 1973. The test site is a 10 mile square area located 12.5 miles west of Amarillo, Texas on Interstate Hwy. 40, in Randall and Potter counties. The center of the area is the Southwestern Great Plains Research Center at Bushland, Texas. Within the test area all wheat fields were identified by ground truth and designated irrigated or dryland. The fields in the test area other than wheat were identified as to pasture or the crop that was grown. A ground truth area of hard red winter wheat was established west of Hale Center, Texas. Maps showing the location of winter wheat fields in excess of 40 acres in size within a 10 mile radius were supplied NASA. Satellite data was collected for this test site (ERTS-1).

Spectral reflectance measurements of plant soil combinations

NASA Technical Reports Server (NTRS)

Macleod, N. H.

1972-01-01

Field and laboratory observations of plant and soil reflectance spectra were made to develop an understanding of the reflectance of solar energy by plants and soils. A related objective is the isolation of factors contributing to the image formed by multispectral scanners and return beam vidicons carried by ERTS or film-filter combinations used in the field or on aircraft. A set of objective criteria are to be developed for identifying plant and soil types and their changing condition through the seasons for application of space imagery to resource management. This is because the global scale of earth observations satellites requires objective rather than subjective techniques, particularly where ground truth is either not available or too costly to acquire. As the acquiring of ground truth for training sets may be impractical in many cases, attempts have been made to identify objectively standard responses which could be used for image interpretation.

Using remote sensing imagery to monitoring sea surface pollution cause by abandoned gold-copper mine

NASA Astrophysics Data System (ADS)

Kao, H. M.; Ren, H.; Lee, Y. T.

2010-08-01

The Chinkuashih Benshen mine was the largest gold-copper mine in Taiwan before the owner had abandoned the mine in 1987. However, even the mine had been closed, the mineral still interacts with rain and underground water and flowed into the sea. The polluted sea surface had appeared yellow, green and even white color, and the pollutants had carried by the coast current. In this study, we used the optical satellite images to monitoring the sea surface. Several image processing algorithms are employed especial the subpixel technique and linear mixture model to estimate the concentration of pollutants. The change detection approach is also applied to track them. We also conduct the chemical analysis of the polluted water to provide the ground truth validation. By the correlation analysis between the satellite observation and the ground truth chemical analysis, an effective approach to monitoring water pollution could be established.

Vehicle detection and orientation estimation using the radon transform

NASA Astrophysics Data System (ADS)

Pelapur, Rengarajan; Bunyak, Filiz; Palaniappan, Kannappan; Seetharaman, Gunasekaran

2013-05-01

Determining the location and orientation of vehicles in satellite and airborne imagery is a challenging task given the density of cars and other vehicles and complexity of the environment in urban scenes almost anywhere in the world. We have developed a robust and accurate method for detecting vehicles using a template-based directional chamfer matching, combined with vehicle orientation estimation based on a refined segmentation, followed by a Radon transform based profile variance peak analysis approach. The same algorithm was applied to both high resolution satellite imagery and wide area aerial imagery and initial results show robustness to illumination changes and geometric appearance distortions. Nearly 80% of the orientation angle estimates for 1585 vehicles across both satellite and aerial imagery were accurate to within 15? of the ground truth. In the case of satellite imagery alone, nearly 90% of the objects have an estimated error within +/-1.0° of the ground truth.

Using Multi-Dimensional Microwave Remote Sensing Information for the Retrieval of Soil Surface Roughness

NASA Astrophysics Data System (ADS)

Marzahn, P.; Ludwig, R.

2016-06-01

In this Paper the potential of multi parametric polarimetric SAR (PolSAR) data for soil surface roughness estimation is investigated and its potential for hydrological modeling is evaluated. The study utilizes microwave backscatter collected from the Demmin testsite in the North-East Germany during AgriSAR 2006 campaign using fully polarimetric L-Band airborne SAR data. For ground truthing extensive soil surface roughness in addition to various other soil physical properties measurements were carried out using photogrammetric image matching techniques. The correlation between ground truth roughness indices and three well established polarimetric roughness estimators showed only good results for Re[ρRRLL] and the RMS Height s. Results in form of multitemporal roughness maps showed only satisfying results due to the fact that the presence and development of particular plants affected the derivation. However roughness derivation for bare soil surfaces showed promising results.

Evaluation of algorithms for estimating wheat acreage from multispectral scanner data. [Kansas and Texas

NASA Technical Reports Server (NTRS)

Nalepka, R. F. (Principal Investigator); Richardson, W.; Pentland, A. P.

1976-01-01

The author has identified the following significant results. Fourteen different classification algorithms were tested for their ability to estimate the proportion of wheat in an area. For some algorithms, accuracy of classification in field centers was observed. The data base consisted of ground truth and LANDSAT data from 55 sections (1 x 1 mile) from five LACIE intensive test sites in Kansas and Texas. Signatures obtained from training fields selected at random from the ground truth were generally representative of the data distribution patterns. LIMMIX, an algorithm that chooses a pure signature when the data point is close enough to a signature mean and otherwise chooses the best mixture of a pair of signatures, reduced the average absolute error to 6.1% and the bias to 1.0%. QRULE run with a null test achieved a similar reduction.

Adopting a constructivist approach to grounded theory: implications for research design.

PubMed

Mills, Jane; Bonner, Ann; Francis, Karen

2006-02-01

Grounded theory is a popular research methodology that is evolving to account for a range of ontological and epistemological underpinnings. Constructivist grounded theory has its foundations in relativism and an appreciation of the multiple truths and realities of subjectivism. Undertaking a constructivist enquiry requires the adoption of a position of mutuality between researcher and participant in the research process, which necessitates a rethinking of the grounded theorist's traditional role of objective observer. Key issues for constructivist grounded theorists to consider in designing their research studies are discussed in relation to developing a partnership with participants that enables a mutual construction of meaning during interviews and a meaningful reconstruction of their stories into a grounded theory model.

Imaging complex objects using learning tomography

NASA Astrophysics Data System (ADS)

Lim, JooWon; Goy, Alexandre; Shoreh, Morteza Hasani; Unser, Michael; Psaltis, Demetri

2018-02-01

Optical diffraction tomography (ODT) can be described using the scattering process through an inhomogeneous media. An inherent nonlinearity exists relating the scattering medium and the scattered field due to multiple scattering. Multiple scattering is often assumed to be negligible in weakly scattering media. This assumption becomes invalid as the sample gets more complex resulting in distorted image reconstructions. This issue becomes very critical when we image a complex sample. Multiple scattering can be simulated using the beam propagation method (BPM) as the forward model of ODT combined with an iterative reconstruction scheme. The iterative error reduction scheme and the multi-layer structure of BPM are similar to neural networks. Therefore we refer to our imaging method as learning tomography (LT). To fairly assess the performance of LT in imaging complex samples, we compared LT with the conventional iterative linear scheme using Mie theory which provides the ground truth. We also demonstrate the capacity of LT to image complex samples using experimental data of a biological cell.

Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture

NASA Technical Reports Server (NTRS)

Rao, R. G. S.; Ulaby, F. T.

1977-01-01

The paper examines optimal sampling techniques for obtaining accurate spatial averages of soil moisture, at various depths and for cell sizes in the range 2.5-40 acres, with a minimum number of samples. Both simple random sampling and stratified sampling procedures are used to reach a set of recommended sample sizes for each depth and for each cell size. Major conclusions from statistical sampling test results are that (1) the number of samples required decreases with increasing depth; (2) when the total number of samples cannot be prespecified or the moisture in only one single layer is of interest, then a simple random sample procedure should be used which is based on the observed mean and SD for data from a single field; (3) when the total number of samples can be prespecified and the objective is to measure the soil moisture profile with depth, then stratified random sampling based on optimal allocation should be used; and (4) decreasing the sensor resolution cell size leads to fairly large decreases in samples sizes with stratified sampling procedures, whereas only a moderate decrease is obtained in simple random sampling procedures.

Influence of coherent mesoscale structures on satellite-based Doppler lidar wind measurements

NASA Technical Reports Server (NTRS)

Emmitt, G. D.; Houston, S.

1985-01-01

Efforts to develop display routines for overlaying gridded and nongridded data sets are discussed. The primary objective is to have the capability to review global patterns of winds and lidar samples; to zoom in on particular wind features or global areas; and to display contours of wind components and derived fields (e.g., divergence, vorticity, deformation, etc.). Current considerations in support of a polar orbiting shuttle lidar mission are discussed. Ground truth for a shuttle lidar experiment may be limited to fortuitous alignment of lidar wind profiles and scheduled rawinsonde profiles. Any improvement on this would require special rawinsonde launches and/or optimization of the shuttle orbit with global wind measurement networks.

Space Weathering of Itokawa Particles: Implications for Regolith Evolution

NASA Technical Reports Server (NTRS)

Berger, Eve L.; Keller, Lindsay P.

2015-01-01

Space weathering processes such as solar wind irradiation and micrometeorite impacts are known to alter the the properties of regolith materials exposed on airless bodies. The rates of space weathering processes however, are poorly constrained for asteroid regoliths, with recent estimates ranging over many orders of magnitude. The return of surface samples by JAXA's Hayabusa mission to asteroid 25143 Itokawa, and their laboratory analysis provides "ground truth" to anchor the timescales for space weathering processes on airless bodies. Here, we use the effects of solar wind irradiation and the accumulation of solar flare tracks recorded in Itokawa grains to constrain the rates of space weathering and yield information about regolith dynamics on these timescales.

The Search for Biosignatures on Mars: Using Predictive Geology to Optimize Exploration Targets

NASA Technical Reports Server (NTRS)

Oehler, Dorothy Z.; Allen, Carlton C.

2011-01-01

Predicting geologic context from satellite data is a method used on Earth for exploration in areas with limited ground truth. The method can be used to predict facies likely to contain organic-rich shales. Such shales concentrate and preserve organics and are major repositories of organic biosignatures on Earth [1]. Since current surface conditions on Mars are unfavorable for development of abundant life or for preservation of organic remains of past life, the chances are low of encountering organics in surface samples. Thus, focusing martian exploration on sites predicted to contain organic-rich shales would optimize the chances of discovering evidence of life, if it ever existed on that planet.

Volatile Analysis by Pyrolysis of Regolith (Vapor) for Planetary Resource Prospecting

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Malespin, C. A.; Ten Kate, I. L.; Mcadam, A.; Getty, S. A.; Mumm, E.; Franz, H. B.; Southard, A. E.; Bleacher, J. E.; Mahaffy, P. R.

2016-01-01

Measuring the chemical composition of planetary bodies and their atmospheres is key to understanding the formation of the Solar System and the evolution of the planets and their moons. In situ volatile measurements enable a ground-truth assessment of the distribution and abundance of resources such as water-ice and oxygen, important for a sustained human presence on the Moon and beyond. The Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument is a compact pyrolysis mass spectrometer designed to detect volatiles released from solid samples that are heated to elevated temperatures and is one technique that should be considered for resource prospecting on the Moon, Mars, and asteroids.

Ground-Truthing a Next Generation Snow Radar

NASA Astrophysics Data System (ADS)

Yan, S.; Brozena, J. M.; Gogineni, P. S.; Abelev, A.; Gardner, J. M.; Ball, D.; Liang, R.; Newman, T.

2016-12-01

During the early spring of 2016 the Naval Research Laboratory (NRL) performed a test of a next generation airborne snow radar over ground truth data collected on several areas of fast ice near Barrow, AK. The radar was developed by the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas, and includes several improvements compared to their previous snow radar. The new unit combines the earlier Ku-band and snow radars into a single unit with an operating frequency spanning the entire 2-18 GHz, an enormous bandwidth which provides the possibility of snow depth measurements with 1.5 cm range resolution. Additionally, the radar transmits on dual polarizations (H and V), and receives the signal through two orthogonally polarized Vivaldi arrays, each with 128 phase centers. The 8 sets of along-track phase centers are combined in hardware to improve SNR and narrow the beamwidth in the along-track, resulting in 8 cross-track effective phase centers which are separately digitized to allow for beam sharpening and forming in post-processing. Tilting the receive arrays 30 degrees from the horizontal also allows the formation of SAR images and the potential for estimating snow-water equivalent (SWE). Ground truth data (snow depth, density, salinity and SWE) were collected over several 60 m wide swaths that were subsequently overflown with the snow radar mounted on a Twin Otter. The radar could be operated in nadir (by beam steering the receive antennas to point beneath the aircraft) or side-looking modes. Results from the comparisons will be shown.

Automated microwave ablation therapy planning with single and multiple entry points

NASA Astrophysics Data System (ADS)

Liu, Sheena X.; Dalal, Sandeep; Kruecker, Jochen

2012-02-01

Microwave ablation (MWA) has become a recommended treatment modality for interventional cancer treatment. Compared with radiofrequency ablation (RFA), MWA provides more rapid and larger-volume tissue heating. It allows simultaneous ablation from different entry points and allows users to change the ablation size by controlling the power/time parameters. Ablation planning systems have been proposed in the past, mainly addressing the needs for RFA procedures. Thus a planning system addressing MWA-specific parameters and workflows is highly desirable to help physicians achieve better microwave ablation results. In this paper, we design and implement an automated MWA planning system that provides precise probe locations for complete coverage of tumor and margin. We model the thermal ablation lesion as an ellipsoidal object with three known radii varying with the duration of the ablation and the power supplied to the probe. The search for the best ablation coverage can be seen as an iterative optimization problem. The ablation centers are steered toward the location which minimizes both un-ablated tumor tissue and the collateral damage caused to the healthy tissue. We assess the performance of our algorithm using simulated lesions with known "ground truth" optimal coverage. The Mean Localization Error (MLE) between the computed ablation center in 3D and the ground truth ablation center achieves 1.75mm (Standard deviation of the mean (STD): 0.69mm). The Mean Radial Error (MRE) which is estimated by comparing the computed ablation radii with the ground truth radii reaches 0.64mm (STD: 0.43mm). These preliminary results demonstrate the accuracy and robustness of the described planning algorithm.

Isolated Effect of Geometry on Mitral Valve Function for In-Silico Model Development

PubMed Central

Siefert, Andrew William; Rabbah, Jean-Pierre Michel; Saikrishnan, Neelakantan; Kunzelman, Karyn Susanne; Yoganathan, Ajit Prithivaraj

2013-01-01

Computational models for the heart’s mitral valve (MV) exhibit several uncertainties which may be reduced by further developing these models using ground-truth data sets. The present study generated a ground-truth data set by quantifying the effects of isolated mitral annular flattening, symmetric annular dilatation, symmetric papillary muscle displacement, and asymmetric papillary muscle displacement on leaflet coaptation, mitral regurgitation (MR), and anterior leaflet strain. MVs were mounted in an in vitro left heart simulator and tested under pulsatile hemodynamics. Mitral leaflet coaptation length, coaptation depth, tenting area, MR volume, MR jet direction, and anterior leaflet strain in the radial and circumferential directions were successfully quantified for increasing levels of geometric distortion. From these data, increasing levels of isolated papillary muscle displacement resulted in the greatest mean change in coaptation depth (70% increase), tenting area (150% increase), and radial leaflet strain (37% increase) while annular dilatation resulted in the largest mean change in coaptation length (50% decrease) and regurgitation volume (134% increase). Regurgitant jets were centrally located for symmetric annular dilatation and symmetric papillary muscle displacement. Asymmetric papillary muscle displacement resulted in asymmetrically directed jets. Peak changes in anterior leaflet strain in the circumferential direction were smaller and exhibited non-significant differences across the tested conditions. When used together, this ground-truth data may be used to parametrically evaluate and develop modeling assumptions for both the MV leaflets and subvalvular apparatus. This novel data may improve MV computational models and provide a platform for the development of future surgical planning tools. PMID:24059354

Biometric correspondence between reface computerized facial approximations and CT-derived ground truth skin surface models objectively examined using an automated facial recognition system.

PubMed

Parks, Connie L; Monson, Keith L

2018-05-01

This study employed an automated facial recognition system as a means of objectively evaluating biometric correspondence between a ReFace facial approximation and the computed tomography (CT) derived ground truth skin surface of the same individual. High rates of biometric correspondence were observed, irrespective of rank class (R k ) or demographic cohort examined. Overall, 48% of the test subjects' ReFace approximation probes (n=96) were matched to his or her corresponding ground truth skin surface image at R 1 , a rank indicating a high degree of biometric correspondence and a potential positive identification. Identification rates improved with each successively broader rank class (R 10 =85%, R 25 =96%, and R 50 =99%), with 100% identification by R 57 . A sharp increase (39% mean increase) in identification rates was observed between R 1 and R 10 across most rank classes and demographic cohorts. In contrast, significantly lower (p<0.01) increases in identification rates were observed between R 10 and R 25 (8% mean increase) and R 25 and R 50 (3% mean increase). No significant (p>0.05) performance differences were observed across demographic cohorts or CT scan protocols. Performance measures observed in this research suggest that ReFace approximations are biometrically similar to the actual faces of the approximated individuals and, therefore, may have potential operational utility in contexts in which computerized approximations are utilized as probes in automated facial recognition systems. Copyright © 2018. Published by Elsevier B.V.

Evaluation of dual-loop data accuracy using video ground truth data

DOT National Transportation Integrated Search

2002-01-01

Washington State Department of Transportation (WSDOT) initiated a : research project entitled Monitoring Freight on Puget Sound Freeways in September : 1999. Dual-loop data from the Seattle area freeway system were selected as the main data : s...

A robust automated left ventricle region of interest localization technique using a cardiac cine MRI atlas

NASA Astrophysics Data System (ADS)

Ben-Zikri, Yehuda Kfir; Linte, Cristian A.

2016-03-01

Region of interest detection is a precursor to many medical image processing and analysis applications, including segmentation, registration and other image manipulation techniques. The optimal region of interest is often selected manually, based on empirical knowledge and features of the image dataset. However, if inconsistently identified, the selected region of interest may greatly affect the subsequent image analysis or interpretation steps, in turn leading to incomplete assessment during computer-aided diagnosis or incomplete visualization or identification of the surgical targets, if employed in the context of pre-procedural planning or image-guided interventions. Therefore, the need for robust, accurate and computationally efficient region of interest localization techniques is prevalent in many modern computer-assisted diagnosis and therapy applications. Here we propose a fully automated, robust, a priori learning-based approach that provides reliable estimates of the left and right ventricle features from cine cardiac MR images. The proposed approach leverages the temporal frame-to-frame motion extracted across a range of short axis left ventricle slice images with small training set generated from les than 10% of the population. This approach is based on histogram of oriented gradients features weighted by local intensities to first identify an initial region of interest depicting the left and right ventricles that exhibits the greatest extent of cardiac motion. This region is correlated with the homologous region that belongs to the training dataset that best matches the test image using feature vector correlation techniques. Lastly, the optimal left ventricle region of interest of the test image is identified based on the correlation of known ground truth segmentations associated with the training dataset deemed closest to the test image. The proposed approach was tested on a population of 100 patient datasets and was validated against the ground truth region of interest of the test images manually annotated by experts. This tool successfully identified a mask around the LV and RV and furthermore the minimal region of interest around the LV that fully enclosed the left ventricle from all testing datasets, yielding a 98% overlap with their corresponding ground truth. The achieved mean absolute distance error between the two contours that normalized by the radius of the ground truth is 0.20 +/- 0.09.

A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, Wendy; Ren, Lei, E-mail: lei.ren@duke.edu; Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina

Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of themore » deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR = 20. For patient data, average tracking errors were less than 2 mm in all directions for all patients. Conclusions: Preliminary studies demonstrated the feasibility of generating real-time VC-MRI for on-board localization of moving targets in radiation therapy.« less

VAS demonstration: (VISSR Atmospheric Sounder) description

NASA Technical Reports Server (NTRS)

Montgomery, H. E.; Uccellini, L. W.

1985-01-01

The VAS Demonstration (VISSR Atmospheric Sounder) is a project designed to evaluate the VAS instrument as a remote sensor of the Earth's atmosphere and surface. This report describes the instrument and ground processing system, the instrument performance, the valiation as a temperature and moisture profiler compared with ground truth and other satellites, and assesses its performance as a valuable meteorological tool. The report also addresses the availability of data for scientific research.

A Hybrid Hierarchical Approach for Brain Tissue Segmentation by Combining Brain Atlas and Least Square Support Vector Machine

PubMed Central

Kasiri, Keyvan; Kazemi, Kamran; Dehghani, Mohammad Javad; Helfroush, Mohammad Sadegh

2013-01-01

In this paper, we present a new semi-automatic brain tissue segmentation method based on a hybrid hierarchical approach that combines a brain atlas as a priori information and a least-square support vector machine (LS-SVM). The method consists of three steps. In the first two steps, the skull is removed and the cerebrospinal fluid (CSF) is extracted. These two steps are performed using the toolbox FMRIB's automated segmentation tool integrated in the FSL software (FSL-FAST) developed in Oxford Centre for functional MRI of the brain (FMRIB). Then, in the third step, the LS-SVM is used to segment grey matter (GM) and white matter (WM). The training samples for LS-SVM are selected from the registered brain atlas. The voxel intensities and spatial positions are selected as the two feature groups for training and test. SVM as a powerful discriminator is able to handle nonlinear classification problems; however, it cannot provide posterior probability. Thus, we use a sigmoid function to map the SVM output into probabilities. The proposed method is used to segment CSF, GM and WM from the simulated magnetic resonance imaging (MRI) using Brainweb MRI simulator and real data provided by Internet Brain Segmentation Repository. The semi-automatically segmented brain tissues were evaluated by comparing to the corresponding ground truth. The Dice and Jaccard similarity coefficients, sensitivity and specificity were calculated for the quantitative validation of the results. The quantitative results show that the proposed method segments brain tissues accurately with respect to corresponding ground truth. PMID:24696800

Evaluation of LANDSAT-4 TM and MSS ground geometry performance without ground control

NASA Technical Reports Server (NTRS)

Bryant, N. A.; Zobrist, A.

1983-01-01

LANDSAT thematic mapper P-data of Washington, D.C., Harrisburg, PA, and Salton Sea, CA were analyzed to determine magnitudes and causes of error in the geometric conformity of the data to known earth-surface geometry. Several tests of data geometry were performed. Intra-band and inter-band correlation and registration were investigated, exclusive of map-based ground truth. Specifically, the magnitudes and statistical trends of pixel offsets between a single band's mirror scans (due to processing procedures) were computed, and the inter-band integrity of registration was analyzed.

Composition and assembly of a spectral and agronomic data base for 1980 spring small grain segments

NASA Technical Reports Server (NTRS)

Helmer, D.; Krantz, J.; Kinsler, M.; Tomkins, M.

1983-01-01

A data set was assembled which consolidates the LANDSAT spectral data, ground truth observation data, and analyst cloud screening data for 28 spring small grain segments collected during the 1980 crop year.

A Method for Assessing Ground-Truth Accuracy of the 5DCT Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dou, Tai H., E-mail: tdou@mednet.ucla.edu; Thomas, David H.; O'Connell, Dylan P.

2015-11-15

Purpose: To develop a technique that assesses the accuracy of the breathing phase-specific volume image generation process by patient-specific breathing motion model using the original free-breathing computed tomographic (CT) scans as ground truths. Methods: Sixteen lung cancer patients underwent a previously published protocol in which 25 free-breathing fast helical CT scans were acquired with a simultaneous breathing surrogate. A patient-specific motion model was constructed based on the tissue displacements determined by a state-of-the-art deformable image registration. The first image was arbitrarily selected as the reference image. The motion model was used, along with the free-breathing phase information of the originalmore » 25 image datasets, to generate a set of deformation vector fields that mapped the reference image to the 24 nonreference images. The high-pitch helically acquired original scans served as ground truths because they captured the instantaneous tissue positions during free breathing. Image similarity between the simulated and the original scans was assessed using deformable registration that evaluated the pointwise discordance throughout the lungs. Results: Qualitative comparisons using image overlays showed excellent agreement between the simulated images and the original images. Even large 2-cm diaphragm displacements were very well modeled, as was sliding motion across the lung–chest wall boundary. The mean error across the patient cohort was 1.15 ± 0.37 mm, and the mean 95th percentile error was 2.47 ± 0.78 mm. Conclusion: The proposed ground truth–based technique provided voxel-by-voxel accuracy analysis that could identify organ-specific or tumor-specific motion modeling errors for treatment planning. Despite a large variety of breathing patterns and lung deformations during the free-breathing scanning session, the 5-dimensionl CT technique was able to accurately reproduce the original helical CT scans, suggesting its applicability to a wide range of patients.« less

Overview of SnowEx Year 1 Activities

NASA Technical Reports Server (NTRS)

Kim, Edward; Gatebe, Charles; Hall, Dorothy; Newlin, Jerry; Misakonis, Amy; Elder, Kelly; Marshall, Hans Peter; Heimstra, Chris; Brucker, Ludovic; De Marco, Eugenia;

Monitoring the vernal advancement and retrogradation (green wave effect) of natural vegetation

NASA Technical Reports Server (NTRS)

Rouse, J. W., Jr. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Preliminary evaluation of autumnal phase ground truth data suggests that the sampling procedures at the Great Plains Corridor network test sites are adequate to show relatively small temporal changes in above-ground vegetation biomass and vegetation condition. Vegetation changes measured August through December, reflect grazing intensity and environmental conditions at the test sites. Preliminary analysis of black and white imagery suggests that detail in vegetation patterns is much greater than originally anticipated. A first look analysis of single band imagery and digital data at two locations shows that woodland, grassland, and cropland areas are easily delineated. Computer derived grey-scale maps from MSS digital data were shown to be useful in identifying the location of small fields and features of the natural and cultivated lands. Single band imagery and digital data are believed to have important application for synoptic land use mapping and inventory. Initial ratio analysis, using band 5 and 7 data, suggests the applicability in the greenness of a vegetative scene.

Effects of varying soil moisture contents and vegetation canopies on microwave emissions

NASA Technical Reports Server (NTRS)

Burke, H.-H. K.; Schmugge, T. J.

1982-01-01

Results of NASA airborne passive microwave scans of bare and vegetated fields for comparison with ground truth tests are discussed and a model for atmospheric scattering of radiation by vegetation is detailed. On-board radiometers obtained data at 21, 2.8, and 1.67 cm during three passes over each of 46 fields, 28 of which were bare and the others having wheat or alfalfa. Ground-based sampling included moisture in five layers down to 15 cm in addition to soil temperature. The relationships among the brightness temperature and soil moisture, as well as the surface roughness and the vegetation canopy were examined. A model was developed for the dielectric coefficient and volume scattering for a vegetation medium. L- to C-band data were found useful for retrieving soil information directly. A surface moisture content of 5-35% yielded an emissivity of 0.9-0.7. The data agreed well with a combined multilayer radiative transfer model with simple roughness correction.

Spatial variability of summer Florida precipitation and its impact on microwave radiometer rainfall-measurement systems

NASA Technical Reports Server (NTRS)

Turner, B. J.; Austin, G. L.

1993-01-01

Three-dimensional radar data for three summer Florida storms are used as input to a microwave radiative transfer model. The model simulates microwave brightness observations by a 19-GHz, nadir-pointing, satellite-borne microwave radiometer. The statistical distribution of rainfall rates for the storms studied, and therefore the optimal conversion between microwave brightness temperatures and rainfall rates, was found to be highly sensitive to the spatial resolution at which observations were made. The optimum relation between the two quantities was less sensitive to the details of the vertical profile of precipitation. Rainfall retrievals were made for a range of microwave sensor footprint sizes. From these simulations, spatial sampling-error estimates were made for microwave radiometers over a range of field-of-view sizes. The necessity of matching the spatial resolution of ground truth to radiometer footprint size is emphasized. A strategy for the combined use of raingages, ground-based radar, microwave, and visible-infrared (VIS-IR) satellite sensors is discussed.

Using Apollo sites and soils to compositionally ground truth Diviner Lunar Radiometer observations

NASA Astrophysics Data System (ADS)

Greenhagen, B. T.; Lucey, P. G.; Song, E.; Thomas, I. R.; Bowles, N. E.; Donaldson Hanna, K. L.; Foote, E. J.; Paige, D. A.; Allen, C.

2012-12-01

Apollo landing sites and returned soils afford us a unique opportunity to "ground truth" Diviner Lunar Radiometer compositional observations, which are the first global, high resolution, thermal infrared measurements of an airless body. The Moon is the most accessible member of the most abundant class of solar system objects, which includes Mercury, asteroids, and icy satellites. And the Apollo samples returned from the Moon are the only extraterrestrial samples with known spatial context. Here we compare Diviner observations of Apollo landing sites and compositional and spectral laboratory measurements of returned Apollo soils. Diviner, onboard NASA's Lunar Reconnaissance Orbiter, has three spectral channels near 8 μm that were designed to characterize the mid-infrared emissivity maximum known as the Christiansen feature (CF), a well-studied indicator of silicate mineralogy. It has been observed that thermal infrared spectra measured in simulated lunar environment (SLE) are significantly altered from spectra measured under terrestrial or martian conditions, with enhanced CF contrast and shifted CF position relative to other spectral features. Therefore only thermal emission experiments conducted in SLE are directly comparable to Diviner data. With known compositions, Apollo landing sites and soils are important calibration points for the Diviner dataset, which includes all six Apollo sites at approximately 200 m spatial resolution. Differences in measured CFs caused by composition and space weathering are apparent in Diviner data. Analyses of Diviner observations and SLE measurements for a range of Apollo soils show good agreement, while comparisons to thermal reflectance measurements under ambient conditions do not agree well, which underscores the need for SLE measurements and validates our measurement technique. Diviner observations of Apollo landing sites are also correlated with geochemical measurements of Apollo soils from the Lunar Sample Compendium. In particular, the correlations between CF and FeO and Al2O3 are very strong, owing to the dependence on the feldspar-mafic ratio. Our analyses suggest that Diviner data may offer an independent measure of soil iron content from the existing optical and gamma-ray spectrometer datasets.

