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1

Microwave landing system autoland system analysis  

NASA Technical Reports Server (NTRS)

The objective was to investigate the ability of present day aircraft equipped with automatic flight control systems to fly advanced Microwave Landing Systems (MLS) approaches. The tactical approach used to achieve this objective included reviewing the design and autoland operation of the MD-80 aircraft, simulating the MLS approaches using a batch computer program, and assessing the performance of the autoland system from computer generated data. The results showed changes were required to present Instrument Landing System (ILS) procedures to accommodate the new MLS curved paths. It was also shown that in some cases, changes to the digital flight guidance systems would be required so that an autoland could be performed.

Feather, J. B.; Craven, B. K.

1991-01-01

2

Entry, Descent and Landing Systems Analysis Study: Phase 1 Report  

NASA Technical Reports Server (NTRS)

NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to make in order to successfully land large payloads at Mars for both robotic and human-scale missions. This paper summarizes the motivation, approach and top-level results from Year 1 of the study, which focused on landing 10-50 mt on Mars, but also included a trade study of the best advanced parachute design for increasing the landed payloads within the EDL architecture of the Mars Science Laboratory (MSL) mission

DwyerCianciolo, Alicia M.; Davis, Jody L.; Komar, David R.; Munk, Michelle M.; Samareh, Jamshid A.; Powell, Richard W.; Shidner, Jeremy D.; Stanley, Douglas O.; Wilhite, Alan W.; Kinney, David J.; McGuire, M. Kathleen; Arnold, James O.; Howard, Austin R.; Sostaric, Ronald R.; Studak, Joseph W.; Zumwalt, Carlie H.; Llama, Eduardo G.; Casoliva, Jordi; Ivanov, Mark C.; Clark, Ian; Sengupta, Anita

2010-01-01

3

Aircraft antenna analysis for microwave landing system  

Microsoft Academic Search

of the best antenna polarization for efficient system operation. In the past, the usual design practice consisted of allocating specific locations to antennas regardless of electronic system requirements but based primarily upon structural specifications. Because of the complexity of the structural configuration of the airframe, analytical investigations for system improvements were not encouraged and due to economic considerations extensive experimental

C. A. Balanis; Y. B. Cheng

1975-01-01

4

An overview of the Land Analysis System (LAS)  

NASA Technical Reports Server (NTRS)

An outline covering the history, development methodology, and major hardware/software components of the Land Analysis System (LAS) is presented. System support services including the Transportable Applications Executive (TAE), Catalog Manager, history files, and applications services are briefly described along with the general functional capabilities of the 224 available applications programs. Example interface menus are given and desired enhancements to the LAS system are listed.

Lu, Yun-Chi

1986-01-01

5

The Land Analysis System (LAS) for multispectral image processing  

USGS Publications Warehouse

The Land Analysis System (LAS) is an interactive software system available in the public domain for the analysis, display, and management of multispectral and other digital image data. LAS provides over 240 applications functions and utilities, a flexible user interface, complete online and hard-copy documentation, extensive image-data file management, reformatting, conversion utilities, and high-level device independent access to image display hardware. The authors summarize the capabilities of the current release of LAS (version 4.0) and discuss plans for future development. Particular emphasis is given to the issue of system portability and the importance of removing and/or isolating hardware and software dependencies.

Wharton, S. W.; Lu, Y. C.; Quirk, Bruce K.; Oleson, Lyndon R.; Newcomer, J. A.; Irani, Frederick M.

1988-01-01

6

Integration of Systems Network (SysNet) tools for regional land use scenario analysis in Asia  

Microsoft Academic Search

This paper introduces the approach of the Systems research Network (SysNet) for land use planning in tropical Asia with a focus on its main scientific–technical output: the development of the land use planning and analysis system (LUPAS) and its component models. These include crop simulation models, expert systems, GIS, and multiple goal linear programming (MGLP) models for land evaluation and

Reimund P. Roetter; Chu Thai Hoanh; Alice G. Laborte; Herman Van Keulen; Martin K. Van Ittersum; Christoph Dreiser; Cees A. Van Diepen; Nico De Ridder; H. H. Van Laar

2005-01-01

7

Entry, Descent and Landing Systems Analysis Study: Phase 2 Report on Exploration Feed-Forward Systems  

NASA Technical Reports Server (NTRS)

NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to successfully land large payloads at Mars for both robotic and human-scale missions. Year 1 of the study focused on technologies required for Exploration-class missions to land payloads of 10 to 50 t. Inflatable decelerators, rigid aeroshell and supersonic retro-propulsion emerged as the top candidate technologies. In Year 2 of the study, low TRL technologies identified in Year 1, inflatables aeroshells and supersonic retropropulsion, were combined to create a demonstration precursor robotic mission. This part of the EDL-SA Year 2 effort, called Exploration Feed Forward (EFF), took much of the systems analysis simulation and component model development from Year 1 to the next level of detail.

Dwyer Ciancolo, Alicia M.; Davis, Jody L.; Engelund, Walter C.; Komar, D. R.; Queen, Eric M.; Samareh, Jamshid A.; Way, David W.; Zang, Thomas A.; Murch, Jeff G.; Krizan, Shawn A.; Olds, Aaron D.; Powell, Richard W.; Shidner, Jeremy D.; Kinney, Daivd J.; McGuire, M. Kathleen; Arnold, James O.; Covington, M. Alan; Sostaric, Ronald R.; Zumwalt, Carlie H.; Llama, Eduardo G.

2011-01-01

8

LAS - LAND ANALYSIS SYSTEM, VERSION 5.0  

NASA Technical Reports Server (NTRS)

The Land Analysis System (LAS) is an image analysis system designed to manipulate and analyze digital data in raster format and provide the user with a wide spectrum of functions and statistical tools for analysis. LAS offers these features under VMS with optional image display capabilities for IVAS and other display devices as well as the X-Windows environment. LAS provides a flexible framework for algorithm development as well as for the processing and analysis of image data. Users may choose between mouse-driven commands or the traditional command line input mode. LAS functions include supervised and unsupervised image classification, film product generation, geometric registration, image repair, radiometric correction and image statistical analysis. Data files accepted by LAS include formats such as Multi-Spectral Scanner (MSS), Thematic Mapper (TM) and Advanced Very High Resolution Radiometer (AVHRR). The enhanced geometric registration package now includes both image to image and map to map transformations. The over 200 LAS functions fall into image processing scenario categories which include: arithmetic and logical functions, data transformations, fourier transforms, geometric registration, hard copy output, image restoration, intensity transformation, multispectral and statistical analysis, file transfer, tape profiling and file management among others. Internal improvements to the LAS code have eliminated the VAX VMS dependencies and improved overall system performance. The maximum LAS image size has been increased to 20,000 lines by 20,000 samples with a maximum of 256 bands per image. The catalog management system used in earlier versions of LAS has been replaced by a more streamlined and maintenance-free method of file management. This system is not dependent on VAX/VMS and relies on file naming conventions alone to allow the use of identical LAS file names on different operating systems. While the LAS code has been improved, the original capabilities of the system have been preserved. These include maintaining associated image history, session logging, and batch, asynchronous and interactive mode of operation. The LAS application programs are integrated under version 4.1 of an interface called the Transportable Applications Executive (TAE). TAE 4.1 has four modes of user interaction: menu, direct command, tutor (or help), and dynamic tutor. In addition TAE 4.1 allows the operation of LAS functions using mouse-driven commands under the TAE-Facelift environment provided with TAE 4.1. These modes of operation allow users, from the beginner to the expert, to exercise specific application options. LAS is written in C-language and FORTRAN 77 for use with DEC VAX computers running VMS with approximately 16Mb of physical memory. This program runs under TAE 4.1. Since TAE 4.1 is not a current version of TAE, TAE 4.1 is included within the LAS distribution. Approximately 130,000 blocks (65Mb) of disk storage space are necessary to store the source code and files generated by the installation procedure for LAS and 44,000 blocks (22Mb) of disk storage space are necessary for TAE 4.1 installation. The only other dependencies for LAS are the subroutine libraries for the specific display device(s) that will be used with LAS/DMS (e.g. X-Windows and/or IVAS). The standard distribution medium for LAS is a set of two 9track 6250 BPI magnetic tapes in DEC VAX BACKUP format. It is also available on a set of two TK50 tape cartridges in DEC VAX BACKUP format. This program was developed in 1986 and last updated in 1992.

Pease, P. B.

1994-01-01

9

Data-Analysis System for Entry, Descent, and Landing  

NASA Technical Reports Server (NTRS)

A report describes the Entry Descent Landing Data Analysis (EDA), which is a system of signal-processing software and computer hardware for acquiring status data conveyed by multiple-frequency-shift-keying tone signals transmitted by a spacecraft during descent to the surface of a remote planet. The design of the EDA meets the challenge of processing weak, fluctuating signals that are Doppler-shifted by amounts that are only partly predictable. The software supports both real-time and post processing. The software performs fast-Fourier-transform integration, parallel frequency tracking with prediction, and mapping of detected tones to specific events. The use of backtrack and refinement parallel-processing threads helps to minimize data gaps. The design affords flexibility to enable division of a descent track into segments, within each of which the EDA is configured optimally for processing in the face of signal conditions and uncertainties. A dynamic-lock-state feature enables the detection of signals using minimum required computing power less when signals are steadily detected, more when signals fluctuate. At present, the hardware comprises eight dual-processor personal-computer modules and a server. The hardware is modular, making it possible to increase computing power by adding computers.

Pham, Timothy; Chang, Christine; Sartorius, Edgar; Finley, Susan; White, Leslie; Estabrook, Polly; Fort, David

2005-01-01

10

An economics systems analysis of land mobile radio telephone services  

NASA Technical Reports Server (NTRS)

The economic interaction of the terrestrial and satellite systems is considered. Parametric equations are formulated to allow examination of necessary user thresholds and growth rates as a function of system costs. Conversely, first order allowable systems costs are found as a function of user thresholds and growth rates. Transitions between satellite and terrestrial service systems are examined. User growth rate density (user/year/sq km) is shown to be a key parameter in the analysis of systems compatibility. The concept of system design matching the price/demand curves is introduced and examples are given. The role of satellite systems is critically examined and the economic conditions necessary for the introduction of satellite service are identified.

Leroy, B. E.; Stevenson, S. M.

1980-01-01

11

Entry, Descent and Landing Systems Analysis: Exploration Feed Forward Internal Peer Review Slide Package  

NASA Technical Reports Server (NTRS)

NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to successfully land large payloads at Mars for both robotic and human-scale missions. Year 1 of the study focused on technologies required for Exploration-class missions to land payloads of 10 to 50 mt. Inflatable decelerators, rigid aeroshell and supersonic retro-propulsion emerged as the top candidate technologies. In Year 2 of the study, low TRL technologies identified in Year 1, inflatables aeroshells and supersonic retropropulsion, were combined to create a demonstration precursor robotic mission. This part of the EDL-SA Year 2 effort, called Exploration Feed Forward (EFF), took much of the systems analysis simulation and component model development from Year 1 to the next level of detail.

Dwyer Cianciolo, Alicia M. (Editor)

2011-01-01

12

Entry, Descent and Landing Systems Analysis: Exploration Class Simulation Overview and Results  

NASA Technical Reports Server (NTRS)

NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to make in order to successfully land large payloads at Mars for both robotic and exploration or human-scale missions. The year one exploration class mission activity considered technologies capable of delivering a 40-mt payload. This paper provides an overview of the exploration class mission study, including technologies considered, models developed and initial simulation results from the EDL-SA year one effort.

DwyerCianciolo, Alicia M.; Davis, Jody L.; Shidner, Jeremy D.; Powell, Richard W.

2010-01-01

13

Air, land, water analysis system (ALWAS): multi-media pathways of organic pollutants in freshwater systems  

SciTech Connect

The Air Land Water Analysis System (ALWAS) is a multi-media environmental model for describing the atmospheric dispersion of toxicants, the surface runoff of deposited toxicants, and the subsequent fate of these materials in surface water bodies. ALWAS depicts the spatial and temporal distribution of contaminant concentrations in a watershed and the air above it. Linked in ALWAS are three submodels that provide for independent and partially coupled usage modes Dispersion and Deposition of Toxics (DiDOT); a modification, called NPSDEP, of the Non-point Source Model; and Exposure Analysis Modeling System (EXAMS). ALWAS' structure, scope and limitations, features, and inputs and outputs are described. The results of a hypothetical test simulation, including sensitivity analysis, are presented.

Tucker, W.A.; Hedden, K.F.

1986-01-01

14

Overview of the NASA Entry, Descent and Landing Systems Analysis Exploration Feed-Forward Study  

NASA Technical Reports Server (NTRS)

Technology required to land large payloads (20 to 50 mt) on Mars remains elusive. In an effort to identify the most viable investment path, NASA and others have been studying various concepts. One such study, the Entry, Descent and Landing Systems Analysis (EDLSA) Study [1] identified three potential options: the rigid aeroshell, the inflatable aeroshell and supersonic retropropulsion (SRP). In an effort to drive out additional levels of design detail, a smaller demonstrator, or exploration feed-forward (EFF), robotic mission was devised that utilized two of the three (inflatable aeroshell and SRP) high potential technologies in a configuration to demonstrate landing a two to four metric ton payload on Mars. This paper presents and overview of the maximum landed mass, inflatable aeroshell controllability and sensor suite capability assessments of the selected technologies and recommends specific technology areas for additional work.

DwyerCianciolo, Alicia M.; Zang, Thomas A.; Sostaric, Ronald R.; McGuire, M. Kathy

2011-01-01

15

Using System Dynamics Analysis for Evaluating Neighborhood Economic Outcomes from Transportation and Land Use Decisions  

EPA Science Inventory

Proposed Title: Using System Dynamics Analysis for Evaluating Neighborhood Economic Outcomes from Transportation and Land Use Decisions Topic (must choose one item from a drop-down list): Community Indicators Learning Objectives (must list 2): • What are the benefits and l...

16

AIR LAND WATER ANALYSIS SYSTEM (ALEAS): A MULTI-MEDIA MODEL FOR TOXIC SUBSTANCES  

EPA Science Inventory

The Air Land Water Analysis System (ALWAS) is a multi-media environmental model for describing the atmospheric dispersion of toxicants, the surface runoff of deposited toxicants, and the subsequent fate of these materials in surface water bodies. ALWAS dipicts the spatial and tem...

17

Multiple criteria land use analysis  

Microsoft Academic Search

Since the early 1980s, the Food and Agriculture Organization of the United Nations (FAO) and the International Institute for Applied Systems Analysis (IIASA) have been collaborating on expanding FAO's Agro-Ecological Zones (AEZ) methodology of land resources appraisal by incorporating decision support tools for optimizing the use of land resources. Initially, these tools consisted of the application of linear optimization techniques

Marek Makowski; Jacques Antoine

1997-01-01

18

Preliminary analysis of several microwave landing system flare elevation configurations  

NASA Technical Reports Server (NTRS)

Configurations of MLS Flare Elevation Systems that can be considered reasonable and practical in actual implementation are identified. Each of these are analyzed and compared with respect to (1) computational requirement, (2) required coverage, and (3) accuracy including altitude and sink-rate estimation error performance.

Goka, T.

1975-01-01

19

A Multidisciplinary Tool for Systems Analysis of Planetary Entry, Descent, and Landing (SAPE)  

NASA Technical Reports Server (NTRS)

SAPE is a Python-based multidisciplinary analysis tool for systems analysis of planetary entry, descent, and landing (EDL) for Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan. The purpose of SAPE is to provide a variable-fidelity capability for conceptual and preliminary analysis within the same framework. SAPE includes the following analysis modules: geometry, trajectory, aerodynamics, aerothermal, thermal protection system, and structural sizing. SAPE uses the Python language-a platform-independent open-source software for integration and for the user interface. The development has relied heavily on the object-oriented programming capabilities that are available in Python. Modules are provided to interface with commercial and government off-the-shelf software components (e.g., thermal protection systems and finite-element analysis). SAPE runs on Microsoft Windows and Apple Mac OS X and has been partially tested on Linux.

Samareh, Jamshid A.

2009-01-01

20

Multidisciplinary Tool for Systems Analysis of Planetary Entry, Descent, and Landing  

NASA Technical Reports Server (NTRS)

Systems analysis of a planetary entry (SAPE), descent, and landing (EDL) is a multidisciplinary activity in nature. SAPE improves the performance of the systems analysis team by automating and streamlining the process, and this improvement can reduce the errors that stem from manual data transfer among discipline experts. SAPE is a multidisciplinary tool for systems analysis of planetary EDL for Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan. It performs EDL systems analysis for any planet, operates cross-platform (i.e., Windows, Mac, and Linux operating systems), uses existing software components and open-source software to avoid software licensing issues, performs low-fidelity systems analysis in one hour on a computer that is comparable to an average laptop, and keeps discipline experts in the analysis loop. SAPE uses Python, a platform-independent, open-source language, for integration and for the user interface. Development has relied heavily on the object-oriented programming capabilities that are available in Python. Modules are provided to interface with commercial and government off-the-shelf software components (e.g., thermal protection systems and finite-element analysis). SAPE currently includes the following analysis modules: geometry, trajectory, aerodynamics, aerothermal, thermal protection system, and interface for structural sizing.

Samareh, Jamshid A.

2011-01-01

21

Air cushion landing system  

NASA Technical Reports Server (NTRS)

Static and dynamic performance of air cushion landing system is simulated in computer program that treats four primary ACLS subsystems: fan, feeding system, trunk, and cushion. Configuration of systems is sufficiently general to represent variety of practical designs.

Boghami, K. M.; Captain, K. M.; Fish, R. B.

1978-01-01

22

Interfacing geographic information systems and remote sensing for rural land-use analysis  

NASA Technical Reports Server (NTRS)

Recent advances in computer-based geographic information systems (GISs) are briefly reviewed, with an emphasis on the incorporation of remote-sensing data in GISs for rural applications. Topics addressed include sampling procedures for rural land-use analyses; GIS-based mapping of agricultural land use and productivity; remote sensing of land use and agricultural, forest, rangeland, and water resources; monitoring the dynamics of irrigation agriculture; GIS methods for detecting changes in land use over time; and the development of land-use modeling strategies.

Nellis, M. Duane; Lulla, Kamlesh; Jensen, John

1990-01-01

23

Land system change and food security: towards multi-scale land system solutions?  

PubMed Central

Land system changes are central to the food security challenge. Land system science can contribute to sustainable solutions by an integrated analysis of land availability and the assessment of the tradeoffs associated with agricultural expansion and land use intensification. A land system perspective requires local studies of production systems to be contextualised in a regional and global context, while global assessments should be confronted with local realities. Understanding of land governance structures will help to support the development of land use policies and tenure systems that assist in designing more sustainable ways of intensification. Novel land systems should be designed that are adapted to the local context and framed within the global socio-ecological system. Such land systems should explicitly account for the role of land governance as a primary driver of land system change and food production. PMID:24143158

Verburg, Peter H; Mertz, Ole; Erb, Karl-Heinz; Haberl, Helmut; Wu, Wenbin

2013-01-01

24

Study of USGS/NASA land use classification system. [computer analysis from LANDSAT data  

NASA Technical Reports Server (NTRS)

The results of a computer mapping project using LANDSAT data and the USGS/NASA land use classification system are summarized. During the computer mapping portion of the project, accuracies of 67 percent to 79 percent were achieved using Level II of the classification system and a 4,000 acre test site centered on Douglasville, Georgia. Analysis of response to a questionaire circulated to actual and potential LANDSAT data users reveals several important findings: (1) there is a substantial desire for additional information related to LANDSAT capabilities; (2) a majority of the respondents feel computer mapping from LANDSAT data could aid present or future projects; and (3) the costs of computer mapping are substantially less than those of other methods.

Spann, G. W.

1975-01-01

25

Mars Exploration Rovers Landing Dispersion Analysis  

NASA Technical Reports Server (NTRS)

Landing dispersion estimates for the Mars Exploration Rover missions were key elements in the site targeting process and in the evaluation of landing risk. This paper addresses the process and results of the landing dispersion analyses performed for both Spirit and Opportunity. The several contributors to landing dispersions (navigation and atmospheric uncertainties, spacecraft modeling, winds, and margins) are discussed, as are the analysis tools used. JPL's MarsLS program, a MATLAB-based landing dispersion visualization and statistical analysis tool, was used to calculate the probability of landing within hazardous areas. By convolving this with the probability of landing within flight system limits (in-spec landing) for each hazard area, a single overall measure of landing risk was calculated for each landing ellipse. In-spec probability contours were also generated, allowing a more synoptic view of site risks, illustrating the sensitivity to changes in landing location, and quantifying the possible consequences of anomalies such as incomplete maneuvers. Data and products required to support these analyses are described, including the landing footprints calculated by NASA Langley's POST program and JPL's AEPL program, cartographically registered base maps and hazard maps, and flight system estimates of in-spec landing probabilities for each hazard terrain type. Various factors encountered during operations, including evolving navigation estimates and changing atmospheric models, are discussed and final landing points are compared with approach estimates.

Knocke, Philip C.; Wawrzyniak, Geoffrey G.; Kennedy, Brian M.; Desai, Prasun N.; Parker, TImothy J.; Golombek, Matthew P.; Duxbury, Thomas C.; Kass, David M.

2004-01-01

26

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

Investigation of problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks have been under study: vehicle model design, mathematical modeling of a dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer sybsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement.

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1972-01-01

27

Analysis and design of a capsule landing system and surface vehicle control system for Mars exporation  

NASA Technical Reports Server (NTRS)

The problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars were investigated. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; navigation, terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks were studied: vehicle model design, mathematical modeling of dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement and transport parameter evaluation.

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1972-01-01

28

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

Problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars are reported. Problem areas include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis, terrain modeling and path selection; and chemical analysis of specimens. These tasks are summarized: vehicle model design, mathematical model of vehicle dynamics, experimental vehicle dynamics, obstacle negotiation, electrochemical controls, remote control, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, and chromatograph model evaluation and improvement.