Using Apollo Sites and Soils to Compositionally Ground Truth Diviner Lunar Radiometer Observations

NASA Technical Reports Server (NTRS)

Greenhagen, Benjamin T.; Lucey, P. G.; Song, E.; Thomas, I R.; Bowles, N. E.; DonaldsonHanna, K. L.; Allen, C.; Foote, E. J.; Paige, D .A.

2012-01-01

Apollo landing sites and returned soils afford us a unique opportunity to "ground truth" Diviner Lunar Radiometer compositional observations, which are the first global, high resolution , thermal infrared measurements of an airless body. The Moon is the most accessible member of the most abundant class of solar system objects, which includes Mercury, asteroids, and icy satellites. And the Apollo samples returned from the Moon are the only extraterrestrial samples with known spatial context. Here we compare Diviner observations of Apollo landing sites and compositional and spectral laboratory measurements of returned Apollo soils. Diviner, onboard NASA's Lunar Reconnaissance Orbiter, has three spectral channels near 8 micron that were designed to characterize the mid-infrared emissivity maximum known as the Christiansen feature (CF), a well-studied indicator of silicate mineralogy. It has been observed that thermal infrared spectra measured in simulated lunar environment (SLE) are significantly altered from spectra measured under terrestrial or martian conditions, with enhanced CF contrast and shifted CF position relative to other spectral features. Therefore only thermal emission experiments conducted in SLE are directly comparable to Diviner data. With known compositions, Apollo landing sites and soils are important calibration points for the Diviner dataset, which includes all six Apollo sites at approximately 200 m spatial resolution. Differences in measured CFs caused by composition and space weathering are apparent in Diviner data. Analyses of Diviner observations and SLE measurements for a range of Apollo soils show good agreement, while comparisons to thermal reflectance measurements under ambient conditions do not agree well, which underscores the need for SLE measurements and validates our measurement technique. Diviner observations of Apollo landing sites are also correlated with geochemical measurements of Apollo soils from the Lunar Sample Compendium. In particular, the correlations between CF and FeO and AI203 are very strong, owing to the dependence on the feldspar-mafic ratio. Our analyses suggest that Diviner data may offer an independent measure of soil iron content from the existing optical and gamma-ray spectrometer datasets.

The Value of Instruction for a Commitment to Truth.

ERIC Educational Resources Information Center

Bugeja, Michael J.

1997-01-01

Describes the redesign of a media ethics course in which students analyze such topics as truth, falsehood, manipulation, temptation, unfairness, and power. Notes that students keep an ethics journal in the course, and discusses sample journal topics. (PA)

Improved Gridded Aerosol Data for India

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gueymard, C.; Sengupta, M.

Using point data from ground sites in and around India equipped with multiwavelength sunphotometers, as well as gridded data from space measurements or from existing aerosol climatologies, an improved gridded database providing the monthly aerosol optical depth at 550 nm (AOD550) and Angstrom exponent (AE) over India is produced. Data from 83 sunphotometer sites are used here as ground truth tocalibrate, optimally combine, and validate monthly gridded data during the period from 2000 to 2012.

Applying a contemporary grounded theory methodology.

PubMed

Licqurish, Sharon; Seibold, Carmel

2011-01-01

The aim of this paper is to discuss the application of a contemporary grounded theory methodology to a research project exploring the experiences of students studying for a degree in midwifery. Grounded theory is a qualitative research approach developed by Glaser and Strauss in the 1950s but the methodology for this study was modelled on Clarke's (2005) approach and was underpinned by a symbolic interactionist theoretical perspective, post-structuralist theories of Michel Foucault and a constructionist epistemology. The study participants were 19 midwifery students completing their final placement. Data were collected through individual in-depth interviews and participant observation, and analysed using the grounded theory analysis techniques of coding, constant comparative analysis and theoretical sampling, as well as situational maps. The analysis focused on social action and interaction and the operation of power in the students' environment. The social process in which the students were involved, as well as the actors and discourses that affected the students' competency development, were highlighted. The methodology allowed a thorough exploration of the students' experiences of achieving competency. However, some difficulties were encountered. One of the major issues related to the understanding and application of complex sociological theories that challenged positivist notions of truth and power. Furthermore, the mapping processes were complex. Despite these minor challenges, the authors recommend applying this methodology to other similar research projects.

Lagrange constraint neural networks for massive pixel parallel image demixing

NASA Astrophysics Data System (ADS)

Szu, Harold H.; Hsu, Charles C.

2002-03-01

We have shown that the remote sensing optical imaging to achieve detailed sub-pixel decomposition is a unique application of blind source separation (BSS) that is truly linear of far away weak signal, instantaneous speed of light without delay, and along the line of sight without multiple paths. In early papers, we have presented a direct application of statistical mechanical de-mixing method called Lagrange Constraint Neural Network (LCNN). While the BSAO algorithm (using a posteriori MaxEnt ANN and neighborhood pixel average) is not acceptable for remote sensing, a mirror symmetric LCNN approach is all right assuming a priori MaxEnt for unknown sources to be averaged over the source statistics (not neighborhood pixel data) in a pixel-by-pixel independent fashion. LCNN reduces the computation complexity, save a great number of memory devices, and cut the cost of implementation. The Landsat system is designed to measure the radiation to deduce surface conditions and materials. For any given material, the amount of emitted and reflected radiation varies by the wavelength. In practice, a single pixel of a Landsat image has seven channels receiving 0.1 to 12 microns of radiation from the ground within a 20x20 meter footprint containing a variety of radiation materials. A-priori LCNN algorithm provides the spatial-temporal variation of mixture that is hardly de-mixable by other a-posteriori BSS or ICA methods. We have already compared the Landsat remote sensing using both methods in WCCI 2002 Hawaii. Unfortunately the absolute benchmark is not possible because of lacking of the ground truth. We will arbitrarily mix two incoherent sampled images as the ground truth. However, the constant total probability of co-located sources within the pixel footprint is necessary for the remote sensing constraint (since on a clear day the total reflecting energy is constant in neighborhood receiving pixel sensors), we have to normalized two image pixel-by-pixel as well. Then, the result is indeed as expected.

Modeling and Simulation in Support of Testing and Evaluation

DTIC Science & Technology

1997-03-01

contains standardized automated test methodology, synthetic stimuli and environments based on TECOM Ground Truth data and physics . The VPG is a distributed...Systems Acquisition Management (FSAM) coursebook , Defense Systems Management College, January 1994. Crocker, Charles M. “Application of the Simulation

Ground Truthing the 'Conventional Wisdom' of Lead Corrosion Control Using Mineralogical Analysis

EPA Science Inventory

For drinking water distribution systems (DWDS) with lead-bearing plumbing materials some form of corrosion control is typically necessary, with the goal of mitigating lead release by forming adherent, stable corrosion scales composed of low-solubility mineral phases. Conventional...

OSIRIS-REx Asteroid Sample-Return Mission

NASA Astrophysics Data System (ADS)

DellaGiustina, D. N.; Lauretta, D. S.

2016-12-01

Launching in September 2016, the primary objective of the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission is to return a pristine sample of asteroid (101955) Bennu to Earth for sample analysis. Bennu is a carbonaceous primitive near-Earth object, and is expected to be rich in volatile and organic material leftover from the formation of the Solar System. OSIRIS-REx will return a minimum of 60 g of bulk surface material from this body using a novel "touch-and-go" sample acquisition mechanism. Analyses of these samples will provide unprecedented knowledge about presolar history, from the initial stages of planet formation to the origin of life. Before sample acquisition, OSIRIS-REx will perform global mapping of Bennu, detailing the asteroid's composition and texture, resolving surface features, revealing its geologic and dynamic history, and providing context for the returned samples. The mission will also document the sampling site in situ at sub-centimeter scales, as well as the asteroid sampling event. In addition, OSIRIS-REx will measure the Yarkovsky effect, a non-Keplerian force affecting the orbit of this potentially hazardous asteroid, and provide a ground truth data for the interpretation of telescopic observations of carbonaceous asteroids.

A hybrid approach to estimate the complex motions of clouds in sky images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Zhenzhou; Yu, Dantong; Huang, Dong

Tracking the motion of clouds is essential to forecasting the weather and to predicting the short-term solar energy generation. Existing techniques mainly fall into two categories: variational optical flow, and block matching. In this article, we summarize recent advances in estimating cloud motion using ground-based sky imagers and quantitatively evaluate state-of-the-art approaches. Then we propose a hybrid tracking framework to incorporate the strength of both block matching and optical flow models. To validate the accuracy of the proposed approach, we introduce a series of synthetic images to simulate the cloud movement and deformation, and thereafter comprehensively compare our hybrid approachmore » with several representative tracking algorithms over both simulated and real images collected from various sites/imagers. The results show that our hybrid approach outperforms state-of-the-art models by reducing at least 30% motion estimation errors compared with the ground-truth motions in most of simulated image sequences. Furthermore, our hybrid model demonstrates its superior efficiency in several real cloud image datasets by lowering at least 15% Mean Absolute Error (MAE) between predicted images and ground-truth images.« less

A hybrid approach to estimate the complex motions of clouds in sky images

DOE PAGES

Peng, Zhenzhou; Yu, Dantong; Huang, Dong; ...

2016-09-14

Tracking the motion of clouds is essential to forecasting the weather and to predicting the short-term solar energy generation. Existing techniques mainly fall into two categories: variational optical flow, and block matching. In this article, we summarize recent advances in estimating cloud motion using ground-based sky imagers and quantitatively evaluate state-of-the-art approaches. Then we propose a hybrid tracking framework to incorporate the strength of both block matching and optical flow models. To validate the accuracy of the proposed approach, we introduce a series of synthetic images to simulate the cloud movement and deformation, and thereafter comprehensively compare our hybrid approachmore » with several representative tracking algorithms over both simulated and real images collected from various sites/imagers. The results show that our hybrid approach outperforms state-of-the-art models by reducing at least 30% motion estimation errors compared with the ground-truth motions in most of simulated image sequences. Furthermore, our hybrid model demonstrates its superior efficiency in several real cloud image datasets by lowering at least 15% Mean Absolute Error (MAE) between predicted images and ground-truth images.« less

Functional connectivity analysis in resting state fMRI with echo-state networks and non-metric clustering for network structure recovery

NASA Astrophysics Data System (ADS)

Wismüller, Axel; DSouza, Adora M.; Abidin, Anas Z.; Wang, Xixi; Hobbs, Susan K.; Nagarajan, Mahesh B.

2015-03-01

Echo state networks (ESN) are recurrent neural networks where the hidden layer is replaced with a fixed reservoir of neurons. Unlike feed-forward networks, neuron training in ESN is restricted to the output neurons alone thereby providing a computational advantage. We demonstrate the use of such ESNs in our mutual connectivity analysis (MCA) framework for recovering the primary motor cortex network associated with hand movement from resting state functional MRI (fMRI) data. Such a framework consists of two steps - (1) defining a pair-wise affinity matrix between different pixel time series within the brain to characterize network activity and (2) recovering network components from the affinity matrix with non-metric clustering. Here, ESNs are used to evaluate pair-wise cross-estimation performance between pixel time series to create the affinity matrix, which is subsequently subject to non-metric clustering with the Louvain method. For comparison, the ground truth of the motor cortex network structure is established with a task-based fMRI sequence. Overlap between the primary motor cortex network recovered with our model free MCA approach and the ground truth was measured with the Dice coefficient. Our results show that network recovery with our proposed MCA approach is in close agreement with the ground truth. Such network recovery is achieved without requiring low-pass filtering of the time series ensembles prior to analysis, an fMRI preprocessing step that has courted controversy in recent years. Thus, we conclude our MCA framework can allow recovery and visualization of the underlying functionally connected networks in the brain on resting state fMRI.

The Parallel Implementation of Algorithms for Finding the Reflection Symmetry of the Binary Images

NASA Astrophysics Data System (ADS)

Fedotova, S.; Seredin, O.; Kushnir, O.

2017-05-01

In this paper, we investigate the exact method of searching an axis of binary image symmetry, based on brute-force search among all potential symmetry axes. As a measure of symmetry, we use the set-theoretic Jaccard similarity applied to two subsets of pixels of the image which is divided by some axis. Brute-force search algorithm definitely finds the axis of approximate symmetry which could be considered as ground-truth, but it requires quite a lot of time to process each image. As a first step of our contribution we develop the parallel version of the brute-force algorithm. It allows us to process large image databases and obtain the desired axis of approximate symmetry for each shape in database. Experimental studies implemented on "Butterflies" and "Flavia" datasets have shown that the proposed algorithm takes several minutes per image to find a symmetry axis. However, in case of real-world applications we need computational efficiency which allows solving the task of symmetry axis search in real or quasi-real time. So, for the task of fast shape symmetry calculation on the common multicore PC we elaborated another parallel program, which based on the procedure suggested before in (Fedotova, 2016). That method takes as an initial axis the axis obtained by superfast comparison of two skeleton primitive sub-chains. This process takes about 0.5 sec on the common PC, it is considerably faster than any of the optimized brute-force methods including ones implemented in supercomputer. In our experiments for 70 percent of cases the found axis coincides with the ground-truth one absolutely, and for the rest of cases it is very close to the ground-truth.

Southwest U.S. Seismo-Acoustic Network: An Autonomous Data Aggregation, Detection, Localization and Ground-Truth Bulletin for the Infrasound Community

NASA Astrophysics Data System (ADS)

Jones, K. R.; Arrowsmith, S.

2013-12-01

The Southwest U.S. Seismo-Acoustic Network (SUSSAN) is a collaborative project designed to produce infrasound event detection bulletins for the infrasound community for research purposes. We are aggregating a large, unique, near real-time data set with available ground truth information from seismo-acoustic arrays across New Mexico, Utah, Nevada, California, Texas and Hawaii. The data are processed in near real-time (~ every 20 minutes) with detections being made on individual arrays and locations determined for networks of arrays. The detection and location data are then combined with any available ground truth information and compiled into a bulletin that will be released to the general public directly and eventually through the IRIS infrasound event bulletin. We use the open source Earthworm seismic data aggregation software to acquire waveform data either directly from the station operator or via the Incorporated Research Institutions for Seismology Data Management Center (IRIS DMC), if available. The data are processed using InfraMonitor, a powerful infrasound event detection and localization software program developed by Stephen Arrowsmith at Los Alamos National Laboratory (LANL). Our goal with this program is to provide the infrasound community with an event database that can be used collaboratively to study various natural and man-made sources. We encourage participation in this program directly or by making infrasound array data available through the IRIS DMC or other means. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. R&A 5317326

Low relative error in consumer-grade GPS units make them ideal for measuring small-scale animal movement patterns

PubMed Central

Severns, Paul M.

2015-01-01

Consumer-grade GPS units are a staple of modern field ecology, but the relatively large error radii reported by manufacturers (up to 10 m) ostensibly precludes their utility in measuring fine-scale movement of small animals such as insects. Here we demonstrate that for data collected at fine spatio-temporal scales, these devices can produce exceptionally accurate data on step-length and movement patterns of small animals. With an understanding of the properties of GPS error and how it arises, it is possible, using a simple field protocol, to use consumer grade GPS units to collect step-length data for the movement of small animals that introduces a median error as small as 11 cm. These small error rates were measured in controlled observations of real butterfly movement. Similar conclusions were reached using a ground-truth test track prepared with a field tape and compass and subsequently measured 20 times using the same methodology as the butterfly tracking. Median error in the ground-truth track was slightly higher than the field data, mostly between 20 and 30 cm, but even for the smallest ground-truth step (70 cm), this is still a signal-to-noise ratio of 3:1, and for steps of 3 m or more, the ratio is greater than 10:1. Such small errors relative to the movements being measured make these inexpensive units useful for measuring insect and other small animal movements on small to intermediate scales with budgets orders of magnitude lower than survey-grade units used in past studies. As an additional advantage, these units are simpler to operate, and insect or other small animal trackways can be collected more quickly than either survey-grade units or more traditional ruler/gird approaches. PMID:26312190

Evaluation of state-of-the-art segmentation algorithms for left ventricle infarct from late Gadolinium enhancement MR images.

PubMed

Karim, Rashed; Bhagirath, Pranav; Claus, Piet; James Housden, R; Chen, Zhong; Karimaghaloo, Zahra; Sohn, Hyon-Mok; Lara Rodríguez, Laura; Vera, Sergio; Albà, Xènia; Hennemuth, Anja; Peitgen, Heinz-Otto; Arbel, Tal; Gonzàlez Ballester, Miguel A; Frangi, Alejandro F; Götte, Marco; Razavi, Reza; Schaeffter, Tobias; Rhode, Kawal

2016-05-01

Studies have demonstrated the feasibility of late Gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging for guiding the management of patients with sequelae to myocardial infarction, such as ventricular tachycardia and heart failure. Clinical implementation of these developments necessitates a reproducible and reliable segmentation of the infarcted regions. It is challenging to compare new algorithms for infarct segmentation in the left ventricle (LV) with existing algorithms. Benchmarking datasets with evaluation strategies are much needed to facilitate comparison. This manuscript presents a benchmarking evaluation framework for future algorithms that segment infarct from LGE CMR of the LV. The image database consists of 30 LGE CMR images of both humans and pigs that were acquired from two separate imaging centres. A consensus ground truth was obtained for all data using maximum likelihood estimation. Six widely-used fixed-thresholding methods and five recently developed algorithms are tested on the benchmarking framework. Results demonstrate that the algorithms have better overlap with the consensus ground truth than most of the n-SD fixed-thresholding methods, with the exception of the Full-Width-at-Half-Maximum (FWHM) fixed-thresholding method. Some of the pitfalls of fixed thresholding methods are demonstrated in this work. The benchmarking evaluation framework, which is a contribution of this work, can be used to test and benchmark future algorithms that detect and quantify infarct in LGE CMR images of the LV. The datasets, ground truth and evaluation code have been made publicly available through the website: https://www.cardiacatlas.org/web/guest/challenges. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panfil, J; Patel, R; Surucu, M

Purpose: To compare markerless template-based tracking of lung tumors using dual energy (DE) cone-beam computed tomography (CBCT) projections versus single energy (SE) CBCT projections. Methods: A RANDO chest phantom with a simulated tumor in the upper right lung was used to investigate the effectiveness of tumor tracking using DE and SE CBCT projections. Planar kV projections from CBCT acquisitions were captured at 60 kVp (4 mAs) and 120 kVp (1 mAs) using the Varian TrueBeam and non-commercial iTools Capture software. Projections were taken at approximately every 0.53° while the gantry rotated. Due to limitations of the phantom, angles for whichmore » the shoulders blocked the tumor were excluded from tracking analysis. DE images were constructed using a weighted logarithmic subtraction that removed bony anatomy while preserving soft tissue structures. The tumors were tracked separately on DE and SE (120 kVp) images using a template-based tracking algorithm. The tracking results were compared to ground truth coordinates designated by a physician. Matches with a distance of greater than 3 mm from ground truth were designated as failing to track. Results: 363 frames were analyzed. The algorithm successfully tracked the tumor on 89.8% (326/363) of DE frames compared to 54.3% (197/363) of SE frames (p<0.0001). Average distance between tracking and ground truth coordinates was 1.27 +/− 0.67 mm for DE versus 1.83+/−0.74 mm for SE (p<0.0001). Conclusion: This study demonstrates the effectiveness of markerless template-based tracking using DE CBCT. DE imaging resulted in better detectability with more accurate localization on average versus SE. Supported by a grant from Varian Medical Systems.« less

Low relative error in consumer-grade GPS units make them ideal for measuring small-scale animal movement patterns.

PubMed

Breed, Greg A; Severns, Paul M

2015-01-01

Consumer-grade GPS units are a staple of modern field ecology, but the relatively large error radii reported by manufacturers (up to 10 m) ostensibly precludes their utility in measuring fine-scale movement of small animals such as insects. Here we demonstrate that for data collected at fine spatio-temporal scales, these devices can produce exceptionally accurate data on step-length and movement patterns of small animals. With an understanding of the properties of GPS error and how it arises, it is possible, using a simple field protocol, to use consumer grade GPS units to collect step-length data for the movement of small animals that introduces a median error as small as 11 cm. These small error rates were measured in controlled observations of real butterfly movement. Similar conclusions were reached using a ground-truth test track prepared with a field tape and compass and subsequently measured 20 times using the same methodology as the butterfly tracking. Median error in the ground-truth track was slightly higher than the field data, mostly between 20 and 30 cm, but even for the smallest ground-truth step (70 cm), this is still a signal-to-noise ratio of 3:1, and for steps of 3 m or more, the ratio is greater than 10:1. Such small errors relative to the movements being measured make these inexpensive units useful for measuring insect and other small animal movements on small to intermediate scales with budgets orders of magnitude lower than survey-grade units used in past studies. As an additional advantage, these units are simpler to operate, and insect or other small animal trackways can be collected more quickly than either survey-grade units or more traditional ruler/gird approaches.

Simulation of brain tumors in MR images for evaluation of segmentation efficacy.

PubMed

Prastawa, Marcel; Bullitt, Elizabeth; Gerig, Guido

2009-04-01

Obtaining validation data and comparison metrics for segmentation of magnetic resonance images (MRI) are difficult tasks due to the lack of reliable ground truth. This problem is even more evident for images presenting pathology, which can both alter tissue appearance through infiltration and cause geometric distortions. Systems for generating synthetic images with user-defined degradation by noise and intensity inhomogeneity offer the possibility for testing and comparison of segmentation methods. Such systems do not yet offer simulation of sufficiently realistic looking pathology. This paper presents a system that combines physical and statistical modeling to generate synthetic multi-modal 3D brain MRI with tumor and edema, along with the underlying anatomical ground truth, Main emphasis is placed on simulation of the major effects known for tumor MRI, such as contrast enhancement, local distortion of healthy tissue, infiltrating edema adjacent to tumors, destruction and deformation of fiber tracts, and multi-modal MRI contrast of healthy tissue and pathology. The new method synthesizes pathology in multi-modal MRI and diffusion tensor imaging (DTI) by simulating mass effect, warping and destruction of white matter fibers, and infiltration of brain tissues by tumor cells. We generate synthetic contrast enhanced MR images by simulating the accumulation of contrast agent within the brain. The appearance of the the brain tissue and tumor in MRI is simulated by synthesizing texture images from real MR images. The proposed method is able to generate synthetic ground truth and synthesized MR images with tumor and edema that exhibit comparable segmentation challenges to real tumor MRI. Such image data sets will find use in segmentation reliability studies, comparison and validation of different segmentation methods, training and teaching, or even in evaluating standards for tumor size like the RECIST criteria (response evaluation criteria in solid tumors).

Pressure demagnetization of the Martian crust: Ground truth from SNC meteorites

NASA Astrophysics Data System (ADS)

Bezaeva, Natalia S.; Rochette, Pierre; Gattacceca, Jérôme; Sadykov, Ravil A.; Trukhin, Vladimir I.

2007-12-01

We performed hydrostatic pressure demagnetization experiments up to 1.3 GPa on Martian meteorites: nakhlite NWA998 (magnetite-bearing), basaltic shergottites NWA1068 (pyrrhotite-bearing) and Los Angeles (titanomagnetite-bearing) as well as terrestrial rocks: rhyolite (hematite-bearing) and basalt (titanomagnetite-bearing), using a new non-magnetic high-pressure cell. The detailed description of measuring techniques and experimental set-up is presented. We found that under 1.3 GPa the samples lost up to 54% of their initial saturation isothermal remanent magnetization (IRM). Repeated loading resulted in a further decrease of magnetization of the samples. Our experiments show that the resistance of IRM to hydrostatic pressure is not exclusively controlled by the remanent coercivity of the sample, but is strongly dependant on its magnetic mineralogy. There is no simple equivalence between pressure demagnetization and alternating field demagnetization. The extrapolation of these results of pressure demagnetization of IRM of Martian meteorites to the demagnetization of the Martian crust by impacts is discussed.

A new device for acquiring ground truth on the absorption of light by turbid waters

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Srna, R.; Treasure, W.

1974-01-01

The author has identified the following significant results. A new device, called a Spectral Attenuation Board, has been designed and tested, which enables ERTS-1 sea truth collection teams to monitor the attenuation depths of three colors continuously, as the board is being towed behind a boat. The device consists of a 1.2 x 1.2 meter flat board held below the surface of the water at a fixed angle to the surface of the water. A camera mounted above the water takes photographs of the board. The resulting film image is analyzed by a micro-densitometer trace along the descending portion of the board. This yields information on the rate of attenuation of light penetrating the water column and the Secchi depth. Red and green stripes were painted on the white board to approximate band 4 and band 5 of the ERTS MSS so that information on the rate of light absorption by the water column of light in these regions of the visible spectrum could be concurrently measured. It was found that information from a red, green, and white stripe may serve to fingerprint the composition of the water mass. A number of these devices, when automated, could also be distributed over a large region to provide a cheap method of obtaining valuable satellite ground truth data at present time intervals.

Evaluation of multiple precipitation products across Mainland China using the triple collocation method without ground truth

NASA Astrophysics Data System (ADS)

Tang, G.; Li, C.; Hong, Y.; Long, D.

2017-12-01

Proliferation of satellite and reanalysis precipitation products underscores the need to evaluate their reliability, particularly over ungauged or poorly gauged regions. However, it is really challenging to perform such evaluations over regions lacking ground truth data. Here, using the triple collocation (TC) method that is capable of evaluating relative uncertainties in different products without ground truth, we evaluate five satellite-based precipitation products and comparatively assess uncertainties in three types of independent precipitation products, e.g., satellite-based, ground-observed, and model reanalysis over Mainland China, including a ground-based precipitation dataset (the gauge based daily precipitation analysis, CGDPA), the latest version of the European reanalysis agency reanalysis (ERA-interim) product, and five satellite-based products (i.e., 3B42V7, 3B42RT of TMPA, IMERG, CMORPH-CRT, PERSIANN-CDR) on a regular 0.25° grid at the daily timescale from 2013 to 2015. First, the effectiveness of the TC method is evaluated by comparison with traditional methods based on ground observations in a densely gauged region. Results show that the TC method is reliable because the correlation coefficient (CC) and root mean square error (RMSE) are close to those based on the traditional method with a maximum difference only up to 0.08 and 0.71 (mm/day) for CC and RMSE, respectively. Then, the TC method is applied to Mainland China and the Tibetan Plateau (TP). Results indicate that: (1) the overall performance of IMERG is better than the other satellite products over Mainland China; (2) over grid cells without rain gauges in the TP, IMERG and ERA show better performance than CGDPA, indicating the potential of remote sensing and reanalysis data over these regions and the inherent uncertainty of CGDPA due to interpolation using sparsely gauged data; (3) both TMPA-3B42 and CMORPH-CRT have some unexpected CC values over certain grid cells that contain water bodies, reaffirming the overestimation of precipitation over inland water bodies. Overall, the TC method provides not only reliable cross-validation results of precipitation estimates over Mainland China but also a new perspective as to compressively assess multi-source precipitation products, particularly over poorly gauged regions.

Comparative evaluation of ERTS-A imagery for resource inventory in land-use planning

NASA Technical Reports Server (NTRS)

Simonson, G. H. (Principal Investigator)

1972-01-01

There are no author-identified significant results in this report. The overall objectives of this program are: (1) use of multidiscipline team approach to determine features that can be successfully monitored by ERTS-1 imagery for resource inventory, planning, land use zoning, and resource development; and (2) using carefully selected sample areas, develop a comprehensive resource inventory mapping system for use in planning, zoning, and resource development. Progress has included compilation and organization of ground truth data and observations in the primary study area of Crook County; resource inventory legend development; assembly and testing of color enhancement equipment; development and adaption of programs for digital data processing; and quick-look evaluations of initial ERTS-1 imagery for Oregon.

The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Remote sensing and physical data and the Moon. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Leake, M. A.

1982-01-01

Imagery data from Mariner 10 and Lunar Orbiter IV form the major base of observations analyzed. But a variety of other information aids in constraining the composition and structure of the Moon and Mercury, and in particular, provides input to the problem of the nature and origin of their intercrater plains. This information for Mercury is remotely sensed from Earth or from the Mariner 10 spacecraft. Lunar data includes, of course, ground truth information from the Apollo landing sites. Since neither intercrater region was sampled, lunar and Mercurian data are similar in type and limitations. Constraints on surface and interior composition and structure are reviewed.

Multispectral color photography for mineral exploration by the remote sensing of biogeochemical anomalies

NASA Technical Reports Server (NTRS)

Yost, E.

1975-01-01

Selected band multispectral photography was evaluated as a mineral exploration tool by detecting stress on trees caused by underground mineralization. Ground truth consisted of two test sites in the Prescott National Forest within which the mineralization had been established by a drilling program. Species of trees were categorized as background, intermediate, and anomalous based upon where they grew with respect to this underlying mineralization. Soil geochemistry and the metal content of ashed samples of the trees were studied in relation to the inferred locus of mineralization. Computer analysis of the reflectance spectra of mineralized trees confirmed that the relative percent reflectance differences of trees growing in anomalous areas was less than that of the same tree species growing in background areas.

Integrated Airborne and In-Situ Measurements over Land-Fast Ice near Barrow, AK.

NASA Astrophysics Data System (ADS)

Brozena, J. M.; Gardner, J. M.; Liang, R.; Ball, D.; Richter-Menge, J.; Claffey, K. J.; Abelev, A.; Hebert, D. A.; Jones, K.

2014-12-01

During March of 2014, the Naval Research Laboratory and the Cold Regions Research and Engineering Laboratory collected an integrated set of airborne and in-situ measurements over two areas of floating, but land-fast ice near the coast of Barrow, AK. The near-shore site was just north of Point Barrow, and the "offshore" site was ~ 20 km east of Point Barrow. The in-situ data provided ground-truth for airborne measurements from a scanning LiDAR (Riegl Q 560i), digital photogrammetry (Applanix DSS-439) and a snow radar procured from the Center for Remote Sensing of Ice Sheets of the University of Kansas. The objective of the survey was to aid our understanding of the use of the airborne data to calibrate/validate Cryosat-2 data. Sampling size or "footprint" plays a critical role in the attempt to compare in-situ measurements with airborne (or satellite) measurements. Thus the in-situ data were arranged to minimize aliasing. Ground measurements were collected along transects at both sites consisting of a 2 km long profile of snow depth and ice thickness measurements with periodic boreholes. A 60 m x 400 m swath of snow depth measurements was centered on this profile. Airborne data were collected on five overflights of the two transect areas. The LiDAR measured total freeboard (ice + snow) referenced to leads in the ice, and produced swaths 200-300 m wide. The radar measured snow thickness. The freeboard and snow thickness measurements are used to estimate ice thickness via isostasy and density estimates. The central swath of in situ snow depth data allows examination of the effects of cross-track variations considering the relatively large footprint of the snow radar. Assuming a smooth, flat surface the radar range resolution in air is < 4 cm, but the along-track sampling distance is ~ 3 m after unfocussed SAR processing. The width of the footprint varies from ~ 9 m up to about 40 m (beam-limited) for uneven surfaces. However, the radar could not resolve snow thickness except in areas of relatively flat snow and ice. The LiDAR had a ground point spacing of ~25-50 cm (depending on survey altitude) and so easily encompassed all other data. Comparisons and processing methodology will be shown. The results of this ground-truth experiment will inform our analysis of grids of airborne data collected over areas of sea-ice illuminated by Cryosat-2.

Precipitation Measurements From Space: Workshop report. An element of the climate observing system study

NASA Technical Reports Server (NTRS)

Atlas, D. (Editor); Thiele, O. W. (Editor)

1981-01-01

Global climate, agricultural uses for precipitation information, hydrological uses for precipitation, severe thunderstorms and local weather, global weather are addressed. Ground truth measurement, visible and infrared techniques, microwave radiometry and hybrid precipitation measurements, and spaceborne radar are discussed.

A Ranking-Theoretic Approach to Conditionals

ERIC Educational Resources Information Center

Spohn, Wolfgang

2013-01-01

Conditionals somehow express conditional beliefs. However, conditional belief is a bi-propositional attitude that is generally not truth-evaluable, in contrast to unconditional belief. Therefore, this article opts for an expressivistic semantics for conditionals, grounds this semantics in the arguably most adequate account of conditional belief,…

Ground Truth in Building Human Security

DTIC Science & Technology

2012-11-01

Peace, Charles Call and Vanessa Wyeth, Editors, International Peace Institute, 2008, pp. 164-5. 9. Sandra F. Joireman, Where There is No...that company. http://grm.thomsonreuters.com/news/july-2011/thomson-reuters- completes-acquisition-of-manatron/ 73. P.J.M. van Oosterom, C.H.J

Ground Truthing the ‘Conventional Wisdom’ of Lead Corrosion Control Using Mineralogical Analysis

EPA Science Inventory

For drinking water distribution systems (DWDS) with lead-bearing plumbing materials some form of corrosion control is typically necessary, with the goal of mitigating lead release by forming adherent, stable corrosion scales composed of low-solubility mineral phases. Conventional...

Comparisons of Ground Truth and Remote Spectral Measurements of the FORMOSAT and ANDE Spacecrafts

NASA Technical Reports Server (NTRS)

JorgensenAbercromby, Kira; Hamada, Kris; Okada, Jennifer; Guyote, Michael; Barker, Edwin

2006-01-01

Determining the material type of objects in space is conducted using laboratory spectral reflectance measurements from common spacecraft materials and comparing the results to remote spectra. This past year, two different ground-truth studies commenced. The first, FORMOSAT III, is a Taiwanese set of six satellites to be launched in March 2006. The second is ANDE (Atmospheric Neutral Density Experiment), a Naval Research Laboratory set of two satellites set to launch from the Space Shuttle in November 2006. Laboratory spectra were obtained of the spacecraft and a model of the anticipated spectra response was created for each set of satellites. The model takes into account phase angle and orientation of the spacecraft relative to the observer. Once launched, the spacecraft are observed once a month to determine the space aging effects of materials as deduced from the remote spectra. Preliminary results will be shown of the FORMOSAT III comparison with laboratory data and remote data while results from only the laboratory data will be shown for the ANDE spacecraft.

Object Segmentation and Ground Truth in 3D Embryonic Imaging.

PubMed

Rajasekaran, Bhavna; Uriu, Koichiro; Valentin, Guillaume; Tinevez, Jean-Yves; Oates, Andrew C

2016-01-01

Many questions in developmental biology depend on measuring the position and movement of individual cells within developing embryos. Yet, tools that provide this data are often challenged by high cell density and their accuracy is difficult to measure. Here, we present a three-step procedure to address this problem. Step one is a novel segmentation algorithm based on image derivatives that, in combination with selective post-processing, reliably and automatically segments cell nuclei from images of densely packed tissue. Step two is a quantitative validation using synthetic images to ascertain the efficiency of the algorithm with respect to signal-to-noise ratio and object density. Finally, we propose an original method to generate reliable and experimentally faithful ground truth datasets: Sparse-dense dual-labeled embryo chimeras are used to unambiguously measure segmentation errors within experimental data. Together, the three steps outlined here establish a robust, iterative procedure to fine-tune image analysis algorithms and microscopy settings associated with embryonic 3D image data sets.

Object Segmentation and Ground Truth in 3D Embryonic Imaging

PubMed Central

Rajasekaran, Bhavna; Uriu, Koichiro; Valentin, Guillaume; Tinevez, Jean-Yves; Oates, Andrew C.

2016-01-01

Many questions in developmental biology depend on measuring the position and movement of individual cells within developing embryos. Yet, tools that provide this data are often challenged by high cell density and their accuracy is difficult to measure. Here, we present a three-step procedure to address this problem. Step one is a novel segmentation algorithm based on image derivatives that, in combination with selective post-processing, reliably and automatically segments cell nuclei from images of densely packed tissue. Step two is a quantitative validation using synthetic images to ascertain the efficiency of the algorithm with respect to signal-to-noise ratio and object density. Finally, we propose an original method to generate reliable and experimentally faithful ground truth datasets: Sparse-dense dual-labeled embryo chimeras are used to unambiguously measure segmentation errors within experimental data. Together, the three steps outlined here establish a robust, iterative procedure to fine-tune image analysis algorithms and microscopy settings associated with embryonic 3D image data sets. PMID:27332860

The ground-truth problem for satellite estimates of rain rate

NASA Technical Reports Server (NTRS)

North, Gerald R.; Valdes, Juan B.; Eunho, HA; Shen, Samuel S. P.

1994-01-01

In this paper a scheme is proposed to use a point raingage to compare contemporaneous measurements of rain rate from a single-field-of-view (FOV) estimate based on a satellite remote sensor such as a microwave radiometer. Even in the ideal case the measurements are different because one is at a point and the other is an area average over the field of view. Also the point gage will be located randomly inside the field of view on different overpasses. A space-time spectral formalism is combined with a simple stochastic rain field to find the mean-square deviations between the two systems. It is found that by combining about 60 visits of the satellite to the ground-truth site, the expected error can be reduced to about 10% of the standard deviation of the fluctuations of the systems alone. This seems to be a useful level of tolerance in terms of isolating and evaluating typical biases that might be contaminating retrieval algorithms.

Presentation video retrieval using automatically recovered slide and spoken text

NASA Astrophysics Data System (ADS)

Cooper, Matthew

2013-03-01

Video is becoming a prevalent medium for e-learning. Lecture videos contain text information in both the presentation slides and lecturer's speech. This paper examines the relative utility of automatically recovered text from these sources for lecture video retrieval. To extract the visual information, we automatically detect slides within the videos and apply optical character recognition to obtain their text. Automatic speech recognition is used similarly to extract spoken text from the recorded audio. We perform controlled experiments with manually created ground truth for both the slide and spoken text from more than 60 hours of lecture video. We compare the automatically extracted slide and spoken text in terms of accuracy relative to ground truth, overlap with one another, and utility for video retrieval. Results reveal that automatically recovered slide text and spoken text contain different content with varying error profiles. Experiments demonstrate that automatically extracted slide text enables higher precision video retrieval than automatically recovered spoken text.

Identification of marsh vegetation and coastal land use in ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Klemas, V.; Daiber, F. C.; Bartlett, D. S.

1973-01-01

Coastal vegetation species appearing in the ERTS-1 images taken of Delaware Bay on August 16, and October 10, 1972 have been correlated with ground truth vegetation maps and imagery obtained from high altitude RB-57 and U-2 overflights. The vegetation maps of the entire Delaware Coast were prepared during the summer of 1972 and checked out with ground truth data collected on foot, in small boats, and from low-altitude aircraft. Multispectral analysis of high altitude RB-57 and U-2 photographs indicated that five vegetation communities could be clearly discriminated from 60,000 feet altitude including: (1) salt marsh cord grass, (2) salt marsh hay and spike grass, (3) reed grass, (4) high tide bush and sea myrtle, and (5) a group of fresh water species found in impoundments built to attract water fowl. All of these species are shown in fifteen overlay maps, covering all of Delaware's wetlands prepared to match the USGS topographic map size of 1:24,000.

Toward building a comprehensive data mart

NASA Astrophysics Data System (ADS)

Boulware, Douglas; Salerno, John; Bleich, Richard; Hinman, Michael L.

2004-04-01

To uncover new relationships or patterns one must first build a corpus of data or what some call a data mart. How can we make sure we have collected all the pertinent data and have maximized coverage? There are hundreds of search engines that are available for use on the Internet today. Which one is best? Is one better for one problem and a second better for another? Are meta-search engines better than individual search engines? In this paper we look at one possible approach in developing a methodology to compare a number of search engines. Before we present this methodology, we first provide our motivation towards the need for increased coverage. We next investigate how we can obtain ground truth and what the ground truth can provide us in the way of some insight into the Internet and search engine capabilities. We then conclude our discussion by developing a methodology in which we compare a number of the search engines and how we can increase overall coverage and thus a more comprehensive data mart.

Interactive semiautomatic contour delineation using statistical conditional random fields framework.

PubMed

Hu, Yu-Chi; Grossberg, Michael D; Wu, Abraham; Riaz, Nadeem; Perez, Carmen; Mageras, Gig S

2012-07-01

Contouring a normal anatomical structure during radiation treatment planning requires significant time and effort. The authors present a fast and accurate semiautomatic contour delineation method to reduce the time and effort required of expert users. Following an initial segmentation on one CT slice, the user marks the target organ and nontarget pixels with a few simple brush strokes. The algorithm calculates statistics from this information that, in turn, determines the parameters of an energy function containing both boundary and regional components. The method uses a conditional random field graphical model to define the energy function to be minimized for obtaining an estimated optimal segmentation, and a graph partition algorithm to efficiently solve the energy function minimization. Organ boundary statistics are estimated from the segmentation and propagated to subsequent images; regional statistics are estimated from the simple brush strokes that are either propagated or redrawn as needed on subsequent images. This greatly reduces the user input needed and speeds up segmentations. The proposed method can be further accelerated with graph-based interpolation of alternating slices in place of user-guided segmentation. CT images from phantom and patients were used to evaluate this method. The authors determined the sensitivity and specificity of organ segmentations using physician-drawn contours as ground truth, as well as the predicted-to-ground truth surface distances. Finally, three physicians evaluated the contours for subjective acceptability. Interobserver and intraobserver analysis was also performed and Bland-Altman plots were used to evaluate agreement. Liver and kidney segmentations in patient volumetric CT images show that boundary samples provided on a single CT slice can be reused through the entire 3D stack of images to obtain accurate segmentation. In liver, our method has better sensitivity and specificity (0.925 and 0.995) than region growing (0.897 and 0.995) and level set methods (0.912 and 0.985) as well as shorter mean predicted-to-ground truth distance (2.13 mm) compared to regional growing (4.58 mm) and level set methods (8.55 mm and 4.74 mm). Similar results are observed in kidney segmentation. Physician evaluation of ten liver cases showed that 83% of contours did not need any modification, while 6% of contours needed modifications as assessed by two or more evaluators. In interobserver and intraobserver analysis, Bland-Altman plots showed our method to have better repeatability than the manual method while the delineation time was 15% faster on average. Our method achieves high accuracy in liver and kidney segmentation and considerably reduces the time and labor required for contour delineation. Since it extracts purely statistical information from the samples interactively specified by expert users, the method avoids heuristic assumptions commonly used by other methods. In addition, the method can be expanded to 3D directly without modification because the underlying graphical framework and graph partition optimization method fit naturally with the image grid structure.

The use of remote sensing in solving Florida's geological and coastal engineering problems

NASA Technical Reports Server (NTRS)

Brooks, H. K.; Ruth, B. E.; Wang, Y. H.; Ferguson, R. L.

1977-01-01

LANDSAT imagery and NASA high altitude color infrared (CIR) photography were used to select suitable sites for sanitary landfill in Volusia County, Florida and to develop techniques for preventing sand deposits in the Clearwater inlet. Activities described include the acquisition of imagery, its analysis by the IMAGE 100 system, conventional photointerpretation, evaluation of existing data sources (vegetation, soil, and ground water maps), site investigations for ground truth, and preparation of displays for reports.

Localizing Ground Penetrating RADAR: A Step Towards Robust Autonomous Ground Vehicle Localization

DTIC Science & Technology

2015-05-27

truth reference unit is coupled with a local base station that allows local 2cm accuracy location measurements. The RT3003 uses a MEMS -based IMU and...of different electromagnetic properties; for example the interface between soil and pipes , roots, or rocks. However, it is not these discrete...depth is determined by soil losses caused by Joule heating and dipole losses. High conductivity soils, such as those with high moisture and salinity

SLAPex Freeze/Thaw 2015: The First Dedicated Soil Freeze/Thaw Airborne Campaign

NASA Technical Reports Server (NTRS)

Kim, Edward; Wu, Albert; DeMarco, Eugenia; Powers, Jarrett; Berg, Aaron; Rowlandson, Tracy; Freeman, Jacqueline; Gottfried, Kurt; Toose, Peter; Roy, Alexandre;

Usability of calcium carbide gas pressure method in hydrological sciences

NASA Astrophysics Data System (ADS)

Arsoy, S.; Ozgur, M.; Keskin, E.; Yilmaz, C.

2013-10-01

Soil moisture is a key engineering variable with major influence on ecological and hydrological processes as well as in climate, weather, agricultural, civil and geotechnical applications. Methods for quantification of the soil moisture are classified into three main groups: (i) measurement with remote sensing, (ii) estimation via (soil water balance) simulation models, and (iii) measurement in the field (ground based). Remote sensing and simulation modeling require rapid ground truthing with one of the ground based methods. Calcium carbide gas pressure (CCGP) method is a rapid measurement procedure for obtaining soil moisture and relies on the chemical reaction of the calcium carbide reagent with the water in soil pores. However, the method is overlooked in hydrological science applications. Therefore, the purpose of this study is to evaluate the usability of the CCGP method in comparison with standard oven-drying and dielectric methods in terms of accuracy, time efficiency, operational ease, cost effectiveness and safety for quantification of the soil moisture over a wide range of soil types. The research involved over 250 tests that were carried out on 15 different soil types. It was found that the accuracy of the method is mostly within ±1% of soil moisture deviation range in comparison to oven-drying, and that CCGP method has significant advantages over dielectric methods in terms of accuracy, cost, operational ease and time efficiency for the purpose of ground truthing.

Exploring Normalization and Network Reconstruction Methods using In Silico and In Vivo Models

EPA Science Inventory

Abstract: Lessons learned from the recent DREAM competitions include: The search for the best network reconstruction method continues, and we need more complete datasets with ground truth from more complex organisms. It has become obvious that the network reconstruction methods t...

Validation of the Soil Moisture Active Passive mission using USDA-ARS experimental watersheds

USDA-ARS?s Scientific Manuscript database

The calibration and validation program of the Soil Moisture Active Passive mission (SMAP) relies upon an international cooperative of in situ networks to provide ground truth references across a variety of landscapes. The USDA Agricultural Research Service operates several experimental watersheds wh...

Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study

NASA Astrophysics Data System (ADS)

Bowen, S. R.; Nyflot, M. J.; Herrmann, C.; Groh, C. M.; Meyer, J.; Wollenweber, S. D.; Stearns, C. W.; Kinahan, P. E.; Sandison, G. A.

2015-05-01

Effective positron emission tomography / computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [18F]FDG. The lung lesion insert was driven by six different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses, and 2%-2 mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10-20%, treatment planning errors were 5-10%, and treatment delivery errors were 5-30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5-10% in PET/CT imaging, <5% in treatment planning, and <2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT delivery under a dose painting paradigm is feasible within an integrated respiratory motion phantom workflow. For a limited set of cases, the magnitude of errors was comparable during PET/CT imaging and treatment delivery without motion compensation. Errors were moderately mitigated during PET/CT imaging and significantly mitigated during RT delivery with motion compensation. This dynamic motion phantom end-to-end workflow provides a method for quality assurance of 4D PET/CT-guided radiotherapy, including evaluation of respiratory motion compensation methods during imaging and treatment delivery.

Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study.

PubMed

Bowen, S R; Nyflot, M J; Herrmann, C; Groh, C M; Meyer, J; Wollenweber, S D; Stearns, C W; Kinahan, P E; Sandison, G A

2015-05-07

Effective positron emission tomography / computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [(18)F]FDG. The lung lesion insert was driven by six different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses, and 2%-2 mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10-20%, treatment planning errors were 5-10%, and treatment delivery errors were 5-30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5-10% in PET/CT imaging, <5% in treatment planning, and <2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT delivery under a dose painting paradigm is feasible within an integrated respiratory motion phantom workflow. For a limited set of cases, the magnitude of errors was comparable during PET/CT imaging and treatment delivery without motion compensation. Errors were moderately mitigated during PET/CT imaging and significantly mitigated during RT delivery with motion compensation. This dynamic motion phantom end-to-end workflow provides a method for quality assurance of 4D PET/CT-guided radiotherapy, including evaluation of respiratory motion compensation methods during imaging and treatment delivery.

Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study

PubMed Central

Bowen, S R; Nyflot, M J; Hermann, C; Groh, C; Meyer, J; Wollenweber, S D; Stearns, C W; Kinahan, P E; Sandison, G A

2015-01-01

Effective positron emission tomography/computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [18F]FDG. The lung lesion insert was driven by 6 different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy (VMAT) were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses (EUD), and 2%-2mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10–20%, treatment planning errors were 5–10%, and treatment delivery errors were 5–30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5–10% in PET/CT imaging, < 5% in treatment planning, and < 2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT delivery under a dose painting paradigm is feasible within an integrated respiratory motion phantom workflow. For a limited set of cases, the magnitude of errors was comparable during PET/CT imaging and treatment delivery without motion compensation. Errors were moderately mitigated during PET/CT imaging and significantly mitigated during RT delivery with motion compensation. This dynamic motion phantom end-to-end workflow provides a method for quality assurance of 4D PET/CT-guided radiotherapy, including evaluation of respiratory motion compensation methods during imaging and treatment delivery. PMID:25884892

Building an Internet of Samples: The Australian Contribution

NASA Astrophysics Data System (ADS)

Wyborn, Lesley; Klump, Jens; Bastrakova, Irina; Devaraju, Anusuriya; McInnes, Brent; Cox, Simon; Karssies, Linda; Martin, Julia; Ross, Shawn; Morrissey, John; Fraser, Ryan

2017-04-01

Physical samples are often the ground truth to research reported in the scientific literature across multiple domains. They are collected by many different entities (individual researchers, laboratories, government agencies, mining companies, citizens, museums, etc.). Samples must be curated over the long-term to ensure both that their existence is known, and to allow any data derived from them through laboratory and field tests to be linked to the physical samples. For example, having unique identifiers that link back ground truth data on the original sample helps calibrate large volumes of remotely sensed data. Access to catalogues of reliably identified samples from several collections promotes collaboration across all Earth Science disciplines. It also increases the cost effectiveness of research by reducing the need to re-collect samples in the field. The assignment of web identifiers to the digital representations of these physical objects allows us to link to data, literature, investigators and institutions, thus creating an "Internet of Samples". An Australian implementation of the "Internet of Samples" is using the IGSN (International Geo Sample Number, http://igsn.github.io) to identify samples in a globally unique and persistent way. IGSN was developed in the solid earth science community and is recommended for sample identification by the Coalition for Publishing Data in the Earth and Space Sciences (COPDESS). IGSN is interoperable with other persistent identifier systems such as DataCite. Furthermore, the basic IGSN description metadata schema is compatible with existing schemas such as OGC Observations and Measurements (O&M) and DataCite Metadata Schema which makes crosswalks to other metadata schemas easy. IGSN metadata is disseminated through the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) allowing it to be aggregated in other applications such as portals (e.g. the Australian IGSN catalogue http://igsn2.csiro.au). The metadata is available in more than one format. The software for IGSN web services is based on components developed for DataCite and adapted to the specific requirements of IGSN. This cooperation in open source development ensures sustainable implementation and faster turnaround times for updates. IGSN, in particular in its Australian implementation, is characterised by a federated approach to system architecture and organisational governance giving it the necessary flexibility to adapt to particular local practices within multiple domains, whilst maintaining an overarching international standard. The three current IGSN allocation agents in Australia: Geoscience Australia, CSIRO and Curtin University, represent different sectors. Through funding from the Australian Research Data Services Program they have combined to develop a common web portal that allows discovery of physical samples and sample collections at a national level.International governance then ensures we can link to an international community but at the same time act locally to ensure the services offered are relevant to the needs of Australian researchers. This flexibility aids the integration of new disciplines into a global community of a physical samples information network.

Non-invasive evaluation of blood oxygen saturation and hematocrit from T1 and T2 relaxation times: In-vitro validation in fetal blood.

PubMed

Portnoy, Sharon; Seed, Mike; Sled, John G; Macgowan, Christopher K

2017-12-01

We propose an analytical method for calculating blood hematocrit (Hct) and oxygen saturation (sO 2 ) from measurements of its T 1 and T 2 relaxation times. Through algebraic substitution, established two-compartment relationships describing R1=T1-1 and R2=T2-1 as a function of hematocrit and oxygen saturation were rearranged to solve for Hct and sO 2 in terms of R 1 and R 2 . Resulting solutions for Hct and sO 2 are the roots of cubic polynomials. Feasibility of the method was established by comparison of Hct and sO 2 estimates obtained from relaxometry measurements (at 1.5 Tesla) in cord blood specimens to ground-truth values obtained by blood gas analysis. Monte Carlo simulations were also conducted to assess the effect of T 1 , T 2 measurement uncertainty on precision of Hct and sO 2 estimates. Good agreement was observed between estimated and ground-truth blood properties (bias = 0.01; 95% limits of agreement = ±0.13 for Hct and sO 2 ). Considering the combined effects of biological variability and random measurement noise, we estimate a typical uncertainty of ±0.1 for Hct, sO 2 estimates. Results demonstrate accurate quantification of Hct and sO 2 from T 1 and T 2 . This method is applicable to noninvasive fetal vessel oximetry-an application where existing oximetry devices are unusable or require risky blood-sampling procedures. Magn Reson Med 78:2352-2359, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Assessing the Ability of Vegetation Indices to Identify Shallow Subsurface Water Flow Pathways from Hyperspectral Imagery Using Machine Learning: Application

NASA Astrophysics Data System (ADS)

Doctor, K.; Byers, J. M.

2017-12-01

Shallow underground water flow pathways expressed as slight depressions are common in the land surface. Under conditions of saturated overland flow, such as during heavy rain or snow melt, these areas of preferential flow might appear on the surface as very shallow flowing streams. When there is no water flowing in these ephemeral channels it can be difficult to identify them. It is especially difficult to discern the slight depressions above the subsurface water flow pathways (SWFP) when the area is covered by vegetation. Since the soil moisture content in these SWFP is often greater than the surrounding area, the vegetation growing on top of these channels shows different vigor and moisture content than the vegetation growing above the non-SWFP area. Vegetation indices (VI) are used in visible and near infrared (VNIR) hyperspectral imagery to enhance biophysical properties of vegetation, and so the brightness values between vegetation atop SWFP and the surrounding vegetation were highlighted. We performed supervised machine learning using ground-truth class labels to determine the conditional probability of a SWFP at a given pixel given either the spectral distribution or VI at that pixel. The training data estimates the probability distributions to a determined finite sampling accuracy for a binary Naïve Bayes classifier between SWFP and non-SWFP. The ground-truth data provides a test bed for understanding the ability to build SWFP classifiers using hyperspectral imagery. SWFP were distinguishable in the imagery within corn and grass fields and in areas with low-lying vegetation. However, the training data is limited to particular types of terrain and vegetation cover in the Shenandoah Valley, Virginia and this would limit the resulting classifier. Further training data could extend its use to other environments.

Relationship of Hotspots to the Distribution of Surficial Surf-Zone Sediments along the Outer Banks of North Carolina

NASA Astrophysics Data System (ADS)

Schupp, C. A.; McNinch, J. E.; List, J. H.; Farris, A. S.

2002-12-01

The formation and behavior of hotspots, or sections of the beach that exhibit markedly higher shoreline change rates than adjacent regions, are poorly understood. Several hotspots have been identified on the Outer Banks, a developed barrier island in North Carolina. To better understand hotspot dynamics and the potential relationship to the geologic framework in which they occur, the surf zone between Duck and Bodie Island was surveyed in June 2002 as part of a research effort supported by the U.S. Geological Survey and U.S. Army Corps of Engineers. Swath bathymetry, sidescan sonar, and chirp seismic were used to characterize a region 40 km long and1 km wide. Hotspot locations were pinpointed using standard deviation values for shoreline position as determined by monthly SWASH buggy surveys of the mean high water contour between October 1999 and September 2002. Observational data and sidescan images were mapped to delineate regions of surficial sediment distributions, and regions of interest were ground-truthed via grab samples or visual inspection. General kilometer-scale correlation between acoustic backscatter and high shoreline standard deviation is evident. Acoustic returns are uniform in a region of Duck where standard deviation is low, but backscatter is patchy around the Kitty Hawk hotspot, where standard deviation is higher. Based on ground-truthing of an area further north, these patches are believed to be an older ravinement surface of fine sediment. More detailed analyses of the correlation between acoustic data, standard deviation, and hotspot locations will be presented. Future work will include integration of seismic, bathymetric, and sidescan data to better understand the links between sub-bottom geology, temporal changes in surficial sediments, surf-zone sediment budgets, and short-term changes in shoreline position and morphology.

Potential for remote sensing of agriculture from the international space station

NASA Astrophysics Data System (ADS)

Morgenthaler, George W.; Khatib, Nader

1999-01-01

Today's spatial resolution of orbital sensing systems is too coarse to economically serve the yield-improvement/contamination-reduction needs of the small to mid-size farm enterprise. Remote sensing from aircraft is being pressed into service. However, satellite remote sensing constellations with greater resolution and more spectral bands, i.e., with resolutions of 1 m in the panchromatic, 4 m in the multi-spectral, and 8 m in the hyper-spectral are expected to be in orbit by the year 2000. Such systems coupled with Global Positioning System (GPS) capability will make ``precision agriculture,'' i.e., the identification of specific and timely fertilizer, irrigation, herbicide, and insecticide needs on an acre-by-acre basis and the ability to meet these needs with precision delivery systems at affordable costs, is what is needed and can be achieved. Current plans for remote sensing systems on the International Space Station (ISS) include externally attached payloads and a window observation platform. The planned orbit of the Space Station will result in overflight of a specific latitude and longitude at the same clock time every 3 months. However, a pass over a specific latitude and longitude during ``daylight hours'' could occur much more frequently. The ISS might thus be a space platform for experimental and developmental testing of future commercial space remote sensing precision agriculture systems. There is also a need for agricultural ``truth'' sites so that predictive crop yield and pollution models can be devised and corrective suggestions delivered to farmers at affordable costs. In Summer 1998, the University of Colorado at Boulder and the Center for the Study of Terrestrial and Extraterrestrial Atmospheres (CSTEA) at Howard University, under NASA Goddard Space Flight Center funding, established an agricultural ``truth'' site in eastern Colorado. The ``truth'' site was highly instrumented for measuring trace gas concentrations (NOx, SOx, CO2, O3, organics, and aerosols), ground water contamination via drain-tile catch from the fields, and Leaf Area Index (LAI). Also, a tethered balloon flight sampled the site's vertical air column and both aerial infrared photography and satellite imagery were acquired. This paper summarizes the 1998 activities in establishing and operating the ``truth'' site. The goal of such a ``truth'' site is to develop and validate precision agriculture predictive models to improve farming practices. ISS sensor testing can greatly accelerate development of such systems.