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. V.; Yerazunis, S. W.

1973-01-01

29

LandCaRe DSS--an interactive decision support system for climate change impact assessment and the analysis of potential agricultural land use adaptation strategies.  

PubMed

Decision support to develop viable climate change adaptation strategies for agriculture and regional land use management encompasses a wide range of options and issues. Up to now, only a few suitable tools and methods have existed for farmers and regional stakeholders that support the process of decision-making in this field. The interactive model-based spatial information and decision support system LandCaRe DSS attempts to close the existing methodical gap. This system supports interactive spatial scenario simulations, multi-ensemble and multi-model simulations at the regional scale, as well as the complex impact assessment of potential land use adaptation strategies at the local scale. The system is connected to a local geo-database and via the internet to a climate data server. LandCaRe DSS uses a multitude of scale-specific ecological impact models, which are linked in various ways. At the local scale (farm scale), biophysical models are directly coupled with a farm economy calculator. New or alternative simulation models can easily be added, thanks to the innovative architecture and design of the DSS. Scenario simulations can be conducted with a reasonable amount of effort. The interactive LandCaRe DSS prototype also offers a variety of data analysis and visualisation tools, a help system for users and a farmer information system for climate adaptation in agriculture. This paper presents the theoretical background, the conceptual framework, and the structure and methodology behind LandCaRe DSS. Scenario studies at the regional and local scale for the two Eastern German regions of Uckermark (dry lowlands, 2600 km(2)) and Weißeritz (humid mountain area, 400 km(2)) were conducted in close cooperation with stakeholders to test the functionality of the DSS prototype. The system is gradually being transformed into a web version (http://www.landcare-dss.de) to ensure the broadest possible distribution of LandCaRe DSS to the public. The system will be continuously developed, updated and used in different research projects and as a learning and knowledge-sharing tool for students. The main objective of LandCaRe DSS is to provide information on the complex long-term impacts of climate change and on potential management options for adaptation by answering "what-if" type questions. PMID:23582740

Wenkel, Karl-Otto; Berg, Michael; Mirschel, Wilfried; Wieland, Ralf; Nendel, Claas; Köstner, Barbara

2013-09-01

30

Space shuttle post-entry and landing analysis. Volume 1: Candidate system evaluations  

NASA Technical Reports Server (NTRS)

The general purpose of this study is to aid in the evaluation and design of multi-sensor navigation schemes proposed for the orbiter. The scope of the effort is limited to the post-entry, energy management, and approach and landing mission phases. One candidate system based on conventional navigation aids is illustrated including two DME (Distance Measuring Equipment) stations and ILS (Instrument Landing System) glide slope and localizer antennas. Some key elements of the system not shown are the onboard IMUs (Inertial Measurement Units), altimeters, and a computer. The latter is programmed to mix together (filter) the IMU data and the externally-derived data. A completely automatic, all-weather landing capability is required. Since no air-breathing engines will be carried on orbital flights, there will be no chance to go around and try again following a missed approach.

Crawford, B. S.; Duiven, E. M.

1973-01-01

31

Analysis of Summertime Convective Initiation in Central Alabama Using the Land Information System  

NASA Technical Reports Server (NTRS)

During the summer months in the southeastern United States, convective initiation presents a frequent challenge to operational forecasters. Thunderstorm development has traditionally been referred to as random due to their disorganized, sporadic appearance and lack of atmospheric forcing. Horizontal variations in land surface characteristics such as soil moisture, soil type, land and vegetation cover could possibly be a focus mechanism for afternoon convection during the summer months. The NASA Land Information System (LIS) provides a stand-alone land surface modeling framework that incorporates these varying soil and vegetation properties, antecedent precipitation, and atmospheric forcing to represent the soil state at high resolution. The use of LIS as a diagnostic tool may help forecasters to identify boundaries in land surface characteristics that could correlate to favored regions of convection initiation. The NASA Shortterm Prediction Research and Transition (SPoRT) team has been collaborating with the National Weather Service Office in Birmingham, AL to help incorporate LIS products into their operational forecasting methods. This paper highlights selected convective case dates from summer 2009 when synoptic forcing was weak, and identifies any boundaries in land surface characteristics that may have contributed to convective initiation. The LIS output depicts the effects of increased sensible heat flux from urban areas on the development of convection, as well as convection along gradients in land surface characteristics and surface sensible and latent heat fluxes. These features may promote mesoscale circulations and/or feedback processes that can either enhance or inhibit convection. With this output previously unavailable to operational forecasters, LIS provides a new tool to forecasters in order to help eliminate the randomness of summertime convective initiation.

James, Robert S.; Case, Jonathan L.; Molthan, Andrew L.; Jedlovec, Gary J.

2011-01-01

32

Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters. [Instrument Meteorological Conditions  

NASA Technical Reports Server (NTRS)

The present investigation is concerned with a sensitivity analysis of the Decelerated Steep Approach and Landing (DSAL) maneuver to on-board and ground-based navigation system parameters. The Instrument Meteorological Conditions (IMC) DSAL maneuver involves decelerating to zero range rate while tracking the localizer and glideslope. The considered study investigated the performance of the navigation systems using Constant Deceleration Profile (CDP) guidance and a six degrees glideslope trajectory. A closed-loop computer simulation of the UH1H helicopter DSAL system was developed for the sensitivity analysis. Conclusions on system performance parameter sensitivity are discussed.

Karmali, M. S.; Phatak, A. V.; Bull, J. S.; Peach, L. L.; Demko, P. S.

1984-01-01

33

Variational sensitivity analysis and data assimilation studies of the coupled land surface-atmospheric boundary layer system  

E-print Network

One of the fundamental components of Earth system science is understanding coupled land-atmosphere processes. The land plays an especially important role in the climate system principally via the regulation of surface ...

Margulis, Steven A. (Steven Adam), 1973-

2002-01-01

34

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

The following tasks related to the design, construction, and evaluation of a mobile planetary vehicle for unmanned exploration of Mars are discussed: (1) design and construction of a 0.5 scale dynamic vehicle; (2) mathematical modeling of vehicle dynamics; (3) experimental 0.4 scale vehicle dynamics measurements and interpretation; (4) vehicle electro-mechanical control systems; (5) remote control systems; (6) collapsibility and deployment concepts and hardware; (7) design, construction and evaluation of a wheel with increased lateral stiffness, (8) system design optimization; (9) design of an on-board computer; (10) design and construction of a laser range finder; (11) measurement of reflectivity of terrain surfaces; (12) obstacle perception by edge detection; (13) terrain modeling based on gradients; (14) laser scan systems; (15) path selection system simulation and evaluation; (16) gas chromatograph system concepts; (17) experimental chromatograph separation measurements and chromatograph model improvement and evaluation.

Frederick, D. K.; Lashmet, P. K.; Moyer, W. R.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1973-01-01

35

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration  

NASA Technical Reports Server (NTRS)

Problems related to an unmanned exploration of the planet Mars by means of an autonomous roving planetary vehicle are investigated. These problems include: design, construction and evaluation of the vehicle itself and its control and operating systems. More specifically, vehicle configuration, dynamics, control, propulsion, hazard detection systems, terrain sensing and modelling, obstacle detection concepts, path selection, decision-making systems, and chemical analyses of samples are studied. Emphasis is placed on development of a vehicle capable of gathering specimens and data for an Augmented Viking Mission or to provide the basis for a Sample Return Mission.

Gisser, D. G.; Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Yerazunis, S. Y.

1975-01-01

36

Analysis of Multiple Precipitation Products and Preliminary Assessment of Their Impact on Global Land Data Assimilation System (GLDAS) Land Surface States  

NASA Technical Reports Server (NTRS)

Land surface models (LSMs) are computer programs, similar to weather and climate prediction models, which simulate the stocks and fluxes of water (including soil moisture, snow, evaporation, and runoff) and energy (including the temperature of and sensible heat released from the soil) after they arrive on the land surface as precipitation and sunlight. It is not currently possible to measure all of the variables of interest everywhere on Earth with sufficient accuracy and space-time resolution. Hence LSMs have been developed to integrate the available observations with our understanding of the physical processes involved, using powerful computers, in order to map these stocks and fluxes as they change in time. The maps are used to improve weather forecasts, support water resources and agricultural applications, and study the Earth's water cycle and climate variability. NASA's Global Land Data Assimilation System (GLDAS) project facilitates testing of several different LSMs with a variety of input datasets (e.g., precipitation, plant type). Precipitation is arguably the most important input to LSMs. Many precipitation datasets have been produced using satellite and rain gauge observations and weather forecast models. In this study, seven different global precipitation datasets were evaluated over the United States, where dense rain gauge networks contribute to reliable precipitation maps. We then used the seven datasets as inputs to GLDAS simulations, so that we could diagnose their impacts on output stocks and fluxes of water. In terms of totals, the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) had the closest agreement with the US rain gauge dataset for all seasons except winter. The CMAP precipitation was also the most closely correlated in time with the rain gauge data during spring, fall, and winter, while the satellitebased estimates performed best in summer. The GLDAS simulations revealed that modeled soil moisture is highly sensitive to precipitation, with differences in spring and summer as large as 45% depending on the choice of precipitation input.

Gottschalck, Jon; Meng, Jesse; Rodel, Matt; Houser, paul

2005-01-01

37

Skin Temperature Analysis and Bias Correction in a Coupled Land-Atmosphere Data Assimilation System  

NASA Technical Reports Server (NTRS)

In an initial investigation, remotely sensed surface temperature is assimilated into a coupled atmosphere/land global data assimilation system, with explicit accounting for biases in the model state. In this scheme, an incremental bias correction term is introduced in the model's surface energy budget. In its simplest form, the algorithm estimates and corrects a constant time mean bias for each gridpoint; additional benefits are attained with a refined version of the algorithm which allows for a correction of the mean diurnal cycle. The method is validated against the assimilated observations, as well as independent near-surface air temperature observations. In many regions, not accounting for the diurnal cycle of bias caused degradation of the diurnal amplitude of background model air temperature. Energy fluxes collected through the Coordinated Enhanced Observing Period (CEOP) are used to more closely inspect the surface energy budget. In general, sensible heat flux is improved with the surface temperature assimilation, and two stations show a reduction of bias by as much as 30 Wm(sup -2) Rondonia station in Amazonia, the Bowen ratio changes direction in an improvement related to the temperature assimilation. However, at many stations the monthly latent heat flux bias is slightly increased. These results show the impact of univariate assimilation of surface temperature observations on the surface energy budget, and suggest the need for multivariate land data assimilation. The results also show the need for independent validation data, especially flux stations in varied climate regimes.

Bosilovich, Michael G.; Radakovich, Jon D.; daSilva, Arlindo; Todling, Ricardo; Verter, Frances

2006-01-01

38

A design for a new catalog manager and associated file management for the Land Analysis System (LAS)  

NASA Technical Reports Server (NTRS)

Due to the larger number of different types of files used in an image processing system, a mechanism for file management beyond the bounds of typical operating systems is necessary. The Transportable Applications Executive (TAE) Catalog Manager was written to meet this need. Land Analysis System (LAS) users at the EROS Data Center (EDC) encountered some problems in using the TAE catalog manager, including catalog corruption, networking difficulties, and lack of a reliable tape storage and retrieval capability. These problems, coupled with the complexity of the TAE catalog manager, led to the decision to design a new file management system for LAS, tailored to the needs of the EDC user community. This design effort, which addressed catalog management, label services, associated data management, and enhancements to LAS applications, is described. The new file management design will provide many benefits including improved system integration, increased flexibility, enhanced reliability, enhanced portability, improved performance, and improved maintainability.

Greenhagen, Cheryl

1986-01-01

39

Advanced Land Imager Assessment System  

NASA Technical Reports Server (NTRS)

The Advanced Land Imager Assessment System (ALIAS) supports radiometric and geometric image processing for the Advanced Land Imager (ALI) instrument onboard NASA s Earth Observing-1 (EO-1) satellite. ALIAS consists of two processing subsystems for radiometric and geometric processing of the ALI s multispectral imagery. The radiometric processing subsystem characterizes and corrects, where possible, radiometric qualities including: coherent, impulse; and random noise; signal-to-noise ratios (SNRs); detector operability; gain; bias; saturation levels; striping and banding; and the stability of detector performance. The geometric processing subsystem and analysis capabilities support sensor alignment calibrations, sensor chip assembly (SCA)-to-SCA alignments and band-to-band alignment; and perform geodetic accuracy assessments, modulation transfer function (MTF) characterizations, and image-to-image characterizations. ALIAS also characterizes and corrects band-toband registration, and performs systematic precision and terrain correction of ALI images. This system can geometrically correct, and automatically mosaic, the SCA image strips into a seamless, map-projected image. This system provides a large database, which enables bulk trending for all ALI image data and significant instrument telemetry. Bulk trending consists of two functions: Housekeeping Processing and Bulk Radiometric Processing. The Housekeeping function pulls telemetry and temperature information from the instrument housekeeping files and writes this information to a database for trending. The Bulk Radiometric Processing function writes statistical information from the dark data acquired before and after the Earth imagery and the lamp data to the database for trending. This allows for multi-scene statistical analyses.

Chander, Gyanesh; Choate, Mike; Christopherson, Jon; Hollaren, Doug; Morfitt, Ron; Nelson, Jim; Nelson, Shar; Storey, James; Helder, Dennis; Ruggles, Tim; Kaita, Ed; Levy, Raviv; Ong, Lawrence; Markham, Brian; Schweiss, Robert

2008-01-01

40

Adaptive variable structure guidance system design of a longitudinal automatic carrier landing system  

Microsoft Academic Search

The design problem of guidance system of a longitudinal automatic carrier landing system is considered. The mathematic model of the landing guidance problem is created based on the analysis of the main architecture of a longitudinal automatic carrier landing system. The landing guidance system is designed via adaptive variable structure sliding mode control theory and the stability of guidance system

Zhu Qi-dan; Wang Tong; Zhong Xun-yu; Zhou Fang

2009-01-01

41

Agricultural drought analysis and famine early warning with the FEWS NET land data assimilation system  

NASA Astrophysics Data System (ADS)

Global and regional changes related to water resources and agriculture affect food and fresh water security. To mitigate and adapt to these changes it is important to quantify how climate variability and change has impacted agricultural production and water resources. This research examines trends in supply and demand for moisture availability in rain-fed agro-pastoral regions. With a focus on the Sahel region of Africa we ask the following two questions: (1) Do land surface models, forced with remotely sensed data, detect the spatio-temporal patterns of agricultural drought over the past 30 years? (2) How have these trends impacted agricultural productivity and food security? To explore implications of hydro-climatic (e.g. precipitation and potential evapotranspiration (PET)) change on agriculture, we use the Famine Early Warning Systems Network Land Data Assimilation System (FLDAS) forced with rainfall from the University of California Santa Barbara Climate Hazards Infrared-Precipitation with Stations (CHIRPS) dataset (1981-present) and 10 km meteorological data (wind, temperature, radiation, humidity) from Cheney and Sheffield, released in 2012, for continental Africa north of 10S (1979-2008). We examine trends in model outputs (e.g. soil moisture and evapotranspiration (ET)), as well as composite indices, such at the evapotranspiration-rainfall ratio and water requirement satisfaction index (WRSI). We compare these results to the Normalized Difference Vegetation Index (NDVI) and microwave soil moisture. Finally, we examine how the different model outputs and composite indices relate to reported trends in agricultural production. Preliminary results show that the FLDAS Noah3.2 and geoWRSI models accurately estimate near surface (0-40cm) soil moisture anomalies as defined by microwave and in-situ observations across the Sahel. With respect to ET, the literature reports that vegetation biomass, as indicated by NDVI, has increased in conjunction with rainfall (i.e. ';re-greening' of the Sahel). However, at least one study has reported a downward trend in modeled ET in the Sahel. Preliminary results indicate that the spatial and temporal patterns of transpiration in Noah3.2 and geoWRSI are highly sensitive to their respective vegetation parameterizations. Our model runs explore the timing and magnitude of ';crop' vegetation parameters, such as LAI and green vegetation fraction, to assess agricultural drought trends and confirm findings from previous work.

McNally, A.; Shukla, S.; Funk, C. C.; Husak, G. J.; Arsenault, K. R.; Peters-Lidard, C. D.; Verdin, J. P.

2013-12-01

42

The land Gini coefficient and its application for land use structure analysis in China.  

PubMed

We introduce the Gini coefficient to assess the rationality of land use structure. The rapid transformation of land use in China provides a typical case for land use structure analysis. In this study, a land Gini coefficient (LGC) analysis tool was developed. The land use structure rationality was analyzed and evaluated based on statistical data for China between 1996 and 2008. The results show: (1)The LGC of three major land use types-farmland, built-up land and unused land-was smaller when the four economic districts were considered as assessment units instead of the provinces. Therefore, the LGC is spatially dependent; if the calculation unit expands, then the LGC decreases, and this relationship does not change with time. Additionally, land use activities in different provinces of a single district differed greatly. (2) At the national level, the LGC of the three main land use types indicated that during the 13 years analyzed, the farmland and unused land were evenly distributed across China. However, the built-up land distribution was relatively or absolutely unequal and highlights the rapid urbanization in China. (3) Trends in the distribution of the three major land use types are very different. At the national level, when using a district as the calculation unit, the LGC of the three main land use types increased, and their distribution became increasingly concentrated. However, when a province was used as the calculation unit, the LGC of the farmland increased, while the LGC of the built-up and unused land decreased. These findings indicate that the distribution of the farmland became increasingly concentrated, while the built-up land and unused land became increasingly uniform. (4) The LGC analysis method of land use structure based on geographic information systems (GIS) is flexible and convenient. PMID:24130764

Zheng, Xinqi; Xia, Tian; Yang, Xin; Yuan, Tao; Hu, Yecui

2013-01-01

43

The Land Gini Coefficient and Its Application for Land Use Structure Analysis in China  

PubMed Central

We introduce the Gini coefficient to assess the rationality of land use structure. The rapid transformation of land use in China provides a typical case for land use structure analysis. In this study, a land Gini coefficient (LGC) analysis tool was developed. The land use structure rationality was analyzed and evaluated based on statistical data for China between 1996 and 2008. The results show: (1)The LGC of three major land use types–farmland, built-up land and unused land–was smaller when the four economic districts were considered as assessment units instead of the provinces. Therefore, the LGC is spatially dependent; if the calculation unit expands, then the LGC decreases, and this relationship does not change with time. Additionally, land use activities in different provinces of a single district differed greatly. (2) At the national level, the LGC of the three main land use types indicated that during the 13 years analyzed, the farmland and unused land were evenly distributed across China. However, the built-up land distribution was relatively or absolutely unequal and highlights the rapid urbanization in China. (3) Trends in the distribution of the three major land use types are very different. At the national level, when using a district as the calculation unit, the LGC of the three main land use types increased, and their distribution became increasingly concentrated. However, when a province was used as the calculation unit, the LGC of the farmland increased, while the LGC of the built-up and unused land decreased. These findings indicate that the distribution of the farmland became increasingly concentrated, while the built-up land and unused land became increasingly uniform. (4) The LGC analysis method of land use structure based on geographic information systems (GIS) is flexible and convenient. PMID:24130764

Zheng, Xinqi; Xia, Tian; Yang, Xin; Yuan, Tao; Hu, Yecui

2013-01-01

44

HOW DO LEGAL SYSTEMS AFFECT LAND DISTRIBUTION?: A LONG-RUN DISAGGREGATED ANALYSIS*  

E-print Network

. Bhattacharya± and Mehmet A. Ulubasoglu¶ School of Accounting, Economics and Finance Deakin University Melbourne, Islamic law and traces of early Roman law have higher land inequality. Importantly, Civil law and French, Economics and Finance, Faculty of Business and Law, Deakin University, 70 Elgar Road, Burwood, Victoria 3125

Bandyopadhyay, Antar

45

Analysis of land bridge transportation  

Microsoft Academic Search

Land bridge transportation means transportation from one seaport to another by railway across continents instead of by ocean\\u000a ship. At present, there are two common routes for using land bridge transportation in the world. One is Asia—America—Europe\\u000a land bridge, the other is Europe—Asia land bridge.\\u000a \\u000a Eurasia land bridge has obvious advantages over Asia—America—Europe land bridge due to its shorter distance,

Yong Qi; Yan Wang

1991-01-01

46

Landing gear energy absorption system  

NASA Technical Reports Server (NTRS)

A landing pad system is described for absorbing horizontal and vertical impact forces upon engagement with a landing surface where circumferentially arranged landing struts respectively have a clevis which receives a slidable rod member and where the upper portion of a slidable rod member is coupled to the clevis by friction washers which are force fit onto the rod member to provide for controlled constant force energy absorption when the rod member moves relative to the clevis. The lower end of the friction rod is pivotally attached by a ball and socket to a support plate where the support plate is arranged to slide in a transverse direction relative to a housing which contains an energy absorption material for absorbing energy in a transverse direction.

Hansen, Christopher P. (inventor)

1994-01-01

47

An Automated Land Analysis System (ALAS) for applications at a range of spatial scales: Watershed to global  

SciTech Connect

Recent advances in Digital Elevation Model (DEM) data availability and topographic analysis have enabled us to develop an Automated Land Analysis System (ALAS). ALAS is based on a series of codes which determine topographic and hydrologic characteristics at each pixel, watershed, and each large scale cell. The input requirements are a DEM from any location in the world, it`s resolution, and array size. A Motif accessed script reads in these inputs and generates a series of data sets which further describe the watershed properties such as flow directions, hydrologic characteristic probability density functions, etc.). Postscript files and arrays indicating the fme river networks and each subcatchment, as well as numerous other properties, are produced and catalogued. The motivation behind the development of ALAS is a direct response to the conceptualization of convergent scales between hydrologic and atmospheric models as defined by the World Climate Research Programme. The remainder of this paper highlights ALAS components, capabilities, and provides some discussion on its applications.

Miller, N.L.