Methods of extending signatures and training without ground information. [data processing, pattern recognition

NASA Technical Reports Server (NTRS)

Henderson, R. G.; Thomas, G. S.; Nalepka, R. F.

1975-01-01

Methods of performing signature extension, using LANDSAT-1 data, are explored. The emphasis is on improving the performance and cost-effectiveness of large area wheat surveys. Two methods were developed: ASC, and MASC. Two methods, Ratio, and RADIFF, previously used with aircraft data were adapted to and tested on LANDSAT-1 data. An investigation into the sources and nature of between scene data variations was included. Initial investigations into the selection of training fields without in situ ground truth were undertaken.

Global Ground Truth Data Set with Waveform and Improved Arrival Data

DTIC Science & Technology

2006-09-29

local network. Sb) c) -I w .15Ř’ *•S| -195.4’ - .. " -in’ 410 -1115 -IisA " l Figure 4. (a) RCA geometry for the Kilauea Volcano south flank, Hawaii ...Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies Our next example (Figure 4) is from the south flank of Kilauea Volcano ...status all 56 events, including the two offshore events near the underwater volcano , Loihi, off the coast of Hawaii and more than 20 km outside the

Equator and High-Latitude Ionosphere-to-Magnetosphere Research

DTIC Science & Technology

2010-12-04

characterizing plasma velocity profile in the heated region above HAARP has been clearly established. Specification of D region absorption from Digisonde...Electron density profile, Ground truth, Cal/Val, Doppler skymap, HAARP , Plasma velocity profile, Ionogram autoscaling, D region absorption...2  3  HAARP INVESTIGATIONS ............................................................................ 5  3.1

Development of Mine Explosion Ground Truth Smart Sensors

DTIC Science & Technology

2011-09-01

interest. The two candidates are the GS11-D by Oyo Geospace that is used extensively in seismic monitoring of geothermal fields and the Sensor Nederland SM...Technologies 853 Figure 4. Our preferred sensors and processor for the GTMS. (a) Sensor Nederland SM-6 geophone with emplacement spike. (b

Initial validation of the Soil Moisture Active Passive mission using USDA-ARS watersheds

USDA-ARS?s Scientific Manuscript database

The Soil Moisture Active Passive (SMAP) Mission was launched in January 2015 to measure global surface soil moisture. The calibration and validation program of SMAP relies upon an international cooperative of in situ networks to provide ground truth references across a variety of landscapes. The U...

Toward a Methodology of Death: Deleuze's "Event" as Method for Critical Ethnography

ERIC Educational Resources Information Center

Rodriguez, Sophia

2016-01-01

This article examines how qualitative researchers, specifically ethnographers, might utilize complex philosophical concepts in order to disrupt the normative truth-telling practices embedded in social science research. Drawing on my own research experiences, I move toward a methodology of death (for researcher/researched alike) grounded in…

Global Ground Truth Data Set with Waveform and Arrival Data

DTIC Science & Technology

2007-07-30

Redonda, Leeward Islands 15/13 Rowe, C.A., C.H. Thurber and R.A. White, Dome growth behavior at Soufriere Hills Volcano, Montserrat, revealed by...Thurber and R.A. White, Dome growth behavior at Soufriere Hills Volcano, Montserrat, revealed by relocation of volcanic event swarms, 1995-1996, J. Volc

An integrated approach to mapping forest conditions in the Southern Appalachians (North Carolina)

Treesearch

Weimin Xi; Lei Wang; Andrew G Birt; Maria D. Tchakerian; Robert N. Coulson; Kier D. Klepzig

2009-01-01

Accurate and continuous forest cover information is essential for forest management and restoration (SAMAB 1996, Xi et al. 2007). Ground-truthed, spatially explicit forest data, however, are often limited to federally managed land or large-scale commercial forestry operations where forest inventories are regularly collected. Moreover,...

The Role of Science in Behavioral Disorders.

ERIC Educational Resources Information Center

Kauffman, James M.

1999-01-01

A scientific, rule-governed approach to solving problems suggests the following assumptions: we need different rules for different purposes; rules are grounded in values; the origins and applications of rules are often misunderstood; personal experience and idea popularity are unreliable; and all truths are tentative. Each assumption is related to…

Spatially Explicit West Nile Virus Risk Modeling in Santa Clara County, CA

USDA-ARS?s Scientific Manuscript database

A geographic information systems model designed to identify regions of West Nile virus (WNV) transmission risk was tested and calibrated with data collected in Santa Clara County, California. American Crows that died from WNV infection in 2005, provided spatial and temporal ground truth. When the mo...

Spatially explicit West Nile virus risk modeling in Santa Clara County, California

USDA-ARS?s Scientific Manuscript database

A previously created Geographic Information Systems model designed to identify regions of West Nile virus (WNV) transmission risk is tested and calibrated in Santa Clara County, California. American Crows that died from WNV infection in 2005 provide the spatial and temporal ground truth. Model param...

NEAR INFRARED AERIAL PHOTO-DETECTION OF ZOSTERA JAPONICA COMMUNITIES IN PACIFIC NORTHWEST ESTUARINE INTERTIDAL HABITATS

EPA Science Inventory

Near infrared color aerial photography (-1:7200) of Yaquina Bay, Oregon, flown at minus tides during summer months of 1997 was used to produce digital stereo ortho-photographs covering tidally exposed eelgrass habitat. GIS analysis coupled with GPS positioning of ground-truth da...

76 FR 36934 - Endangered Species; Marine Mammals; Receipt of Applications for Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-23

... quantitative information or studies; and (2) Those that include citations to, and analyses of, the applicable... bears (Ursus maritimus) by adjusting the video camera equipment and conducting aerial surveys using FLIR (forward looking infrared) and ground-truth surveys with snowmobiles near dens for the purpose of...

Dsm Based Orientation of Large Stereo Satellite Image Blocks

NASA Astrophysics Data System (ADS)

d'Angelo, P.; Reinartz, P.

2012-07-01

High resolution stereo satellite imagery is well suited for the creation of digital surface models (DSM). A system for highly automated and operational DSM and orthoimage generation based on CARTOSAT-1 imagery is presented, with emphasis on fully automated georeferencing. The proposed system processes level-1 stereo scenes using the rational polynomial coefficients (RPC) universal sensor model. The RPC are derived from orbit and attitude information and have a much lower accuracy than the ground resolution of approximately 2.5 m. In order to use the images for orthorectification or DSM generation, an affine RPC correction is required. In this paper, GCP are automatically derived from lower resolution reference datasets (Landsat ETM+ Geocover and SRTM DSM). The traditional method of collecting the lateral position from a reference image and interpolating the corresponding height from the DEM ignores the higher lateral accuracy of the SRTM dataset. Our method avoids this drawback by using a RPC correction based on DSM alignment, resulting in improved geolocation of both DSM and ortho images. Scene based method and a bundle block adjustment based correction are developed and evaluated for a test site covering the nothern part of Italy, for which 405 Cartosat-1 Stereopairs are available. Both methods are tested against independent ground truth. Checks against this ground truth indicate a lateral error of 10 meters.

Investigating crater lake warming using ASTER thermal imagery: Case studies at Ruapehu, Poás, Kawah Ijen, and Copahué Volcanoes

NASA Astrophysics Data System (ADS)

Trunk, Laura; Bernard, Alain

2008-12-01

A two-channel or split-window algorithm designed to correct for atmospheric conditions was applied to thermal images taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) of Lake Yugama on Kusatsu-Shirane volcano in Japan in order to measure the temperature of its crater lake. These temperature calculations were validated using lake water temperatures that were collected on the ground. Overall, the agreement between the temperatures calculated using the split-window method and ground truth is quite good, typically ± 1.5 °C for cloud-free images. Data from fieldwork undertaken in the summer of 2004 at Kusatsu-Shirane allow a comparison of ground-truth data with the radiant temperatures measured using ASTER imagery. Further images were analyzed of Ruapehu, Poás, Kawah Ijen, and Copahué volcanoes to acquire time-series of lake temperatures. A total of 64 images of these 4 volcanoes covering a wide range of geographical locations and climates were analyzed. Results of the split-window algorithm applied to ASTER images are reliable for monitoring thermal changes in active volcanic lakes. These temperature data, when considered in conjunction with traditional volcano monitoring techniques, lead to a better understanding of whether and how thermal changes in crater lakes aid in eruption forecasting.

Avoiding Stair-Step Artifacts in Image Registration for GOES-R Navigation and Registration Assessment

NASA Technical Reports Server (NTRS)

Grycewicz, Thomas J.; Tan, Bin; Isaacson, Peter J.; De Luccia, Frank J.; Dellomo, John

2016-01-01

In developing software for independent verification and validation (IVV) of the Image Navigation and Registration (INR) capability for the Geostationary Operational Environmental Satellite R Series (GOES-R) Advanced Baseline Imager (ABI), we have encountered an image registration artifact which limits the accuracy of image offset estimation at the subpixel scale using image correlation. Where the two images to be registered have the same pixel size, subpixel image registration preferentially selects registration values where the image pixel boundaries are close to lined up. Because of the shape of a curve plotting input displacement to estimated offset, we call this a stair-step artifact. When one image is at a higher resolution than the other, the stair-step artifact is minimized by correlating at the higher resolution. For validating ABI image navigation, GOES-R images are correlated with Landsat-based ground truth maps. To create the ground truth map, the Landsat image is first transformed to the perspective seen from the GOES-R satellite, and then is scaled to an appropriate pixel size. Minimizing processing time motivates choosing the map pixels to be the same size as the GOES-R pixels. At this pixel size image processing of the shift estimate is efficient, but the stair-step artifact is present. If the map pixel is very small, stair-step is not a problem, but image correlation is computation-intensive. This paper describes simulation-based selection of the scale for truth maps for registering GOES-R ABI images.

Soil moisture variation patterns observed in Hand County, South Dakota

NASA Technical Reports Server (NTRS)

Jones, E. B.; Owe, M.; Schmugge, T. J. (Principal Investigator)

1981-01-01

Soil moisture data were taken during 1976 (April, June, October), 1977 (April, May, June), and 1978 (May, June, July) Hand County, South Dakota as part of the ground truth used in NASA's aircraft experiments to study the use of microwave radiometers for the remote sensing of soil moisture. The spatial variability observed on the ground during each of the sampling events was studied. The data reported are the mean gravimetric soil moisture contained in three surface horizon depths: 0 to 2.5, 0 to 5 and 0 to 10 cm. The overall moisture levels ranged from extremely dry conditions in June 1976 to very wet in May 1978, with a relatively even distribution of values within that range. It is indicated that well drained sites have to be partitioned from imperfectly drained areas when attempting to characterize the general moisture profile throughout an area of varying soil and cover type conditions. It is also found that the variability in moisture content is greatest in the 0 to 2.5 cm measurements and decreases as the measurements are integrated over a greater depth. It is also determined that the sampling intensity of 10 measurements per km is adequate to estimate the mean moisture with an uncertainty of + or - 3 percent under average moisture conditions in areas of moderate to good drainage.

A novel microaneurysms detection approach based on convolutional neural networks with reinforcement sample learning algorithm.

PubMed

Budak, Umit; Şengür, Abdulkadir; Guo, Yanhui; Akbulut, Yaman

2017-12-01

Microaneurysms (MAs) are known as early signs of diabetic-retinopathy which are called red lesions in color fundus images. Detection of MAs in fundus images needs highly skilled physicians or eye angiography. Eye angiography is an invasive and expensive procedure. Therefore, an automatic detection system to identify the MAs locations in fundus images is in demand. In this paper, we proposed a system to detect the MAs in colored fundus images. The proposed method composed of three stages. In the first stage, a series of pre-processing steps are used to make the input images more convenient for MAs detection. To this end, green channel decomposition, Gaussian filtering, median filtering, back ground determination, and subtraction operations are applied to input colored fundus images. After pre-processing, a candidate MAs extraction procedure is applied to detect potential regions. A five-stepped procedure is adopted to get the potential MA locations. Finally, deep convolutional neural network (DCNN) with reinforcement sample learning strategy is used to train the proposed system. The DCNN is trained with color image patches which are collected from ground-truth MA locations and non-MA locations. We conducted extensive experiments on ROC dataset to evaluate of our proposal. The results are encouraging.

Accuracy assessment in the Large Area Crop Inventory Experiment

NASA Technical Reports Server (NTRS)

Houston, A. G.; Pitts, D. E.; Feiveson, A. H.; Badhwar, G.; Ferguson, M.; Hsu, E.; Potter, J.; Chhikara, R.; Rader, M.; Ahlers, C.

1979-01-01

The Accuracy Assessment System (AAS) of the Large Area Crop Inventory Experiment (LACIE) was responsible for determining the accuracy and reliability of LACIE estimates of wheat production, area, and yield, made at regular intervals throughout the crop season, and for investigating the various LACIE error sources, quantifying these errors, and relating them to their causes. Some results of using the AAS during the three years of LACIE are reviewed. As the program culminated, AAS was able not only to meet the goal of obtaining accurate statistical estimates of sampling and classification accuracy, but also the goal of evaluating component labeling errors. Furthermore, the ground-truth data processing matured from collecting data for one crop (small grains) to collecting, quality-checking, and archiving data for all crops in a LACIE small segment.

Microwave radiometer experiment of soil moisture sensing at BARC test site during summer 1981

NASA Technical Reports Server (NTRS)

Wang, J.; Jackson, T.; Engman, E. T.; Gould, W.; Fuchs, J.; Glazer, W.; Oneill, P.; Schmugge, T. J.; Mcmurtrey, J., III

1984-01-01

Soil moisture was measured by truck mounted microwave radiometers at the frequencies of 1.4 GHz, 5 GHz, and 10.7 GHz. The soil textures in the two test sites were different so that the soil type effect of microwave radiometric response could be studied. Several fields in each test site were prepared with different surface roughnesses and vegetation covers. Ground truth on the soil moisture, temperature, and the biomass of the vegetation was acquired in support of the microwave radiometric measurements. Soil bulk density for each of the fields in both test sites was sampled. The soils in both sites were measured mechanically and chemically. A tabulation of the measured data is presented and the sensors and operational problems associated with the measurements are discussed.

Remote sensing capacity of Raman spectroscopy in identification of mineral and organic constituents

NASA Astrophysics Data System (ADS)

Chen, Bin; Stoker, Carol; Cabrol, Nathalie; McKay, Christopher P.

2007-09-01

We present design, integration and test results for a field Raman spectrometer science payload, integrated into the Mars Analog Research and Technology (MARTE) drilling platform. During the drilling operation, the subsurface Raman spectroscopy inspection system has obtained signatures of organic and mineral compositions. We also performed ground truth studies using both this field unit and a laboratory micro Raman spectrometer equipped with multiple laser excitation wavelengths on series of field samples including Mojave rocks, Laguna Verde salty sediment and Rio Tinto topsoil. We have evaluated laser excitation conditions and optical probe designs for further improvement. We have demonstrated promising potential for Raman spectroscopy as a non-destructive in situ, high throughput, subsurface detection technique, as well as a desirable active remote sensing tool for future planetary and space missions.

Innovative computational tools for reducing exploration risk through integration of water-rock interactions and magnetotelluric surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Joseph

2017-04-20

Mapping permeability distributions in geothermal reservoirs is essential for reducing the cost of geothermal development. To avoid the cost and sampling bias of measuring permeability directly through drilling, we require remote methods of imaging permeability such as geophysics. Electrical resistivity (or its inverse, conductivity) is one of the most sensitive geophysical properties known to reflect long range fluid interconnection and thus the likelihood of permeability. Perhaps the most widely applied geophysical methods for imaging subsurface resistivity is magnetotellurics (MT) due to its relatively great penetration depths. A primary goal of this project is to confirm through ground truthing at existingmore » geothermal systems that MT resistivity structure interpreted integratively is capable of revealing permeable fluid pathways into geothermal systems.« less

Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack

USGS Publications Warehouse

Clark, Roger N.; Swayze, Gregg A.; Hoefen, Todd M.; Green, Robert O.; Livo, Keith E.; Meeker, Gregory P.; Sutley, Stephen J.; Plumlee, Geoffrey S.; Pavri, Betina; Sarture, Charles M.; Boardman, Joe; Brownfield, Isabelle; Morath, Laurie C.

2009-01-01

The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over the World Trade Center area on September 16, 18, 22, and 23, 2001. The data were used to map the WTC debris plume and its contents, including the spectral signatures of asbestiform minerals. Samples were collected and used as ground truth for the AVARIS mapping. A number of thermal hot spots were observed with temperatures greater than 700 °C. The extent and temperatures of the fires were mapped as a function of time. By September 23, most of the fires observed by AVIRIS had been eliminated or reduced in intensity. The mineral absorption features mapped by AVARIS only indicated the presence of serpentine mineralogy and not if the serpentine has asbestiform.

Thermal Inertia of Rocks and Rock Populations and Implications for Landing Hazards on Mars

NASA Technical Reports Server (NTRS)

Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

2001-01-01

Rocks represent an obvious potential hazard to a landing spacecraft. They also represent an impediment to rover travel and objects of prime scientific interest. Although Mars Orbiter Camera (MOC) images are of high enough resolution to distinguish the largest rocks (an extremely small population several meters diameter or larger), traditionally the abundance and distribution of rocks on Mars have been inferred from thermal inertia and radar measurements, our meager ground truth sampling of landing sites, and terrestrial rock populations. In this abstract, we explore the effective thermal inertia of rocks and rock populations, interpret the results in terms of abundances and populations of potentially hazardous rocks, and conclude with interpretations of rock hazards on the Martian surface and in extremely high thermal inertia areas.

Airborne profiling of ice thickness using a short pulse radar

NASA Technical Reports Server (NTRS)

Vickers, R. S.; Heighway, J. E.; Gedney, R. T.

1973-01-01

This paper describes helicopter-borne measurements of ice thickness in Lake Superior, Lake St. Clair, and the St. Clair river as part of NASA's program to develop an ice information system. The profiler described is a high resolution, nonimaging, short pulse radar, operating at a carrier frequency of 2.7 GHz. The system can resolve reflective surfaces separated by as little as 10 cm and permits measurement of the distance between resolvable surfaces with an accuracy of about 1 cm. Data samples are given for measurements both in a static (helicopter hovering), and a traverse mode. Ground truth measurements taken by an ice auger team traveling with the helicopter are compared with the remotely sensed data and the accuracy of the profiler is discussed based on these measurements.

Severe storm electricity

NASA Technical Reports Server (NTRS)

Rust, W. D.; Macgorman, D. R.

1985-01-01

During FY-85, Researchers conducted a field program and analyzed data. The field program incorporated coordinated measurements made with a NASA U2. Results include the following: (1) ground truth measurements of lightning for comparison with those obtained by the U2; (2) analysis of dual-Doppler radar and dual-VHF lightning mapping data from a supercell storm; (3) analysis of synoptic conditions during three simultaneous storm systems on 13 May 1983 when unusually large numbers of positive cloud-to-ground (+CG) flashes occurred; (4) analysis of extremely low frequency (ELF) wave forms; and (5) an assessment of a cloud -ground strike location system using a combination of mobile laboratory and fixed-base TV video data.

ERTS-1 imagery and native plant distributions

NASA Technical Reports Server (NTRS)

Musick, H. B.; Mcginnies, W.; Haase, E.; Lepley, L. K.

1974-01-01

A method is developed for using ERTS spectral signature data to determine plant community distribution and phenology without resolving individual plants. An Exotech ERTS radiometer was used near ground level to obtain spectral signatures for a desert plant community, including two shrub species, ground covered with live annuals in April and dead ones in June, and bare ground. It is shown that comparisons of scene types can be made when spectral signatures are expressed as a ratio of red reflectivity to IR reflectivity or when they are plotted as red reflectivity vs. IR reflectivity, in which case the signature clusters of each component are more distinct. A method for correcting and converting the ERTS radiance values to reflectivity values for comparison with ground truth data is appended.

Basic truths for planning and executing an inventory

Treesearch

2000-01-01

A number of basic truths are presented. The importance of carefully developing the objectives for an inventory is stressed. The use of permanent plots and temporary plots is covered. The necessity of obtaining a representative sample, training effectively, and collecting quality data is discussed. The future direction for forest inventories is suggested.

A Multi-Sample Investigation of the Assessment and Locomotion Scales in a Population of Secondary School Students

ERIC Educational Resources Information Center

Hodis, Flaviu A.

2015-01-01

Understanding human motivation requires gauging individuals' strivings to be effective in controlling goal pursuits and establishing the truth about themselves and their experiences. Two constructs, assessment and locomotion, capture well truth and control strivings, respectively. The validation process of the instruments measuring assessment and…

Mars Analog Rio Tinto Experiment (MARTE): 2003 Drilling Campaign to Search for a Subsurface Biosphere at Rio Tinto Spain

NASA Astrophysics Data System (ADS)

Stoker, C.; Dunagan, S.; Stevens, T.; Amils, R.; Gómez-Elvira, J.; Fernández, D.; Hall, J.; Lynch, K.; Cannon, H.; Zavaleta, J.; Glass, B.; Lemke, L.

2004-03-01

The results of an drilling experiment to search for a subsurface biosphere in a pyritic mineral deposit at Rio Tinto, Spain, are described. The experiment provides ground truth for a simulation of a Mars drilling mission to search for subsurface life.

Active microwave water equivalence

NASA Technical Reports Server (NTRS)

Boyne, H. S.; Ellerbruch, D. A.

1980-01-01

Measurements of water equivalence using an active FM-CW microwave system were conducted over the past three years at various sites in Colorado, Wyoming, and California. The measurement method is described. Measurements of water equivalence and stratigraphy are compared with ground truth. A comparison of microwave, federal sampler, and snow pillow measurements at three sites in Colorado is described.

Medium Spatial Resolution Satellite Characterization

NASA Technical Reports Server (NTRS)

Stensaas, Greg

2007-01-01

This project provides characterization and calibration of aerial and satellite systems in support of quality acquisition and understanding of remote sensing data, and verifies and validates the associated data products with respect to ground and and atmospheric truth so that accurate value-added science can be performed. The project also provides assessment of new remote sensing technologies.

EREP geothermal. [northern California

NASA Technical Reports Server (NTRS)

Johnston, E. W. (Principal Investigator); Dunklee, A. L.; Wychgram, D. C.

1974-01-01

The author has identified the following significant results. A reasonably good agreement was found for the radiometric temperatures calculated from the ground truth data and the radiometric temperatures measured by the S192 scanner. This study showed that the S192 scanner data could be used to create good thermal images, particularly with the x-5 detector array.

The Use of Narrative Therapy with Clients Diagnosed with Bipolar Disorder

ERIC Educational Resources Information Center

Ngazimbi, Evadne E.; Lambie, Glenn W.; Shillingford, M. Ann

2008-01-01

Clients diagnosed with bipolar disorder often suffer from mood instability, and research suggests that these clients need both counseling services and pharmacotherapy. Narrative therapy is a social constructionist approach grounded on the premise that there is no single "truth"; individuals may create new meanings and retell their stories to…

Skepticism, Truth as Coherence, and Constructivist Epistemology: Grounds for Resolving the Discord between Science and Religion?

ERIC Educational Resources Information Center

Staver, John R.

2010-01-01

Science and religion exhibit multiple relationships as ways of knowing. These connections have been characterized as cousinly, mutually respectful, non-overlapping, competitive, proximate-ultimate, dominant-subordinate, and opposing-conflicting. Some of these ties create stress, and tension between science and religion represents a significant…

Ground-Truthing Validation to Assess the Effect of Facility Locational Error on Cumulative Impacts Screening Tools

EPA Science Inventory

Over the past three decades, a number of researchers in the fields of environmental justice (EJ) and environmental public health have highlighted the existence of regional and local scale differences in exposure to air pollution, as well as calculated health risk and impacts of a...

Shakespeare: Finding and Teaching the Comic Vision.

ERIC Educational Resources Information Center

Lasser, Michael L.

1969-01-01

Comedy is the middle ground upon which the absurd and the serious meet. Concerned with illuminating pain, human imperfection, and man's failure to measure up to his own or the world's concept of perfection, comedy provides "an escape, not from truth but from despair." If tragedy says that some ideals are worth dying for, comedy asserts…

Spatio-Temporal Analysis of Surface Soil Moisture in Evaluating Ground Truth Monitoring Sites for Remotely Sensed Observations

USDA-ARS?s Scientific Manuscript database

Soil moisture is an intrinsic state variable that varies considerably in space and time. Although soil moisture is highly variable, repeated measurements of soil moisture at the field or small watershed scale can often reveal certain locations as being temporally stable and representative of the are...

EREP users handbook

NASA Technical Reports Server (NTRS)

1971-01-01

Revised Skylab spacecraft, experiments, and mission planning information is presented for the Earth Resources Experiment Package (EREP) users. The major hardware elements and the medical, scientific, engineering, technology and earth resources experiments are described. Ground truth measurements and EREP data handling procedures are discussed. The mission profile, flight planning, crew activities, and aircraft support are also outlined.

Late diagenetic indicators of buried oil and gas: II, Direct detection experiment at Cement and Garza oil fields, Oklahoma and Texas, using enhanced LANDSAT I and II images

USGS Publications Warehouse

Donovan, Terrence J.; Termain, Patricia A.; Henry, Mitchell E.

1979-01-01

The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite are the major alteration phenomena at Cement. The bedrock alterations are partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters biased by detailed ground truth were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation. Similar techniques were applied at a secondary test site (Garza oil field, Texas), where similar alterations in surface rocks occur. Enhanced LANDSAT images resolved the alteration zone to a biased interpreter and some individual altered outcrops could be mapped using higher resolution SKYLAB color and conventional black and white aerial photographs suggesting repeat experiments with LANDSAT C and D.

Extraction of Capillary Non-perfusion from Fundus Fluorescein Angiogram

NASA Astrophysics Data System (ADS)

Sivaswamy, Jayanthi; Agarwal, Amit; Chawla, Mayank; Rani, Alka; Das, Taraprasad

Capillary Non-Perfusion (CNP) is a condition in diabetic retinopathy where blood ceases to flow to certain parts of the retina, potentially leading to blindness. This paper presents a solution for automatically detecting and segmenting CNP regions from fundus fluorescein angiograms (FFAs). CNPs are modelled as valleys, and a novel technique based on extrema pyramid is presented for trough-based valley detection. The obtained valley points are used to segment the desired CNP regions by employing a variance-based region growing scheme. The proposed algorithm has been tested on 40 images and validated against expert-marked ground truth. In this paper, we present results of testing and validation of our algorithm against ground truth and compare the segmentation performance against two others methods.The performance of the proposed algorithm is presented as a receiver operating characteristic (ROC) curve. The area under this curve is 0.842 and the distance of ROC from the ideal point (0,1) is 0.31. The proposed method for CNP segmentation was found to outperform the watershed [1] and heat-flow [2] based methods.

Constructing Benchmark Databases and Protocols for Medical Image Analysis: Diabetic Retinopathy

PubMed Central

Kauppi, Tomi; Kämäräinen, Joni-Kristian; Kalesnykiene, Valentina; Sorri, Iiris; Uusitalo, Hannu; Kälviäinen, Heikki

2013-01-01

We address the performance evaluation practices for developing medical image analysis methods, in particular, how to establish and share databases of medical images with verified ground truth and solid evaluation protocols. Such databases support the development of better algorithms, execution of profound method comparisons, and, consequently, technology transfer from research laboratories to clinical practice. For this purpose, we propose a framework consisting of reusable methods and tools for the laborious task of constructing a benchmark database. We provide a software tool for medical image annotation helping to collect class label, spatial span, and expert's confidence on lesions and a method to appropriately combine the manual segmentations from multiple experts. The tool and all necessary functionality for method evaluation are provided as public software packages. As a case study, we utilized the framework and tools to establish the DiaRetDB1 V2.1 database for benchmarking diabetic retinopathy detection algorithms. The database contains a set of retinal images, ground truth based on information from multiple experts, and a baseline algorithm for the detection of retinopathy lesions. PMID:23956787

Natural Language Processing Techniques for Extracting and Categorizing Finding Measurements in Narrative Radiology Reports.

PubMed

Sevenster, M; Buurman, J; Liu, P; Peters, J F; Chang, P J

2015-01-01

Accumulating quantitative outcome parameters may contribute to constructing a healthcare organization in which outcomes of clinical procedures are reproducible and predictable. In imaging studies, measurements are the principal category of quantitative para meters. The purpose of this work is to develop and evaluate two natural language processing engines that extract finding and organ measurements from narrative radiology reports and to categorize extracted measurements by their "temporality". The measurement extraction engine is developed as a set of regular expressions. The engine was evaluated against a manually created ground truth. Automated categorization of measurement temporality is defined as a machine learning problem. A ground truth was manually developed based on a corpus of radiology reports. A maximum entropy model was created using features that characterize the measurement itself and its narrative context. The model was evaluated in a ten-fold cross validation protocol. The measurement extraction engine has precision 0.994 and recall 0.991. Accuracy of the measurement classification engine is 0.960. The work contributes to machine understanding of radiology reports and may find application in software applications that process medical data.

Flight data acquisition methodology for validation of passive ranging algorithms for obstacle avoidance

NASA Technical Reports Server (NTRS)

Smith, Phillip N.

1990-01-01

The automation of low-altitude rotorcraft flight depends on the ability to detect, locate, and navigate around obstacles lying in the rotorcraft's intended flightpath. Computer vision techniques provide a passive method of obstacle detection and range estimation, for obstacle avoidance. Several algorithms based on computer vision methods have been developed for this purpose using laboratory data; however, further development and validation of candidate algorithms require data collected from rotorcraft flight. A data base containing low-altitude imagery augmented with the rotorcraft and sensor parameters required for passive range estimation is not readily available. Here, the emphasis is on the methodology used to develop such a data base from flight-test data consisting of imagery, rotorcraft and sensor parameters, and ground-truth range measurements. As part of the data preparation, a technique for obtaining the sensor calibration parameters is described. The data base will enable the further development of algorithms for computer vision-based obstacle detection and passive range estimation, as well as provide a benchmark for verification of range estimates against ground-truth measurements.

Hybrid wavefront sensing and image correction algorithm for imaging through turbulent media

NASA Astrophysics Data System (ADS)

Wu, Chensheng; Robertson Rzasa, John; Ko, Jonathan; Davis, Christopher C.

2017-09-01

It is well known that passive image correction of turbulence distortions often involves using geometry-dependent deconvolution algorithms. On the other hand, active imaging techniques using adaptive optic correction should use the distorted wavefront information for guidance. Our work shows that a hybrid hardware-software approach is possible to obtain accurate and highly detailed images through turbulent media. The processing algorithm also takes much fewer iteration steps in comparison with conventional image processing algorithms. In our proposed approach, a plenoptic sensor is used as a wavefront sensor to guide post-stage image correction on a high-definition zoomable camera. Conversely, we show that given the ground truth of the highly detailed image and the plenoptic imaging result, we can generate an accurate prediction of the blurred image on a traditional zoomable camera. Similarly, the ground truth combined with the blurred image from the zoomable camera would provide the wavefront conditions. In application, our hybrid approach can be used as an effective way to conduct object recognition in a turbulent environment where the target has been significantly distorted or is even unrecognizable.

Automatic Diabetic Macular Edema Detection in Fundus Images Using Publicly Available Datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giancardo, Luca; Meriaudeau, Fabrice; Karnowski, Thomas Paul

2011-01-01

Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, we introduce a new methodology for diagnosis of DME using a novel set of features based on colour, wavelet decomposition and automatic lesion segmentation. These features are employed to train a classifier able to automatically diagnose DME. We present a new publicly available dataset with ground-truth data containing 169 patients from various ethnic groups and levels of DME. This and other two publiclymore » available datasets are employed to evaluate our algorithm. We are able to achieve diagnosis performance comparable to retina experts on the MESSIDOR (an independently labelled dataset with 1200 images) with cross-dataset testing. Our algorithm is robust to segmentation uncertainties, does not need ground truth at lesion level, and is very fast, generating a diagnosis on an average of 4.4 seconds per image on an 2.6 GHz platform with an unoptimised Matlab implementation.« less

Application of Landsat Thematic Mapper data for coastal thermal plume analysis at Diablo Canyon

NASA Technical Reports Server (NTRS)

Gibbons, D. E.; Wukelic, G. E.; Leighton, J. P.; Doyle, M. J.

1989-01-01

The possibility of using Landsat Thematic Mapper (TM) thermal data to derive absolute temperature distributions in coastal waters that receive cooling effluent from a power plant is demonstrated. Landsat TM band 6 (thermal) data acquired on June 18, 1986, for the Diablo Canyon power plant in California were compared to ground truth temperatures measured at the same time. Higher-resolution band 5 (reflectance) data were used to locate power plant discharge and intake positions and identify locations of thermal pixels containing only water, no land. Local radiosonde measurements, used in LOWTRAN 6 adjustments for atmospheric effects, produced corrected ocean surface radiances that, when converted to temperatures, gave values within approximately 0.6 C of ground truth. A contour plot was produced that compared power plant plume temperatures with those of the ocean and coastal environment. It is concluded that Landsat can provide good estimates of absolute temperatures of the coastal power plant thermal plume. Moreover, quantitative information on ambient ocean surface temperature conditions (e.g., upwelling) may enhance interpretation of numerical model prediction.

Spatial Statistics for Segmenting Histological Structures in H&E Stained Tissue Images.

PubMed

Nguyen, Luong; Tosun, Akif Burak; Fine, Jeffrey L; Lee, Adrian V; Taylor, D Lansing; Chennubhotla, S Chakra

2017-07-01

Segmenting a broad class of histological structures in transmitted light and/or fluorescence-based images is a prerequisite for determining the pathological basis of cancer, elucidating spatial interactions between histological structures in tumor microenvironments (e.g., tumor infiltrating lymphocytes), facilitating precision medicine studies with deep molecular profiling, and providing an exploratory tool for pathologists. This paper focuses on segmenting histological structures in hematoxylin- and eosin-stained images of breast tissues, e.g., invasive carcinoma, carcinoma in situ, atypical and normal ducts, adipose tissue, and lymphocytes. We propose two graph-theoretic segmentation methods based on local spatial color and nuclei neighborhood statistics. For benchmarking, we curated a data set of 232 high-power field breast tissue images together with expertly annotated ground truth. To accurately model the preference for histological structures (ducts, vessels, tumor nets, adipose, etc.) over the remaining connective tissue and non-tissue areas in ground truth annotations, we propose a new region-based score for evaluating segmentation algorithms. We demonstrate the improvement of our proposed methods over the state-of-the-art algorithms in both region- and boundary-based performance measures.

Label Identification from Statistical Tabulation (LIST) temporal extendability study. [North Dakota, South Dakota, and Minnesota

NASA Technical Reports Server (NTRS)

Dennis, T. B. (Principal Investigator)

1980-01-01

The author has identified the following significant results. The most apparent contributors to the problem of poor temporal extension of LIST are the drastic changes in the brightness keys and an inadequate set of AI responses in Phase 3. The brightness trajectories change drastically from Phase 3 to the transition year (TY). Removing brightness channels from the discriminant does not completely correct the lack of extendability. Removing brightness increases the accuracy of the extension from Phase 3 to TY from 57.7 percent to 64.18 percent. The removal of the Al keys increases accuracy to 65.76 percent. Although the latter increase appears insignificant when compared to the first, the removal of only the Al keys increased accuracy to 63.58 percent. Proper weighting of the responses explains 73.8 percent of the ground truth labels but only 56.7 percent of the Al labels. By contrast, the TY responses which were weighted to explain the TY ground truth labels fared equally well, explaining 73.6 percent of those labels and 87.1 percent of the Al labels.

Leaf Area Index Estimation in Vineyards from Uav Hyperspectral Data, 2d Image Mosaics and 3d Canopy Surface Models

NASA Astrophysics Data System (ADS)

Kalisperakis, I.; Stentoumis, Ch.; Grammatikopoulos, L.; Karantzalos, K.

2015-08-01

The indirect estimation of leaf area index (LAI) in large spatial scales is crucial for several environmental and agricultural applications. To this end, in this paper, we compare and evaluate LAI estimation in vineyards from different UAV imaging datasets. In particular, canopy levels were estimated from i.e., (i) hyperspectral data, (ii) 2D RGB orthophotomosaics and (iii) 3D crop surface models. The computed canopy levels have been used to establish relationships with the measured LAI (ground truth) from several vines in Nemea, Greece. The overall evaluation indicated that the estimated canopy levels were correlated (r2 > 73%) with the in-situ, ground truth LAI measurements. As expected the lowest correlations were derived from the calculated greenness levels from the 2D RGB orthomosaics. The highest correlation rates were established with the hyperspectral canopy greenness and the 3D canopy surface models. For the later the accurate detection of canopy, soil and other materials in between the vine rows is required. All approaches tend to overestimate LAI in cases with sparse, weak, unhealthy plants and canopy.

Mineral Potential in India Using Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) Data

NASA Astrophysics Data System (ADS)

Oommen, T.; Chatterjee, S.

2017-12-01

NASA and the Indian Space Research Organization (ISRO) are generating Earth surface features data using Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) within 380 to 2500 nm spectral range. This research focuses on the utilization of such data to better understand the mineral potential in India and to demonstrate the application of spectral data in rock type discrimination and mapping for mineral exploration by using automated mapping techniques. The primary focus area of this research is the Hutti-Maski greenstone belt, located in Karnataka, India. The AVIRIS-NG data was integrated with field analyzed data (laboratory scaled compositional analysis, mineralogy, and spectral library) to characterize minerals and rock types. An expert system was developed to produce mineral maps from AVIRIS-NG data automatically. The ground truth data from the study areas was obtained from the existing literature and collaborators from India. The Bayesian spectral unmixing algorithm was used in AVIRIS-NG data for endmember selection. The classification maps of the minerals and rock types were developed using support vector machine algorithm. The ground truth data was used to verify the mineral maps.

Using simulated fluorescence cell micrographs for the evaluation of cell image segmentation algorithms.

PubMed

Wiesmann, Veit; Bergler, Matthias; Palmisano, Ralf; Prinzen, Martin; Franz, Daniela; Wittenberg, Thomas

2017-03-18

Manual assessment and evaluation of fluorescent micrograph cell experiments is time-consuming and tedious. Automated segmentation pipelines can ensure efficient and reproducible evaluation and analysis with constant high quality for all images of an experiment. Such cell segmentation approaches are usually validated and rated in comparison to manually annotated micrographs. Nevertheless, manual annotations are prone to errors and display inter- and intra-observer variability which influence the validation results of automated cell segmentation pipelines. We present a new approach to simulate fluorescent cell micrographs that provides an objective ground truth for the validation of cell segmentation methods. The cell simulation was evaluated twofold: (1) An expert observer study shows that the proposed approach generates realistic fluorescent cell micrograph simulations. (2) An automated segmentation pipeline on the simulated fluorescent cell micrographs reproduces segmentation performances of that pipeline on real fluorescent cell micrographs. The proposed simulation approach produces realistic fluorescent cell micrographs with corresponding ground truth. The simulated data is suited to evaluate image segmentation pipelines more efficiently and reproducibly than it is possible on manually annotated real micrographs.

Comparison of thyroid segmentation techniques for 3D ultrasound

NASA Astrophysics Data System (ADS)

Wunderling, T.; Golla, B.; Poudel, P.; Arens, C.; Friebe, M.; Hansen, C.

2017-02-01

The segmentation of the thyroid in ultrasound images is a field of active research. The thyroid is a gland of the endocrine system and regulates several body functions. Measuring the volume of the thyroid is regular practice of diagnosing pathological changes. In this work, we compare three approaches for semi-automatic thyroid segmentation in freehand-tracked three-dimensional ultrasound images. The approaches are based on level set, graph cut and feature classification. For validation, sixteen 3D ultrasound records were created with ground truth segmentations, which we make publicly available. The properties analyzed are the Dice coefficient when compared against the ground truth reference and the effort of required interaction. Our results show that in terms of Dice coefficient, all algorithms perform similarly. For interaction, however, each algorithm has advantages over the other. The graph cut-based approach gives the practitioner direct influence on the final segmentation. Level set and feature classifier require less interaction, but offer less control over the result. All three compared methods show promising results for future work and provide several possible extensions.

A High-Resolution Tile-Based Approach for Classifying Biological Regions in Whole-Slide Histopathological Images

PubMed Central

Hoffman, R.A.; Kothari, S.; Phan, J.H.; Wang, M.D.

2016-01-01

Computational analysis of histopathological whole slide images (WSIs) has emerged as a potential means for improving cancer diagnosis and prognosis. However, an open issue relating to the automated processing of WSIs is the identification of biological regions such as tumor, stroma, and necrotic tissue on the slide. We develop a method for classifying WSI portions (512x512-pixel tiles) into biological regions by (1) extracting a set of 461 image features from each WSI tile, (2) optimizing tile-level prediction models using nested cross-validation on a small (600 tile) manually annotated tile-level training set, and (3) validating the models against a much larger (1.7x106 tile) data set for which ground truth was available on the whole-slide level. We calculated the predicted prevalence of each tissue region and compared this prevalence to the ground truth prevalence for each image in an independent validation set. Results show significant correlation between the predicted (using automated system) and reported biological region prevalences with p < 0.001 for eight of nine cases considered. PMID:27532012

A High-Resolution Tile-Based Approach for Classifying Biological Regions in Whole-Slide Histopathological Images.

PubMed

Hoffman, R A; Kothari, S; Phan, J H; Wang, M D

Computational analysis of histopathological whole slide images (WSIs) has emerged as a potential means for improving cancer diagnosis and prognosis. However, an open issue relating to the automated processing of WSIs is the identification of biological regions such as tumor, stroma, and necrotic tissue on the slide. We develop a method for classifying WSI portions (512x512-pixel tiles) into biological regions by (1) extracting a set of 461 image features from each WSI tile, (2) optimizing tile-level prediction models using nested cross-validation on a small (600 tile) manually annotated tile-level training set, and (3) validating the models against a much larger (1.7x10 6 tile) data set for which ground truth was available on the whole-slide level. We calculated the predicted prevalence of each tissue region and compared this prevalence to the ground truth prevalence for each image in an independent validation set. Results show significant correlation between the predicted (using automated system) and reported biological region prevalences with p < 0.001 for eight of nine cases considered.

A large dataset of synthetic SEM images of powder materials and their ground truth 3D structures.

PubMed

DeCost, Brian L; Holm, Elizabeth A

2016-12-01

This data article presents a data set comprised of 2048 synthetic scanning electron microscope (SEM) images of powder materials and descriptions of the corresponding 3D structures that they represent. These images were created using open source rendering software, and the generating scripts are included with the data set. Eight particle size distributions are represented with 256 independent images from each. The particle size distributions are relatively similar to each other, so that the dataset offers a useful benchmark to assess the fidelity of image analysis techniques. The characteristics of the PSDs and the resulting images are described and analyzed in more detail in the research article "Characterizing powder materials using keypoint-based computer vision methods" (B.L. DeCost, E.A. Holm, 2016) [1]. These data are freely available in a Mendeley Data archive "A large dataset of synthetic SEM images of powder materials and their ground truth 3D structures" (B.L. DeCost, E.A. Holm, 2016) located at http://dx.doi.org/10.17632/tj4syyj9mr.1[2] for any academic, educational, or research purposes.

Seafloor monitoring west of Helgoland (German Bight, North Sea) using the acoustic ground discrimination system RoxAnn

NASA Astrophysics Data System (ADS)

Hass, H. Christian; Mielck, Finn; Fiorentino, Dario; Papenmeier, Svenja; Holler, Peter; Bartholomä, Alexander

2017-04-01

Marine habitats of shelf seas are in constant dynamic change and therefore need regular assessment particularly in areas of special interest. In this study, the single-beam acoustic ground discrimination system RoxAnn served to assess seafloor hardness and roughness, and combine these parameters into one variable expressed as RGB (red green blue) color code followed by k-means fuzzy cluster analysis (FCA). The data were collected at a monitoring site west of the island of Helgoland (German Bight, SE North Sea) in the course of four surveys between September 2011 and November 2014. The study area has complex characteristics varying from outcropping bedrock to sandy and muddy sectors with mostly gradual transitions. RoxAnn data enabled to discriminate all seafloor types that were suggested by ground-truth information (seafloor samples, video). The area appears to be quite stable overall; sediment import (including fluid mud) was detected only from the NW. Although hard substrates (boulders, bedrock) are clearly identified, the signal can be modified by inclination and biocover. Manually, six RoxAnn zones were identified; for the FCA, only three classes are suggested. The latter classification based on `hard' boundaries would suffice for stakeholder issues, but the former classification based on `soft' boundaries is preferred to meet state-of-the-art scientific objectives.

Orbit and sampling requirements: TRMM experience

NASA Technical Reports Server (NTRS)

North, Gerald

1993-01-01

The Tropical Rainfall Measuring Mission (TRMM) concept originated in 1984. Its overall goal is to produce datasets that can be used in the improvement of general circulation models. A primary objective is a multi-year data stream of monthly averages of rain rate over 500 km boxes over the tropical oceans. Vertical distributions of the hydrometers, related to latent heat profiles, and the diurnal cycle of rainrates are secondary products believed to be accessible. The mission is sponsored jointly by the U.S. and Japan. TRMM is an approved mission with launch set for 1997. There are many retrieval and ground truth issues still being studied for TRMM, but here we concentrate on sampling since it is the single largest term in the error budget. The TRMM orbit plane is inclined by 35 degrees to the equator, which leads to a precession of the visits to a given grid box through the local hours of the day, requiring three to six weeks to complete the diurnal cycle, depending on latitude. For sampling studies we can consider the swath width to be about 700 km.

Evaluation of seabed mapping methods for fine-scale classification of extremely shallow benthic habitats - Application to the Venice Lagoon, Italy

NASA Astrophysics Data System (ADS)

Montereale Gavazzi, G.; Madricardo, F.; Janowski, L.; Kruss, A.; Blondel, P.; Sigovini, M.; Foglini, F.

2016-03-01

Recent technological developments of multibeam echosounder systems (MBES) allow mapping of benthic habitats with unprecedented detail. MBES can now be employed in extremely shallow waters, challenging data acquisition (as these instruments were often designed for deeper waters) and data interpretation (honed on datasets with resolution sometimes orders of magnitude lower). With extremely high-resolution bathymetry and co-located backscatter data, it is now possible to map the spatial distribution of fine scale benthic habitats, even identifying the acoustic signatures of single sponges. In this context, it is necessary to understand which of the commonly used segmentation methods is best suited to account for such level of detail. At the same time, new sampling protocols for precisely geo-referenced ground truth data need to be developed to validate the benthic environmental classification. This study focuses on a dataset collected in a shallow (2-10 m deep) tidal channel of the Lagoon of Venice, Italy. Using 0.05-m and 0.2-m raster grids, we compared a range of classifications, both pixel-based and object-based approaches, including manual, Maximum Likelihood Classifier, Jenks Optimization clustering, textural analysis and Object Based Image Analysis. Through a comprehensive and accurately geo-referenced ground truth dataset, we were able to identify five different classes of the substrate composition, including sponges, mixed submerged aquatic vegetation, mixed detritic bottom (fine and coarse) and unconsolidated bare sediment. We computed estimates of accuracy (namely Overall, User, Producer Accuracies and the Kappa statistic) by cross tabulating predicted and reference instances. Overall, pixel based segmentations produced the highest accuracies and the accuracy assessment is strongly dependent on the number of classes chosen for the thematic output. Tidal channels in the Venice Lagoon are extremely important in terms of habitats and sediment distribution, particularly within the context of the new tidal barrier being built. However, they had remained largely unexplored until now, because of the surveying challenges. The application of this remote sensing approach, combined with targeted sampling, opens a new perspective in the monitoring of benthic habitats in view of a knowledge-based management of natural resources in shallow coastal areas.

Segmentation of thalamus from MR images via task-driven dictionary learning

NASA Astrophysics Data System (ADS)

Liu, Luoluo; Glaister, Jeffrey; Sun, Xiaoxia; Carass, Aaron; Tran, Trac D.; Prince, Jerry L.

2016-03-01

Automatic thalamus segmentation is useful to track changes in thalamic volume over time. In this work, we introduce a task-driven dictionary learning framework to find the optimal dictionary given a set of eleven features obtained from T1-weighted MRI and diffusion tensor imaging. In this dictionary learning framework, a linear classifier is designed concurrently to classify voxels as belonging to the thalamus or non-thalamus class. Morphological post-processing is applied to produce the final thalamus segmentation. Due to the uneven size of the training data samples for the non-thalamus and thalamus classes, a non-uniform sampling scheme is pro- posed to train the classifier to better discriminate between the two classes around the boundary of the thalamus. Experiments are conducted on data collected from 22 subjects with manually delineated ground truth. The experimental results are promising in terms of improvements in the Dice coefficient of the thalamus segmentation overstate-of-the-art atlas-based thalamus segmentation algorithms.

Segmentation of Thalamus from MR images via Task-Driven Dictionary Learning.

PubMed

Liu, Luoluo; Glaister, Jeffrey; Sun, Xiaoxia; Carass, Aaron; Tran, Trac D; Prince, Jerry L

2016-02-27

Automatic thalamus segmentation is useful to track changes in thalamic volume over time. In this work, we introduce a task-driven dictionary learning framework to find the optimal dictionary given a set of eleven features obtained from T1-weighted MRI and diffusion tensor imaging. In this dictionary learning framework, a linear classifier is designed concurrently to classify voxels as belonging to the thalamus or non-thalamus class. Morphological post-processing is applied to produce the final thalamus segmentation. Due to the uneven size of the training data samples for the non-thalamus and thalamus classes, a non-uniform sampling scheme is proposed to train the classifier to better discriminate between the two classes around the boundary of the thalamus. Experiments are conducted on data collected from 22 subjects with manually delineated ground truth. The experimental results are promising in terms of improvements in the Dice coefficient of the thalamus segmentation over state-of-the-art atlas-based thalamus segmentation algorithms.

Data-adaptive test statistics for microarray data.

PubMed

Mukherjee, Sach; Roberts, Stephen J; van der Laan, Mark J

2005-09-01

An important task in microarray data analysis is the selection of genes that are differentially expressed between different tissue samples, such as healthy and diseased. However, microarray data contain an enormous number of dimensions (genes) and very few samples (arrays), a mismatch which poses fundamental statistical problems for the selection process that have defied easy resolution. In this paper, we present a novel approach to the selection of differentially expressed genes in which test statistics are learned from data using a simple notion of reproducibility in selection results as the learning criterion. Reproducibility, as we define it, can be computed without any knowledge of the 'ground-truth', but takes advantage of certain properties of microarray data to provide an asymptotically valid guide to expected loss under the true data-generating distribution. We are therefore able to indirectly minimize expected loss, and obtain results substantially more robust than conventional methods. We apply our method to simulated and oligonucleotide array data. By request to the corresponding author.

The MicrOmega Investigation Onboard Hayabusa2

NASA Astrophysics Data System (ADS)

Bibring, J.-P.; Hamm, V.; Langevin, Y.; Pilorget, C.; Arondel, A.; Bouzit, M.; Chaigneau, M.; Crane, B.; Darié, A.; Evesque, C.; Hansotte, J.; Gardien, V.; Gonnod, L.; Leclech, J.-C.; Meslier, L.; Redon, T.; Tamiatto, C.; Tosti, S.; Thoores, N.

2017-07-01

MicrOmega is a near-IR hyperspectral microscope designed to characterize in situ the texture and composition of the surface materials of the Hayabusa2 target asteroid. MicrOmega is implemented within the MASCOT lander (Ho et al. in Space Sci. Rev., 2016, this issue, doi:10.1007/s11214-016-0251-6). The spectral range (0.99-3.65 μm) and the spectral sampling (20 cm^{-1}) of MicrOmega have been chosen to allow the identification of most potential constituent minerals, ices and organics, within each 25 μm pixel of the 3.2× 3.2 mm2 FOV. Such an unprecedented characterization will (1) enable the identification of most major and minor phases, including the potential organic phases, and ascribe their mineralogical context, as a critical set of clues to decipher the origin and evolution of this primitive body, and (2) provide the ground truth for the orbital measurements as well as a reference for the analyses later performed on returned samples.

A novel visual pipework inspection system

NASA Astrophysics Data System (ADS)

Summan, Rahul; Jackson, William; Dobie, Gordon; MacLeod, Charles; Mineo, Carmelo; West, Graeme; Offin, Douglas; Bolton, Gary; Marshall, Stephen; Lille, Alexandre

2018-04-01

The interior visual inspection of pipelines in the nuclear industry is a safety critical activity conducted during outages to ensure the continued safe and reliable operation of plant. Typically, the video output by a manually deployed probe is viewed by an operator looking to identify and localize surface defects such as corrosion, erosion and pitting. However, it is very challenging to estimate the nature and extent of defects by viewing a large structure through a relatively small field of view. This work describes a new visual inspection system employing photogrammetry using a fisheye camera and a structured light system to map the internal geometry of pipelines by generating a photorealistic, geometrically accurate surface model. The error of the system output was evaluated through comparison to a ground truth laser scan (ATOS GOM Triple Scan) of a nuclear grade split pipe sample (stainless steel 304L, 80mm internal diameter) containing defects representative of the application - the error was found to be submillimeter across the sample.

Reflectance of vegetation, soil, and water

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1973-01-01

The author has identified the following significant results. A ratio of MSS channels 5 and 7 (5/7) and 5 to 6 (5/6) signals resulted in a correct recognition of 86.9% of the members of representative crop and soil conditions, compared with recognitions of 60.0, 64.1, 74.1, and 81.4% for channels 4, 5, 6, and 7 taken individually. Based on this result a satellite channel ratio procedure has been developed that enhances line printer gray maps for more efficient experimental test site location in the CCT data. Because independent estimates are not available to judge acreage estmates derived from ERTS-1 data against, except for a few crops, an interpenetrating sample constituting 3.5% of the county is ground truthed periodically. The crop of land uses and their acreages, respectively, as estimated from the interpenetrating samples, are: cotton, 129, 714; sorghum, 182,783; mixed citrus, 53,954; oranges, 16,929; grapefruit, 13,863; rangeland, 137,845; and, improved pastures, 57.169.

Sedimentologic characteristics of recent washover deposits from Assateague Island, Maryland

USGS Publications Warehouse

Bernier, Julie C.; Zaremba, Nicholas J.; Wheaton, Cathryn J.; Ellis, Alisha M.; Marot, Marci E.; Smith, Christopher G.

2016-06-08

This report describes sediment data collected using sand augers in active overwash zones on Assateague Island in Maryland. Samples were collected by the U.S. Geological Survey (USGS) during two surveys in March/April and October 2014 (USGS Field Activity Numbers [FAN] 2014-301-FA and 2014-322-FA, respectively). The physical characteristics (for example, sediment texture or bedding structure) of and spatial differences among these deposits will provide information about overwash processes and sediment transport from the sandy barrier-island reaches to the back-barrier environments. Metrics derived from these data, such as mean grain size or deposit thicknesses, can be used to ground-truth remote sensing and geophysical data and can also be incorporated into sediment transport models. Data products, including sample location tables, descriptive core logs, core photographs and x-radiographs, the results of sediment grain-size analyses, and Geographic Information System (GIS) data files with accompanying formal Federal Geographic Data Committee (FGDC) metadata can be downloaded from the Data Downloads page.

TH-C-BRD-06: A Novel MRI Based CT Artifact Correction Method for Improving Proton Range Calculation in the Presence of Severe CT Artifacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, P; Schreibmann, E; Fox, T

2014-06-15

Purpose: Severe CT artifacts can impair our ability to accurately calculate proton range thereby resulting in a clinically unacceptable treatment plan. In this work, we investigated a novel CT artifact correction method based on a coregistered MRI and investigated its ability to estimate CT HU and proton range in the presence of severe CT artifacts. Methods: The proposed method corrects corrupted CT data using a coregistered MRI to guide the mapping of CT values from a nearby artifact-free region. First patient MRI and CT images were registered using 3D deformable image registration software based on B-spline and mutual information. Themore » CT slice with severe artifacts was selected as well as a nearby slice free of artifacts (e.g. 1cm away from the artifact). The two sets of paired MRI and CT images at different slice locations were further registered by applying 2D deformable image registration. Based on the artifact free paired MRI and CT images, a comprehensive geospatial analysis was performed to predict the correct CT HU of the CT image with severe artifact. For a proof of concept, a known artifact was introduced that changed the ground truth CT HU value up to 30% and up to 5cm error in proton range. The ability of the proposed method to recover the ground truth was quantified using a selected head and neck case. Results: A significant improvement in image quality was observed visually. Our proof of concept study showed that 90% of area that had 30% errors in CT HU was corrected to 3% of its ground truth value. Furthermore, the maximum proton range error up to 5cm was reduced to 4mm error. Conclusion: MRI based CT artifact correction method can improve CT image quality and proton range calculation for patients with severe CT artifacts.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, J; Gu, X; Lu, W

Purpose: A novel distance-dose weighting method for label fusion was developed to increase segmentation accuracy in dosimetrically important regions for prostate radiation therapy. Methods: Label fusion as implemented in the original SIMPLE (OS) for multi-atlas segmentation relies iteratively on the majority vote to generate an estimated ground truth and DICE similarity measure to screen candidates. The proposed distance-dose weighting puts more values on dosimetrically important regions when calculating similarity measure. Specifically, we introduced distance-to-dose error (DDE), which converts distance to dosimetric importance, in performance evaluation. The DDE calculates an estimated DE error derived from surface distance differences between the candidatemore » and estimated ground truth label by multiplying a regression coefficient. To determine the coefficient at each simulation point on the rectum, we fitted DE error with respect to simulated voxel shift. The DEs were calculated by the multi-OAR geometry-dosimetry training model previously developed in our research group. Results: For both the OS and the distance-dose weighted SIMPLE (WS) results, the evaluation metrics for twenty patients were calculated using the ground truth segmentation. The mean difference of DICE, Hausdorff distance, and mean absolute distance (MAD) between OS and WS have shown 0, 0.10, and 0.11, respectively. In partial MAD of WS which calculates MAD within a certain PTV expansion voxel distance, the lower MADs were observed at the closer distances from 1 to 8 than those of OS. The DE results showed that the segmentation from WS produced more accurate results than OS. The mean DE error of V75, V70, V65, and V60 were decreased by 1.16%, 1.17%, 1.14%, and 1.12%, respectively. Conclusion: We have demonstrated that the method can increase the segmentation accuracy in rectum regions adjacent to PTV. As a result, segmentation using WS have shown improved dosimetric accuracy than OS. The WS will provide dosimetrically important label selection strategy in multi-atlas segmentation. CPRIT grant RP150485.« less

A Decade Remote Sensing River Bathymetry with the Experimental Advanced Airborne Research LiDAR

NASA Astrophysics Data System (ADS)

Kinzel, P. J.; Legleiter, C. J.; Nelson, J. M.; Skinner, K.