1995-08-01

48

Application and analysis of anchored geosynthetic systems for stabilization of abandoned mine land slopes  

SciTech Connect

An anchored geosynthetic system (AGS) was used in the remediation of a landslide associated with an abandoned coal mine located near Hindman, Kentucky. In concept, AGS is a system that provides in-situ stabilization of soil slopes by combining a surface-deployed geosynthetic with an anchoring system of driven reinforcing rods similar to soil nailing. Installation of the system of driven reinforcing rods similar to soil nailing. Installation of the system involves tensioning a geosynthetic over a slope`s surface by driving anchors through the geosynthetic at a given spacing and distance. By tensioning the geosynthetic over the slope`s surface, a compressive load is applied to the slope. Benefits of AGS are described to include the following: (1) increase soil strength due to soil compression including increased compressive loading on potential failure surfaces, (2) soil reinforcement through soil nailing, (3), halt of soil creep, (4) erosion control, and (5) long term soil consolidation. Following installation of the AGS and one year of monitoring, it was found that the anchored geosynthetic system only provided some of the reported benefits and in general did not function as an active stabilization system. This was due in part to the inability of the system to provide and maintain loading on the geosynthetic. The geosynthetic, however, did tension when slope movement occurred and prevented the slope from failing. Thus, the system functioned more as a passive restraint system and appeared to function well over the monitoring period.

Vitton, S.J. [Michigan Technological Univ., Houghton, MI (United States); Whitman, F. [Testing Inc., Decatur, AL (United States); Liang, R.Y. [Univ. of Akron, OH (United States); Harris, W.W.

1996-12-31

49

Land mobile satellite demonstration system  

NASA Technical Reports Server (NTRS)

A land mobile satellite demonstration system is described. It ulilizes the INMARSAT MARECS B2 satellite at 26 degrees W. The system provides data transmission using a poll-response protocol with error detection and retransmission at 200 b/s rate. For most tests a 1.8 inch monopole antenna was used, along with a satellite EIRP normally used for four voice channels. A brief summary of the results are given and the overall system consisting of three elements in addition to the satellite (the mobile unit, the base station, and the office terminal and map display) is described. Throughput statistics from one trip are summarized.

Gooch, Guy M.; Nicholas, David C.

1988-01-01

50

Scaling the land use system  

Microsoft Academic Search

IntroductionThere is a growing demand for quantitative information on actual land use\\/land cover and their future changes in space and time. Particularly during the last decade, land use and land cover change have become important issues. Besides local and direct effects like loss of biodiversity through deforestation or soil degradation through unsustainable land use, increasing importance is given to the

K. Kok

2001-01-01

51

Analysis of Landing-Gear Behavior  

NASA Technical Reports Server (NTRS)

This report presents a theoretical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection. The applicability of the analysis to actual landing gears has been investigated for the particular case of a vertical landing gear in the absence of drag loads by comparing calculated results with experimental drop-test data for impacts with and without tire bottoming. The calculated behavior of the landing gear was found to be in good agreement with the drop-test data.

Milwitzky, Benjamin; Cook, Francis E

1953-01-01

52

Land Condition -Trend Analysis Data Dictionary  

E-print Network

Land Condition - Trend Analysis Data Dictionary William L. Sprouse and Alan B. Anderson Center Dictionary Center for Ecological Management of Military Lands i Table of Contents INTRODUCTION 1 LCTA A APPENDIX B B ENTITY (TABLE) INFORMATION B #12;LCTA Data Dictionary Center for Ecological Management

53

Sensitivity Analysis in Agent-Based Models of Socio-Ecological Systems: An Example in Agricultural Land Conservation for Lake Water Quality Improvement  

NASA Astrophysics Data System (ADS)

Socio-ecological systems are dynamic and nonlinear. To account for this complexity, we employ agent-based models (ABMs) to study macro-scale phenomena resulting from micro-scale interactions among system components. Because ABMs typically have many parameters, it is challenging to identify which parameters contribute to the emerging macro-scale patterns. In this paper, we address the following question: What is the extent of participation in agricultural land conservation programs given heterogeneous landscape, economic, social, and individual decision making criteria in complex lakesheds? To answer this question, we: [1] built an ABM for our model system; [2] simulated land use change resulting from agent decision making, [3] estimated the uncertainty of the model output, decomposed it and apportioned it to each of the parameters in the model. Our model system is a freshwater socio-ecological system - that of farmland and lake water quality within a region containing a large number of lakes and high proportions of agricultural lands. Our study focuses on examining how agricultural land conversion from active to fallow reduces freshwater nutrient loading and improves water quality. Consequently, our ABM is composed of farmer agents who make decisions related to participation in a government-sponsored Conservation Reserve Program (CRP) managed by the Farm Service Agency (FSA). We also include an FSA agent, who selects enrollment offers made by farmers and announces the signup results leading to land use change. The model is executed in a Monte Carlo simulation framework to generate a distribution of maps of fallow lands that are used for calculating nutrient loading to lakes. What follows is a variance-based sensitivity analysis of the results. We compute sensitivity indices for individual parameters and their combinations, allowing for identification of the most influential as well as the insignificant inputs. In the case study, we observe that farmland conservation is first and foremost driven by the FSA signup choices. Environmental criteria used in FSA offer selection play a secondary role in farmland-to-fallow-land conversion. Farmer decision making is mainly influenced by the willingness to reduce the potential annual rental payments. As the case study demonstrates, our approach leads to ABM simplification without the loss of outcome variability. It also shows how to represent the magnitude of ABM complexity and isolate the effects of the interconnected explanatory variables on the simulated emergent phenomena. More importantly, the results of our research indicate that some of the parameters exert influence on model outcomes only if analyzed in combination with other parameters. Without evaluating the interaction effects among inputs, we risk losing important functional relationships among ABM components and, consequently, we potentially reduce its explanatory power.

Ligmann-Zielinska, A.; Kramer, D. B.; Spence Cheruvelil, K.; Soranno, P.

2012-12-01

54

LDAS Land Data Assimilation Systems  

NASA Technical Reports Server (NTRS)

The land-surface component of the hydrological cycle is fundamental to the overall functioning of the atmospheric and climate processes. The characterization of the spatial and temporal variability of water and energy cycles is critical to improve our understanding of the land-surface-atmosphere interaction and the impact of land-surface processes on climate extremes. Because the accurate knowledge of these processes and their variability is important for climate predictions, most Numerical Weather Prediction (NWP) centers have incorporated land-surface schemes in their models. However, errors in the NWP forcing accumulate in the surface and energy stores, leading to incorrect surface water and energy partitioning and related processes.

Rodell, Matthew; Mocko, David; Beaudoing, Hiroko Kato

2014-01-01

55

Edwards plateau: Analysis of land cover trends  

USGS Publications Warehouse

The Land Cover Trends project studies the rates, causes, and consequences of contemporary (1973-2000) change in land use and land cover in the United States on an ecoregional basis. The Edwards Plateau ecoregion is the focus of this report. Landsat imagery from five dates during a nearly 30-year period are interpreted for randomly selected sample blocks. The resulting data provide the foundation for estimating change. Along with the image analysis, site visits to 90% of the sampled areas, geographical profiles, and socioeconomic data for the ecoregion are synthesized to assess regional driving forces and consequences of change. Complete project methodology can be found in Loveland et al [1].

Friesen, B.A.; Hester, D.J.; Casey, K.A.

2004-01-01

56

Flight test evaluation of the E-systems Differential GPS category 3 automatic landing system  

NASA Technical Reports Server (NTRS)

Test flights were conducted to evaluate the capability of Differential Global Positioning System (DGPS) to provide the accuracy and integrity required for International Civil Aviation Organization (ICAO) Category (CAT) III precision approach and landings. These test flights were part of a Federal Aviation Administration (FAA) program to evaluate the technical feasibility of using DGPS based technology for CAT III precision approach and landing applications. An IAI Westwind 1124 aircraft (N24RH) was equipped with DGPS receiving equipment and additional computing capability provided by E-Systems. The test flights were conducted at NASA Ames Research Center's Crows Landing Flight Facility, Crows Landing, California. The flight test evaluation was based on completing 100 approaches and landings. The navigation sensor error accuracy requirements were based on ICAO requirements for the Microwave Landing System (MLS). All of the approaches and landings were evaluated against ground truth reference data provided by a laser tracker. Analysis of these approaches and landings shows that the E-Systems DGPS system met the navigation sensor error requirements for a successful approach and landing 98 out of 100 approaches and landings, based on the requirements specified in the FAA CAT III Level 2 Flight Test Plan. In addition, the E-Systems DGPS system met the integrity requirements for a successful approach and landing or stationary trial for all 100 approaches and landings and all ten stationary trials, based on the requirements specified in the FAA CAT III Level 2 Flight Test Plan.

Kaufmann, David N.; Mcnally, B. David

1995-01-01

57

Land Information Systems in Developing Countries  

E-print Network

Limitations to Registration of Title in Tropical Africa. Seminar on problems of land tenure in African Information System Workshop. Bali, Indonesia: FIG. 253-256. Andersson, Sune (1988). Problems and Issues (1984). Aerophotogrammetric Techniques for Demarcation and Measuring of Rural Lands and Use of Data

California at Santa Barbara, University of

58

Land-based hatchery systems for finfish  

Technology Transfer Automated Retrieval System (TEKTRAN)

The early rearing of most marine species will be land-based because of the need for precise control of the rearing environment. This chapter evaluates the resource and energy requirements of six different types of land-based, hatchery production systems: flow-through with a gravity water supply, flo...

59

Reorienting land degradation towards sustainable land management: Linking sustainable livelihoods with ecosystem services in rangeland systems.  

PubMed

This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management. PMID:25617787

Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

2015-03-15

60

A visual navigation system for autonomous land vehicles  

Microsoft Academic Search

A modular system architecture has been developed to support visual navigation by an autonomous land vehicle. The system consists of vision modules performing image processing, three-dimensional shape recovery, and geometric reasoning, as well as modules for planning, navigating, and piloting. The system runs in two distinct modes, bootstrap and feedforward. The bootstrap mode requires analysis of entire images to find

ALLEN M. WAXMAN; JACQUELINE J. LEMOIGNE; LARRY S. DAVIS; BABU SRINIVASAN; TODD R. KUSHNER; Eli Liang; THARAKESH SIDDALINGAIAH

1987-01-01

61

77 FR 44144 - National Forest System Land Management Planning; Correction  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning; Correction AGENCY: Forest...National Forest System land management planning rule in the Federal Register...National Forest System Land Management Planning (36 CFR part 219,...

2012-07-27

62

78 FR 13316 - National Forest System Land Management Planning Directives  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning Directives AGENCY: Forest...Forest System (NFS) land management planning regulation. Issuance of these...Forest System (NFS) land management planning regulation set out at 36...

2013-02-27

63

77 FR 21161 - National Forest System Land Management Planning  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning; Final Rule Federal Register...National Forest System Land Management Planning AGENCY: Forest Service...National Forest System land management planning rule (planning rule)....

2012-04-09

64

Autonomous landing guidance system validation  

Microsoft Academic Search

ALG is a combination of raster imaging sensor, head-up displays, flight guidance and procedures which allow pilots to perform hand flown aircraft maneuvers in adverse weather, at night, or in low visibility conditions at facilities with minimal or no ground aids. Maneuvers in the context of ALG relate to takeoff, landing, rollout, taxi and terminal parking. Commercial needs are driven

Long Q. Bui; Michael R. Franklin; Christopher Taylor; Graham Neilson

1997-01-01

65

An analysis of Milwaukee county land use  

NASA Technical Reports Server (NTRS)

The identification and classification of urban and suburban phenomena through analysis of remotely-acquired sensor data can provide information of great potential value to many regional analysts. Such classifications, particularly those using spectral data obtained from satellites such as the first Earth Resources Technology Satellite (ERTS-1) orbited by NASA, allow rapid frequent and accurate general land use inventories that are of value in many types of spatial analyses. In this study, Milwaukee County, Wisconsin was classified into several broad land use categories on the basis of computer analysis of four bands of ERTS spectral data (ERTS Frame Number E1017-16093). Categories identified were: (1) road-central business district, (2) grass (green vegetation), (3) suburban, (4) wooded suburb, (5) heavy industry, (6) inner city, and (7) water. Overall, 90 percent accuracy was attained in classification of these urban land use categories.

Todd, W. J.; Mausel, P. E.

1973-01-01

66

Title : "SMALL Savannah: An Information System for the integrated analysis of land use change in the Far North Cameroon"  

E-print Network

, poverty and achieve sustainable development through collective knowledge generation, management competition among land uses, more conflicts between actors and increasing poverty. The model developed of the developed model through appropriate data collection and cross-scaled methods 2) the development

Hille, Sander

67

78 FR 23491 - National Forest System Land Management Planning; Correction  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning; Correction AGENCY: Forest...revising, and monitoring land management plans (the planning rule). The National Forest...National Forest System Land Management Planning Rule Final...

2013-04-19

68

76 FR 8479 - National Forest System Land Management Planning  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning; Proposed Rule Federal Register...National Forest System Land Management Planning AGENCY: Forest Service...to guide land and resource management planning for all units of the...

2011-02-14

69

An overview of the methods of GIS-based land-use suitability analysis  

NASA Astrophysics Data System (ADS)

The land-use suitability mapping and analysis is one of the most useful applications of GIS for planning and management. There are four objectives of this paper: (a) to present a historical overview of methods and techniques of GIS-based land-use suitability analysis, (b) to overview multi-criteria synthetically overlay land-use evaluation models, (c) to discuss GIS-based land-use evaluation system, (d) to identify the trends, challenges and prospects of GIS-based land-use suitability analysis. There are two focused perspectives of GIS-based land-use suitability analysis in the paper, the techno-positivist perspective and the socio-political, public participation perspectives. It is organized into six chapters. Chapter 1 defines land-use suitability analysis, and provides an introduction to GIS-based land-use suitability analysis along with a historical perspective. Chapter 2 gives an overview of the development of methods and techniques of GIS-based land-use suitability analysis. The multi-criteria synthetically overlay land-use analysis models is discussed in chapter 3. Chapter 4 offers GIS-based land-use evaluation system. Chapter 5 introduces expert systems for GIS-based land-use suitability evaluation. The concluding chapter summarizes the main points of the papers and discusses problems and prospects from GIS-based land-use suitability analysis. Along with the in-depth development of land research and the constant advancement of GIS technology, GIS-based land-use suitability analysis will toward greater depth.

Yang, Jing; Liu, Yongxue; Wang, Songhui

2007-06-01

70

Magneto-rheological (MR) damper for landing gear system  

NASA Astrophysics Data System (ADS)

Depending on the different sink speeds, angles of attack and masses; aircraft landing gears could face a wide range of impact conditions which may possibly cause structural damage or failure. Thus, in hard landing scenarios, the landing gear must absorb sufficient energy in order to minimize dynamic stress on the aircraft airframe. Semi-active control systems are the recent potential solutions to overcome these limitations. Among semi-active control strategies, those based on smart fluids such as magneto-rheological (MR) fluids have received recent attraction as their rheological properties can be continuously controlled using magnetic or electric field and they are not sensitive to the contaminants and the temperature variation and also require lower powers. This thesis focuses on modeling of a MR damper for landing gear system and analysis of semi-active controller to attenuate dynamic load and landing impact. First, passive landing gear of a Navy aircraft is modeled and the forces associated with the shock strut are formulated. The passive shock strut is then integrated with a MR valve to design MR shock strut. Here, MR shock strut is integrated with the landing gear system modeled as the 2DOF system and governing equations of motion are derived in order to simulate the dynamics of the system under different impact conditions. Subsequently the inverse model of the MR shock strut relating MR yield stress to the MR shock strut force and strut velocity is formulated. Using the developed governing equations and inverse model, a PID controller is formulated to reduce the acceleration of the system. Controlled performance of the simulated MR landing gear system is demonstrated and compared with that of passive system.

Khani, Mahboubeh

2010-11-01

71

A comparative analysis of the Global Land Cover 2000 and MODIS land cover data sets  

USGS Publications Warehouse

Accurate and up-to-date global land cover data sets are necessary for various global change research studies including climate change, biodiversity conservation, ecosystem assessment, and environmental modeling. In recent years, substantial advancement has been achieved in generating such data products. Yet, we are far from producing geospatially consistent high-quality data at an operational level. We compared the recently available Global Land Cover 2000 (GLC-2000) and MODerate resolution Imaging Spectrometer (MODIS) global land cover data to evaluate the similarities and differences in methodologies and results, and to identify areas of spatial agreement and disagreement. These two global land cover data sets were prepared using different data sources, classification systems, and methodologies, but using the same spatial resolution (i.e., 1 km) satellite data. Our analysis shows a general agreement at the class aggregate level except for savannas/shrublands, and wetlands. The disagreement, however, increases when comparing detailed land cover classes. Similarly, percent agreement between the two data sets was found to be highly variable among biomes. The identified areas of spatial agreement and disagreement will be useful for both data producers and users. Data producers may use the areas of spatial agreement for training area selection and pay special attention to areas of disagreement for further improvement in future land cover characterization and mapping. Users can conveniently use the findings in the areas of agreement, whereas users might need to verify the informaiton in the areas of disagreement with the help of secondary information. Learning from past experience and building on the existing infrastructure (e.g., regional networks), further research is necessary to (1) reduce ambiguity in land cover definitions, (2) increase availability of improved spatial, spectral, radiometric, and geometric resolution satellite data, and (3) develop advanced classification algorithms. ?? 2004 Elsevier Inc. All rights reserved.

Giri, C.; Zhu, Z.; Reed, B.

2005-01-01

72

Estimating Evapotranspiration with Land Data Assimilation Systems  

NASA Technical Reports Server (NTRS)

Advancements in both land surface models (LSM) and land surface data assimilation, especially over the last decade, have substantially advanced the ability of land data assimilation systems (LDAS) to estimate evapotranspiration (ET). This article provides a historical perspective on international LSM intercomparison efforts and the development of LDAS systems, both of which have improved LSM ET skill. In addition, an assessment of ET estimates for current LDAS systems is provided along with current research that demonstrates improvement in LSM ET estimates due to assimilating satellite-based soil moisture products. Using the Ensemble Kalman Filter in the Land Information System, we assimilate both NASA and Land Parameter Retrieval Model (LPRM) soil moisture products into the Noah LSM Version 3.2 with the North American LDAS phase 2 (NLDAS-2) forcing to mimic the NLDAS-2 configuration. Through comparisons with two global reference ET products, one based on interpolated flux tower data and one from a new satellite ET algorithm, over the NLDAS2 domain, we demonstrate improvement in ET estimates only when assimilating the LPRM soil moisture product.

Peters-Lidard, C. D.; Kumar, S. V.; Mocko, D. M.; Tian, Y.

2011-01-01

73

Inertial navigation system for mobile land vehicles  

Microsoft Academic Search

This paper describes a prototype of an inertial navigation system for use in mobile land vehicles, such as cars or mobile robots. The complete system is composed by sensors, their mechanical mount and cabling, these connect to a PC card with local processing and memory, based on a Intel 80C196KC microcontroller. The sensors used were a piezoelectric vibrating gyroscope, two

Jorge Lobo; Paulo Lucas; Jorge Dias; A. Traca de Almeida

1995-01-01

74

Biofuels, land and water : a systems approach to sustainability.  

SciTech Connect

There is a strong societal need to evaluate and understand the sustainability of biofuels, especially because of the significant increases in production mandated by many countries, including the United States. Sustainability will be a strong factor in the regulatory environment and investments in biofuels. Biomass feedstock production is an important contributor to environmental, social, and economic impacts from biofuels. This study presents a systems approach where the agricultural, energy, and environmental sectors are considered as components of a single system, and environmental liabilities are used as recoverable resources for biomass feedstock production. We focus on efficient use of land and water resources. We conducted a spatial analysis evaluating marginal land and degraded water resources to improve feedstock productivity with concomitant environmental restoration for the state of Nebraska. Results indicate that utilizing marginal land resources such as riparian and roadway buffer strips, brownfield sites, and marginal agricultural land could produce enough feedstocks to meet a maximum of 22% of the energy requirements of the state compared to the current supply of 2%. Degraded water resources such as nitrate-contaminated groundwater and wastewater were evaluated as sources of nutrients and water to improve feedstock productivity. Spatial overlap between degraded water and marginal land resources was found to be as high as 96% and could maintain sustainable feedstock production on marginal lands. Other benefits of implementing this strategy include feedstock intensification to decrease biomass transportation costs, restoration of contaminated water resources, and mitigation of greenhouse gas emissions.

Gopalakrishnan, G.; Negri, M. C.; Wang, M.; Wu, M.; Snyder, S. W.; LaFreniere, L.

2009-08-01

75

Spectroradiometric considerations for advanced land observing systems  

NASA Technical Reports Server (NTRS)

Research aimed at improving the inflight absolute radiometric calibration of advanced land observing systems was initiated. Emphasis was on the satellite sensor calibration program at White Sands. Topics addressed include: absolute radiometric calibration of advanced remote sensing; atmospheric effects on reflected radiation; inflight radiometric calibration; field radiometric methods for reflectance and atmospheric measurement; and calibration of field relectance radiometers.

Slater, P. N.

1986-01-01

76

A land mobile satellite data system  

NASA Technical Reports Server (NTRS)

The Telesat Mobile Incorporated (TMI) Mobile Data System (MDS) was developed to apply satellite technology to the transportation industry's requirement for a fleet management system. It will provide two-way messaging and automatic position reporting capabilities between dispatch centers and customers' fleets of trucks. The design was based on the Inmarsat L-Band space segment with system link parameters and margins adjusted to meet the land mobile satellite channel characteristics. The system interfaces with the Teleglobe Des Laurentides earth station at Weir, Quebec. The signaling protocols were derived from the Inmarsat Standard C packet signalling system with unique trucking requirements incorporated where necessary.

Kent, John D. B.

1990-01-01

77

Supervising passenger land-transport systems  

Microsoft Academic Search

In this paper, we propose a supervisory control approach, based on controlled automata concepts, for the planning for online service-operations control of a new class of passenger land-transport systems ( PLanTSs). A PLanTS belongs to a class of dynamic demand-responsive transportation systems. Rapid advances in information and communication technologies are providing a new infrastructural and communications basis upon which higher

Kiam Tian Seow; Michel Pasquier

2004-01-01

78

The Land Use and Land Cover Dichotomy: A Comparison of Two Land Classification Systems in Support of Urban Earth Science Applications  

NASA Technical Reports Server (NTRS)

One is likely to read the terms 'land use' and 'land cover' in the same sentence, yet these concepts have different origins and different applications. Land cover is typically analyzed by earth scientists working with remotely sensed images. Land use is typically studied by urban planners who must prescribe solutions that could prevent future problems. This apparent dichotomy has led to different classification systems for land-based data. The works of earth scientists and urban planning practitioners are beginning to come together in the field of spatial analysis and in their common use of new spatial analysis technology. In this context, the technology can stimulate a common 'language' that allows a broader sharing of ideas. The increasing amount of land use and land cover change challenges the various efforts to classify in ways that are efficient, effective, and agreeable to all groups of users. If land cover and land uses can be identified by remote methods using aerial photography and satellites, then these ways are more efficient than field surveys of the same area. New technology, such as high-resolution satellite sensors, and new methods, such as more refined algorithms for image interpretation, are providing refined data to better identify the actual cover and apparent use of land, thus effectiveness is improved. However, the closer together and the more vertical the land uses are, the more difficult the task of identification is, and the greater is the need to supplement remotely sensed data with field study (in situ). Thus, a number of land classification methods were developed in order to organize the greatly expanding volume of data on land characteristics in ways useful to different groups. This paper distinguishes two land based classification systems, one developed primarily for remotely sensed data, and the other, a more comprehensive system requiring in situ collection methods. The intent is to look at how the two systems developed and how they can work together so that land based information can be shared among different users and compared over time.

McAllister, William K.

2003-01-01

79

Vision System for an Unmanned Helicopter Landing in Complex Environment  

Microsoft Academic Search

This paper presents a vision-based navigation algorithm for an autonomous helicopter landing in complex environment include appointed landing mark coupled with several similar targets. The vision navigation system is integrated with algorithms of vision detection, target recognition and navigation instruction calculation. The navigation is used for indicating the helicopter to land on the landing mark exactly. In our algorithm, we

Guanlin Wang; Haiqing Shi; Hong Wang; Jihong Zhu

2009-01-01

80

76 FR 37826 - Public Land Order No. 7773; Emergency Withdrawal of Public and National Forest System Lands...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Withdrawal of Public and National Forest System Lands, Coconino and Mohave Counties...acres of public and National Forest System lands from location...776 acres public and National Forest System lands in Coconino and Mohave...

2011-06-28

81

Landing Characteristics of a Re-entry Vehicle with a Passive Landing System for Impact Alleviation  

NASA Technical Reports Server (NTRS)

Landing Characteristics of a Re-entry Vehicle with a Passive Landing System for Impact Alleviation. An experimental investigation was made to determine the landing characteristics of a 1/8-scale dynamic model of a reentry vehicle using a passive landing system to alleviate the landing-impact loads. The passive landing system consisted of a flexible heat shield with a small section of aluminum honeycomb placed between the heat shield and the crew compartment at the point that would be the first to contact the landing surface. The model was landed on concrete and sand landing surfaces at parachute letdown velocities. The investigations simulated a vertical velocity of 30 ft/sec (full scale), horizontal velocities of 0, 15, 30, 40, and 50 ft/sec (full scale), and landing attitudes ranging from -30 degrees to 20 degrees. The model investigation indicated that stable landings could be made on a concrete surface at horizontal velocities up to about 30 ft/sec, but the stable landing-attitude range at these speeds was small. The aluminum honeycomb bottomed occasionally during landings on concrete. When bottoming did not occur, maximum normal and longitudinal accelerations at the center of gravity of the vehicle were approximately 50g and 30g, respectively. [Entire movie available on DVD from CASI as Doc ID 20070030981. Contact help@sti.nasa.gov

1963-01-01

82

The Auto-Tuned Land Data Assimilation System (ATLAS)  

NASA Astrophysics Data System (ADS)

Land data assimilation systems are commonly tasked with merging remotely sensed surface soil moisture retrievals with information derived from a soil water balance model driven by observed rainfall. The performance of such systems can be degraded by the incorrect specification of parameters describing modeling and observation errors. Here the Auto-Tuned Land Data Assimilation System (ATLAS) is introduced to simultaneously solve for all parameters required for the application of a simple land data assimilation system to integrate satellite-based rainfall and soil moisture retrievals for drought monitoring applications. The approach is based on combining a triple collocation (TC) strategy with the statistical analysis of filtering innovations and designed to leverage the simultaneous availability of satellite-based soil moisture products acquired from both active and passive microwave remote sensing. A number of variants of the ATLAS approach—each based on a different strategy for leveraging TC and innovation analysis within an adaptive filtering framework—are derived and evaluated through a synthetic twin experiment. In addition, a preliminary real data analysis is conducted using actual satellite-based products and evaluated against independent ground-based observations. Results illustrate the potential of ATLAS to improve the analysis of soil moisture anomalies using data products derived from the Global Precipitation Measurement (GPM) and the NASA Soil Moisture Active/Passive missions.

Crow, W. T.; Yilmaz, M. Tugrul

2014-01-01

83

Spatiotemporal analysis of land use and land cover change in the Brazilian Amazon  

PubMed Central

This paper provides a comparative analysis of land use and land cover (LULC) changes among three study areas with different biophysical environments in the Brazilian Amazon at multiple scales, from per-pixel, polygon, census sector, to study area. Landsat images acquired in the years of 1990/1991, 1999/2000, and 2008/2010 were used to examine LULC change trajectories with the post-classification comparison approach. A classification system composed of six classes – forest, savanna, other-vegetation (secondary succession and plantations), agro-pasture, impervious surface, and water, was designed for this study. A hierarchical-based classification method was used to classify Landsat images into thematic maps. This research shows different spatiotemporal change patterns, composition and rates among the three study areas and indicates the importance of analyzing LULC change at multiple scales. The LULC change analysis over time for entire study areas provides an overall picture of change trends, but detailed change trajectories and their spatial distributions can be better examined at a per-pixel scale. The LULC change at the polygon scale provides the information of the changes in patch sizes over time, while the LULC change at census sector scale gives new insights on how human-induced activities (e.g., urban expansion, roads, and land use history) affect LULC change patterns and rates. This research indicates the necessity to implement change detection at multiple scales for better understanding the mechanisms of LULC change patterns and rates. PMID:24127130

Li, Guiying; Moran, Emilio; Hetrick, Scott

2013-01-01

84

The Sand Land Soil System and Society  

NASA Astrophysics Data System (ADS)

Worldwide arid soils such as Latterites from African Savannas to the Xeralfs and Xererts of the Mediterranean Basin Ortents and Orthids of Asian Deserts are uniquely different in their strategic roles for utilizing the land in places where a delicate balance between annual climatic cycles and general trends toward desertification predominate Arid lands cover 1 3 of global land surface and contain irreplaceable natural resources with potential productivity of meeting the demands of more than two billion people and serving as sources and sinks of atmospheric CO2 to combat global warming The soil system in these arid areas are being degraded underutilized and kept in a stage of obliviousness due to inadequate public literacy and most importantly in-sufficient scientific evaluations based on pedology and soil taxonomy standards Implementation of food security projects and sustainable development programs on randomly selected sites and assessment of land degradation worldwide by powerful computers and satellite imagery techniques without field work and identification of Representative Soil Units are data producing and grant attracting but counter productive We live in a world in which there is an order out there and things are precisely measured and categorized for efficient utilization Why not the soils mainly in arid areas How we could generalize the world of soils under our feet by concept of soils are the same Expansion of educational programs quantification of multiple ecosystems within the arid regions through detailed and correlated

Mahjoory, R. A.

85

The land potential knowledge system (LandPKS): Increasing land productivity and resilience  

Technology Transfer Automated Retrieval System (TEKTRAN)

Africa must significantly increase agricultural production to meet the needs of a growing population. Current efforts focus on intensifying production on currently used lands and expanding to un- or under-utilized lands. The success of both strategies requires understanding the land’s potential prod...

86

Video guidance, landing, and imaging systems  

NASA Technical Reports Server (NTRS)

The adaptive potential of video guidance technology for earth orbital and interplanetary missions was explored. The application of video acquisition, pointing, tracking, and navigation technology was considered to three primary missions: planetary landing, earth resources satellite, and spacecraft rendezvous and docking. It was found that an imaging system can be mechanized to provide a spacecraft or satellite with a considerable amount of adaptability with respect to its environment. It also provides a level of autonomy essential to many future missions and enhances their data gathering ability. The feasibility of an autonomous video guidance system capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was successfully demonstrated in the laboratory. The techniques developed for acquisition, pointing, and tracking show promise for recognizing and tracking coastlines, rivers, and other constituents of interest. Routines were written and checked for rendezvous, docking, and station-keeping functions.

Schappell, R. T.; Knickerbocker, R. L.; Tietz, J. C.; Grant, C.; Rice, R. B.; Moog, R. D.

1975-01-01

87

Surface Landing Site Weather Analysis for NASA's Constellation Program  

NASA Technical Reports Server (NTRS)

Weather information is an important asset for NASA's Constellation Program in developing the next generation space transportation system to fly to the International Space Station, the Moon and, eventually, to Mars. Weather conditions can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing of the Ares vehicles to landing and recovery operations, including all potential abort scenarios. Meteorological analysis is art important contributor, not only to the development and verification of system design requirements but also to mission planning and active ground operations. Of particular interest are the surface weather conditions at both nominal and abort landing sites for the manned Orion capsule. Weather parameters such as wind, rain, and fog all play critical roles in the safe landing of the vehicle and subsequent crew and vehicle recovery. The Marshall Space Flight Center (MSFC) Natural Environments Branch has been tasked by the Constellation Program with defining the natural environments at potential landing zones. This paper wiI1 describe the methodology used for data collection and quality control, detail the types of analyses performed, and provide a sample of the results that cab be obtained.

Altino, Karen M.; Burns, K. L.

2008-01-01

88

Human Planetary Landing System (HPLS) Capability Roadmap NRC Progress Review  

NASA Technical Reports Server (NTRS)

Capability Roadmap Team. Capability Description, Scope and Capability Breakdown Structure. Benefits of the HPLS. Roadmap Process and Approach. Current State-of-the-Art, Assumptions and Key Requirements. Top Level HPLS Roadmap. Capability Presentations by Leads. Mission Drivers Requirements. "AEDL" System Engineering. Communication & Navigation Systems. Hypersonic Systems. Super to Subsonic Decelerator Systems. Terminal Descent and Landing Systems. A Priori In-Situ Mars Observations. AEDL Analysis, Test and Validation Infrastructure. Capability Technical Challenges. Capability Connection Points to other Roadmaps/Crosswalks. Summary of Top Level Capability. Forward Work.

Manning, Rob; Schmitt, Harrison H.; Graves, Claude

2005-01-01

89

Land use changes and its impact on land surface temperature of Yancheng City from 2000 to 2009 analysis  

NASA Astrophysics Data System (ADS)

In the paper, based on the technology of remote sensing and geographic information system, and according to the Landsat TM images obtained the land use database and land surface temperature of Yancheng city in the year of 2000 and 2009. Five land use types were identified, namely: farmland, building site, forest and grassland, water, and beach wetland. And then analysis of the urban expansion model based on the Defense Meteorological satellite data. The results show that: (1) In the five kinds of land use types, the largest rate of land use change is beach wetland, which is -8.23, followed by water as -5.17, forest and grassland is 3.27, building site is 2.24, farmland is 0.69. (2) During the 2000-2009, the towns of Yancheng city continuous outward expansion. In the old town, the expansion model is similar to the concentric circles spread to the periphery, but in the new district, which mainly concentrated in the northeast and southeast, the expansion model is re-planning, development and construction. (3) The land use structure change, especially the changes of beach wetland have a largest influence on the land surface temperature of Yancheng city. Among them, the average land surface temperature has increased over 8 degrees. However, the farmland change due to the overall land surface temperature decreased. And the increase of building site, making the urban heat island effect has been enhanced, while the town where the land surface temperature increases in value added in 0 to 5 degrees. At the same time, the water changes, this due to the land surface temperature increases and the added value in the range of 5 to 8 degrees.

Wang, Xinghan

2014-02-01

90

Modelling an Aircraft Landing System in Dominique Mery  

E-print Network

of the landing gear system. The models are formalized in Event-B modelling language, which supports stepwise, Proof-based development, Refine- ment, Landing Gear System 1 Introduction In the cutting edge technologyModelling an Aircraft Landing System in Event-B Dominique M´ery Universit´e de Lorraine, LORIA BP

Boyer, Edmond

91

Quantitative Geomorphological Analysis & Land Use/ Land Cover Change Detection of Two Sub-Watersheds in NE region of Punjab, India  

NASA Astrophysics Data System (ADS)

Morphometric analysis is the measurement and mathematical analysis of the landforms. The delineation of drainage system is of utmost importance in understanding hydrological system of an area, water resource management and it's planning in an effective manner. Morphometric analysis and land use change detection of two sub-watersheds namely Kukar Suha and Ratewal of district Shahid Bhagat Singh Nagar, Punjab, India was carried out for quantitative description of drainage and characterisation. The stream order, stream number, stream length, mean stream length, and other morphometric analysis like bifurcation ratio, drainage density, texture, relief ratio, ruggedness number etc. were measured. The drainage pattern of Kukar Suha and Ratewal is mainly dendritic. The agriculture and settlements came up along the drainage network causes the pattern disturbance in the watershed. The study was undertaken to spotlight the morphometric parameters, their impact on the basin and the land use land cover changes occurred over the period of time. Morphometric parameters such as linear aspect, areal aspect and relief aspect of the watershed are computed. The land use/land cover change was extracted from LISS IV Mx + Cartosat1 PAN data. ASTER data is used to prepare DEM (digital elevation model) and geographical information system (GIS) was used to evaluate various morphometric parameters in ArcGIS10 software.

Kaur, M.; Singh, S.; Verma, V. K.; Pateriya, B.

2014-11-01

92

23 CFR 973.214 - Indian lands congestion management system (CMS).  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Indian lands congestion management system (CMS). 973...TRANSPORTATION FEDERAL LANDS HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO... § 973.214 Indian lands congestion management system...

2014-04-01

93

23 CFR 973.214 - Indian lands congestion management system (CMS).  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Indian lands congestion management system (CMS). 973...TRANSPORTATION FEDERAL LANDS HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO... § 973.214 Indian lands congestion management system...

2012-04-01

94

23 CFR 973.214 - Indian lands congestion management system (CMS).  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Indian lands congestion management system (CMS). 973...TRANSPORTATION FEDERAL LANDS HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO... § 973.214 Indian lands congestion management system...

2011-04-01

95

23 CFR 973.214 - Indian lands congestion management system (CMS).  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Indian lands congestion management system (CMS). 973...TRANSPORTATION FEDERAL LANDS HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO... § 973.214 Indian lands congestion management system...

2013-04-01

96

Experimental land observing data system feasibility study  

NASA Technical Reports Server (NTRS)

An end-to-end data system to support a Shuttle-based Multispectral Linear Array (MLA) mission in the mid-1980's was defined. The experimental Land Observing System (ELOS) is discussed. A ground system that exploits extensive assets from the LANDSAT-D Program to effectively meet the objectives of the ELOS Mission was defined. The goal of 10 meter pixel precision, the variety of data acquisition capabilities, and the use of Shuttle are key to the mission requirements, Ground mission management functions are met through the use of GSFC's Multi-Satellite Operations Control Center (MSOCC). The MLA Image Generation Facility (MIGF) combines major hardware elements from the Applications Development Data System (ADDS) facility and LANDSAT Assessment System (LAS) with a special purpose MLA interface unit. LANDSAT-D image processing techniques, adapted to MLA characteristics, form the basis for the use of existing software and the definition of new software required.

Buckley, J. L.; Kraiman, H.

1982-01-01

97

A new digital land mobile satellite system  

NASA Technical Reports Server (NTRS)

A description is given of the different digital services planned to be carried over existing and planned mobile satellite systems. These systems are then compared with analog services in terms of bandwidth and power efficiency. This comparison provides the rationale for the establishment of a digital land mobile satellite service (DLMSS) to use frequencies that are currently available but not yet assigned to a domestic mobile satellite system in the United States. The focus here is on the expected advantages of digital transmission techniques in accommodating additional mobile satellite systems in this portion of the spectrum, and how such techniques can fully satisfy voice, data and facsimile mobile communications requirements in a cost effective manner. A description is given of the system architecture of the DMLSS service proposed by the Geostar Messaging Corporation (GMC) and the market potential of DLMSS.

Schneider, Philip

1990-01-01

98

A land suitability system for spate irrigation schemes in Eritrea  

Microsoft Academic Search

Spate irrigation is a system used for wetting land prior to planting. Use is made of seasonal rivers (wadis) producing flash floods in the uplands, which are directed by structures to irrigate fields in the lowlands. A land suitability system for spate irrigation schemes in Eritrea was studied in the Sheeb area of Eritrea with and without land improvements. The

M. H. Tesfai

2002-01-01

99

ORIGINAL ARTICLE Monitoring severe aquifer-system compaction and land  

E-print Network

ORIGINAL ARTICLE Monitoring severe aquifer-system compaction and land subsidence in Taiwan using of ground- water caused large-scale aquifer-system compaction and land subsidence in the Choshui River there is insufficient surface water to meet the demand, groundwater is explored. Land subsidence due to with- drawal

Hwang, Cheinway

100

Design and implementation of multi-source data mining system for land use  

NASA Astrophysics Data System (ADS)

With the development of "3S" technologies, a large quantity of spatial-temporal data related to land use has been accessed. Being scattered across different departments and lacking of relevant analysis tools made them utilize insufficiently. Although some experts have applied data mining to solve this problem, most of them have only provided one method for single task to build the mining systems. However, it is undesirable to use just one method to mine. In addition, the single function systems can not be used widely and conveniently. Hence, under full investigation on operations of land use, a multi-source data mining prototype system for land use is proposed by integrating of technologies of GIS and spatial data mining. According to the general data mining process, aiming at the multi-demands of land evaluation and land planning and so on, the system is developed by using ArcEngine 9.0 and VB.net. The system integrates basic geospatial data, land use/cover data, and thematic data as data sources, excavates different knowledge of land Quality, land use zoning rules, land use patterns and change rules and so on. Based on the types of knowledge, the system accordingly provides several different mining methods, including decision tree, support vector machine, artificial neural network, time series, spatial association rules, etc. Wide adaptability of the system is demonstrated by using some cases. The results of the system can meet multipurpose needs and be used to support decision-making of the land management department.

Hong, Xiaofeng; Liu, Yaolin; Liu, Dianfeng; Xia, Yin; Hu, Xi

2009-10-01

101

Configuration development of the Land Mobile Satellite System (LMSS) Spacecraft  

NASA Technical Reports Server (NTRS)

Configurations for a Land Mobile Satellite System Spacecraft are discussed. It is a preliminary concept of a quad aperture reflector spacecraft capable of relaying radio messages to land mobile units throughout the United States.

Golden, C. T.; Lackey, J. A.; Spear, E. E.

1982-01-01

102

Airplane takeoff and landing performance monitoring system  

NASA Technical Reports Server (NTRS)

The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (VR) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane acceleration and engine-performance anomalies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a continually predicted nominal performance based upon given conditions, performance deficiencies are detected by the system and conveyed to pilot in form of both elemental information and integrated information.

Middleton, David B. (inventor); Srivatsan, Raghavachari (inventor); Person, Lee H., Jr. (inventor)

1994-01-01

103

Airplane takeoff and landing performance monitoring system  

NASA Technical Reports Server (NTRS)

The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V.sub.R) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane acceleration and engine-performance anomalies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a continually predicted nominal performance based upon given conditions, performance deficiencies are detected by the system and conveyed to pilot in form of both elemental information and integrated information.

Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Jr., Lee H. (Inventor)

1996-01-01

104

Airplane takeoff and landing performance monitoring system  

NASA Technical Reports Server (NTRS)

The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V.sub.R) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane and engine performance deficiencies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a predicted nominal performance based upon given conditions, performance deficiencies are detected by the system.

Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Jr., Lee H. (Inventor)

1991-01-01

105

Analysis of Land Suitable for Algae State of Hawaii  

E-print Network

Analysis of Land Suitable for Algae Production State of Hawaii Prepared for the U.S. Department agency thereof. #12;Analysis of Land Suitable for Algae Production State of Hawaii Prepared by Mele University of Hawaii at Manoa August 2011 #12;i Executive Summary Algae are considered to be a viable crop

106

Surface Landing Site Weather Analysis for Constellation Program  

NASA Technical Reports Server (NTRS)

Weather information is an important asset for NASA's Constellation Program in developing the next generation space transportation system to fly to the International Space Station, the Moon and, eventually, to Mars. Weather conditions can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing to landing and recovery operations, including all potential abort scenarios. Meteorological analysis is an important contributor, not only to the development and verification of system design requirements but also to mission planning and active ground operations. Of particular interest are the surface atmospheric conditions at both nominal and abort landing sites for the manned Orion capsule. Weather parameters such as wind, rain, and fog all play critical roles in the safe landing of the vehicle and subsequent crew and vehicle recovery. The Marshall Space Flight Center Natural Environments Branch has been tasked by the Constellation Program with defining the natural environments at potential landing zones. Climatological time series of operational surface weather observations are used to calculate probabilities of occurrence of various sets of hypothetical vehicle constraint thresholds, Data are available for numerous geographical locations such that statistical analysis can be performed for single sites as well as multiple-site network configurations. Results provide statistical descriptions of how often certain weather conditions are observed at the site(s) and the percentage that specified criteria thresholds are matched or exceeded. Outputs are tabulated by month and hour of day to show both seasonal and diurnal variation. This paper will describe the methodology used for data collection and quality control, detail the types of analyses performed, and provide a sample of the results that can be obtained,

Altino, Karen M.; Burns, K. Lee

2008-01-01

107

Preliminary study of a possible automatic landing system  

NASA Technical Reports Server (NTRS)

Navigation and control laws for a possible automatic landing system have been investigated. The system makes use of data from an inertial table and either an airborne or ground radar to generate signals that guide the airplane to a landing. All landing maneuvers take place within a zone that extends 6000 m out from the touchdown point, 4000 m on each side of the runway center line, and 540 m high. The results show that the system can adequately control the airplane on steep, curved decelerating approaches to a landing that takes place with small errors from the desired landing point and desired airplane attitude. The system studied would interface well with the scanning beam microwave landing system (MLS). The use of this system with the MLS makes it possible to incorporate an independent landing monitor.