2012-12-01

Since 2002, the first generation of the Experimental Advanced Airborne Research LiDAR (EAARL-A) sensor has been deployed for mapping rivers and streams. We present and summarize the results of comparisons between ground truth surveys and bathymetry collected by the EAARL-A sensor in a suite of rivers across the United States. These comparisons include reaches on the Platte River (NE), Boise and Deadwood Rivers (ID), Blue and Colorado Rivers (CO), Klamath and Trinity Rivers (CA), and the Shenandoah River (VA). In addition to diverse channel morphologies (braided, single thread, and meandering) these rivers possess a variety of substrates (sand, gravel, and bedrock) and a wide range of optical characteristics which influence the attenuation and scattering of laser energy through the water column. Root mean square errors between ground truth elevations and those measured by the EAARL-A ranged from 0.15-m in rivers with relatively low turbidity and highly reflective sandy bottoms to over 0.5-m in turbid rivers with less reflective substrates. Mapping accuracy with the EAARL-A has proved challenging in pools where bottom returns are either absent in waveforms or are of such low intensity that they are treated as noise by waveform processing algorithms. Resolving bathymetry in shallow depths where near surface and bottom returns are typically convolved also presents difficulties for waveform processing routines. The results of these evaluations provide an empirical framework to discuss the capabilities and limitations of the EAARL-A sensor as well as previous generations of post-processing software for extracting bathymetry from complex waveforms. These experiences and field studies not only provide benchmarks for the evaluation of the next generation of bathymetric LiDARs for use in river mapping, but also highlight the importance of developing and standardizing more rigorous methods to characterize substrate reflectance and in-situ optical properties at study sites. They also point out the continued necessity of ground truth data for algorithm refinement and survey verification.

An easy method to differentiate retinal arteries from veins by spectral domain optical coherence tomography: retrospective, observational case series

PubMed Central

2014-01-01

Background Recently it was shown that retinal vessel diameters could be measured using spectral domain optical coherence tomography (OCT). It has also been suggested that retinal vessels manifest different features on spectral domain OCT (SD-OCT) depending on whether they are arteries or veins. Our study was aimed to present a reliable SD-OCT assisted method of differentiating retinal arteries from veins. Methods Patients who underwent circular OCT scans centred at the optic disc using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels for subsequent grading. Vessel types (artery, vein or uncertain) assessed by IR and/or fluorescein angiography (FA) were referenced as ground truth. From OCT, presence/absence of the hyperreflective lower border reflectivity feature was assessed. Presence of this feature was considered indicative for retinal arteries and compared with the ground truth. Results A total of 452 vessels from 26 eyes of 18 patients were labelled and 398 with documented vessel type (302 by IR and 96 by FA only) were included in the study. Using SD-OCT, 338 vessels were assigned a final grade, of which, 86.4% (292 vessels) were classified correctly. Forty three vessels (15 arteries and 28 veins) that IR failed to differentiate were correctly classified by SD-OCT. When using only IR based ground truth for vessel type the SD-OCT based classification approach reached a sensitivity of 0.8758/0.9297, and a specificity of 0.9297/0.8758 for arteries/veins, respectively. Conclusion Our method was able to classify retinal arteries and veins with a commercially available SD-OCT alone, and achieved high classification performance. Paired with OCT based vessel measurements, our study has expanded the potential clinical implication of SD-OCT in evaluation of a variety of retinal and systemic vascular diseases. PMID:24884611

Energy accounting and optimization for mobile systems

NASA Astrophysics Data System (ADS)

Dong, Mian

Energy accounting determines how much a software process contributes to the total system energy consumption. It is the foundation for evaluating software and has been widely used by operating system based energy management. While various energy accounting policies have been tried, there is no known way to evaluate them directly simply because it is hard to track every hardware use by software in a heterogeneous multi-core system like modern smartphones and tablets. In this thesis, we provide the ground truth for energy accounting based on multi-player game theory and offer the first evaluation of existing energy accounting policies, revealing their important flaws. The proposed ground truth is based on Shapley value, a single value solution to multi-player games of which four axiomatic properties are natural and self-evident to energy accounting. To obtain the Shapley value-based ground truth, one only needs to know if a process is active during the time under question and the system energy consumption during the same time. We further provide a utility optimization formulation of energy management and show, surprisingly, that energy accounting does not matter for existing energy management solutions that control the energy use of a process by giving it an energy budget, or budget based energy management (BEM). We show an optimal energy management (OEM) framework can always outperform BEM. While OEM does not require any form of energy accounting, it is related to Shapley value in that both require the system energy consumption for all possible combination of processes under question. We provide a novel system solution that meet this requirement by acquiring system energy consumption in situ for an OS scheduler period, i.e.,10 ms. We report a prototype implementation of both Shapley value-based energy accounting and OEM based scheduling. Using this prototype and smartphone workload, we experimentally demonstrate how erroneous existing energy accounting policies can be, show that existing BEM solutions are unnecessarily complicated yet underperforming by 20% compared to OEM.

TH-CD-202-07: A Methodology for Generating Numerical Phantoms for Radiation Therapy Using Geometric Attribute Distribution Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolly, S; Chen, H; Mutic, S

Purpose: A persistent challenge for the quality assessment of radiation therapy treatments (e.g. contouring accuracy) is the absence of the known, ground truth for patient data. Moreover, assessment results are often patient-dependent. Computer simulation studies utilizing numerical phantoms can be performed for quality assessment with a known ground truth. However, previously reported numerical phantoms do not include the statistical properties of inter-patient variations, as their models are based on only one patient. In addition, these models do not incorporate tumor data. In this study, a methodology was developed for generating numerical phantoms which encapsulate the statistical variations of patients withinmore » radiation therapy, including tumors. Methods: Based on previous work in contouring assessment, geometric attribute distribution (GAD) models were employed to model both the deterministic and stochastic properties of individual organs via principle component analysis. Using pre-existing radiation therapy contour data, the GAD models are trained to model the shape and centroid distributions of each organ. Then, organs with different shapes and positions can be generated by assigning statistically sound weights to the GAD model parameters. Organ contour data from 20 retrospective prostate patient cases were manually extracted and utilized to train the GAD models. As a demonstration, computer-simulated CT images of generated numerical phantoms were calculated and assessed subjectively and objectively for realism. Results: A cohort of numerical phantoms of the male human pelvis was generated. CT images were deemed realistic both subjectively and objectively in terms of image noise power spectrum. Conclusion: A methodology has been developed to generate realistic numerical anthropomorphic phantoms using pre-existing radiation therapy data. The GAD models guarantee that generated organs span the statistical distribution of observed radiation therapy patients, according to the training dataset. The methodology enables radiation therapy treatment assessment with multi-modality imaging and a known ground truth, and without patient-dependent bias.« less

Ground truth and detection threshold from WWII naval clean-up in Denmark

NASA Astrophysics Data System (ADS)

Larsen, Tine B.; Dahl-Jensen, Trine; Voss, Peter

2013-04-01

The sea bed below the Danish territorial waters is still littered with unexploded mines and other ammunition from World War II. The mines were air dropped by the RAF and the positions of the mines are unknown. As the mines still pose a potential threat to fishery and other marine activities, the Admiral Danish Fleet under the Danish Navy searches for the mines and destroy them by detonation, where they are found. The largest mines destroyed in this manner in 2012 are equivalent to 800 kg TNT each. The Seismological Service at the National Geological Survey of Denmark and Greenland is notified by the navy when ammunition in excess of 100 kg TNT is detonated. The notifications include information about position, detonation time and the estimated amount of explosives. The larger explosions are clearly registered not only on the Danish seismographs, but also on seismographs in the neighbouring countries. This includes the large seismograph arrays in Norway, Sweden, and Finland. Until recently the information from the Danish navy was only utilized to rid the Danish earthquake catalogue of explosions. But the high quality information provided by the navy enables us to use these ground truth events to assess the quality of our earthquake catalogue. The mines are scattered though out the Danish territorial waters, thus we can use the explosions to test the accuracy of the determined epicentres in all parts of the country. E.g. a detonation of 135 kg in Begstrup Vig in the central part of Denmark was located using Danish, Norwegian and Swedish stations with an accuracy of less than 2 km from ground truth. A systematic study of the explosions will sharpen our understanding of the seismicity in Denmark, and result in a more detailed understanding of the detection threshold. Furthermore the study will shed light on the sensitivity of the network to various seismograph outages.

TU-F-17A-03: A 4D Lung Phantom for Coupled Registration/Segmentation Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markel, D; El Naqa, I; Levesque, I

2014-06-15

Purpose: Coupling the processes of segmentation and registration (regmentation) is a recent development that allows improved efficiency and accuracy for both steps and may improve the clinical feasibility of online adaptive radiotherapy. Presented is a multimodality animal tissue model designed specifically to provide a ground truth to simultaneously evaluate segmentation and registration errors during respiratory motion. Methods: Tumor surrogates were constructed from vacuum sealed hydrated natural sea sponges with catheters used for the injection of PET radiotracer. These contained two compartments allowing for two concentrations of radiotracer mimicking both tumor and background signals. The lungs were inflated to different volumesmore » using an air pump and flow valve and scanned using PET/CT and MRI. Anatomical landmarks were used to evaluate the registration accuracy using an automated bifurcation tracking pipeline for reproducibility. The bifurcation tracking accuracy was assessed using virtual deformations of 2.6 cm, 5.2 cm and 7.8 cm of a CT scan of a corresponding human thorax. Bifurcations were detected in the deformed dataset and compared to known deformation coordinates for 76 points. Results: The bifurcation tracking accuracy was found to have a mean error of −0.94, 0.79 and −0.57 voxels in the left-right, anterior-posterior and inferior-superior axes using a 1×1×5 mm3 resolution after the CT volume was deformed 7.8 cm. The tumor surrogates provided a segmentation ground truth after being registered to the phantom image. Conclusion: A swine lung model in conjunction with vacuum sealed sponges and a bifurcation tracking algorithm is presented that is MRI, PET and CT compatible and anatomically and kinetically realistic. Corresponding software for tracking anatomical landmarks within the phantom shows sub-voxel accuracy. Vacuum sealed sponges provide realistic tumor surrogate with a known boundary. A ground truth with minimal uncertainty is thus realized that can be used for comparing the performance of registration and segmentation algorithms.« less

Dual-Tracer PET Using Generalized Factor Analysis of Dynamic Sequences

PubMed Central

Fakhri, Georges El; Trott, Cathryn M.; Sitek, Arkadiusz; Bonab, Ali; Alpert, Nathaniel M.

2013-01-01

Purpose With single-photon emission computed tomography, simultaneous imaging of two physiological processes relies on discrimination of the energy of the emitted gamma rays, whereas the application of dual-tracer imaging to positron emission tomography (PET) imaging has been limited by the characteristic 511-keV emissions. Procedures To address this limitation, we developed a novel approach based on generalized factor analysis of dynamic sequences (GFADS) that exploits spatio-temporal differences between radiotracers and applied it to near-simultaneous imaging of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) (brain metabolism) and 11C-raclopride (D2) with simulated human data and experimental rhesus monkey data. We show theoretically and verify by simulation and measurement that GFADS can separate FDG and raclopride measurements that are made nearly simultaneously. Results The theoretical development shows that GFADS can decompose the studies at several levels: (1) It decomposes the FDG and raclopride study so that they can be analyzed as though they were obtained separately. (2) If additional physiologic/anatomic constraints can be imposed, further decomposition is possible. (3) For the example of raclopride, specific and nonspecific binding can be determined on a pixel-by-pixel basis. We found good agreement between the estimated GFADS factors and the simulated ground truth time activity curves (TACs), and between the GFADS factor images and the corresponding ground truth activity distributions with errors less than 7.3±1.3 %. Biases in estimation of specific D2 binding and relative metabolism activity were within 5.9±3.6 % compared to the ground truth values. We also evaluated our approach in simultaneous dual-isotope brain PET studies in a rhesus monkey and obtained accuracy of better than 6 % in a mid-striatal volume, for striatal activity estimation. Conclusions Dynamic image sequences acquired following near-simultaneous injection of two PET radiopharmaceuticals can be separated into components based on the differences in the kinetics, provided their kinetic behaviors are distinct. PMID:23636489

Identifying retail food stores to evaluate the food environment.

PubMed

Hosler, Akiko S; Dharssi, Aliza

2010-07-01

The availability of food stores is the most frequently used measure of the food environment, but identifying them poses a technical challenge. This study evaluated eight administrative lists of retailers for identifying food stores in an urban community. Lists of inspected food stores (IFS), cigarette retailers, liquor licenses, lottery retailers, gasoline retailers, farmers' markets, and authorized WIC (Program for Women, Infants, and Children) and Supplemental Nutrition Assistance Program (SNAP) retailers for Albany NY were obtained from government agencies. Sensitivity and positive predictive value (PPV) were assessed, using ground-truthing as the validation measure. Stores were also grouped by the number of lists they were documented on, and the proportion of food stores in each group was obtained. Data were collected and analyzed in 2009. A total of 166 stores, including four from ground-truthing, were identified. Forty-three stores were disqualified, as a result of having no targeted foods (n=17); being in the access-restricted area of a building (n=15); and being out of business (n=11). Sensitivity was highest in IFS (87.0%), followed by the cigarette retailers' list (76.4%). PPV was highest in WIC and farmers' markets lists (100%), followed by SNAP (97.8%). None of the lists had both sensitivity and PPV greater than 90%. All stores that were listed by four or more lists were food stores. The proportion of food stores was lowest (33.3%) for stores listed by only one list. Individual lists had limited utility for identifying food stores, but when they were combined, the likelihood of a retail store being a food store could be predicted by the number of lists the store was documented on. This information can be used to increase the efficiency of ground-truthing. Copyright 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Dynamic data integration and stochastic inversion of a confined aquifer

NASA Astrophysics Data System (ADS)

Wang, D.; Zhang, Y.; Irsa, J.; Huang, H.; Wang, L.

2013-12-01

Much work has been done in developing and applying inverse methods to aquifer modeling. The scope of this paper is to investigate the applicability of a new direct method for large inversion problems and to incorporate uncertainty measures in the inversion outcomes (Wang et al., 2013). The problem considered is a two-dimensional inverse model (50×50 grid) of steady-state flow for a heterogeneous ground truth model (500×500 grid) with two hydrofacies. From the ground truth model, decreasing number of wells (12, 6, 3) were sampled for facies types, based on which experimental indicator histograms and directional variograms were computed. These parameters and models were used by Sequential Indicator Simulation to generate 100 realizations of hydrofacies patterns in a 100×100 (geostatistical) grid, which were conditioned to the facies measurements at wells. These realizations were smoothed with Simulated Annealing, coarsened to the 50×50 inverse grid, before they were conditioned with the direct method to the dynamic data, i.e., observed heads and groundwater fluxes at the same sampled wells. A set of realizations of estimated hydraulic conductivities (Ks), flow fields, and boundary conditions were created, which centered on the 'true' solutions from solving the ground truth model. Both hydrofacies conductivities were computed with an estimation accuracy of ×10% (12 wells), ×20% (6 wells), ×35% (3 wells) of the true values. For boundary condition estimation, the accuracy was within × 15% (12 wells), 30% (6 wells), and 50% (3 wells) of the true values. The inversion system of equations was solved with LSQR (Paige et al, 1982), for which coordinate transform and matrix scaling preprocessor were used to improve the condition number (CN) of the coefficient matrix. However, when the inverse grid was refined to 100×100, Gaussian Noise Perturbation was used to limit the growth of the CN before the matrix solve. To scale the inverse problem up (i.e., without smoothing and coarsening and therefore reducing the associated estimation uncertainty), a parallel LSQR solver was written and verified. For the 50×50 grid, the parallel solver sped up the serial solution time by 14X using 4 CPUs (research on parallel performance and scaling is ongoing). A sensitivity analysis was conducted to examine the relation between the observed data and the inversion outcomes, where measurement errors of increasing magnitudes (i.e., ×1, 2, 5, 10% of the total head variation and up to ×2% of the total flux variation) were imposed on the observed data. Inversion results were stable but the accuracy of Ks and boundary estimation degraded with increasing errors, as expected. In particular, quality of the observed heads is critical to hydraulic head recovery, while quality of the observed fluxes plays a dominant role in K estimation. References: Wang, D., Y. Zhang, J. Irsa, H. Huang, and L. Wang (2013), Data integration and stochastic inversion of a confined aquifer with high performance computing, Advances in Water Resources, in preparation. Paige, C. C., and M. A. Saunders (1982), LSQR: an algorithm for sparse linear equations and sparse least squares, ACM Transactions on Mathematical Software, 8(1), 43-71.

Ground-truthing AVIRIS mineral mapping at Cuprite, Nevada

NASA Technical Reports Server (NTRS)

Swayze, Gregg; Clark, Roger N.; Kruse, Fred; Sutley, Steve; Gallagher, Andrea

1992-01-01

Mineral abundance maps of 18 minerals were made of the Cuprite Mining District using 1990 AVIRIS data and the Multiple Spectral Feature Mapping Algorithm (MSFMA) as discussed in Clark et al. This technique uses least-squares fitting between a scaled laboratory reference spectrum and ground calibrated AVIRIS data for each pixel. Multiple spectral features can be fitted for each mineral and an unlimited number of minerals can be mapped simultaneously. Quality of fit and depth from continuum numbers for each mineral are calculated for each pixel and the results displayed as a multicolor image.

Progress in utilization of a mobile laboratory for making storm electricity measurements

NASA Technical Reports Server (NTRS)

Rust, W. David

1988-01-01

A mobile atmospheric science laboratory has been used to intercept and track storms on the Great Plains region of the U.S., with the intention of combining the data obtained with those from Doppler and conventional radars, NASA U-2 aircraft overflights, balloon soundings, and fixed-base storm electricity measurements. The mobile lab has proven to be valuable in the gathering of ground truth verifications for the two commercially operated lightning ground-strike locating systems. Data acquisition has recently been expanded by means of mobile ballooning before and during storms.

AgRISTARS: Agriculture and Resources Inventory Surveys Through Aerospace Remote Sensing. Enumerator's manual, 1981 ground data survey

NASA Technical Reports Server (NTRS)

1981-01-01

General information and administrative instructions are provided for individuals gathering ground truth data to support research and development techniques for estimating crop acreage and production by remote sensing by satellite. Procedures are given for personal safety with regards to organophosphorus insecticides, for conducting interviews for periodic observations, for coding the crops identified and their growth stages, and for selecting sites for placing rain gages. Forms are included for those citizens agreeing to monitor the gages and record the rainfall. Segment selection is also considered.

Impact of Conifer Forest Litter on Microwave Emission at L-Band

NASA Technical Reports Server (NTRS)

Kurum, Mehmet; O'Neill, Peggy E.; Lang, Roger H.; Cosh, Michael H.; Joseph, Alicia T.; Jackson, Thomas J.

2011-01-01

This study reports on the utilization of microwave modeling, together with ground truth, and L-band (1.4-GHz) brightness temperatures to investigate the passive microwave characteristics of a conifer forest floor. The microwave data were acquired over a natural Virginia Pine forest in Maryland by a ground-based microwave active/passive instrument system in 2008/2009. Ground measurements of the tree biophysical parameters and forest floor characteristics were obtained during the field campaign. The test site consisted of medium-sized evergreen conifers with an average height of 12 m and average diameters at breast height of 12.6 cm. The site is a typical pine forest site in that there is a surface layer of loose debris/needles and an organic transition layer above the mineral soil. In an effort to characterize and model the impact of the surface litter layer, an experiment was conducted on a day with wet soil conditions, which involved removal of the surface litter layer from one half of the test site while keeping the other half undisturbed. The observations showed detectable decrease in emissivity for both polarizations after the surface litter layer was removed. A first-order radiative transfer model of the forest stands including the multilayer nature of the forest floor in conjunction with the ground truth data are used to compute forest emission. The model calculations reproduced the major features of the experimental data over the entire duration, which included the effects of surface litter and ground moisture content on overall emission. Both theory and experimental results confirm that the litter layer increases the observed canopy brightness temperature and obscure the soil emission.

Evaluation of motion artifact metrics for coronary CT angiography.

PubMed

Ma, Hongfeng; Gros, Eric; Szabo, Aniko; Baginski, Scott G; Laste, Zachary R; Kulkarni, Naveen M; Okerlund, Darin; Schmidt, Taly G

2018-02-01

This study quantified the performance of coronary artery motion artifact metrics relative to human observer ratings. Motion artifact metrics have been used as part of motion correction and best-phase selection algorithms for Coronary Computed Tomography Angiography (CCTA). However, the lack of ground truth makes it difficult to validate how well the metrics quantify the level of motion artifact. This study investigated five motion artifact metrics, including two novel metrics, using a dynamic phantom, clinical CCTA images, and an observer study that provided ground-truth motion artifact scores from a series of pairwise comparisons. Five motion artifact metrics were calculated for the coronary artery regions on both phantom and clinical CCTA images: positivity, entropy, normalized circularity, Fold Overlap Ratio (FOR), and Low-Intensity Region Score (LIRS). CT images were acquired of a dynamic cardiac phantom that simulated cardiac motion and contained six iodine-filled vessels of varying diameter and with regions of soft plaque and calcifications. Scans were repeated with different gantry start angles. Images were reconstructed at five phases of the motion cycle. Clinical images were acquired from 14 CCTA exams with patient heart rates ranging from 52 to 82 bpm. The vessel and shading artifacts were manually segmented by three readers and combined to create ground-truth artifact regions. Motion artifact levels were also assessed by readers using a pairwise comparison method to establish a ground-truth reader score. The Kendall's Tau coefficients were calculated to evaluate the statistical agreement in ranking between the motion artifacts metrics and reader scores. Linear regression between the reader scores and the metrics was also performed. On phantom images, the Kendall's Tau coefficients of the five motion artifact metrics were 0.50 (normalized circularity), 0.35 (entropy), 0.82 (positivity), 0.77 (FOR), 0.77(LIRS), where higher Kendall's Tau signifies higher agreement. The FOR, LIRS, and transformed positivity (the fourth root of the positivity) were further evaluated in the study of clinical images. The Kendall's Tau coefficients of the selected metrics were 0.59 (FOR), 0.53 (LIRS), and 0.21 (Transformed positivity). In the study of clinical data, a Motion Artifact Score, defined as the product of FOR and LIRS metrics, further improved agreement with reader scores, with a Kendall's Tau coefficient of 0.65. The metrics of FOR, LIRS, and the product of the two metrics provided the highest agreement in motion artifact ranking when compared to the readers, and the highest linear correlation to the reader scores. The validated motion artifact metrics may be useful for developing and evaluating methods to reduce motion in Coronary Computed Tomography Angiography (CCTA) images. © 2017 American Association of Physicists in Medicine.

HYDICE data from Lake Tahoe: comparison to coincident AVIRIS and in-situ measurements

NASA Astrophysics Data System (ADS)

Kappus, Mary E.; Davis, Curtiss O.; Rhea, W. J.

1996-11-01

Coordinated flights of two calibrated airborne imaging spectrometers, HYDICE and AVIRIS, were conducted on June 22, 1995 over Lake Tahoe. As part of HYDICE's first operational mission, one objective was to test the system performance over the dark homogeneous target provided by the clear deep waters of the lake. The high altitude and clear atmosphere makes Lake Tahoe a simpler test target than near-shore marine environments, where large aerosols complicate atmospheric correction and sediment runoff and high chlorophyll levels make interpretation of he data difficult. Calibrated data from both runoff and high chlorophyll levels make interpretation of the data difficult. Calibrated data from both sensors was provided in physical units of radiance. The atmospheric radiative transfer code, MODTRAN was used to remove the path radiance between the ground and sensor and the skylight reflected from the water surface. The resulting water-leaving spectrometer, and with values calculated form in-water properties using the HYDROLIGHT radiative transfer code. The agreement of the water-leaving radiance for the HYDICE data, the ground-truth spectral measurements, and the results of the radiative transfer code are excellent for wavelengths greater than 0.45 micrometers . The AVIRIS flight took place more than an hour closer to noon, which makes the radiance measurements not directly comparable. Comparisons to radiative transfer output for this later time indicate that the AVIRIS data is strongly by sun glint. Because water-leaving radiance is dependent upon the characteristics of the water, it can be analyzed for some of those properties. Using the CZCS algorithm based on the water-leaving radiance at two wavelengths, the chlorophyll content of Lake Tahoe was computed from the HYDICE and ground-truth data. Resulting values are slightly higher than measurements made two weeks earlier from water samples, indicating a growth in the phytoplankton population which is very plausible given the intervening atmospheric conditions. The success in determining water-leaving radiance and interpreting it for pigment concentration are very positive results for this early HYDICE flight. The interpretations made so far do not make use of the full spectral content of the data, so much room for advancement remains.

Integrated Airborne and In-Situ Measurements Over Land-Fast Ice Near Barrow, AK.

NASA Astrophysics Data System (ADS)

Gardner, J. M.; Brozena, J. M.; Richter-Menge, J.; Abelev, A.; Liang, R.; Ball, D.; Claffey, K. J.; Hebert, D. A.; Jones, K.

2015-12-01

The Naval Research Laboratory has collected two field seasons of integrated airborne and in-situ measurements over multiple sites of floating, but land-fast ice north of Barrow, AK. During the first season in March of 2014 the Cold Regions Research and Engineering Laboratory led the on-ice group including NRL personnel and Naval Academy midshipmen. The second season (March 2015) included only NRL scientists and midshipmen. The in-situ data provided ground-truth for airborne measurements from a scanning LiDAR (Riegl Q 560i), digital photogrammetry (Applanix DSS-439), a low-frequency SAR (P-band in 2014 and P and L bands in 2015) and a snow/Ku radar procured from the Center for Remote Sensing of Ice Sheets of the University of Kansas. The CReSIS radar was updated in 2015 to integrate the snow and Ku radars into a single continuous chirp, thus improving resolution. The objective of the survey was to aid our understanding of the use of the airborne data to calibrate/validate Cryosat-2 data. Sampling size or "footprint" plays a critical role in the attempt to compare in-situ measurements with airborne (or satellite) measurements. Thus the in-situ data were arranged to minimize aliasing. Ground measurements were collected along transects a sites generally consisting of a 2 km long profile of Magnaprobe and EM31 measurements with periodic boreholes. A 60 m x 400 m swath of Magnaprobe measurements was centered on this profile. Airborne data were collected on multiple overflights of the transect areas. The LiDAR measured total freeboard (ice + snow) referenced to leads in the ice, and produced swaths 200-300 m wide. The SAR imaged the ice beneath the snow and the snow/Ku radar measured snow thickness. The freeboard measurements and snow thickness are used to estimate ice thickness via isostasy and density estimates. Comparisons and processing methodology will be shown. The results of this ground-truth experiment will inform our analysis of grids of airborne data collected over areas of sea-ice illuminated by Cryosat-2.

Image resolution: Its significance in a wildland area

NASA Technical Reports Server (NTRS)

Lauer, D. T.; Thaman, R. R.

1970-01-01

The information content of simulated space photos as a function of various levels of image resolution was determined by identifying major vegetation-terrain types in a series of images purposely degraded optically to different levels of ground resolution resolvable distance. Comparison of cumulative interpretation results with actual ground truth data indicates that although there is definite decrease in interpretability as ground resolvable distance increases, some valuable information is gained by using even the poorest aerial photography. Developed is the importance of shape and texture for correct identification of broadleaf or coniferous vegetation types and the relative unimportance of shape and texture for the recognition of grassland, water bodies, and nonvegetated areas. Imagery must have a ground resolvable distance of at least 50 feet to correctly discriminate between primary types of woody vegetation.

Realism without truth: a review of Giere's science without laws and scientific perspectivism.

PubMed

Hackenberg, Timothy D

2009-05-01

An increasingly popular view among philosophers of science is that of science as action-as the collective activity of scientists working in socially-coordinated communities. Scientists are seen not as dispassionate pursuers of Truth, but as active participants in a social enterprise, and science is viewed on a continuum with other human activities. When taken to an extreme, the science-as-social-process view can be taken to imply that science is no different from any other human activity, and therefore can make no privileged claims about its knowledge of the world. Such extreme views are normally contrasted with equally extreme views of classical science, as uncovering Universal Truth. In Science Without Laws and Scientific Perspectivism, Giere outlines an approach to understanding science that finds a middle ground between these extremes. He acknowledges that science occurs in a social and historical context, and that scientific models are constructions designed and created to serve human ends. At the same time, however, scientific models correspond to parts of the world in ways that can legitimately be termed objective. Giere's position, perspectival realism, shares important common ground with Skinner's writings on science, some of which are explored in this review. Perhaps most fundamentally, Giere shares with Skinner the view that science itself is amenable to scientific inquiry: scientific principles can and should be brought to bear on the process of science. The two approaches offer different but complementary perspectives on the nature of science, both of which are needed in a comprehensive understanding of science.