Sherman, W. L.; Winfrey, S. W.

1974-01-01

108

Terrain modeling for microwave landing system  

NASA Technical Reports Server (NTRS)

A powerful analytical approach for evaluating the terrain effects on a microwave landing system (MLS) is presented. The approach combines a multiplate model with a powerful and exhaustive ray tracing technique and an accurate formulation for estimating the electromagnetic fields due to the antenna array in the presence of terrain. Both uniform theory of diffraction (UTD) and impedance UTD techniques have been employed to evaluate these fields. Innovative techniques are introduced at each stage to make the model versatile to handle most general terrain contours and also to reduce the computational requirement to a minimum. The model is applied to several terrain geometries, and the results are discussed.

Poulose, M. M.

1991-01-01

109

Constellation Program (CxP) Crew Exploration Vehicle (CEV) Project Integrated Landing System  

NASA Technical Reports Server (NTRS)

Crew Exploration Vehicle (CEV) Chief Engineer requested a risk comparison of the Integrated Landing System design developed by NASA and the design developed by Contractor- referred to as the LM 604 baseline. Based on the results of this risk comparison, the CEV Chief engineer requested that the NESC evaluate identified risks and develop strategies for their reduction or mitigation. The assessment progressed in two phases. A brief Phase I analysis was performed by the Water versus Land-Landing Team to compare the CEV Integrated Landing System proposed by the Contractor against the NASA TS-LRS001 baseline with respect to risk. A phase II effort examined the areas of critical importance to the overall landing risk, evaluating risk to the crew and to the CEV Crew Module (CM) during a nominal land-landing. The findings of the assessment are contained in this report.

Baker, John D.; Yuchnovicz, Daniel E.; Eisenman, David J.; Peer, Scott G.; Fasanella, Edward L.; Lawrence, Charles

2009-01-01

110

Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System  

NASA Technical Reports Server (NTRS)

The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters, and the single scattering albedo. After this climatological calibration, the modeling system can provide L-band brightness temperatures with a global mean absolute bias of less than 10K against SMOS observations, across multiple incidence angles and for horizontal and vertical polarization. Third, seasonal and regional variations in the residual biases are addressed by estimating the vegetation optical depth through state augmentation during the assimilation of the L-band brightness temperatures. This strategy, tested here with SMOS data, is part of the baseline approach for the Level 4 Surface and Root Zone Soil Moisture data product from the planned Soil Moisture Active Passive (SMAP) satellite mission.

Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

2012-01-01

111

The Pilot Land Data System: Report of the Program Planning Workshops  

NASA Technical Reports Server (NTRS)

An advisory report to be used by NASA in developing a program plan for a Pilot Land Data System (PLDS) was developed. The purpose of the PLDS is to improve the ability of NASA and NASA sponsored researchers to conduct land-related research. The goal of the planning workshops was to provide and coordinate planning and concept development between the land related science and computer science disciplines, to discuss the architecture of the PLDs, requirements for information science technology, and system evaluation. The findings and recommendations of the Working Group are presented. The pilot program establishes a limited scale distributed information system to explore scientific, technical, and management approaches to satisfying the needs of the land science community. The PLDS paves the way for a land data system to improve data access, processing, transfer, and analysis, which land sciences information synthesis occurs on a scale not previously permitted because of limits to data assembly and access.

1984-01-01

112

Failure analysis of nose landing gear assembly  

Microsoft Academic Search

This paper analyses the causes of the incident of an F-4 which landed abnormally due to a crack in the nose landing gear hydraulic actuator cylinder. Striations, typical of a fatigue crack, were observed on the fracture surface and a large quantity of corrosive oxide was detected in the initial stage of the crack. Furthermore, surface pits caused by corrosion

Hong-Chul Lee; Young-Ha Hwang; Tae-Gu Kim

2003-01-01

113

Aircraft Landing Gear Simulation and Analysis1  

Microsoft Academic Search

A computer aided graphical synthesis was undertaken to understand the kinematics of a nose wheel landing gear mechanism such as that on the Lockheed F-16 using Working Model software. The mobility of the design was verified by computer animation. To contrast the nose gear kinematic simulation, the main landing gear located under the wing of a light weight aircraft such

Derek Morrison; Gregory Neff; Mohammad Zahraee

114

US army land condition-trend analysis (LCTA) program  

NASA Astrophysics Data System (ADS)

The US Army Land Condition-Trend Analysis (LCTA) program is a standardized method of data collection, analysis, and reporting designed to meet multiple goals and objectives. The method utilizes vascular plant inventories, permanent field plot data, and wildlife inventories. Vascular plant inventories are used for environmental documentation, training of personnel, species identification during LCTA implementation, and as a survey for state and federal endangered or threatened species. The permanent field plot data documents the vegetational, edaphic, topographic, and disturbance characteristics of the installation. Inventory plots are allocated in a stratified random fashion across the installation utilizing a geographic information system that integrates satellite imagery and soil survey information. Ground cover, canopy cover, woody plant density, slope length, slope gradient, soil information, and disturbance data are collected at each plot. Plot data are used to: (1) describe plant communities, (2) characterize wildlife and threatened and endangered species habitat, (3) document amount and kind of military and nonmilitary disturbance, (4) determine the impact of military training on vegetation and soil resources, (5) estimate soil erosion potential, (6) classify land as to the kind and amount of use it can support, (7) determine allowable use estimates for tracked vehicle training, (8) document concealment resources, (9) identify lands that require restoration and evaluate the effectiveness of restorative techniques, and (10) evaluate potential acquisition property. Wildlife inventories survey small and midsize mammals, birds, bats, amphibians, and reptiles. Data from these surveys can be used for environmental documentation, to identify state and federal endangered and threatened species, and to evaluate the impact of military activities on wildlife populations. Short- and long-term monitoring of permanent field plots is used to evaluate and adjust land management decisions.

Diersing, Victor E.; Shaw, Robert B.; Tazik, David J.

1992-05-01

115

Airplane takeoff and landing performance monitoring system  

NASA Technical Reports Server (NTRS)

The invention is a real-time takeoff and landing performance monitoring system which provides the pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V sub R) within the safe zone of the runway or stopping the aircraft on the runway after landing or take off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. An important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in headwind occurring as the takeoff roll progresses. The system displays the position of the airplane on the runway, indicating runway used and runway available, summarizes the critical information into a situation advisory flag, flags engine failures and off-nominal acceleration performance, and indicates where on the runway particular events such as decision speed (V sub 1), rotation speed (V sub R) and expected stop points will occur based on actual or predicted performance. The display also indicates airspeed, wind vector, engine pressure ratios, second segment climb speed, and balanced field length (BFL). The system detects performance deficiencies by comparing the airplane's present performance with a predicted nominal performance based upon the given conditions.

Middleton, David B. (inventor); Srivatsan, Raghavachari (inventor); Person, Lee H. (inventor)

1989-01-01

116

Evaluation Information System for Land Seismic Resistance Suitability Based on GIS  

Microsoft Academic Search

Systematic analysis to the land seismic resistance suitability is made in Dongying and evaluating indicator system of seismic resistance suitability is established in Dongying, we comprehensively study land seismic resistance suitability with grey theory integrated method. It causes the measure results to be more scientific and reasonably that using gray statistics method to establish evaluation matrix, determining the weight of

Jun-Feng Xin; Qi-Min Feng; Jun-Jie Wang

2008-01-01

117

Land System Science: between global challenges and local realities?  

PubMed Central

This issue of Current Opinion in Environmental Sustainability provides an overview of recent advances in Land System Science while at the same time setting the research agenda for the Land System Science community. Land System Science is not just representing land system changes as either a driver or a consequence of global environmental change. Land systems also offer solutions to global change through adaptation and mitigation and can play a key role in achieving a sustainable future earth. The special issue assembles 14 articles that entail different perspectives on land systems and their dynamics, synthesizing current knowledge, highlighting currently under-researched topics, exploring scientific frontiers and suggesting ways ahead, integrating a plethora of scientific disciplines. PMID:24851141

Verburg, Peter H; Erb, Karl-Heinz; Mertz, Ole; Espindola, Giovana

2013-01-01

118

Land System Science: between global challenges and local realities.  

PubMed

This issue of Current Opinion in Environmental Sustainability provides an overview of recent advances in Land System Science while at the same time setting the research agenda for the Land System Science community. Land System Science is not just representing land system changes as either a driver or a consequence of global environmental change. Land systems also offer solutions to global change through adaptation and mitigation and can play a key role in achieving a sustainable future earth. The special issue assembles 14 articles that entail different perspectives on land systems and their dynamics, synthesizing current knowledge, highlighting currently under-researched topics, exploring scientific frontiers and suggesting ways ahead, integrating a plethora of scientific disciplines. PMID:24851141

Verburg, Peter H; Erb, Karl-Heinz; Mertz, Ole; Espindola, Giovana

2013-10-01

119

A Land Surface Data Assimilation Framework Using the Land Information System: Description and Application  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Land Information System (LIS) is a hydrologic modeling framework that integrates various community land surface models, ground and satellite-based observations, and high performance computing and data management tools to enable assessment and prediction of hydrologic conditions at various spatia...

120

Forewarning system of dynamic balance between cultivated land supply and demand at multimeasures based on remote sensing techniques  

NASA Astrophysics Data System (ADS)

This article discusses the importance of forewarning system of dynamic balance between cultivated land supply and demand at multi-measures, and the application of remote sensing technique to it. It presents the structure of forewarning system of dynamic balance between cultivated land supply and demand based on the land use change monitoring and predicting, balance state analysis, finding the imbalance, potential analysis for regulating the balance and warning eliminating. And it simply illuminates its implementation as software system.

Liu, Yanfang; Liu, Yaolin; Ren, Zhouqiao

2004-02-01

121

Policy implications in developing a land use management information systems  

NASA Technical Reports Server (NTRS)

The current land use map for the city of Los Angeles was developed by the guesstimation process and provides single stage information for each level in the critical geographical hierarchy for land use planning management. Processing and incorporation of LANDSAT data in the land use information system requires special funding; however, computergraphic maps are able to provide a viable information system for city planning and management.

Landini, A. J.

1975-01-01

122

Analysis of the densification of reclaimed surface mined land  

E-print Network

ANALYSIS OF THE DENSIFICATION OF RECLAIMED SURFACE MINED LAND A Thesis by WILLIAM JOSEPH SCHNEIDER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May... 1977 Major Subject: Geology ANALYSIS OF THE DENSIFICATION OF RECLAIMED SURFACED MINED LAND A Thesis WILLIAM JOSEPH SCHNEIDER Approved as to style and content by: (Chairman of Committee) (Head of Department) (Member) Member) May 1977 cgQ$ 7'g...

Schneider, William Joseph

1977-01-01

123

Small Aircraft Nose Landing Gear Structure Analysis  

Microsoft Academic Search

Pipe spring type nose landing gear strut and fork design has been performed for small aircraft. Structurally weak area is selected in currently used parts, and improvement has been studied. Again, weight saving optimization design will be performed for actual aircraft.

JinWon Kim; SeokMin Ahn

124

Incorporating JULES into NASA's Land Information System (LIS) and Investigations of Land-Atmosphere Coupling  

NASA Technical Reports Server (NTRS)

NASA's Land Information System (LIS; lis.gsfc.nasa.gov) is a flexible land surface modeling and data assimilation framework developed over the past decade with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. LIS features a high performance and flexible design, and operates on an ensemble of land surface models for extension over user-specified regional or global domains. The extensible interfaces of LIS allow the incorporation of new domains, land surface models (LSMs), land surface parameters, meteorological inputs, data assimilation and optimization algorithms. In addition, LIS has also been demonstrated for parameter estimation and uncertainty estimation, and has been coupled to the Weather Research and Forecasting (WRF) mesoscale model. A visiting fellowship is currently underway to implement JULES into LIS and to undertake some fundamental science on the feedbacks between the land surface and the atmosphere. An overview of the LIS system, features, and sample results will be presented in an effort to engage the community in the potential advantages of LIS-JULES for a range of applications. Ongoing efforts to develop a framework for diagnosing land-atmosphere coupling will also be presented using the suite of LSM and PBL schemes available in LIS and WRF along with observations from the U. S .. Southern Great Plains. This methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.

Santanello, Joseph

2011-01-01

125

GEOGRAPHIC INFORMATION SYSTEMS CENTER FOR ENVIRONMENTAL MANAGEMENT OF MILITARY LANDS  

E-print Network

GEOGRAPHIC INFORMATION SYSTEMS CENTER FOR ENVIRONMENTAL MANAGEMENT OF MILITARY LANDS CEMML | 1490@cemml.colostate.edu | http://www.cemml.colostate.edu A Geographic Information System (GIS) is a necessary tool for effective and efficient decision making, planning, and management of military training lands. GIS provides a spatial

126

A land use and land cover classification system for use with remote sensor data  

USGS Publications Warehouse

The framework of a national land use and land cover classification system is presented for use with remote sensor data. The classification system has been developed to meet the needs of Federal and State agencies for an up-to-date overview of land use and land cover throughout the country on a basis that is uniform in categorization at the more generalized first and second levels and that will be receptive to data from satellite and aircraft remote sensors. The proposed system uses the features of existing widely used classification systems that are amenable to data derived from remote sensing sources. It is intentionally left open-ended so that Federal, regional, State, and local agencies can have flexibility in developing more detailed land use classifications at the third and fourth levels in order to meet their particular needs and at the same time remain compatible with each other and the national system. Revision of the land use classification system as presented in U.S. Geological Survey Circular 671 was undertaken in order to incorporate the results of extensive testing and review of the categorization and definitions.

Anderson, James R.; Hardy, Ernest E.; Roach, John T.; Witmer, Richard E.

1976-01-01

127

A Meta-Analysis of Global Urban Land Expansion  

PubMed Central

The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land area of 58,000 km2 from 1970 to 2000. India, China, and Africa have experienced the highest rates of urban land expansion, and the largest change in total urban extent has occurred in North America. Across all regions and for all three decades, urban land expansion rates are higher than or equal to urban population growth rates, suggesting that urban growth is becoming more expansive than compact. Annual growth in GDP per capita drives approximately half of the observed urban land expansion in China but only moderately affects urban expansion in India and Africa, where urban land expansion is driven more by urban population growth. In high income countries, rates of urban land expansion are slower and increasingly related to GDP growth. However, in North America, population growth contributes more to urban expansion than it does in Europe. Much of the observed variation in urban expansion was not captured by either population, GDP, or other variables in the model. This suggests that contemporary urban expansion is related to a variety of factors difficult to observe comprehensively at the global level, including international capital flows, the informal economy, land use policy, and generalized transport costs. Using the results from the global model, we develop forecasts for new urban land cover using SRES Scenarios. Our results show that by 2030, global urban land cover will increase between 430,000 km2 and 12,568,000 km2, with an estimate of 1,527,000 km2 more likely. PMID:21876770

Seto, Karen C.; Fragkias, Michail; Güneralp, Burak; Reilly, Michael K.

2011-01-01

128

Analysis of human spatial perception during lunar landing  

E-print Network

Crewed lunar landings require astronauts to interact with automated systems to identify a location that is level and free of hazards and to guide the vehicle to the lunar surface through a controlled descent. However, ...

Clark, Torin K.

129

Post2 End-to-End Descent and Landing Simulation for ALHAT Design Analysis Cycle 2  

NASA Technical Reports Server (NTRS)

The ALHAT project is an agency-level program involving NASA centers, academia, and industry, with a primary goal to develop a safe, autonomous, precision-landing system for robotic and crew-piloted lunar and planetary descent vehicles. POST2 is used as the 6DOF descent and landing trajectory simulation for determining integrated system performance of ALHAT landing-system models and lunar environment models. This paper presents updates in the development of the ALHAT POST2 simulation, as well as preliminary system performance analysis for ALDAC-2 used for the testing and assessment of ALHAT system models. The ALDAC-2 POST2 Monte Carlo simulation results have been generated and focus on HRN model performance with the fully integrated system, as well performance improvements of AGNC and TSAR model since the previous design analysis cycle

Davis, Jody L.; Striepe, Scott A.; Maddock, Robert W.; Johnson, Andrew E.; Paschall, Stephen C., II

2010-01-01

130

A Reusable Design for Precision Lunar Landing Systems  

NASA Technical Reports Server (NTRS)

The top-level architecture to accomplish NASA's Vision for Space Exploration is to use Lunar missions and systems not just as an end in themselves, but also as testbeds for the more ambitious goals of Human Mars Exploration (HME). This approach means that Lunar missions and systems are most likely going to be targeted for (Lunar) polar missions, and also for long-duration (months) surface stays. This overacting theme creates basic top-level requirements for any next-generation lander system: 1) Long duration stays: a) Multiple landers in close proximity; b) Pinpoint landings for "surface rendezvous"; c) Autonomous landing of pre-positioned assets; and d) Autonomous Hazard Detection and Avoidance. 2) Polar and deep-crater landings (dark); 3) Common/extensible systems for Moon and Mars, crew and cargo. These requirements pose challenging technology and capability needs. Compare and contrast: 4) Apollo: a) 1 km landing accuracy; b) Lunar near-side (well imaged and direct-to-Earth com. possible); c) Lunar equatorial (landing trajectories offer best navigation support from Earth); d) Limited lighting conditions; e) Significant ground-in-the-loop operations; 5) Lunar Access: a) 10-100m landing precision; b) "Anywhere" access includes polar (potentially poor nav. support from Earth) and far side (poor gravity and imaging; no direct-to-Earth com); c) "Anytime" access includes any lighting condition (including dark); d) Full autonomous landing capability; e) Extensible design for tele-operation or operator-in-the-loop; and f) Minimal ground support to reduce operations costs. The Lunar Access program objectives, therefore, are to: a) Develop a baseline Lunar Precision Landing System (PLS) design to enable pinpoint "anywhere, anytime" landings; b) landing precision 10m-100m; c) Any LAT, LON; and d) Any lighting condition; This paper will characterize basic features of the next generation Lunar landing system, including trajectory types, sensor suite options and a reference system architecture.

Fuhrman, Linda; Brand, Timothy; Fill, Tom; Norris, Lee; Paschall, Steve

2005-01-01

131

77 FR 2563 - Public Land Order No. 7787; Withdrawal of Public and National Forest System Lands in the Grand...  

Federal Register 2010, 2011, 2012, 2013, 2014

...The public and National Forest System lands described...order are within Coconino and Mohave Counties...the Grand Canyon National Park and Navajo Indian...acres of public and National Forest System lands in Coconino and Mohave...

2012-01-18

132

Online Time Series Analysis of Land Products over Asia Monsoon Region via Giovanni  

NASA Technical Reports Server (NTRS)

Time series analysis is critical to the study of land cover/land use changes and climate. Time series studies at local-to-regional scales require higher spatial resolution, such as 1km or less, data. MODIS land products of 250m to 1km resolution enable such studies. However, such MODIS land data files are distributed in 10ox10o tiles, due to large data volumes. Conducting a time series study requires downloading all tiles that include the study area for the time period of interest, and mosaicking the tiles spatially. This can be an extremely time-consuming process. In support of the Monsoon Asia Integrated Regional Study (MAIRS) program, NASA GES DISC (Goddard Earth Sciences Data and Information Services Center) has processed MODIS land products at 1 km resolution over the Asia monsoon region (0o-60oN, 60o-150oE) with a common data structure and format. The processed data have been integrated into the Giovanni system (Goddard Interactive Online Visualization ANd aNalysis Infrastructure) that enables users to explore, analyze, and download data over an area and time period of interest easily. Currently, the following regional MODIS land products are available in Giovanni: 8-day 1km land surface temperature and active fire, monthly 1km vegetation index, and yearly 0.05o, 500m land cover types. More data will be added in the near future. By combining atmospheric and oceanic data products in the Giovanni system, it is possible to do further analyses of environmental and climate changes associated with the land, ocean, and atmosphere. This presentation demonstrates exploring land products in the Giovanni system with sample case scenarios.

Shen, Suhung; Leptoukh, Gregory G.; Gerasimov, Irina

2011-01-01

133

LanguageLand : a multimodal conversational spoken language learning system  

E-print Network

LanguageLand is a multimodal conversational spoken language learning system whose purpose is to help native English users learn Mandarin Chinese. The system is centered on a game that involves navigation on a simulated ...

Lee, Vivienne C. (Vivienne Catherine)

2004-01-01

134

SANITARY SEWER SYSTEMS - LAND APPLICATION AREAS, NEUSE RIVER WATERSHED, NC  

EPA Science Inventory

The North Carolina Rural Economic Development Center (NCREDC) in conjunction with Hobbs, Upchurch & Associates developed the digital Sewer system land applications as mapped by individual system owners as required by contract. The data collected will facilitate planning, siting a...

135

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration. [performance tests of remote control equipment for roving vehicles  

NASA Technical Reports Server (NTRS)

Problems related to the design and control of an autonomous rover for the purpose of unmanned exploration of the planets were considered. Building on the basis of prior studies, a four wheeled rover of unusual mobility and maneuverability was further refined and tested under both laboratory and field conditions. A second major effort was made to develop autonomous guidance. Path selection systems capable of dealing with relatively formidable hazard and terrains involving various short range (1.0-3.0 meters), hazard detection systems using a triangulation detection concept were simulated and evaluated. The mechanical/electronic systems required to implement such a scheme were constructed and tested. These systems include: laser transmitter, photodetectors, the necessary data handling/controlling systems and a scanning mast. In addition, a telemetry system to interface the vehicle, the off-board computer and a remote control module for operator intervention were developed. Software for the autonomous control concept was written. All of the systems required for complete autonomous control were shown to be satisfactory except for that portion of the software relating to the handling of interrupt commands.

Gisser, D. G.; Frederick, D. K.; Sandor, G. N.; Shen, C. N.; Yerazunis, S. W.

1976-01-01

136

ForEnvironmentalManagementofMilitaryLands Land Condition-Trend Analysis  

E-print Network

of an earlier format to MS Access 2000 is an easy process. Be aware that once converted, the database may MS Access version, maintain a copy. 1) Open the current MS Access version. Select the database Using MS Access to Analyze Land Condition-Trend Analysis Data A Beginner's Guide By Christine Bern

137

Improved aircraft dynamic response and fatigue life during ground operations using an active control landing gear system  

NASA Technical Reports Server (NTRS)

A three-degree-of-freedom aircraft landing analysis incorporating a series-hydraulic active control main landing gear has been developed and verified using preliminary experimental data from drop tests of a modified main landing gear from a 2722 kg (6000 lbm) class of airplane. The verified analysis was also employed to predict the landing dynamics of a supersonic research airplane with an active control main landing gear system. The results of this investigation have shown that this type of active gear is feasible and indicate a potential for improving airplane dynamic response and reducing structural fatigue damage during ground operations by approximately 90% relative to that incurred with the passive gear.

Mcgehee, J. R.; Carden, H. D.; Edson, R.

1978-01-01

138

Preliminary analysis of knee stress in Full Extension Landing  

PubMed Central

OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm), using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities. PMID:24141832

Makinejad, Majid Davoodi; Abu Osman, Noor Azuan; Wan Abas, Wan Abu Bakar; Bayat, Mehdi

2013-01-01

139

Figure 1. Extent of the Kirkwood-Cohansey aquifer system in New Jersey, areas of agricultural land use, and locations of wells sampled for analysis of radium concentrations, 1988-96.  

E-print Network

Figure 1. Extent of the Kirkwood-Cohansey aquifer system in New Jersey, areas of agricultural land) indicate that concentrations of total radium in water samples from 33 percent of 170 wells in the Kirkwood-Cohansey° 30' 74° 30' Extent of the Kirkwood- Cohansey aquifer system Area of agricultural land

140

Mars Science Laboratory entry, descent, and landing system  

Microsoft Academic Search

In 2010, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic entry, descent, and landing (EDL) systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than prior missions to Mars, MSL will offer access to regions of Mars that have been previously unreachable.

Adam Steltzner; Devin Kipp; Allen Chen; Dan Burkhart; Carl Guernsey; Gavin Mendeck; Robert Mitcheltree; Richard Powell; Tommaso Rivellini; Miguel San Martin

2006-01-01

141

Developing Cost-effective and Resilient Land Administration Systems in  

Microsoft Academic Search

SUMMARY In this paper I briefly review the wealth of experience in Latin America with initiatives to strengthen and modernize land administration systems. The review shows that there is more experience with land administration projects in this region than in any other. I go on to focus on the question of costs associated with formalizing property in an attempt to

Grenville BARNES

142

Image interpretation for a multilevel land use classification system  

NASA Technical Reports Server (NTRS)

The potential use is discussed of three remote sensors for developing a four level land use classification system. Three types of imagery for photointerpretation are presented: ERTS-1 satellite imagery, high altitude photography, and medium altitude photography. Suggestions are given as to which remote sensors and imagery scales may be most effectively employed to provide data on specific types of land use.

1973-01-01

143

Techniques of UAV system land use changes detection application  

Microsoft Academic Search

The unmanned aerial vehicle( UAV) was able to acquire remote sensing images with low cost, precise and high spatial resolution information needed by management of Land use at desired time. The aim of this paper was to present an overview of the ongoing research on the potential and techniques of low-altitude UAV system for land use applications. The development of

Youying Zhang; Hongxia Cui

2011-01-01

144

PLANS FOR THE LAND MANAGEMENT SYSTEM (LMS) INITIATIVE  

EPA Science Inventory

The Land Management System (LMS) is an initiative of the U.S. Army Engineer Research and Development Center (ERDC) to address technology requirements related to land and water resource management in both military and Civil Works mission areas. The purpose of LMS is to provide rel...

145

Land use planning and early warning systems for limiting drought  

E-print Network

Land use planning and early warning systems for limiting drought impacts and promoting recovery J-term agroecological potential? 3a. Land use plans: what/how to produce + drought response plan 1a. Soil + climate maps 2b. What is current status relative to potential (ecosystem health/soil quality)? 4. Drought

146

Treatment of systematic errors in land data assimilation systems  

NASA Astrophysics Data System (ADS)

Data assimilation systems are generally designed to minimize the influence of random error on the estimation of system states. Yet, experience with land data assimilation systems has also revealed the presence of large systematic differences between model-derived and remotely-sensed estimates of land surface states. Such differences are commonly resolved prior to data assimilation through implementation of a pre-processing rescaling step whereby observations are scaled (or non-linearly transformed) to somehow "match" comparable predictions made by an assimilation model. While the rationale for removing systematic differences in means (i.e., bias) between models and observations is well-established, relatively little theoretical guidance is currently available to determine the appropriate treatment of higher-order moments during rescaling. This talk presents a simple analytical argument to define an optimal linear-rescaling strategy for observations prior to their assimilation into a land surface model. While a technique based on triple collocation theory is shown to replicate this optimal strategy, commonly-applied rescaling techniques (e.g., so called "least-squares regression" and "variance matching" approaches) are shown to represent only sub-optimal approximations to it. Since the triple collocation approach is likely infeasible in many real-world circumstances, general advice for deciding between various feasible (yet sub-optimal) rescaling approaches will be presented with an emphasis of the implications of this work for the case of directly assimilating satellite radiances. While the bulk of the analysis will deal with linear rescaling techniques, its extension to nonlinear cases will also be discussed.

Crow, W. T.; Yilmaz, M.

2012-12-01

147

Analysis of Land Suitable for Algae State of Hawaii  

E-print Network

Analysis of Land Suitable for Algae Production State of Hawaii Prepared by Mele Chillingworth Scott of Hawaii at Manoa August 2011 #12;i Executive Summary Algae are considered to be a viable crop for biofuel for biofuels has increased interest in growing algae in Hawaii for biofuels. An analysis of algae production

148

Failure analysis of a civil aircraft landing gear  

Microsoft Academic Search

This paper describes the analysis and investigation of the causes of the failure of the main landing gear of a Cessna 402B civil aircraft. Optical analysis of the failed elements indicated possible fatigue crack failure initiation. However, further scanning electron microscopy examination ruled out this failure mechanism showing shear failure mode as the cause of fracture.

E. A. Ossa

2006-01-01

149

US army land condition-trend analysis (LCTA) program  

Microsoft Academic Search

The US Army Land Condition-Trend Analysis (LCTA) program is a standardized method of data collection, analysis, and reporting designed to meet multiple goals and objectives. The method utilizes vascular plant inventories, permanent field plot data, and wildlife inventories. Vascular plant inventories are used for environmental documentation, training of personnel, species identification during LCTA implementation, and as a survey for state

Victor E. Diersing; Robert B. Shaw; David J. Tazik

1992-01-01

150

Temporal Land Cover Analysis for Net Ecosystem Improvement  

SciTech Connect

We delineated 8 watersheds contributing to previously defined river reaches within the 1,468-km2 historical floodplain of the tidally influenced lower Columbia River and estuary. We assessed land-cover change at the watershed, reach, and restoration site scales by reclassifying remote-sensing data from the National Oceanic and Atmospheric Administration Coastal Change Analysis Program’s land cover/land change product into forest, wetland, and urban categories. The analysis showed a 198.3 km2 loss of forest cover during the first 6 years of the Columbia Estuary Ecosystem Restoration Program, 2001–2006. Total measured urbanization in the contributing watersheds of the estuary during the full 1996-2006 change analysis period was 48.4 km2. Trends in forest gain/loss and urbanization differed between watersheds. Wetland gains and losses were within the margin of error of the satellite imagery analysis. No significant land cover change was measured at restoration sites, although it was visible in aerial imagery, therefore, the 30-m land-cover product may not be appropriate for assessment of early-stage wetland restoration. These findings suggest that floodplain restoration sites in reaches downstream of watersheds with decreasing forest cover will be subject to increased sediment loads, and those downstream of urbanization will experience effects of increased impervious surfaces on hydrologic processes.

Ke, Yinghai; Coleman, Andre M.; Diefenderfer, Heida L.

2013-04-09

151

78 FR 68811 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning Rule AGENCY: Forest Service...National Forest System Land Management Planning Rule will meet in Arlington...National Forest System Land Management Planning Rule. The purpose of...

2013-11-15

152

76 FR 81911 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning Rule AGENCY: USDA Forest...National Forest System Land Management Planning Rule (Committee). In accordance...National Forest System Land Management Planning Rule (Planning Rule)....

2011-12-29

153

78 FR 46565 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning Rule AGENCY: Forest Service...National Forest System Land Management Planning Rule will meet in West Valley...National Forest System Land Management Planning Rule. The purpose of...

2013-08-01

154

23 CFR 971.214 - Federal lands congestion management system (CMS).  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Federal lands congestion management system (CMS). 971...TRANSPORTATION FEDERAL LANDS HIGHWAYS FOREST SERVICE MANAGEMENT SYSTEMS Forest Highway...971.214 Federal lands congestion management system...

2012-04-01

155

23 CFR 971.214 - Federal lands congestion management system (CMS).  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Federal lands congestion management system (CMS). 971...TRANSPORTATION FEDERAL LANDS HIGHWAYS FOREST SERVICE MANAGEMENT SYSTEMS Forest Highway...971.214 Federal lands congestion management system...

2013-04-01

156

23 CFR 971.214 - Federal lands congestion management system (CMS).  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Federal lands congestion management system (CMS). 971...TRANSPORTATION FEDERAL LANDS HIGHWAYS FOREST SERVICE MANAGEMENT SYSTEMS Forest Highway...971.214 Federal lands congestion management system...

2011-04-01

157

23 CFR 971.214 - Federal lands congestion management system (CMS).  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Federal lands congestion management system (CMS). 971...TRANSPORTATION FEDERAL LANDS HIGHWAYS FOREST SERVICE MANAGEMENT SYSTEMS Forest Highway...971.214 Federal lands congestion management system...

2014-04-01

158

Applications of Skylab data to land use and climatological analysis  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Skylab study in Central Atlantic Regional Ecological Test Site encompassed two separate but related tasks: (1) evaluation of photographic sensors S190A and B as sources of land use data for planning and managing land resources in major metropolitan regions, and (2) evaluation of the multispectral scanner S192 used in conjunction with associated data and analytical techniques as a data source on urban climates and the surface energy balance. Photographs from the Skylab S190B earth terrain camera were of greatest interest in the land use analysis task; they were of sufficiently high resolution to identify and map many level 2 and 3 land use categories. After being corrected to allow for atmosphere effects, output from thermal and visible bands of the S192 was employed in constructing computer map plots of albedo and surface temperature.

Alexander, R. H. (principal investigator); Lewis, J. E., Jr.; Lins, H. F., Jr.; Jenner, C. B.; Outcalt, S. I.; Pease, R. W.

1976-01-01

159

Aeroacoustic Analysis of a Simplified Landing Gear  

NASA Technical Reports Server (NTRS)

A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been completed, and comparisons are made between calculations with different turbulence models. Results indicate that the turbulence model has a profound effect on the levels and character of the unsteadiness. Flow data on solid surfaces and a set of permeable surfaces surrounding the gear have been collected. Noise predictions using the porous surfaces appear to be contaminated by errors caused by large wake fluctuations passing through the surfaces. However, comparisons between predictions using the solid surfaces with the near-field CFD solution are in good agreement giving confidence in the far-field results.

Lockard, David P.; Khorrami, Mehdi, R.; Li, Fei

2004-01-01

160

A guide to NASA's Pilot Land Data System (PLDS)  

NASA Technical Reports Server (NTRS)

NASA's Pilot Land Data System (PLDS) is a distributed information management system designed to support NASA's land science community. The PLDS provides a wide range of services including management of information about scientific data, access to a library of scientific data, a data ordering capability, communications, connection to data analysis facilities, and electronic mail. The PLDS provides these services by offering the scientist the capability to search for and order data, and to communicate electronically with other scientists and computers. Three functions enable scientists to find what data are available and where they reside. The first two, Find data summaries and Read detailed descriptions give summary and detailed descriptions about data sets or groups of related data sets, science, projects, and institutions which archive land data. The third, gives information about specific pieces of data. This last function has two components, Search systemwide inventory and Search local inventory. The first component enables the user to find data elements (images, geological samples, transects, maps, etc.) that exist anywhere in the PLDS while the second has only information about data at the local site. The first enables the user to find pieces of data from several different data sets with the same temporal and spatial coverage and other elements common to most data sets, while the second allows the user to select a data set based on these descriptors and on those that are unique to a data set. The PLDS provides capabilities that enable electronic file transfers, intercomputer connection, and electronic mail. Both TCP/IP and DECnet protocols are supported via the NASA Science Internet (NIS). Access is also available through Telenet.

1991-01-01

161

7. Northeast view interior, air traffic control and landing system ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Northeast view interior, air traffic control and landing system room 25 - Selfridge Field, Building No. 1050, Northwest corner of Doolittle Avenue & D Street; Harrison Township, Mount Clemens, Macomb County, MI

162

The shock-absorbed system of the airplane landing gear  

NASA Technical Reports Server (NTRS)

A discussion is given of the behavior of the shock-absorbing system, consisting of elastic struts and tires, under landing, take-off, and taxying conditions, and a general formula derived for obtaining the minimum stroke required to satisfy the conditions imposed on the landing gear. Finally, the operation of some typical shock-absorbing systems are examined and the necessity brought out for taking into account, in dynamic landing-gear tests, the effect of the wing lift at the instant of contact with the ground.

Callerio, Pietro

1940-01-01

163

Validation of a Flexible Aircraft TakeOff and Landing Analysis /FATOLA/ computer program using flight landing data  

NASA Technical Reports Server (NTRS)

A multiple-degree-of-freedom takeoff and landing analysis, Flexible Aircraft TakeOff and Landing Analysis computer program (FATOLA), was used to predict the landing behavior of a rigid-body X-24B reentry research vehicle and of a flexible-body modified-delta-wing supersonic YF-12 research aircraft. The analytical predictions were compared with flight test data for both research vehicles. Predicted time histories of vehicle motion and attitude, landing-gear strut stroke, and axial force transmitted from the landing gear to the airframe during the landing impact and rollout compared well with the actual time histories. Based on the comparisons presented, the versatility and validity of the FATOLA program for predicting landing dynamics of aircraft has been demonstrated.

Carden, H. D.; Mcgehee, J. R.

1977-01-01

164

High-performance Earth system modeling with NASA\\/GSFC's Land Information System  

Microsoft Academic Search

The Land Information System software (LIS; http:\\/\\/lis.gsfc.nasa.gov\\/, 2006) has been developed to support high-performance\\u000a land surface modeling and data assimilation. LIS integrates parallel and distributed computing technologies with modern land\\u000a surface modeling capabilities, and establishes a framework for easy interchange of subcomponents, such as land surface physics,\\u000a input\\/output conventions, and data assimilation routines. The software includes multiple land surface models

Christa D. Peters-lidard; P. R. Houser; Y. Tian; S. V. Kumar; J. Geiger; S. Olden; L. Lighty; B. Doty; P. Dirmeyer; J. Adams; K. Mitchell; E. F. Wood; J. Sheffield

2007-01-01

165

Continental-scale water and energy flux analysis and validation for the North American Land Data Assimilation System project phase 2 (NLDAS-2): 1. Intercomparison and application of model products  

NASA Astrophysics Data System (ADS)

Results are presented from the second phase of the multiinstitution North American Land Data Assimilation System (NLDAS-2) research partnership. In NLDAS, the Noah, Variable Infiltration Capacity, Sacramento Soil Moisture Accounting, and Mosaic land surface models (LSMs) are executed over the conterminous U.S. (CONUS) in realtime and retrospective modes. These runs support the drought analysis, monitoring and forecasting activities of the National Integrated Drought Information System, as well as efforts to monitor large-scale floods. NLDAS-2 builds upon the framework of the first phase of NLDAS (NLDAS-1) by increasing the accuracy and consistency of the surface forcing data, upgrading the land surface model code and parameters, and extending the study from a 3-year (1997-1999) to a 30-year (1979-2008) time window. As the first of two parts, this paper details the configuration of NLDAS-2, describes the upgrades to the forcing, parameters, and code of the four LSMs, and explores overall model-to-model comparisons of land surface water and energy flux and state variables over the CONUS. Focusing on model output rather than on observations, this study seeks to highlight the similarities and differences between models, and to assess changes in output from that seen in NLDAS-1. The second part of the two-part article focuses on the validation of model-simulated streamflow and evaporation against observations. The results depict a higher level of agreement among the four models over much of the CONUS than was found in the first phase of NLDAS. This is due, in part, to recent improvements in the parameters, code, and forcing of the NLDAS-2 LSMs that were initiated following NLDAS-1. However, large inter-model differences still exist in the northeast, Lake Superior, and western mountainous regions of the CONUS, which are associated with cold season processes. In addition, variations in the representation of sub-surface hydrology in the four LSMs lead to large differences in modeled evaporation and subsurface runoff. These issues are important targets for future research by the land surface modeling community. Finally, improvement from NLDAS-1 to NLDAS-2 is summarized by comparing the streamflow measured from U.S. Geological Survey stream gauges with that simulated by four NLDAS models over 961 small basins.

Xia, Youlong; Mitchell, Kenneth; Ek, Michael; Sheffield, Justin; Cosgrove, Brian; Wood, Eric; Luo, Lifeng; Alonge, Charles; Wei, Helin; Meng, Jesse; Livneh, Ben; Lettenmaier, Dennis; Koren, Victor; Duan, Qingyun; Mo, Kingtse; Fan, Yun; Mocko, David

2012-02-01

166

Study on passive momentum exchange landing gear using two-dimensional analysis  

NASA Astrophysics Data System (ADS)

This paper discusses a landing response control system based on the momentum exchange principle for planetary exploration spacecraft. In the past, landing gear systems with cantilever designs that incorporate honeycomb materials to dissipate shock energy through plastic deformation have been used, but once tested before launch, the system cannot be used in a real mission. The sky crane system used for the Mars Science Laboratory by NASA can achieve a safe and precise landing, but it is highly complex. This paper introduces a momentum exchange impact damper (MEID) that absorbs the controlled object's momentum with extra masses called damper masses. The MEID is reusable, which makes it easy to ensure the landing gear's reliability. In this system, only passive elements such as springs are needed. A single-axis (SA) model has already been used to verify the effectiveness of MEIDs through simulations and experiments measuring the rebound height of the spacecraft. However, the SA model cannot address the rotational motion and tipping of the spacecraft. This paper presents a two-landing-gear-system (TLGS) model in which multiple MEIDs are equipped for two-dimensional analysis. Unlike in the authors' previous studies, in this study each MEID is launched when the corresponding landing gear lands and the MEIDs do not contain active actuators. This mechanism can be used to realize advanced control specifications, and it is simply compared with previous mechanisms including actuators, in which all of the MEIDs are launched simultaneously. If each MEID works when the corresponding gear lands, the rebound height of each gear can be minimized, and tipping can be prevented, as demonstrated by the results of our simulations.

Watanabe, Tsubasa; Hara, Susumu; Otsuki, Masatsugu

2014-12-01

167

Automated Loads Analysis System (ATLAS)  

NASA Technical Reports Server (NTRS)

ATLAS is a generalized solution that can be used for launch vehicles. ATLAS is used to produce modal transient analysis and quasi-static analysis results (i.e., accelerations, displacements, and forces) for the payload math models on a specific Shuttle Transport System (STS) flight using the shuttle math model and associated forcing functions. This innovation solves the problem of coupling of payload math models into a shuttle math model. It performs a transient loads analysis simulating liftoff, landing, and all flight events between liftoff and landing. ATLAS utilizes efficient and numerically stable algorithms available in MSC/NASTRAN.

Gardner, Stephen; Frere, Scot; O’Reilly, Patrick

2013-01-01

168

Environmental assessment and land change analysis in seminatural land covers applicable to land management  

NASA Astrophysics Data System (ADS)

The present research is based on the hypertemporal analysis of a set of 212 images from the NDVI index from January 2003 to March 2012 provided by the medium-resolution sensor MODIS TERRA. The study area is located in the center of the Iberian Peninsula (Spain). The specific objectives of the study are to investigate the rhythms of the annual development of the NDVI of each of the classes, determine the classes that are most sensitive to climatic variability and define the interannual sequences of variation in NDVI with an associated trend analysis. The classes situated in lower-altitude areas are strongly dependent on autumn rainfall and present negative temporal tendencies, and those situated at mountaintops and on upper slopes are correlated with spring-summer temperatures and exhibit stable or positive tendencies.