REALISM WITHOUT TRUTH: A REVIEW OF GIERE'S SCIENCE WITHOUT LAWS AND SCIENTIFIC PERSPECTIVISM

PubMed Central

Hackenberg, Timothy D

2009-01-01

An increasingly popular view among philosophers of science is that of science as action—as the collective activity of scientists working in socially-coordinated communities. Scientists are seen not as dispassionate pursuers of Truth, but as active participants in a social enterprise, and science is viewed on a continuum with other human activities. When taken to an extreme, the science-as-social-process view can be taken to imply that science is no different from any other human activity, and therefore can make no privileged claims about its knowledge of the world. Such extreme views are normally contrasted with equally extreme views of classical science, as uncovering Universal Truth. In Science Without Laws and Scientific Perspectivism, Giere outlines an approach to understanding science that finds a middle ground between these extremes. He acknowledges that science occurs in a social and historical context, and that scientific models are constructions designed and created to serve human ends. At the same time, however, scientific models correspond to parts of the world in ways that can legitimately be termed objective. Giere's position, perspectival realism, shares important common ground with Skinner's writings on science, some of which are explored in this review. Perhaps most fundamentally, Giere shares with Skinner the view that science itself is amenable to scientific inquiry: scientific principles can and should be brought to bear on the process of science. The two approaches offer different but complementary perspectives on the nature of science, both of which are needed in a comprehensive understanding of science. PMID:19949495

Seasonal variations of infrasonic arrivals from long-term ground truth observations in Nevada and implication for event location

NASA Astrophysics Data System (ADS)

Negraru, Petru; Golden, Paul

2017-04-01

Long-term ground truth observations were collected at two infrasound arrays in Nevada to investigate how seasonal atmospheric variations affect the detection, traveltime and signal characteristics (azimuth, trace velocity, frequency content and amplitudes) of infrasonic arrivals at regional distances. The arrays were located in different azimuthal directions from a munition disposal facility in Nevada. FNIAR, located 154 km north of the source has a high detection rate throughout the year. Over 90 per cent of the detonations have traveltimes indicative of stratospheric arrivals, while tropospheric waveguides are observed from only 27 per cent of the detonations. The second array, DNIAR, located 293 km southeast of the source exhibits strong seasonal variations with high stratospheric detection rates in winter and the virtual absence of stratospheric arrivals in summer. Tropospheric waveguides and thermospheric arrivals are also observed for DNIAR. Modeling through the Naval Research Laboratory Ground to Space atmospheric sound speeds leads to mixed results: FNIAR arrivals are usually not predicted to be present at all (either stratospheric or tropospheric), while DNIAR arrivals are usually correctly predicted, but summer arrivals show a consistent traveltime bias. In the end, we show the possible improvement in location using empirically calibrated traveltime and azimuth observations. Using the Bayesian Infrasound Source Localization we show that we can decrease the area enclosed by the 90 per cent credibility contours by a factor of 2.5.

Coarse Scale In Situ Albedo Observations over Heterogeneous Land Surfaces and Validation Strategy

NASA Astrophysics Data System (ADS)

Xiao, Q.; Wu, X.; Wen, J.; BAI, J., Sr.

2017-12-01

To evaluate and improve the quality of coarse-pixel land surface albedo products, validation with ground measurements of albedo is crucial over the spatially and temporally heterogeneous land surface. The performance of albedo validation depends on the quality of ground-based albedo measurements at a corresponding coarse-pixel scale, which can be conceptualized as the "truth" value of albedo at coarse-pixel scale. The wireless sensor network (WSN) technology provides access to continuously observe on the large pixel scale. Taking the albedo products as an example, this paper was dedicated to the validation of coarse-scale albedo products over heterogeneous surfaces based on the WSN observed data, which is aiming at narrowing down the uncertainty of results caused by the spatial scaling mismatch between satellite and ground measurements over heterogeneous surfaces. The reference value of albedo at coarse-pixel scale can be obtained through an upscaling transform function based on all of the observations for that pixel. We will devote to further improve and develop new method that that are better able to account for the spatio-temporal characteristic of surface albedo in the future. Additionally, how to use the widely distributed single site measurements over the heterogeneous surfaces is also a question to be answered. Keywords: Remote sensing; Albedo; Validation; Wireless sensor network (WSN); Upscaling; Heterogeneous land surface; Albedo truth at coarse-pixel scale

MAX-91: Polarimetric SAR results on Montespertoli site

NASA Technical Reports Server (NTRS)

Baronti, S.; Luciani, S.; Moretti, S.; Paloscia, S.; Schiavon, G.; Sigismondi, S.

1993-01-01

The polarimetric Synthetic Aperture Radar (SAR) is a powerful sensor for high resolution ocean and land mapping and particularly for monitoring hydrological parameters in large watersheds. There is currently much research in progress to assess the SAR operational capability as well as to estimate the accuracy achievable in the measurements of geophysical parameters with the presently available airborne and spaceborne sensors. An important goal of this research is to improve our understanding of the basic mechanisms that control the interaction of electro-magnetic waves with soil and vegetation. This can be done both by developing electromagnetic models and by analyzing statistical relations between backscattering and ground truth data. A systematic investigation, which aims at a better understanding of the information obtainable from the multi-frequency polarimetric SAR to be used in agro-hydrology, is in progress by our groups within the framework of SIR-C/X-SAR Project and has achieved a most significant milestone with the NASA/JPL Aircraft Campaign named MAC-91. Indeed this experiment allowed us to collect a large and meaningful data set including multi-temporal multi-frequency polarimetric SAR measurements and ground truth. This paper presents some significant results obtained over an agricultural flat area within the Montespertoli site, where intensive ground measurements were carried out. The results are critically discussed with special regard to the information associated with polarimetric data.

Ground truth methods for optical cross-section modeling of biological aerosols

NASA Astrophysics Data System (ADS)

Kalter, J.; Thrush, E.; Santarpia, J.; Chaudhry, Z.; Gilberry, J.; Brown, D. M.; Brown, A.; Carter, C. C.

2011-05-01

Light detection and ranging (LIDAR) systems have demonstrated some capability to meet the needs of a fastresponse standoff biological detection method for simulants in open air conditions. These systems are designed to exploit various cloud signatures, such as differential elastic backscatter, fluorescence, and depolarization in order to detect biological warfare agents (BWAs). However, because the release of BWAs in open air is forbidden, methods must be developed to predict candidate system performance against real agents. In support of such efforts, the Johns Hopkins University Applied Physics Lab (JHU/APL) has developed a modeling approach to predict the optical properties of agent materials from relatively simple, Biosafety Level 3-compatible bench top measurements. JHU/APL has fielded new ground truth instruments (in addition to standard particle sizers, such as the Aerodynamic particle sizer (APS) or GRIMM aerosol monitor (GRIMM)) to more thoroughly characterize the simulant aerosols released in recent field tests at Dugway Proving Ground (DPG). These instruments include the Scanning Mobility Particle Sizer (SMPS), the Ultraviolet Aerodynamic Particle Sizer (UVAPS), and the Aspect Aerosol Size and Shape Analyser (Aspect). The SMPS was employed as a means of measuring smallparticle concentrations for more accurate Mie scattering simulations; the UVAPS, which measures size-resolved fluorescence intensity, was employed as a path toward fluorescence cross section modeling; and the Aspect, which measures particle shape, was employed as a path towards depolarization modeling.

Taxonomy of USA east coast fishing communities in terms of social vulnerability and resilience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pollnac, Richard B., E-mail: pollnac3@gmail.com; Seara, Tarsila, E-mail: tarsila.seara@noaa.gov; Colburn, Lisa L., E-mail: lisa.l.colburn@noaa.gov

Increased concern with the impacts that changing coastal environments can have on coastal fishing communities led to a recent effort by NOAA Fisheries social scientists to develop a set of indicators of social vulnerability and resilience for the U.S. Southeast and Northeast coastal communities. A goal of the NOAA Fisheries social vulnerability and resilience indicator program is to support time and cost effective use of readily available data in furtherance of both social impact assessments of proposed changes to fishery management regulations and climate change adaptation planning. The use of the indicators to predict the response to change in coastalmore » communities would be enhanced if community level analyses could be grouped effectively. This study examines the usefulness of combining 1130 communities into 35 relevant subgroups by comparing results of a numerical taxonomy with data collected by interview methods, a process herein referred to as “ground-truthing.” The validation of the taxonomic method by the method of ground-truthing indicates that the clusters are adequate to be used to select communities for in-depth research. - Highlights: • We develop a taxonomy of fishing communities based on vulnerability indicators. • We validate the community clusters through the use of surveys (“ground-truthing”). • Clusters differ along important aspects of fishing community vulnerability. • Clustering communities allows for accurate and timely social impact assessments.« less

We get the algorithms of our ground truths: Designing referential databases in digital image processing

PubMed Central

Jaton, Florian

2017-01-01

This article documents the practical efforts of a group of scientists designing an image-processing algorithm for saliency detection. By following the actors of this computer science project, the article shows that the problems often considered to be the starting points of computational models are in fact provisional results of time-consuming, collective and highly material processes that engage habits, desires, skills and values. In the project being studied, problematization processes lead to the constitution of referential databases called ‘ground truths’ that enable both the effective shaping of algorithms and the evaluation of their performances. Working as important common touchstones for research communities in image processing, the ground truths are inherited from prior problematization processes and may be imparted to subsequent ones. The ethnographic results of this study suggest two complementary analytical perspectives on algorithms: (1) an ‘axiomatic’ perspective that understands algorithms as sets of instructions designed to solve given problems computationally in the best possible way, and (2) a ‘problem-oriented’ perspective that understands algorithms as sets of instructions designed to computationally retrieve outputs designed and designated during specific problematization processes. If the axiomatic perspective on algorithms puts the emphasis on the numerical transformations of inputs into outputs, the problem-oriented perspective puts the emphasis on the definition of both inputs and outputs. PMID:28950802

Ohio River main stem study - The role of geographic information systems and remote sensing in flood damage assessments

NASA Technical Reports Server (NTRS)

Edwardo, H. A.; Moulis, F. R.; Merry, C. J.; Mckim, H. L.; Kerber, A. G.; Miller, M. A.

1985-01-01

The Pittsburgh District, Corps of Engineers, has conducted feasibility analyses of various procedures for performing flood damage assessments along the main stem of the Ohio River. Procedures using traditional, although highly automated, techniques and those based on geographic information systems have been evaluated at a test site, the City of New Martinsville, Wetzel County, WV. The flood damage assessments of the test site developed from an automated, conventional structure-by-structure appraisal served as the ground truth data set. A geographic information system was developed for the test site which includes data on hydraulic reach, ground and reference flood elevations, and land use/cover. Damage assessments were made using land use mapping developed from an exhaustive field inspection of each tax parcel. This ground truth condition was considered to provide the best comparison of flood damages to the conventional approach. Also, four land use/cover data sets were developed from Thematic Mapper Simulator (TMS) and Landsat-4 Thematic Mapper (TM) data. One of these was also used to develop a damage assessment of the test site. This paper presents the comparative absolute and relative accuracies of land use/cover mapping and flood damage assessments, and the recommended role of geographic information systems aided by remote sensing for conducting flood damage assessments and updates along the main stem of the Ohio River.

Ground Truth Mineralogy vs. Orbital Observations at the Bagnold Dune Field

NASA Technical Reports Server (NTRS)

Achilles, C. N.; Downs, R. T.; Ming, D. W.; Rampe, E. B.; Morris, R. V.; Treiman, A. H.; Morrison, S. M.; Blake, D. F.; Vaniman, D. T.; Bristow, T. F.

2017-01-01

The Mars Science Laboratory (MSL) rover, Curiosity, is analyzing rock and sediments in Gale crater to provide in situ sedimentological, geochemical, and mineralogical assessments of the crater's geologic history. Curiosity's recent traverse through an active, basaltic eolian deposit, informally named the Bagnold Dunes, provided the opportunity for a multi-instrument investigation of the dune field.

Man and the Biosphere: Ground Truthing Coral Reefs for the St. John Island Biosphere Reserve.

ERIC Educational Resources Information Center

Brody, Michael J.; And Others

Research on the coral species composition of St. John's reefs in the Virgin Islands was conducted through the School for Field Studies (SFS) Coral Reef Ecology course (winter 1984). A cooperative study program based on the United Nations Educational, Scientific, and Cultural Organization's (Unesco) program, Man and the Biosphere, was undertaken by…

Healing the Past through Story

ERIC Educational Resources Information Center

Mullet, Judy H.; Akerson, Nels M. K.; Turman, Allison

2013-01-01

Stories matter, and the stories we tell ourselves matter most. Truth has many layers and narrative helps us makes senses of our multilayered reality. We live a personal narrative that is grounded in our past experience, but embodied in our present. As such, it filters what we see and how we interpret events. Attachment theorists tell us our early…

Data and Network Science for Noisy Heterogeneous Systems

ERIC Educational Resources Information Center

Rider, Andrew Kent

2013-01-01

Data in many growing fields has an underlying network structure that can be taken advantage of. In this dissertation we apply data and network science to problems in the domains of systems biology and healthcare. Data challenges in these fields include noisy, heterogeneous data, and a lack of ground truth. The primary thesis of this work is that…

Cloud Study Investigators: Using NASA's CERES S'COOL in Problem-Based Learning

ERIC Educational Resources Information Center

Moore, Susan; Popiolkowski, Gary

2011-01-01

1This article describes how, by incorporating NASA's Students' Cloud Observations On-Line (S'COOL) project into a problem-based learning (PBL) activity, middle school students are engaged in authentic scientific research where they observe and record information about clouds and contribute ground truth data to NASA's Clouds and the Earth's…

Exploring Meaning in Life in the Tel Hai Gifted Children’s Center

ERIC Educational Resources Information Center

Kasler, Jon; Goldfarb-Rivlin, Sima; Levi, Jossef; Elias, Maurice J.

2013-01-01

While high IQ is likely to be an advantage in moral reasoning, it does not guarantee students' putting those morals into practice. A clearly defined sense of purpose grounded in values of social responsibility, exploration of values, and the search for ultimate truths, both personal and collective, is paramount. The Meaning in Life program in…

Modifications to the accuracy assessment analysis routine SPATL to produce an output file

NASA Technical Reports Server (NTRS)

Carnes, J. G.

1978-01-01

The SPATL is an analysis program in the Accuracy Assessment Software System which makes comparisons between ground truth information and dot labeling for an individual segment. In order to facilitate the aggregation cf this information, SPATL was modified to produce a disk output file containing the necessary information about each segment.

No Neutral Ground: Standing by the Values We Prize in Higher Education.

ERIC Educational Resources Information Center

Young, Robert B.

This book is a call to those within higher education to remain clear and consistent about the core values--service, truth, freedom, equality, individuation, justice, and community--that play a critical role in American society. It provides suggestions to help administrators and faculty to incorporate these values into their own practice and…

Initial landscape changes associated with Marcellus shale development—implications for forests and wildlife

Treesearch

Margaret Brittingham; Patrick Drohan; Joseph Bishop

2013-01-01

Marcellus shale development is occurring rapidly across Pennsylvania. We conducted a geographic information system (GIS) analysis using available Pennsylvania Department of Environmental Protection permit data, before and after photos, ground-truthing, and fi eld measurements to describe landscape change within the fi rst 3 years of active Marcellus exploration and...

Regrounding in Place: Paths to Native American Truths at the Margins

ERIC Educational Resources Information Center

Lucas, Michael

2013-01-01

Margin acts as ground to receive the figure of the text. Margin is initially unreadable, but as suggested by gestalt studies, may be reversed, or regrounded. A humanities course, "Native American Architecture and Place," was created for a polytechnic student population, looking to place as an inroad for access to the margins of a better…

SpinSat Mission Ground Truth Characterization

DTIC Science & Technology

2014-09-01

launch via the SpaceX Falcon 9 CRS4 mission on 12 Sept 2014 and is to be deployed from the International Space Station (ISS) on 29 Sept. 2014. 2...ISS as part of the soft-stow cargo allotment on the SpaceX Dragon spacecraft launched by the SpaceX Falcon 9 two stage to orbit launch vehicle during

Evaluation of the procedure 1A component of the 1980 US/Canada wheat and barley exploratory experiment

NASA Technical Reports Server (NTRS)

Chapman, G. M. (Principal Investigator); Carnes, J. G.

1981-01-01

Several techniques which use clusters generated by a new clustering algorithm, CLASSY, are proposed as alternatives to random sampling to obtain greater precision in crop proportion estimation: (1) Proportional Allocation/relative count estimator (PA/RCE) uses proportional allocation of dots to clusters on the basis of cluster size and a relative count cluster level estimate; (2) Proportional Allocation/Bayes Estimator (PA/BE) uses proportional allocation of dots to clusters and a Bayesian cluster-level estimate; and (3) Bayes Sequential Allocation/Bayesian Estimator (BSA/BE) uses sequential allocation of dots to clusters and a Bayesian cluster level estimate. Clustering in an effective method in making proportion estimates. It is estimated that, to obtain the same precision with random sampling as obtained by the proportional sampling of 50 dots with an unbiased estimator, samples of 85 or 166 would need to be taken if dot sets with AI labels (integrated procedure) or ground truth labels, respectively were input. Dot reallocation provides dot sets that are unbiased. It is recommended that these proportion estimation techniques are maintained, particularly the PA/BE because it provides the greatest precision.

Robust and transferable quantification of NMR spectral quality using IROC analysis

NASA Astrophysics Data System (ADS)

Zambrello, Matthew A.; Maciejewski, Mark W.; Schuyler, Adam D.; Weatherby, Gerard; Hoch, Jeffrey C.

2017-12-01

Non-Fourier methods are increasingly utilized in NMR spectroscopy because of their ability to handle nonuniformly-sampled data. However, non-Fourier methods present unique challenges due to their nonlinearity, which can produce nonrandom noise and render conventional metrics for spectral quality such as signal-to-noise ratio unreliable. The lack of robust and transferable metrics (i.e. applicable to methods exhibiting different nonlinearities) has hampered comparison of non-Fourier methods and nonuniform sampling schemes, preventing the identification of best practices. We describe a novel method, in situ receiver operating characteristic analysis (IROC), for characterizing spectral quality based on the Receiver Operating Characteristic curve. IROC utilizes synthetic signals added to empirical data as "ground truth", and provides several robust scalar-valued metrics for spectral quality. This approach avoids problems posed by nonlinear spectral estimates, and provides a versatile quantitative means of characterizing many aspects of spectral quality. We demonstrate applications to parameter optimization in Fourier and non-Fourier spectral estimation, critical comparison of different methods for spectrum analysis, and optimization of nonuniform sampling schemes. The approach will accelerate the discovery of optimal approaches to nonuniform sampling experiment design and non-Fourier spectrum analysis for multidimensional NMR.

A GIS-based method for household recruitment in a prospective pesticide exposure study.

PubMed

Allpress, Justine L E; Curry, Ross J; Hanchette, Carol L; Phillips, Michael J; Wilcosky, Timothy C

2008-04-30

Recent advances in GIS technology and remote sensing have provided new opportunities to collect ecologic data on agricultural pesticide exposure. Many pesticide studies have used historical or records-based data on crops and their associated pesticide applications to estimate exposure by measuring residential proximity to agricultural fields. Very few of these studies collected environmental and biological samples from study participants. One of the reasons for this is the cost of identifying participants who reside near study fields and analyzing samples obtained from them. In this paper, we present a cost-effective, GIS-based method for crop field selection and household recruitment in a prospective pesticide exposure study in a remote location. For the most part, our multi-phased approach was carried out in a research facility, but involved two brief episodes of fieldwork for ground truthing purposes. This method was developed for a larger study designed to examine the validity of indirect pesticide exposure estimates by comparing measured exposures in household dust, water and urine with records-based estimates that use crop location, residential proximity and pesticide application data. The study focused on the pesticide atrazine, a broadleaf herbicide used in corn production and one of the most widely-used pesticides in the U.S. We successfully used a combination of remotely-sensed data, GIS-based methods and fieldwork to select study fields and recruit participants in Illinois, a state with high corn production and heavy atrazine use. Our several-step process consisted of the identification of potential study fields and residential areas using aerial photography; verification of crop patterns and land use via site visits; development of a GIS-based algorithm to define recruitment areas around crop fields; acquisition of geocoded household-level data within each recruitment area from a commercial vendor; and confirmation of final participant household locations via ground truthing. The use of these procedures resulted in a sufficient sample of participants from 14 recruitment areas in seven Illinois counties. One of the challenges in pesticide research is the identification and recruitment of study participants, which is time consuming and costly, especially when the study site is in a remote location. We have demonstrated how GIS-based processes can be used to recruit participants, increase efficiency and enhance accuracy. The method that we used ultimately made it possible to collect biological samples from a specific demographic group within strictly defined exposure areas, with little advance knowledge of the location or population.

Report of secondary flows, boundary layers, turbulence and wave team, report 1

NASA Technical Reports Server (NTRS)

Scoggins, J. R.; Fitzjarrald, D.; Doviak, R.; Cliff, W.

1980-01-01

General criteria for a flight test option are that: (1) there be a good opportunity for comparison with other measurement techniques; (2) the flow to be measured is of considerable scientific or practical interest; and (3) the airborne laser Doppler system is well suited to measure the required quantities. The requirement for comparison, i.e., ground truth, is particularly important because this is the first year of operation for the system. It is necessary to demonstrate that the system does actually measure the winds and compare the results with other methods to provide a check on the system error analysis. The uniqueness of the laser Doppler system precludes any direct comparison, but point measurements from tower mounted wind sensors and two dimensional fields obtained from radars with substantially different sampling volumes are quite useful.

IN-SITU SAMPLING AND CHARACTERIZATION OF NATURALLY OCCURRING MARINE METHANE HYDRATE USING THE D/V JOIDES RESOLUTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank R. Rack; Peter Schultheiss; Melanie Holland

The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) follow-up logging of pressure cores containing hydrate-bearing sediment; and (2) opening of some of these cores to establish ground-truth understanding. The follow-up measurements made on pressure cores in storage are part of a hydrate geriatric study related to ODP Leg 204. These activities are described in detail in Appendices A and B of this report. Work also continued on developing plans for Phase 2 of this cooperative agreement based on evolving plans to schedule a scientific ocean drilling expedition to study marine methane hydratesmore » along the Cascadia margin, in the NE Pacific as part of the Integrated Ocean Drilling Program (IODP) using the R/V JOIDES Resolution.« less

Developing a Satellite Based Automatic System for Crop Monitoring: Kenya's Great Rift Valley, A Case Study

NASA Astrophysics Data System (ADS)

Lucciani, Roberto; Laneve, Giovanni; Jahjah, Munzer; Mito, Collins

2016-08-01

The crop growth stage represents essential information for agricultural areas management. In this study we investigate the feasibility of a tool based on remotely sensed satellite (Landsat 8) imagery, capable of automatically classify crop fields and how much resolution enhancement based on pan-sharpening techniques and phenological information extraction, useful to create decision rules that allow to identify semantic class to assign to an object, can effectively support the classification process. Moreover we investigate the opportunity to extract vegetation health status information from remotely sensed assessment of the equivalent water thickness (EWT). Our case study is the Kenya's Great Rift valley, in this area a ground truth campaign was conducted during August 2015 in order to collect crop fields GPS measurements, leaf area index (LAI) and chlorophyll samples.

Truth Disclosure Practices of Physicians in Jordan.

PubMed

Borgan, Saif M; Amarin, Justin Z; Othman, Areej K; Suradi, Haya H; Qwaider, Yasmeen Z

2018-03-01

Disclosure of health information is a sensitive matter, particularly in the context of serious illness. In conservative societies-those which predominate in the developing world-direct truth disclosure undoubtedly presents an ethical conundrum to the modern physician. The aim of this study is to explore the truth disclosure practices of physicians in Jordan, a developing country. In this descriptive, cross-sectional study, 240 physicians were initially selected by stratified random sampling. The sample was drawn from four major hospitals in Amman, Jordan. A closed-ended questionnaire was distributed and completed by self-report. A total of 164 physicians completed the questionnaire. Thirty-seven physicians (23 per cent) usually withheld the diagnosis of "serious illness" from patients, while 127 physicians (77 per cent) usually divulged the information directly. Among the latter, 108 physicians (86 per cent) made exceptions to their disclosure policy. Specialists were more likely to withhold health information (p = 0.04998). Non-disclosure was primarily motivated by request from the patient's family (seventy-one participants, 54 per cent). In twenty cases (15 per cent), non-disclosure was undertaken independently. In conclusion, most respondents opt to disclose the truth; however, the vast majority of these respondents make exceptions. Instances of non-disclosure are primarily motivated by sociocultural constructs.

Public health applications of remote sensing of vector borne and parasitic diseases

NASA Technical Reports Server (NTRS)

1976-01-01

Results of an investigation of the potential application of remote sensing to various fields of public health are presented. Specific topics discussed include: detection of snail habitats in connection with the epidemiology of schistosomiasis; the detection of certain Anopheles breeding sites, and location of transient human populations, both in connection with malaria eradication programs; and detection of overwintering population sites for the primary screwworm (Cochliomyia americana). Emphasis was placed on the determination of ground truth data on the biological, chemical, and physical characteristics of ground waters which would or would not support the growth of significant populations of mosquitoes.

Evaluation of large area crop estimation techniques using LANDSAT and ground-derived data. [Missouri

NASA Technical Reports Server (NTRS)

Amis, M. L.; Lennington, R. K.; Martin, M. V.; Mcguire, W. G.; Shen, S. S. (Principal Investigator)

1981-01-01

The results of the Domestic Crops and Land Cover Classification and Clustering study on large area crop estimation using LANDSAT and ground truth data are reported. The current crop area estimation approach of the Economics and Statistics Service of the U.S. Department of Agriculture was evaluated in terms of the factors that are likely to influence the bias and variance of the estimator. Also, alternative procedures involving replacements for the clustering algorithm, the classifier, or the regression model used in the original U.S. Department of Agriculture procedures were investigated.

Global Mapping of Cyber Attacks

DTIC Science & Technology

2014-01-01

from any 10 particular vendor is wrong. Moreover, researchers often use anti-virus labels as ground-truth for evaluating new approaches [5, 17, 36...lnstrusions and Defenses (RAID), September 2007. [SJ U. Bayer, P. M. Comparetti, C. Hlauschek, C. Kruegel, and E. Kirda. Scalable, behavior -based...International Development and Confiict Management International crisis behavior project http: I /www. cidcm. umd.edu/icb/. Last accessed: December 2011

Baseline data on the oceanography of Cook Inlet, Alaska

NASA Technical Reports Server (NTRS)

Gatto, L. W.

1975-01-01

Regional relationships between river hydrology, sediment transport, circulation and coastal processes were analyzed utilizing aircraft, ERTS-1 and N.O.A.A. -2 and -3 imagery and corroborative ground truth data. The use of satellite and aircraft imagery provides a means of acquiring synoptic information for analyzing the dynamic processes of Cook Inlet in a fashion not previously possible.

Tactical Satellite 3

DTIC Science & Technology

2008-08-01

identified for static experiments , target arrays have been designed and ground truth systems are already in place. Participation in field ...key objectives are rapid launch and on-orbit checkout, theater commanding, and near -real time theater data integration. It will also feature a rapid...Organisation (DSTO) plan to participate in TacSat-3 experiments . 1. INTRODUCTION In future conflicts, military space forces will likely face

Oceanographic features in the lee of the windward and leeward islands: ERTS and ship data

NASA Technical Reports Server (NTRS)

Hanson, K. J.; Hebard, F.; Cram, R.

1973-01-01

Analysis of the ERTS data in portions of the eastern Caribbean are presented for October 1972 showing features which are, as yet, not explained. Ground truth data obtained in that area during November 1972 are presented. These include vertical temperature structure in the mixed layer and thermocline, and surface measurements of salinity, temperature, and chlorophyll.

The Ethics of Science and/as Research: Deconstruction and the Orientations of a New Academic Responsibility

ERIC Educational Resources Information Center

Trifonas, Peter

2003-01-01

The principle of reason "as principle of grounding, foundation or institution" has tended to guide the science of research toward techno-practical ends. From this epistemic superintendence of the terms of knowledge and inquiry, there has arisen the traditional notion of academic responsibility that is tied to the pursuit of truth via a conception…

Inter-Vehicular Ad Hoc Networks: From the Ground Truth to Algorithm Design and Testbed Architecture

ERIC Educational Resources Information Center

Giordano, Eugenio

2011-01-01

Many of the devices we interact with on a daily basis are currently equipped with wireless connectivity. Soon this will be extended to the vehicles we drive/ride every day. Wirelessly connected vehicles will form a new kind of network that will enable a wide set of innovative applications ranging from enhanced safety to entertainment. To…

The significance of the Skylab altimeter experiment results and potential applications. [measurement of sea surface topography

NASA Technical Reports Server (NTRS)

Mourad, A. G.; Gopalapillai, S.; Kuhner, M.