Bullón, Teresa

2015-02-01

169

Land-surface atmosphere coupling in an earth system model  

NASA Astrophysics Data System (ADS)

The interaction between the atmosphere and the strongly heterogeneous land surface is one of the central scientific topics within Earth system sciences and especially climate research. Many processes, such as vegetation dynamics and the development of spatial patterns in the Subtropics and permafrost regions, take place on scales much below the scale of model resolution. Thus, it is an important scientific challenge to consider the influence of sub-scale heterogeneity on the vertical near-surface fluxes of energy and water. Most climate models do not take into account the actual scale of surface heterogeneities. When coupling a heterogeneous surface to the atmosphere often coupling methods are employed, which include the underlying assumption that the horizontal extent of the individual heterogeneity is so small that the turbulent vertical fluxes stemming from the different surface heterogeneities within one grid-box have mixed horizontally below the lowest model level of the atmosphere. This assumption allows a comparatively simple land-surface-atmosphere coupling with a horizontally homogeneous state of the atmosphere, but it may also be the source of significant errors. In order to access the extent of error introduced we designed an experiment in which the results of three different coupling schemes were compared. The first one is a parameter-aggregation scheme, the second a flux-aggregation scheme based on the assumption of a horizontally homogeneous atmosphere on the lowest atmospheric model level and the third one is a coupling scheme which allows, up to a given height, for the atmosphere to be horizontally heterogeneous within a grid-box. These coupling methods were implemented in the land-surface model JSBACH which was then coupled to the general circulation model ECHAM6, both part of the Max Planck Institute for Meteorology's earth system model MPI-ESM. In a first step sensitivity studies are being carried out to gain process understanding and to disentangle the direct effects of the land-surface-atmosphere coupling and the atmospheric response. To evaluate the overall impact, of a given coupling scheme, 20-year-AMIP-type simulations were performed. First analysis indicates that the results obtained with the three coupling schemes do significantly differ. These differences are not only visible on a sub-grid scale e.g. the sub-grid fluxes, but also on the grid-scale the choice of the coupling scheme significantly affects the simulated global climate and large-scale patterns. Furthermore the difference in the simulated climate between using the improved and the standard flux-aggregation scheme are in the same order of magnitude as those between the parameter aggregation scheme and the standard flux-aggregation scheme.

de Vrese, Philipp; Hagemann, Stefan

2014-05-01

170

14 CFR 23.729 - Landing gear extension and retraction system.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Landing gear extension and retraction system. 23.729 Section...CATEGORY AIRPLANES Design and Construction Landing Gear § 23.729 Landing gear extension and retraction system. (a)...

2010-01-01

171

78 FR 23219 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning Rule AGENCY: Forest Service...National Forest System Land Management Planning Rule will meet in Fort Collins...Secretary on the Proposed Land Management Planning Directives. DATES: The...

2013-04-18

172

78 FR 34034 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land Management Planning Rule AGENCY: Forest Service...National Forest System Land Management Planning Rule will meet in Salt Lake...Secretary on the Proposed Land Management Planning Directives. The meeting...

2013-06-06

173

Analysis of Landing Gear Behaviour for Trainer Aircraft  

Microsoft Academic Search

Abstract. In the field of aircraft landing analysis, the use of a multibody code such as ADAMS has enormous potential: it allows the designer to create as complex a model as desired, with the possibility of integrating subsystems and of accounting, for example, for aerodynamics and structural flexibility. In this paper, an approach to the application of ADAMS in the

Gian Luca Ghiringhelli; Stefania Gualdi; Mario Boschetto; Riccardo Bianco-Mengotti

2000-01-01

174

Task Analysis of Shuttle Entry and Landing Activities  

NASA Technical Reports Server (NTRS)

The Task Analysis of Shuttle Entry and Landing (E/L) Activities documents all tasks required to land the Orbiter following an STS mission. In addition to analysis of tasks performed, task conditions are described, including estimated time for completion, altitude, relative velocity, normal and lateral acceleration, location of controls operated or monitored, and level of g's experienced. This analysis precedes further investigations into potential effects of zero g on piloting capabilities for landing the Orbiter following long-duration missions. This includes, but is not limited to, researching the effects of extended duration missions on piloting capabilities. Four primary constraints of the analysis must be clarified: (1) the analysis depicts E/L in a static manner--the actual process is dynamic; (2) the task analysis was limited to a paper analysis, since it was not feasible to conduct research in the actual setting (i.e., observing or filming duration an actual E/L); (3) the tasks included are those required for E/L during nominal, daylight conditions; and (4) certain E/L tasks will vary according to the flying style of each commander.

Holland, Albert W.; Vanderark, Stephen T.

1993-01-01

175

a Study of Urban Intensive Land Evaluating System  

NASA Astrophysics Data System (ADS)

The contradiction of land supply and demand is becoming increasingly prominent in China. The increasing efficiency of land use is an important means to resolve the conflict. We propose a scientific approach for promoting the urban intensive land use. In this paper, an evaluation system of urban intensive land use is programmed. It is designed to change the manual way of collecting index data and building index system to a dynamical way. The system improves the efficiency and accuracy of the evaluation of urban intensive land use. It achieves intensive evaluation on three scales: macro-level, medium-level and micro-level. We build two data extraction methods. One is XML-based meta-data exchange method that obtains index data from the cadastral database. Another is data monitoring method that writes the index data to the evaluation database at real time. Database technologies are used to calculate index values and build index systems dynamically. GIS technologies are use to achieve three scales evaluation of urban intensive land use.

Jiang, L.; Gu, J.; Chen, X.; You, Y.; Tang, Q.

2012-07-01

176

Consistency of wind erosion assessments across land use and land cover types: A critical analysis  

NASA Astrophysics Data System (ADS)

In recent decades, large areas of rangeland have been converted to cropland or vice versa in the western United States and elsewhere in the world, driven largely by increased crop prices, loss of access to irrigation water, and agricultural expansion/contraction. Wind erosion and dust emissions are key processes that have not been well studied during land use and associated land cover changes. This assessment is challenging because currently no model is available that can provide field- to landscape-scale estimates of wind erosion on both rangeland and cropland, and account for soil, vegetation and management changes. In this paper, we compare aeolian sediment transport estimates from available cropland models and a number of mass flux equations developed for rangelands, for a bare soil surface with different levels of crust and surface roughness under different wind speeds. Our results show that the simulated horizontal sediment mass fluxes are similar for cropland and rangeland models at large surface crust coverage and aerodynamic roughness. In situations of small to moderate crust cover and soil roughness, horizontal mass fluxes varied by over three orders of magnitude among the tested models. A correlation analysis shows that horizontal mass fluxes simulated by cropland and rangeland models are correlated, with correlation R2 of 0.37-0.99 across different models. Finally, we propose an approach to estimate changes in aeolian transport with changes in land use. Although this approach may be limited to situations of unvegetated surfaces, it provides a preliminary method for land managers and policymakers to estimate potential wind erosion changes in response to land use change.

Li, Junran; Okin, Gregory S.; Tatarko, John; Webb, Nicholas P.; Herrick, Jeffrey E.

2014-12-01

177

An analysis of landing rates and separations at the Dallas/Fort Worth International Airport  

NASA Technical Reports Server (NTRS)

Advanced air traffic management systems such as the Center/TRACON Automation System (CTAS) should yield a wide range of benefits, including reduced aircraft delays and controller workload. To determine the traffic-flow benefits achievable from future terminal airspace automation, live radar information was used to perform an analysis of current aircraft landing rates and separations at the Dallas/Fort Worth International Airport. Separation statistics that result when controllers balance complex control procedural constraints in order to maintain high landing rates are presented. In addition, the analysis estimates the potential for airport capacity improvements by determining the unused landing opportunities that occur during rush traffic periods. Results suggest a large potential for improving the accuracy and consistency of spacing between arrivals on final approach, and they support earlier simulation findings that improved air traffic management would increase capacity and reduce delays.

Ballin, Mark G.; Erzberger, Heinz

1996-01-01

178

US army land condition-trend analysis (LCTA) program  

Microsoft Academic Search

The US Army Land Condition-Trend Analysis (LCTA) program is a standardized method of data collection, analysis, and reporting\\u000a designed to meet multiple goals and objectives. The method utilizes vascular plant inventories, permanent field plot data,\\u000a and wildlife inventories. Vascular plant inventories are used for environmental documentation, training of personnel, species\\u000a identification during LCTA implementation, and as a survey for state

Victor E. Diersing; Robert B. Shaw; David J. Tazik

1992-01-01

179

Validation of an Active Gear, Flexible Aircraft Take-off and Landing analysis (AGFATL)  

NASA Technical Reports Server (NTRS)

The results of an analytical investigation using a computer program for active gear, flexible aircraft take off and landing analysis (AGFATL) are compared with experimental data from shaker tests, drop tests, and simulated landing tests to validate the AGFATL computer program. Comparison of experimental and analytical responses for both passive and active gears indicates good agreement for shaker tests and drop tests. For the simulated landing tests, the passive and active gears were influenced by large strut binding friction forces. The inclusion of these undefined forces in the analytical simulations was difficult, and consequently only fair to good agreement was obtained. An assessment of the results from the investigation indicates that the AGFATL computer program is a valid tool for the study and initial design of series hydraulic active control landing gear systems.

Mcgehee, J. R.

1984-01-01

180

Ongoing Development of NASA's Global Land Data Assimilation System  

NASA Technical Reports Server (NTRS)

NASA's Global Land Data Assimilation System (GLDAS) produces global fields of land surface states (e.g., soil moisture and temperature) and fluxes (e.g., latent heat flux and runoff) by driving offline land surface models with observation-based inputs, using the Land Information System (LIS) software. Since production began in 2001, GLDAS has supported more than 100 scientific investigations and applications. Some examples are GEWEX and NASA Energy and Water Cycle Study (NEWS) global water and energy budget analyses, interpretations of hydrologic data derived from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, and forecast model initiation studies at NOAA and NASA. At the same time, the GLDAS team has continued improve results through the development of new modeling and data assimilation techniques. Here we describe several recent and ongoing innovations. These include global implementation of a runoff routing procedure, GRACE data assimilation, advanced snow cover assimilation, and irrigation modeling.

Rodell, Matthew; Kato, Hiroko; Zaitchik, Ben

2008-01-01

181

Space shuttle entry and landing navigation analysis  

NASA Technical Reports Server (NTRS)

A navigation system for the entry phase of a Space Shuttle mission which is an aided-inertial system which uses a Kalman filter to mix IMU data with data derived from external navigation aids is evaluated. A drag pseudo-measurement used during radio blackout is treated as an additional external aid. A comprehensive truth model with 101 states is formulated and used to generate detailed error budgets at several significant time points -- end-of-blackout, start of final approach, over runway threshold, and touchdown. Sensitivity curves illustrating the effect of variations in the size of individual error sources on navigation accuracy are presented. The sensitivity of the navigation system performance to filter modifications is analyzed. The projected overall performance is shown in the form of time histories of position and velocity error components. The detailed results are summarized and interpreted, and suggestions are made concerning possible software improvements.

Jones, H. L.; Crawford, B. S.

1974-01-01

182

Texture feature Extraction for Land-cover Classification of Remote Sensing Data in Land Consolidation District Using Semi-variogram analysis  

Microsoft Academic Search

The areas of the land consolidation projects are generally small, so the remote sensing images used in land- cover classification for the land consolidation are generally high spatial resolution images. The spectral complexity of land consolidation objects results in specific limitation using pixel-based analysis for land cover classification such as farmland, woodland, and water. Considering this problem, two approaches are

Yan Huang; Anzhi Yue; Daoliang Li; Ming Luo; Yijun Jiang; Chao Zhang; Su Wei

2008-01-01

183

Analysis of On-board Hazard Detection and Avoidance for Safe Lunar Landing  

NASA Technical Reports Server (NTRS)

Landing hazard detection and avoidance technology is being pursued within NASA to improve landing safety and increase access to sites of interest on the lunar surface. The performance of a hazard detection and avoidance system depends on properties of the terrain, sensor performance, algorithm design, vehicle characteristics and the overall all guidance navigation and control architecture. This paper analyzes the size of the region that must be imaged, sensor performance parameters and the impact of trajectory angle on hazard detection performance. The analysis shows that vehicle hazard tolerance is the driving parameter for hazard detection system design.

Johnson, Andrew E.; Huertas, Andres; Werner, Robert A.; Montgomery, James F.

2008-01-01

184

Visualization and Analysis of Multi-scale Land Surface Products via Giovanni Portals  

NASA Technical Reports Server (NTRS)

Large volumes of MODIS land data products at multiple spatial resolutions have been integrated into the Giovanni online analysis system to support studies on land cover and land use changes,focused on the Northern Eurasia and Monsoon Asia regions through the LCLUC program. Giovanni (Goddard Interactive Online Visualization ANd aNalysis Infrastructure) is a Web-based application developed by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), providing a simple and intuitive way to visualize, analyze, and access Earth science remotely-sensed and modeled data.Customized Giovanni Web portals (Giovanni-NEESPI andGiovanni-MAIRS) have been created to integrate land, atmospheric,cryospheric, and societal products, enabling researchers to do quick exploration and basic analyses of land surface changes, and their relationships to climate, at global and regional scales. This presentation shows a sample Giovanni portal page, lists selected data products in the system, and illustrates potential analyses with imagesand time-series at global and regional scales, focusing on climatology and anomaly analysis. More information is available at the GES DISCMAIRS data support project portal: http:disc.sci.gsfc.nasa.govmairs.

Shen, Suhung; Kempler, Steven J.; Gerasimov, Irina V.

2013-01-01

185

Valuing agricultural land standard prices based on agricultural land gradation and evaluation information system (ALGEIS)  

Microsoft Academic Search

Agriculture land is the most fundamental material of production, and is man's indispensable living condition for existence. Agricultural land prices reflect not only the uses of agricultural land, but the potential uses as well. This paper reviews the valuation on agricultural land prices in western developed countries and the development courses of agricultural land appraisal, especially valuation on agricultural land

Yaolin Liu; Kun Wang; Yanfang Liu; Nianchao Deng; Yang Liu

2008-01-01

186

Assessing land-use change in Ireland using the Land-Parcel Identification System  

NASA Astrophysics Data System (ADS)

Carbon dynamics linked to Land-Use and Land-Use Change (LULUC) are considered a major factor in the global Greenhouse Gas (GHG) budget. The major sources of carbon to the atmosphere are the loss of above and below ground biomass as well as the loss of soil organic carbon. Estimates have shown that in the decade between 1990 and 2000 emissions related to LULUC and forestry have been between 0.5 and 2.7 Gt C yr-1. The major sources are conversion from forestry to agriculture and grasslands to cropland; conversely land-use change from cropland to grassland can facilitate soil carbon sequestration. While the effects of different types of land-use change on the GHG budget have been well studied, assessing land-use change at a national level is subject to uncertainty. In Ireland LULUC are currently modelled using national statistical data on total land-uses as well as socio-economic data. This may lead to inaccuracies as it neither provides information on direct land-use change trajectories nor spatially explicit information such as soil properties. The aim of this study is to assess the suitability of the land-parcel identification system (LPIS) to assess overall inter-annual land-use change as well as the immediate trajectory of change reported, and to provide tools for this purpose. For the available LPIS datasets (2000 to 2012) a number of issues have been identified. (1) Duplication of parcels led to a major overestimation of the agricultural area. On average 20917.7 ±7157.6 parcels showed one or multiple duplicates, leading to an overestimation of the agricultural area by 58194.2 ±11578.4km2, (2) no continuous identification of parcels through time complicates tracking land-use change, and (3) parcel outline changes over time without indication if the changes represent real-world changes or corrections of the LPIS database. Geoinformation Systems tools have been developed to address those issues, including a tool to remove duplicate parcels and a tool that assigns unique parcels identification codes based on spatial stability. To differentiate between real-world change and corrections in the database minimum criteria based on differences in parcel area (5% of the parcel area) and shifts in the parcel centroid over time (12m) have been introduced. Using the newly assigned parcel identification codes it could be shown that parcel stability between consecutive years is very high (on average 90.5% ±3.2 of the parcels in any year are present in the following year). When looking at the whole timeframe only 48.5% ±7.2 of the parcels recorded in 2000 are still present in 2012. These results indicate that LPIS has a strong potential for identifying inter-annual land-use change between consecutive years, however changes in parcel outlines lead to difficulties when comparing non-consecutive years. Further research will be conducted to adapt the available tools to estimate land-use change from changing parcels.

Zimmermann, Jesko; O'Brien, Phillip; Green, Stuart; Gonzales Del Campo, Ainhoa; Jones, Michael; Stout, Jane

2014-05-01

187

Mars Science Laboratory Entry, Descent, and Landing System Overview  

NASA Technical Reports Server (NTRS)

In 2010, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic Entry, Descent, and Landing (EDL) systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than prior missions to Mars, MSL will offer access to regions of Mars that have been previously unreachable. The MSL EDL sequence is a result of a more stringent requirement set than any of its predecessors. Notable among these requirements is landing a 900 kg rover in a landing ellipse much smaller than that of any previous Mars lander. In meeting these requirements, MSL is extending the limits of the EDL technologies qualified by the Mars Viking, Mars Pathfinder, and Mars Exploration Rover missions.

Prakash, Ravi; Burkhart, P. Dan; Chen, Allen; Comeaux, Keith A.; Guernsey, Carl S.; Devin, M. Kipp; Mendeck, Gavin F.; Powell, Richard W.; Rivellini, Tommaso P.; San Martin, A. Miguel; Sell, Steven W.; Steltzner, Adam D.; Way, David W.

2008-01-01

188

Analysis of land cover change and its driving forces in a desert oasis landscape of southern Xinjiang, China  

NASA Astrophysics Data System (ADS)

The combined effects of drought, warming and the changes in land cover have caused severe land degradation for several decades in the extremely arid desert oases of Southern Xinjiang, Northwest China. This study examined land cover changes during 1990-2008 to characterize and quantify the transformations in the typical oasis of Hotan. Land cover classifications of these images were performed based on the supervised classification scheme integrated with conventional vegetation and soil indexes. Change-detection techniques in remote sensing (RS) and a geographic information system (GIS) were applied to quantify temporal and spatial dynamics of land cover changes. The overall accuracies, Kappa coefficients, and average annual increase rate or decrease rate of land cover classes were calculated to assess classification results and changing rate of land cover. The analysis revealed that major trends of the land cover changes were the notable growth of the oasis and the reduction of the desert-oasis ecotone, which led to accelerated soil salinization and plant deterioration within the oasis. These changes were mainly attributed to the intensified human activities. The results indicated that the newly created agricultural land along the margins of the Hotan oasis could result in more potential areas of land degradation. If no effective measures are taken against the deterioration of the oasis environment, soil erosion caused by land cover change may proceed. The trend of desert moving further inward and the shrinking of the ecotone may lead to potential risks to the eco-environment of the Hotan oasis over the next decades.

Amuti, T.; Luo, G.

2014-07-01

189

Application of the Auto-Tuned Land Assimilation System (ATLAS) to ASCAT and SMOS soil moisture retrieval products  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land data assimilations are typically based on highly uncertain assumptions regarding the statistical structure of observation and modeling errors. Left uncorrected, poor assumptions can degrade the quality of analysis products generated by land data assimilation systems. Recently, Crow and van de...

190

Helical automatic approaches of helicopters with microwave landing systems  

NASA Technical Reports Server (NTRS)

A program is under way to develop a data base for establishing navigation and guidance concepts for all-weather operation of rotorcraft. One of the objectives is to examine the feasibility of conducting simultaneous rotorcraft and conventional fixed-wing, noninterfering, landing operations in instrument meteorological conditions at airports equipped with microwave landing systems (MLSs) for fixed-wing traffic. An initial test program to investigate the feasibility of conducting automatic helical approaches was completed, using the MLS at Crows Landing near Ames. These tests were flown on board a UH-1H helicopter equipped with a digital automatic landing system. A total of 48 automatic approaches and landings were flown along a two-turn helical descent, tangent to the centerline of the MLS-equipped runway to determine helical light performance and to provide a data base for comparison with future flights for which the helical approach path will be located near the edge of the MLS coverage. In addition, 13 straight-in approaches were conducted. The performance with varying levels of state-estimation system sophistication was evaluated as part of the flight tests. The results indicate that helical approaches to MLS-equipped runways are feasible for rotorcraft and that the best position accuracy was obtained using the Kalman-filter state-estimation with inertial navigation systems sensors.

Foster, J. D.; Mcgee, L. A.; Dugan, D. C.

1982-01-01

191

The auto-tuned land data assimilation system (ATLAS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land data assimilation systems are tasked with the merging remotely-sensed soil moisture retrievals with information derived from a soil water balance model driven (principally) by observed rainfall. The performance of such systems is frequently degraded by the imprecise specification of parameters ...

192

A European Land Mobile Satellite System via EMS  

NASA Astrophysics Data System (ADS)

The paper analyzes the technical and market issues that influence the strategy of implementation of a Land Mobile Satellite System via the payload EMS (European Mobile System) embarked on ITALSAT F-2. The final goal is to determine services, network architecture, and added value chain that make LMSS via EMS profitable for a typical telecommunication company.

Ananasso, Fulvio; Mistretta, Ignazio

1991-10-01

193

ON FARM SYSTEM DESIGN AND OPERATION AND LAND MANAGEMENT.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Irrigation water is applied to agricultural crops by many different methods. Irrigation methods can be divided into three broad categories - surface, sprinkler, and micro-irrigation. Surface irrigation systems depend on gravity to spread the water across the surface of the land. Surface systems ar...