1975-01-01

The Skylab Altimeter Experiment has proven the capability of the altimeter for measurement of sea surface topography. The geometric determination of the geoid/mean sea level from satellite altimetry is a new approach having significant applications in many disciplines including geodesy and oceanography. A Generalized Least Squares Collocation Technique was developed for determination of the geoid from altimetry data. The technique solves for the altimetry geoid and determines one bias term for the combined effect of sea state, orbit, tides, geoid, and instrument error using sparse ground truth data. The influence of errors in orbit and a priori geoid values are discussed. Although the Skylab altimeter instrument accuracy is about + or - 1 m, significant results were obtained in identification of large geoidal features such as over the Puerto Rico trench. Comparison of the results of several passes shows that good agreement exists between the general slopes of the altimeter geoid and the ground truth, and that the altimeter appears to be capable of providing more details than are now available with best known geoids. The altimetry geoidal profiles show excellent correlations with bathymetry and gravity. Potential applications of altimetry results to geodesy, oceanography, and geophysics are discussed.

Comparative Study With New Accuracy Metrics for Target Volume Contouring in PET Image Guided Radiation Therapy

PubMed Central

Shepherd, T; Teras, M; Beichel, RR; Boellaard, R; Bruynooghe, M; Dicken, V; Gooding, MJ; Julyan, PJ; Lee, JA; Lefèvre, S; Mix, M; Naranjo, V; Wu, X; Zaidi, H; Zeng, Z; Minn, H

2017-01-01

The impact of positron emission tomography (PET) on radiation therapy is held back by poor methods of defining functional volumes of interest. Many new software tools are being proposed for contouring target volumes but the different approaches are not adequately compared and their accuracy is poorly evaluated due to the ill-definition of ground truth. This paper compares the largest cohort to date of established, emerging and proposed PET contouring methods, in terms of accuracy and variability. We emphasize spatial accuracy and present a new metric that addresses the lack of unique ground truth. Thirty methods are used at 13 different institutions to contour functional volumes of interest in clinical PET/CT and a custom-built PET phantom representing typical problems in image guided radiotherapy. Contouring methods are grouped according to algorithmic type, level of interactivity and how they exploit structural information in hybrid images. Experiments reveal benefits of high levels of user interaction, as well as simultaneous visualization of CT images and PET gradients to guide interactive procedures. Method-wise evaluation identifies the danger of over-automation and the value of prior knowledge built into an algorithm. PMID:22692898

A study to explore the use of orbital remote sensing to determine native arid plant distribution

NASA Technical Reports Server (NTRS)

Mcginnies, W. G. (Principal Investigator); Haase, E. F.; Musick, H. B. (Compiler)

1973-01-01

The author has identified the following significant results. A theory has been developed of a method for determining the reflectivities of natural areas from ERTS-1 data. This method requires the following measurements: (1) ground truth reflectivity data from two different calibration areas; (2) radiance data from ERTS-1 MSS imagery for the same two calibration areas; and (3) radiance data from ERTS-1 MSS imagery for the area(s) in which reflectivity is to be determined. The method takes into account sun angle effects and atmospheric effects on the radiance seen by the space sensor. If certain assumptions are made, the ground truth data collection need not be simultaneous with the ERTS-1 overflight. The method allows the calculation of a conversion factor for converting ERTS-1 MSS radiance measurements of a given overflight to reflectivity values. This conversion factor can be used to determine the reflectivity of any area in the general vicinity of the calibration areas which has a relatively similar overlying atmosphere. This method, or some modification of it, may be useful in ERTS investigations which require the determination of spectral signatures of areas from spacecraft data.

Enhancing Deep-Water Low-Resolution Gridded Bathymetry Using Single Image Super-Resolution

NASA Astrophysics Data System (ADS)

Elmore, P. A.; Nock, K.; Bonanno, D.; Smith, L.; Ferrini, V. L.; Petry, F. E.

2017-12-01

We present research to employ single-image super-resolution (SISR) algorithms to enhance knowledge of the seafloor using the 1-minute GEBCO 2014 grid when 100m grids from high-resolution sonar systems are available for training. Our numerical upscaling experiments of x15 upscaling of the GEBCO grid along three areas of the Eastern Pacific Ocean along mid-ocean ridge systems where we have these 100m gridded bathymetry data sets, which we accept as ground-truth. We show that four SISR algorithms can enhance this low-resolution knowledge of bathymetry versus bicubic or Spline-In-Tension algorithms through upscaling under these conditions: 1) rough topography is present in both training and testing areas and 2) the range of depths and features in the training area contains the range of depths in the enhancement area. We quantitatively judged successful SISR enhancement versus bicubic interpolation when Student's hypothesis testing show significant improvement of the root-mean squared error (RMSE) between upscaled bathymetry and 100m gridded ground-truth bathymetry at p < 0.05. In addition, we found evidence that random forest based SISR methods may provide more robust enhancements versus non-forest based SISR algorithms.

Brain tumor classification and segmentation using sparse coding and dictionary learning.

PubMed

Salman Al-Shaikhli, Saif Dawood; Yang, Michael Ying; Rosenhahn, Bodo

2016-08-01

This paper presents a novel fully automatic framework for multi-class brain tumor classification and segmentation using a sparse coding and dictionary learning method. The proposed framework consists of two steps: classification and segmentation. The classification of the brain tumors is based on brain topology and texture. The segmentation is based on voxel values of the image data. Using K-SVD, two types of dictionaries are learned from the training data and their associated ground truth segmentation: feature dictionary and voxel-wise coupled dictionaries. The feature dictionary consists of global image features (topological and texture features). The coupled dictionaries consist of coupled information: gray scale voxel values of the training image data and their associated label voxel values of the ground truth segmentation of the training data. For quantitative evaluation, the proposed framework is evaluated using different metrics. The segmentation results of the brain tumor segmentation (MICCAI-BraTS-2013) database are evaluated using five different metric scores, which are computed using the online evaluation tool provided by the BraTS-2013 challenge organizers. Experimental results demonstrate that the proposed approach achieves an accurate brain tumor classification and segmentation and outperforms the state-of-the-art methods.

2004 Savannah River Cooling Tower Collection (U)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garrett, Alfred; Parker, Matthew J.; Villa-Aleman, E.

2005-05-01

The Savannah River National Laboratory (SRNL) collected ground truth in and around the Savannah River Site (SRS) F-Area cooling tower during the spring and summer of 2004. The ground truth data consisted of air temperatures and humidity inside and around the cooling tower, wind speed and direction, cooling water temperatures entering; inside adn leaving the cooling tower, cooling tower fan exhaust velocities and thermal images taken from helicopters. The F-Area cooling tower had six cells, some of which were operated with fans off during long periods of the collection. The operating status (fan on or off) for each of themore » six cells was derived from operations logbooks and added to the collection database. SRNL collected the F-Area cooling tower data to produce a database suitable for validation of a cooling tower model used by one of SRNL's customer agencies. SRNL considers the data to be accurate enough for use in a model validation effort. Also, the thermal images of the cooling tower decks and throats combined with the temperature measurements inside the tower provide valuable information about the appearance of cooling towers as a function of fan operating status and time of day.« less

Creating experimental color harmony map

NASA Astrophysics Data System (ADS)

Chamaret, Christel; Urban, Fabrice; Lepinel, Josselin

2014-02-01

Starting in the 17th century with Newton, color harmony is a topic that did not reach a consensus on definition, representation or modeling so far. Previous work highlighted specific characteristics for color harmony on com- bination of color doublets or triplets by means of a human rating on a harmony scale. However, there were no investigation involving complex stimuli or pointing out how harmony is spatially located within a picture. The modeling of such concept as well as a reliable ground-truth would be of high value for the community, since the applications are wide and concern several communities: from psychology to computer graphics. We propose a protocol for creating color harmony maps from a controlled experiment. Through an eye-tracking protocol, we focus on the identification of disharmonious colors in pictures. The experiment was composed of a free viewing pass in order to let the observer be familiar with the content before a second pass where we asked "to search for the most disharmonious areas in the picture". Twenty-seven observers participated to the experiments that was composed of a total of 30 different stimuli. The high inter-observer agreement as well as a cross-validation confirm the validity of the proposed ground-truth.

Error estimation of deformable image registration of pulmonary CT scans using convolutional neural networks.

PubMed

Eppenhof, Koen A J; Pluim, Josien P W

2018-04-01

Error estimation in nonlinear medical image registration is a nontrivial problem that is important for validation of registration methods. We propose a supervised method for estimation of registration errors in nonlinear registration of three-dimensional (3-D) images. The method is based on a 3-D convolutional neural network that learns to estimate registration errors from a pair of image patches. By applying the network to patches centered around every voxel, we construct registration error maps. The network is trained using a set of representative images that have been synthetically transformed to construct a set of image pairs with known deformations. The method is evaluated on deformable registrations of inhale-exhale pairs of thoracic CT scans. Using ground truth target registration errors on manually annotated landmarks, we evaluate the method's ability to estimate local registration errors. Estimation of full domain error maps is evaluated using a gold standard approach. The two evaluation approaches show that we can train the network to robustly estimate registration errors in a predetermined range, with subvoxel accuracy. We achieved a root-mean-square deviation of 0.51 mm from gold standard registration errors and of 0.66 mm from ground truth landmark registration errors.

Gebiss: an ImageJ plugin for the specification of ground truth and the performance evaluation of 3D segmentation algorithms

PubMed Central

2011-01-01

Background Image segmentation is a crucial step in quantitative microscopy that helps to define regions of tissues, cells or subcellular compartments. Depending on the degree of user interactions, segmentation methods can be divided into manual, automated or semi-automated approaches. 3D image stacks usually require automated methods due to their large number of optical sections. However, certain applications benefit from manual or semi-automated approaches. Scenarios include the quantification of 3D images with poor signal-to-noise ratios or the generation of so-called ground truth segmentations that are used to evaluate the accuracy of automated segmentation methods. Results We have developed Gebiss; an ImageJ plugin for the interactive segmentation, visualisation and quantification of 3D microscopic image stacks. We integrated a variety of existing plugins for threshold-based segmentation and volume visualisation. Conclusions We demonstrate the application of Gebiss to the segmentation of nuclei in live Drosophila embryos and the quantification of neurodegeneration in Drosophila larval brains. Gebiss was developed as a cross-platform ImageJ plugin and is freely available on the web at http://imaging.bii.a-star.edu.sg/projects/gebiss/. PMID:21668958

On Sea Ice Characterisation By Multi-Frequency SAR

NASA Astrophysics Data System (ADS)

Grahn, Jakob; Brekke, Camilla; Eltoft, Torbjorn; Holt, Benjamin

2013-12-01

By means of polarimetric target decomposition, quad-pol SAR data of sea ice is analysed at two frequency bands. In particular, the non negative eigenvalue decomposition (NNED) is applied on L- and C-band NASA/JPL AIR- SAR data acquired over the Beaufort sea in 2004. The de- composition separates the scattered radar signal into three types, dominated by double, volume and single bounce scattering respectively. Using ground truth derived from RADARSAT-1 and meteorological data, we investigate how the different frequency bands compare in terms of these scattering types. The ground truth contains multi year ice and three types of first year ice of different age and thickness. We find that C-band yields a higher scattered intensity in most ice and scattering types, as well as a more homogeneous intensity. L-band on the other hand yields more pronounced deformation features, such as ridges. The mean intensity contrast between the two thinnest ice types is highest in the double scattering component of C- band, although the contrast of the total signal is greater in L-band. This may indicate that the choice of polarimetric parameters is important for discriminating thin ice types.

A rapid method to characterize seabed habitats and associated macro-organisms

USGS Publications Warehouse

Anderson, T.J.; Cochrane, G.R.; Roberts, D.A.; Chezar, H.; Hatcher, G.; ,

2007-01-01

This study presents a method for rapidly collecting, processing, and interrogating real-time abiotic and biotic seabed data to determine seabed habitat classifications. This is done from data collected over a large area of an acoustically derived seabed map, along multidirectional transects, using a towed small camera-sled. The seabed, within the newly designated Point Harris Marine Reserve on the northern coast of San Miguel Island, California, was acoustically imaged using sidescan sonar then ground-truthed using a towed small camera-sled. Seabed characterizations were made from video observations, and were logged to a laptop computer (PC) in real time. To ground-truth the acoustic mosaic, and to characterize abiotic and biotic aspects of the seabed, a three-tiered characterization scheme was employed that described the substratum type, physical structure (i.e., bedform or vertical relief), and the occurrence of benthic macrofauna and flora. A crucial advantage of the method described here, is that preliminary seabed characterizations can be interrogated and mapped over the sidescan mosaic and other seabed information within hours of data collection. This ability to rapidly process seabed data is invaluable to scientists and managers, particularly in modifying concurrent or planning subsequent surveys.

Effects of temporal variability in ground data collection on classification accuracy

USGS Publications Warehouse

Hoch, G.A.; Cully, J.F.

1999-01-01

This research tested whether the timing of ground data collection can significantly impact the accuracy of land cover classification. Ft. Riley Military Reservation, Kansas, USA was used to test this hypothesis. The U.S. Army's Land Condition Trend Analysis (LCTA) data annually collected at military bases was used to ground truth disturbance patterns. Ground data collected over an entire growing season and data collected one year after the imagery had a kappa statistic of 0.33. When using ground data from only within two weeks of image acquisition the kappa statistic improved to 0.55. Potential sources of this discrepancy are identified. These data demonstrate that there can be significant amounts of land cover change within a narrow time window on military reservations. To accurately conduct land cover classification at military reservations, ground data need to be collected in as narrow a window of time as possible and be closely synchronized with the date of the satellite imagery.

Innovative method for optimizing Side-Scan Sonar mapping: The blind band unveiled

NASA Astrophysics Data System (ADS)

Pergent, Gérard; Monnier, Briac; Clabaut, Philippe; Gascon, Gilles; Pergent-Martini, Christine; Valette-Sansevin, Audrey

2017-07-01

Over the past few years, the mapping of Mediterranean marine habitats has become a priority for scientists, environment managers and stakeholders, in particular in order to comply with European directives (Water Framework Directive and Marine Strategy Framework Directive) and to implement legislation to ensure their conservation. Side-scan sonar (SSS) is recognised as one of the most effective tool for underwater mapping. However, interpretation of acoustic data (sonograms) requires extensive field calibration and the ground-truthing process remains essential. Several techniques are commonly used, with sampling methods involving grabs, scuba diving observations or Remotely Operated Vehicle (ROV) underwater video recordings. All these techniques are time consuming, expensive and only provide sporadic informations. In the present study, the possibility of coupling a camera with a SSS and acquiring underwater videos in a continuous way has been tested. During the 'PosidCorse' oceanographic survey carried out along the eastern coast of Corsica, optical and acoustic data were respectively obtained using a GoPro™ camera and a Klein 3000™ SSS. Thereby, five profiles were performed between 10 and 50 m depth, corresponding to more than 20 km of data acquisition. The vertical images recorded with the camera fixed under the SSS and positioned facing downwards provided photo mosaics of very good quality corresponding to the entire sonograms's blind band. From the photo mosaics, 94% of the different bottom types and main habitats have been identified; specific structures linked to hydrodynamics conditions, anthropic and biological activities have also been observed as well as the substrate on which the Posidonia oceanica meadow grows. The association between acoustic data and underwater videos has proved to be a non-destructive and cost-effective method for ground-truthing in marine habitats mapping. Nevertheless, in order to optimize the results over the next surveys, certain limitations will need to be remedied.

Ground-truthing the Foraminifera-bound Nitrogen Isotope Paleo-proxy in the Modern Sargasso Sea

NASA Astrophysics Data System (ADS)

Smart, S.; Ren, H. A.; Fawcett, S. E.; Conte, M. H.; Rafter, P. A.; Ellis, K. K.; Weigand, M. A.; Sigman, D. M.

2016-02-01

We present the nitrogen isotope ratios (δ15N) of planktonic foraminifera, a type of calcifying zooplankton, collected from surface ocean net tows, moored sediment traps and core-top sediments at the Bermuda Atlantic Time-series Study site in the Sargasso Sea between 2009 and 2013. Consistent with previous measurements from low-latitude core-top sediments, the annually averaged δ15N of organic matter bound within the shells of euphotic zone-dwelling foraminifera approximates that of thermocline nitrate, the dominant source of new nitrogen to Sargasso Sea surface waters. Based on net tow collections in the upper 200 m of the water column, we observe no systematic difference between the biomass δ15N and shell-bound δ15N of a given foraminifera species. For multiple species, the δ15N of net tow-collected upper ocean shells is lower than shells from sediment traps (by 0.5-2.1‰) and lower than shells from seafloor sediments (by 0.5-1.4‰). We are currently investigating whether these differences reflect actual processes affecting shell-bound δ15N or instead relate to the different time periods over which the three sample types integrate. The foraminiferal biomass δ15N time-series from the surface Sargasso Sea exhibits significant seasonal variations, with the lowest values in fall and the highest values in spring. The roles of hydrography, biogeochemistry, and ecosystem dynamics in driving these seasonal variations will be discussed. These data from the modern subtropical ocean form part of a greater effort to ground-truth the use of foram-bound δ15N to reconstruct past nutrient conditions, not only as a recorder of the isotopic composition of nitrogen supply in oligotrophic environments but also as a recorder of the degree of nitrate consumption in high-latitude regions such as the Southern Ocean.

Development of Whole Slide Imaging on Smartphones and Evaluation With ThinPrep Cytology Test Samples: Follow-Up Study

PubMed Central

Ma, Shuoxin; Yu, Hong; Jin, Yu-Biao; Zheng, Jun

2018-01-01

Background The smartphone-based whole slide imaging (WSI) system represents a low-cost and effective alternative to automatic scanners for telepathology. In a previous study, the development of one such solution, named scalable whole slide imaging (sWSI), was presented and analyzed. A clinical evaluation of its iOS version with 100 frozen section samples verified the diagnosis-readiness of the produced virtual slides. Objective The first aim of this study was to delve into the quantifying issues encountered in the development of an Android version. It should also provide insights into future high-resolution real-time feedback medical imaging apps on Android and invoke the awareness of smartphone manufacturers for collaboration. The second aim of this study was to further verify the clinical value of sWSI with cytology samples. This type is different from the frozen section samples in that they require finer detail on the cellular level. Methods During sWSI development on Android, it was discovered that many models do not support uncompressed camera pixel data with sufficient resolution and full field of view. The proportion of models supporting the optimal format was estimated in a test on 200 mainstream Android models. Other factors, including slower processing speed and camera preview freezing, also led to inferior performance of sWSI on Android compared with the iOS version. The processing speed was mostly determined by the central processing unit frequency in theory, and the relationship was investigated in the 200-model simulation experiment with physical devices. The camera preview freezing was caused by the lag between triggering photo capture and resuming preview. In the clinical evaluation, 100 ThinPrep cytology test samples covering 6 diseases were scanned with sWSI and compared against the ground truth of optical microscopy. Results Among the tested Android models, only 3.0% (6/200) provided an optimal data format, meeting all criteria of quality and efficiency. The image-processing speed demonstrated a positive relationship with the central processing unit frequency but to a smaller degree than expected and was highly model-dependent. The virtual slides produced by sWSI on Android and iOS of ThinPrep cytology test samples achieved similar high quality. Using optical microscopy as the ground truth, pathologists made a correct diagnosis on 87.5% (175/200) of the cases with sWSI virtual slides. Depending on the sWSI version and the pathologist in charge, the kappa value varied between .70 and .82. All participating pathologists considered the quality of the sWSI virtual slides in the experiment to be adequate for routine usage. Conclusions Limited by hardware and operating system support, the performance of sWSI on mainstream Android smartphones did not fully match the iOS version. However, in practice, this difference was not significant, and both were adequate for digitizing most of the sample types for telepathology consultation. PMID:29618454

Application of Multifunctional Doppler LIDAR for Noncontact Track Speed, Distance, and Curvature Assessment

NASA Astrophysics Data System (ADS)

Munoz, Joshua

The primary focus of this research is evaluation of feasibility, applicability, and accuracy of Doppler Light Detection And Ranging (LIDAR) sensors as non-contact means for measuring track speed, distance traveled, and curvature. Speed histories, currently measured with a rotary, wheelmounted encoder, serve a number of useful purposes, one significant use involving derailment investigations. Distance calculation provides a spatial reference system for operators to locate track sections of interest. Railroad curves, using an IMU to measure curvature, are monitored to maintain track infrastructure within regulations. Speed measured with high accuracy leads to highfidelity distance and curvature data through utilization of processor clock rate and left-and rightrail speed differentials during curve navigation, respectively. Wheel-mounted encoders, or tachometers, provide a relatively low-resolution speed profile, exhibit increased noise with increasing speed, and are subject to the inertial behavior of the rail car which affects output data. The IMU used to measure curvature is dependent on acceleration and yaw rate sensitivity and experiences difficulty in low-speed conditions. Preliminary system tests onboard a "Hy-Rail" utility vehicle capable of traveling on rail show speed capture is possible using the rails as the reference moving target and furthermore, obtaining speed profiles from both rails allows for the calculation of speed differentials in curves to estimate degrees curvature. Ground truth distance calibration and curve measurement were also carried out. Distance calibration involved placement of spatial landmarks detected by a sensor to synchronize distance measurements as a pre-processing procedure. Curvature ground truth measurements provided a reference system to confirm measurement results and observe alignment variation throughout a curve. Primary testing occurred onboard a track geometry rail car, measuring rail speed over substantial mileage in various weather conditions, providing highaccuracy data to further calculate distance and curvature along the test routes. Tests results indicate the LIDAR system measures speed at higher accuracy than the encoder, absent of noise influenced by increasing speed. Distance calculation is also high in accuracy, results showing high correlation with encoder and ground truth data. Finally, curvature calculation using speed data is shown to have good correlation with IMU measurements and a resolution capable of revealing localized track alignments. Further investigations involve a curve measurement algorithm and speed calibration method independent from external reference systems, namely encoder and ground truth data. The speed calibration results show a high correlation with speed data from the track geometry vehicle. It is recommended that the study be extended to provide assessment of the LIDAR's sensitivity to car body motion in order to better isolate the embedded behavior in the speed and curvature profiles. Furthermore, in the interest of progressing the system toward a commercially viable unit, methods for self-calibration and pre-processing to allow for fully independent operation is highly encouraged.

The micron- to kilometer-scale Moon: linking samples to orbital observations, Apollo to LRO

NASA Astrophysics Data System (ADS)

Crites, S.; Lucey, P. G.; Taylor, J.; Martel, L.; Sun, L.; Honniball, C.; Lemelin, M.

2017-12-01

The Apollo missions have shaped the field of lunar science and our understanding of the Moon, from global-scale revelations like the magma ocean hypothesis, to providing ground truth for compositional remote sensing and absolute ages to anchor cratering chronologies. While lunar meteorite samples can provide a global- to regional-level view of the Moon, samples returned from known locations are needed to directly link orbital-scale observations with laboratory measurements-a link that can be brought to full fruition with today's extremely high spatial resolution observations from Lunar Reconnaissance Orbiter and other recent missions. Korotev et al. (2005) described a scenario of the Moon without Apollo to speculate about our understanding of the Moon if our data were confined to lunar meteorites and remote sensing. I will review some of the major points discussed by Korotev et al. (2005), and focus on some of the ways in which spectroscopic remote sensing in particular has benefited from the Apollo samples. For example, could the causes and effects of lunar-style space weathering have been unraveled without the Apollo samples? What would be the limitations on remote sensing compositional measurements that rely on Apollo samples for calibration and validation? And what new opportunities to bring together orbital and sample analyses now exist, in light of today's high spatial and spectral resolution remote sensing datasets?

Remote sensing for grassland management in the arid Southwest

USGS Publications Warehouse

Marsett, R.C.; Qi, J.; Heilman, P.; Biedenbender, S.H.; Watson, M.C.; Amer, S.; Weltz, M.; Goodrich, D.; Marsett, R.

2006-01-01

We surveyed a group of rangeland managers in the Southwest about vegetation monitoring needs on grassland. Based on their responses, the objective of the RANGES (Rangeland Analysis Utilizing Geospatial Information Science) project was defined to be the accurate conversion of remotely sensed data (satellite imagery) to quantitative estimates of total (green and senescent) standing cover and biomass on grasslands and semidesert grasslands. Although remote sensing has been used to estimate green vegetation cover, in arid grasslands herbaceous vegetation is senescent much of the year and is not detected by current remote sensing techniques. We developed a ground truth protocol compatible with both range management requirements and Landsat's 30 m resolution imagery. The resulting ground-truth data were then used to develop image processing algorithms that quantified total herbaceous vegetation cover, height, and biomass. Cover was calculated based on a newly developed Soil Adjusted Total Vegetation Index (SATVI), and height and biomass were estimated based on reflectance in the near infrared (NIR) band. Comparison of the remotely sensed estimates with independent ground measurements produced r2 values of 0.80, 0.85, and 0.77 and Nash Sutcliffe values of 0.78, 0.70, and 0.77 for the cover, plant height, and biomass, respectively. The approach for estimating plant height and biomass did not work for sites where forbs comprised more than 30% of total vegetative cover. The ground reconnaissance protocol and image processing techniques together offer land managers accurate and timely methods for monitoring extensive grasslands. The time-consuming requirement to collect concurrent data in the field for each image implies a need to share the high fixed costs of processing an image across multiple users to reduce the costs for individual rangeland managers.

The carbon or silicon colonization of the universe?

PubMed

Parkinson, Bob

2005-01-01

At the time of the Apollo Programme, a first human mission to Mars was proposed as early as 1984 with the argument that the higher costs of human exploration would be more than justified by the increased effectiveness of human explorers. This was based on the Apollo experience, where "ground truth" measurements and sampling provided the basis for subsequent unmanned exploration of the Solar System. A human Mars mission is now not seen until 2030, at the end of a series of increasingly sophisticated unmanned probes. Each robot mission not only teaches us something about Mars, but also through experience increases our capabilities for the unmanned exploration of that planet. As a consequence, what a human mission would have to do becomes progressively more demanding. Any extended plan for the human exploration of Space will tend to be overtaken by advances in technology, and if this is not factored into the scenario the proposals will become progressively unrealistic.

Multiple-instance ensemble learning for hyperspectral images

NASA Astrophysics Data System (ADS)

Ergul, Ugur; Bilgin, Gokhan

2017-10-01

An ensemble framework for multiple-instance (MI) learning (MIL) is introduced for use in hyperspectral images (HSIs) by inspiring the bagging (bootstrap aggregation) method in ensemble learning. Ensemble-based bagging is performed by a small percentage of training samples, and MI bags are formed by a local windowing process with variable window sizes on selected instances. In addition to bootstrap aggregation, random subspace is another method used to diversify base classifiers. The proposed method is implemented using four MIL classification algorithms. The classifier model learning phase is carried out with MI bags, and the estimation phase is performed over single-test instances. In the experimental part of the study, two different HSIs that have ground-truth information are used, and comparative results are demonstrated with state-of-the-art classification methods. In general, the MI ensemble approach produces more compact results in terms of both diversity and error compared to equipollent non-MIL algorithms.

Remote Sensing techniques used to characterize soil erosion in southwestern Sao Paulo state. M.S. Thesis - 29 Sep. 1982; [Brazil

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Pinto, S. D. A. F.

1983-01-01

Within randomly sampled squares of a 1 km x 1 km grid, rill/gullies frequency, land cover/land use type and shape of the slopes were extracted from aerial photographs of the Ribeirao Anhumas drainage basin. Mean slope gradient, stream frequency and slope length were calculated on topographic maps. Ground truth data on fine sand/coarse sand ratio and vegetation cover densities were obtained. The MSS-LANDSAT-2 data (CCTs) were analyzed using single-cell, cluster synthesis and slicer algorithms. Graphical and statistical analyses of the data indicate that different slope gradients and land cover/land use types are the most significant factors related to the soil erosion process. The digital analysis of MSS data allowed the association among gray level classes and vegetation cover classes, which defined seven classes. These gray level classes and slope gradient classes were used to rank erosion risk.

Automatic Cell Segmentation Using a Shape-Classification Model in Immunohistochemically Stained Cytological Images

NASA Astrophysics Data System (ADS)

Shah, Shishir

This paper presents a segmentation method for detecting cells in immunohistochemically stained cytological images. A two-phase approach to segmentation is used where an unsupervised clustering approach coupled with cluster merging based on a fitness function is used as the first phase to obtain a first approximation of the cell locations. A joint segmentation-classification approach incorporating ellipse as a shape model is used as the second phase to detect the final cell contour. The segmentation model estimates a multivariate density function of low-level image features from training samples and uses it as a measure of how likely each image pixel is to be a cell. This estimate is constrained by the zero level set, which is obtained as a solution to an implicit representation of an ellipse. Results of segmentation are presented and compared to ground truth measurements.

Dynamic Bayesian network modeling for longitudinal brain morphometry

PubMed Central

Chen, Rong; Resnick, Susan M; Davatzikos, Christos; Herskovits, Edward H

2011-01-01

Identifying interactions among brain regions from structural magnetic-resonance images presents one of the major challenges in computational neuroanatomy. We propose a Bayesian data-mining approach to the detection of longitudinal morphological changes in the human brain. Our method uses a dynamic Bayesian network to represent evolving inter-regional dependencies. The major advantage of dynamic Bayesian network modeling is that it can represent complicated interactions among temporal processes. We validated our approach by analyzing a simulated atrophy study, and found that this approach requires only a small number of samples to detect the ground-truth temporal model. We further applied dynamic Bayesian network modeling to a longitudinal study of normal aging and mild cognitive impairment — the Baltimore Longitudinal Study of Aging. We found that interactions among regional volume-change rates for the mild cognitive impairment group are different from those for the normal-aging group. PMID:21963916