194

Analysis of land use and land cover change in a coastal area of Rio de Janeiro using  

E-print Network

1 Analysis of land use and land cover change in a coastal area of Rio de Janeiro using high decades in a coastal area of the state of Rio de Janeiro, Brazil. Historical aerial photographs from 1976 of anthropogenic impacts and geoconservation activities in this coastal area of Rio de Janeiro. Keywords: coastal

195

Information Processing Analysis of Human Land Mine Detection Skill James J. Staszewski1  

E-print Network

Information Processing Analysis of Human Land Mine Detection Skill James J. Staszewski1 Carnegie the highest levels of human land mine detection skill. A recent assessment of land mine detection capability to the problems of land mine detection and discrimination. Studies of experts across a variety of skill domains

Creswell, J. David

196

LandSpaCES: A Spatial Expert System for Land Consolidation  

Microsoft Academic Search

\\u000a Land fragmentation is a major issue in many rural areas around the world, preventing rational agricultural production and\\u000a sustainable rural development. Traditionally, land consolidation has been the primary land management approach for solving\\u000a this problem. Land reallocation is recognised as the most important, complex, and time-consuming process of land consolidation.\\u000a It is split into two components: land redistribution and land

Demetris Demetriou; John Stillwell; Linda Seel

197

Development of a spatio-temporal data model based on events and objects in land reclamation information system  

NASA Astrophysics Data System (ADS)

The land resource in the mining area has been destroyed badly, therefore to establish a land reclamation information system of mining area based on GIS is of great significance. However, mining land reclamation is a complex systemic project, there are a lot of spatial data and spatial information during the whole reclamation procedure. The spatial information database of land reclamation is a temporal one due to the change of the land resource within the coal mining area. The damaged land is always above the corresponding underground working face of the mine, there are many pieces of destroyed land in the mining area. A piece of reclaiming land area can be acted as one object, On the basis of the analysis of the changing course of the land object in the subsidence region and the advantage of event-based spatio-temporal data model, a spatio-temporal data model based on objects and events was proposed in this paper, this model can be applied to administer land information in the mining area. Meanwhile, the spatial information query and the analytic method were also studied in this paper. The advantage of this model is to connect surface event and underground mining event which cause the land information change in the mining area.

Hu, Jinshan; He, Zongyi; Kang, Jianrong; Liu, Pengcheng; Wei, Xiuqin

2009-10-01

198

Using Geo-informational System for determining land degradation processes  

NASA Astrophysics Data System (ADS)

The largest part of agricultural lands of the Republic of Moldova is concentrated in the arid zone Frequent droughts once in 2-4 years inflict vital causalities to agriculture of the Republic of Moldova However droughts influence doesn t only limit itself to forming production Drought after-effect is highly ruinous for water reserves industrial enterprises functioning rhythm and human health Droughts make for the drying up and crumbling of soil which is subject to excessive human influence and result in land degradation desertification Term desertification means land degradation in the droughty zones It is necessary to mention that the droughty ecosystems are extremely fragile and sensitive overexploitation Nowadays in the Republic of Moldova 33-37 of agricultural lands is eroded Republic of Moldova joined the United Nations Convention to Combat Desertification on December 24 1998 The Government of the Republic of Moldova ratified the National Action Plan to Combat Desertification in 2000 Within the framework of executing the National Action Plan by National Committee to Combat Desertification Geo-informational System on arid questions was organized In addition a lot of indexes corresponding to international standards were used for the evaluation of drought of the territory and land degradation processes Mostly this information is presented in maps erosion landslides aridity water resources A rich experience of using satellite information for determining land degradation demonstrates high effectiveness of this method Satellite

Mangul, I.; Mangul, S.

199

Satellite Power System (SPS) resource requirements (critical materials, energy and land)  

NASA Technical Reports Server (NTRS)

The resource impacts of the proposed satellite power system are evaluated. Three classes of resource impacts are considered separately: critical materials, energy, and land use. The analysis focuses on the requirements associated with the annual development of two five-gigawatt satellites and the associated receiving facilities.

Kotin, A. D.

1978-01-01

200

Performance of APSK modulation in wireless tactical scenarios for land mobile systems  

Microsoft Academic Search

In this paper we extend the analysis of the performance of the APSK modulation, often limited to the AWGN channel, by considering its application in wireless tactical scenarios for land mobile systems. First, the implica- tions of reduced PAPR on the total degradation are explored, taking into account the non-linear effects due to HPAs and the need to use adaptive

Marco Baldi; Franco Chiaraluce; Antonio de Angelis; Rossano Marchesani; Sebastiano Schillaci

2011-01-01

201

Commercialization of the land remote sensing system: An examination of mechanisms and issues  

NASA Technical Reports Server (NTRS)

In September 1982 the Secretary of Commerce was authorized (by Title II of H.R. 5890 of the 97th Congress) to plan and provide for the management and operation of the civil land remote sensing satellite systems, to provide for user fees, and to plan for the transfer of the ownership and operation of future civil operational land remote sensing satellite systems to the private sector. As part of the planning for transfer, a number of approaches were to be compared including wholly private ownership and operation of the system by an entity competitively selected, mixed government/private ownership and operation, and a legislatively-chartered privately-owned corporation. The results of an analysis and comparison of a limited number of financial and organizational approaches for either transfer of the ownership and operation of the civil operational land remote sensing program to the private sector or government retention are presented.

Cauley, J. K.; Gaelick, C.; Greenberg, J. S.; Logsdon, J.; Monk, T.

1983-01-01

202

Selecting landing sites for lunar lander missions using spatial analysis  

NASA Astrophysics Data System (ADS)

Russian Federal Space Agency (Roscosmos) is planning to launch two spacecrafts to the Moon with lander missions in 2015 and 2017. [1] Here, we present an approach to create a method of landing sites selection. We researched the physical features of the Moon using spatial analysis techniques presented in ArcGIS Desktop Software in accordance with its suitability for automatic landing. Hence we analyzed Russian lunar program and received the technical characteristics of the spacecrafts and scientific goals that they should meet [1]. Thus we identified the criteria of surface suitability for landing. We divided them into two groups: scientific criteria (the hydrogen content of the regolith [2] and day and night sur-face temperature [3]) and safety criteria (surface slopes and roughness, sky view factor, the Earth altitude, presence of polar permanently shadowed regions). In conformity with some investigations it is believed that the south polar region of the Moon is the most promising territory where water ice can be found (finding water ice is the main goal for Russian lunar missions [1]). According to the selected criteria and selected area of research we used remote sensing data from LRO (Lunar Reconnaissance Orbiter) [4] as basic data, because it is the most actual and easily available. The data was processed and analyzed using spatial analysis techniques of ArcGIS Desktop Software, so we created a number of maps depicting the criteria and then combined and overlaid them. As a result of overlay process we received five territories where the landing will be safe and the scientific goals will have being met. It should be noted that our analysis is only the first order assessment and the results cannot be used as actual landing sites for the lunar missions in 2015 and 2017, since a number of factors, which can only be analyzed in a very large scale, was not taken into account. However, an area of researching is narrowed to five territories, what can make the future research much easier. The analysis of these five areas in a large scale will be the subject of further research. References: [1] Mitrofanov I. G. et al. (2011) LPS XLII, Abstract #1798 [2] Mitrofanov I. G., et al. Hydrogen Mapping of the Lunar South Pole Using the LRO Neutron Detector Experiment LEND // Science vol. 330 2010, pp. 483-486 [3] Paige D.A. et al. (2011) LPS XLII, Abstract #2544 [4] Zuber M.T. et al. (2010) Space Sci. Rev., 150, 63-80

Djachkova, Maia; Lazarev, Evgeniy

203

Solar System: Stranded in no-man's-land  

NASA Astrophysics Data System (ADS)

The discovery of a second resident in a region of the Solar System called the inner Oort cloud prompts fresh thinking about this no-man's-land between the giant planets and the reservoir of comets of long orbital period. See Letter p.471

Schwamb, Megan E.

2014-03-01

204

LAND ORIENTED WATER RESOURCES DATA SYSTEM IN NEJERSEY  

Microsoft Academic Search

In choosing New Jersey for developing an environmentally oriented data bank ? system and for evaluating extreme surface flows in smaller areas, there were several ? considerations. It was felt that efficient environmental resources planning needs ? interdisciplinary data gathering concentrated in water interaction on the natural ? environment. To succeed in developing a model for a land-oriented water resources

George J. Halasi-Kun

205

FIELD AND LABORATORY EVALUATION OF PETROLEUM LAND TREATMENT SYSTEM CLOSURE  

EPA Science Inventory

The objectives of the research were to measure and interpret the surface soil changes in relation to the quality of runoff water from petroleum refinery land treatment (LT) systems undergoing simulated closure. Waste/soils from four LT sites were studied for chemical transformati...

206

Low cost airborne microwave landing system receiver, task 3  

NASA Technical Reports Server (NTRS)

Work performed on the low cost airborne Microwave Landing System (MLS) receiver is summarized. A detailed description of the prototype low cost MLS receiver is presented. This detail includes block diagrams, schematics, board assembly drawings, photographs of subassemblies, mechanical construction, parts lists, and microprocessor software. Test procedures are described and results are presented.

Hager, J. B.; Vancleave, J. R.

1979-01-01

207

Orion Landing and Recovery Systems Development - Government Contributions  

NASA Technical Reports Server (NTRS)

This slide presentation reviews NASA's work in development of landing and recovery systems for the Orion space craft. It includes a review of the available tools and skills that assist in analyzing the aerodynamic decelerators. There is a description of the work that is being done on the Government Furnished Equipment (GFE) parachutes that will be used with the Orion Crew Exploration Vehicle (CEV)

Machin, Ricardo A.

2010-01-01

208

Facilities and capabilities catalog for landing and escape systems  

NASA Technical Reports Server (NTRS)

This catalog serves as a single source reference for designers of landing and escape systems for spacecraft, aircraft, weapons, and airdrop system. It includes those facilities which may be required by a system designer in planning a development test program for many applications. The primary objective of this catalog is to provide a means for identifying critical facilities with the U.S. which can be used for the development of landing and escape systems. A secondary objective is to provide a useful tool to the system designer for picking and choosing facilities and capabilities. The six chapters in this volume include wind tunnels, drop zones, test aircraft, fabrication facilities, design tools, and other miscellaneous facilities. A different data sheet format is used for each of the chapters which provides information on performance, location, special capabilities, and a local point of contact. All inputs were solicited from the individual facilities and have not been independently verified for accuracy.

Meyerson, Robert E. (editor)

1992-01-01

209

Lunar Navigation Determination System - LaNDS  

NASA Technical Reports Server (NTRS)

A portable comprehensive navigational system has been developed that both robotic and human explorers can use to determine their location, attitude, and heading anywhere on the lunar surface independent of external infrastructure (needs no Lunar satellite network, line of sight to the Sun or Earth, etc.). The system combines robust processing power with an extensive topographical database to create a real-time atlas (GIS Geospatial Information System) that is able to autonomously control and monitor both single unmanned rovers and fleets of rovers, as well as science payload stations. The system includes provisions for teleoperation and tele-presence. The system accepts (but does not require) inputs from a wide range of sensors. A means was needed to establish a location when the search is taken deep in a crater (looking for water ice) and out of view of Earth or any other references. A star camera can be employed to determine the user's attitude in menial space and stellar map in body space. A local nadir reference (e.g., an accelerometer that orients the nadir vector in body space) can be used in conjunction with a digital ephemeris and gravity model of the Moon to isolate the latitude, longitude, and azimuth of the user on the surface. That information can be used in conjunction with a Lunar GIS and advanced navigation planning algorithms to aid astronauts (or other assets) to navigate on the Lunar surface.

Quinn, David; Talabac, Stephen

2012-01-01

210

Developing a Prototype ALHAT Human System Interface for Landing  

NASA Technical Reports Server (NTRS)

The goal of the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project is to safely execute a precision landing anytime/anywhere on the moon. This means the system must operate in any lighting conditions, operate in the presence of any thruster generated regolith clouds, and operate without the help of redeployed navigational aids or prepared landing site at the landing site. In order to reach this ambitious goal, computer aided technologies such as ALHAT will be needed in order to permit these landings to be done safely. Although there will be advanced autonomous capabilities onboard future landers, humans will still be involved (either onboard as astronauts or remotely from mission control) in any mission to the moon or other planetary body. Because many time critical decisions must be made quickly and effectively during the landing sequence, the Descent and Landing displays need to be designed to be as effective as possible at presenting the pertinent information to the operator, and allow the operators decisions to be implemented as quickly as possible. The ALHAT project has established the Human System Interface (HSI) team to lead in the development of these displays and to study the best way to provide operators enhanced situational awareness during landing activities. These displays are prototypes that were developed based on multiple design and feedback sessions with the astronaut office at NASA/ Johnson Space Center. By working with the astronauts in a series of plan/build/evaluate cycles, the HSI team has obtained astronaut feedback from the very beginning of the design process. In addition to developing prototype displays, the HSI team has also worked to provide realistic lunar terrain (and shading) to simulate a "out the window" view that can be adjusted to various lighting conditions (based on a desired date/time) to allow the same terrain to be viewed under varying lighting terrain. This capability will be critical to determining the effect of terrain/lighting on the human pilot, and how they use windows and displays during landing activities. The Apollo missions were limited to about 28 possible launch days a year due to lighting and orbital constraints. In order to take advantage of more landing opportunities and venture to more challenging landing locations, future landers will need to utilize sensors besides human eyes for scanning the surface. The ALHAT HSI system must effectively convey ALHAT produced information to the operator, so that landings can occur during less "optimal" conditions (lighting, surface terrain, slopes, etc) than was possible during Apollo missions. By proving this capability, ALHAT will simultaneously provide more flexible access to the moon, and greater safety margins for future landers. This paper will specifically focus on the development of prototype displays (the Trajectory Profile Display (TPD), Landing Point Designation (LPD), and Crew Camera View (CCV) ), implementation of realistic planetary terrain, human modeling, and future HSI plans.

Hirsh, Robert L.; Chua, Zarrin K.; Heino, Todd A.; Strahan, Al; Major, Laura; Duda, Kevin

2011-01-01

211

Toward a system for road network automatic extraction in land consolidation using high spatial resolution imagery  

Microsoft Academic Search

Land consolidation is a tool for increasing the area of the arable land and improving the effectiveness of land cultivation. This paper presents a practical system for automatic road extraction in land consolidation to monitor the implementation of the project. The system integrates processing of color image data and information from digital spatial databases, takes into account context information, employs

Rui Guo; Ming Luo; Wei Su; Daoliang Li; Yijun Jiang; Zhengshan Ju; Jun Wang

2008-01-01

212

Enhancing Interdisciplinary Discovery, Learning and Engagement Activities to Achieve Sustainable Land Use Systems in Indiana  

E-print Network

Land Use Systems in Indiana Consolidated Proposal for Funding, 2009-2010 Partnering for Land Use. Introduction The Partnering for Land Use Sustainability (PLUS) Area of Excellence was initiated two years ago to address sustainability of land use systems in Indiana. The overarching research question for PLUS was

213

MOLDOVA LAND TENURE SYSTEM Carlton A Brown  

E-print Network

1990s, the United States Agency for International Development (USAID) instituted a cadastral system constitution on September 29, 1994. According to the constitution, Moldova is a democratic state in which back to 1360 A.D. The peak of this medieval Moldovan state was during the rule of Stefan the Great

Onsrud, Harlan J.

214

43 CFR 3140.7 - Lands within the National Park System.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Lands within the National Park System. 3140.7 Section... § 3140.7 Lands within the National Park System. Conversions of existing...hydrocarbon leases within units of the National Park System shall be...

2013-10-01

215

43 CFR 3140.7 - Lands within the National Park System.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Lands within the National Park System. 3140.7 Section... § 3140.7 Lands within the National Park System. Conversions of existing...hydrocarbon leases within units of the National Park System shall be...

2012-10-01

216

43 CFR 3140.7 - Lands within the National Park System.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Lands within the National Park System. 3140.7 Section... § 3140.7 Lands within the National Park System. Conversions of existing...hydrocarbon leases within units of the National Park System shall be...

2014-10-01

217

43 CFR 3140.7 - Lands within the National Park System.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Lands within the National Park System. 3140.7 Section... § 3140.7 Lands within the National Park System. Conversions of existing...hydrocarbon leases within units of the National Park System shall be...

2011-10-01

218

A robust signalling system for land mobile satellite services  

NASA Technical Reports Server (NTRS)

Presented here is a signalling system optimized to ensure expedient call set-up for satellite telephony services in a land mobile environment. In a land mobile environment, the satellite to mobile link is subject to impairments from multipath and shadowing phenomena, which result in signal amplitude and phase variations. Multipath, caused by signal scattering and reflections, results in sufficient link margin to compensate for these variations. Direct signal attenuation caused by shadowing due to buildings and vegetation may result in attenuation values in excess of 10 dB and commonly up to 20 dB. It is not practical to provide a link with sufficient margin to enable communication when the signal is blocked. When a moving vehicle passes these obstacles, the link will experience rapid changes in signal strength due to shadowing. Using statistical models of attenuation as a function of distance travelled, a communication strategy has been defined for the land mobile environment.

Irish, Dale; Shmith, Gary; Hart, Nick; Wines, Marie

1989-01-01

219

Photogrammetric Measurements of CEV Airbag Landing Attenuation Systems  

NASA Technical Reports Server (NTRS)

High-speed photogrammetric measurements are being used to assess the impact dynamics of the Orion Crew Exploration Vehicle (CEV) for ground landing contingency upon return to earth. Test articles representative of the Orion capsule are dropped at the NASA Langley Landing and Impact Research (LandIR) Facility onto a sand/clay mixture representative of a dry lakebed from elevations as high as 62 feet (18.9 meters). Two different types of test articles have been evaluated: (1) half-scale metal shell models utilized to establish baseline impact dynamics and soil characterization, and (2) geometric full-scale drop models with shock-absorbing airbags which are being evaluated for their ability to cushion the impact of the Orion CEV with the earth s surface. This paper describes the application of the photogrammetric measurement technique and provides drop model trajectory and impact data that indicate the performance of the photogrammetric measurement system.

Barrows, Danny A.; Burner, Alpheus W.; Berry, Felecia C.; Dismond, Harriett R.; Cate, Kenneth H.

2008-01-01

220

Mars Science Laboratory Entry, Descent, and Landing System Overview  

NASA Technical Reports Server (NTRS)

In 2012, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic Entry, Descent, and Landing (EDL) systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than prior missions to Mars, MSL will offer access to regions of Mars that have been previously unreachable. The MSL EDL sequence is a result of a more stringent requirement set than any of its predecessors. Notable among these requirements is landing a 900 kg rover in a landing ellipse much smaller than that of any previous Mars lander. In meeting these requirements, MSL is extending the limits of the EDL technologies qualified by the Mars Viking, Mars Pathfinder, and Mars Exploration Rover missions. Thus, there are many design challenges that must be solved for the mission to be successful. Several pieces of the EDL design are technological firsts, such as guided entry and precision landing on another planet, as well as the entire Sky Crane maneuver. This paper discusses the MSL EDL architecture and discusses some of the challenges faced in delivering an unprecedented rover payload to the surface of Mars.

Steltzner, Adam D.; Burkhart, P. Dan; Chen, Allen; Comeaux, Keith A.; Guernsey, Carl S.; Kipp, Devin M.; Lorenzoni, Leila V.; Mendeck, Gavin F.; Powell, Richard W.; Rivellini, Tommaso P.; San Martin, A. Miguel; Sell, Steven W.; Prakash, Ravi; Way, David W.

2010-01-01

221

Development of a total landed cost and risk analysis model for global strategic sourcing  

E-print Network

Total landed cost and supply chain risk analysis are methods that many companies use to assess strategic sourcing decisions. For this project, landed cost is defined as those costs associated with material movement from a ...

Feller, Brian (Brian C.)

2008-01-01

222

NUMERICAL ANALYSIS OF A FRONT SUPPORT LANDING GEAR DYNAMICS AS THE EXAMPLE OF CHOSEN MCAD AND CAE SYSTEMS INTEGRATION IN THE CASE OF THE MILITARY TRANSPORT AIRCRAFT DESIGN  

Microsoft Academic Search

The paper presents the example of MCAD and CAE environments integration in the case of the military transport aircraft front gear dynamic analysis. The gear exact MCAD model is presented with the manner of its simplification. Simplified model is physically similar to the exact one: results of numerical static analysis are the same in both cases. To ensure the credibility

Tadeusz Niezgoda; Jerzy M; Adam Budz

223

Modeling and Simulation of the Second-Generation Orion Crew Module Air Bag Landing System  

NASA Technical Reports Server (NTRS)

Air bags were evaluated as the landing attenuation system for earth landing of the Orion Crew Module (CM). An important element of the air bag system design process is proper modeling of the proposed configuration to determine if the resulting performance meets requirements. Analysis conducted to date shows that airbags are capable of providing a graceful landing of the CM in nominal and off-nominal conditions such as parachute failure, high horizontal winds, and unfavorable vehicle/ground angle combinations. The efforts presented here surround a second generation of the airbag design developed by ILC Dover, and is based on previous design, analysis, and testing efforts. In order to fully evaluate the second generation air bag design and correlate the dynamic simulations, a series of drop tests were carried out at NASA Langley's Landing and Impact Research (LandIR) facility. The tests consisted of a full-scale set of air bags attached to a full-scale test article representing the Orion Crew Module. The techniques used to collect experimental data, construct the simulations, and make comparisons to experimental data are discussed.

Timmers, Richard B.; Welch, Joseph V.; Hardy, Robin C.

2009-01-01

224

Overview of the Phoenix Entry, Descent and Landing System Architecture  

NASA Technical Reports Server (NTRS)

NASA s Phoenix Mars Lander began its journey to Mars from Cape Canaveral, Florida in August 2007, but its journey to the launch pad began many years earlier in 1997 as NASA s Mars Surveyor Program 2001 Lander. In the intervening years, the entry, descent and landing (EDL) system architecture went through a series of changes, resulting in the system flown to the surface of Mars on May 25th, 2008. Some changes, such as entry velocity and landing site elevation, were the result of differences in mission design. Other changes, including the removal of hypersonic guidance, the reformulation of the parachute deployment algorithm, and the addition of the backshell avoidance maneuver, were driven by constant efforts to augment system robustness. An overview of the Phoenix EDL system architecture is presented along with rationales driving these architectural changes.

Grover, Myron R., III; Cichy, Benjamin D.; Desai, Prasun N.

2008-01-01

225

Load-limiting landing gear footpad energy absorption system  

NASA Technical Reports Server (NTRS)

As a precursor to future manned missions to the moon, an inexpensive, unmanned vehicle that could carry small, scientific payloads to the lunar surface was studied by NASA. The vehicle, called the Common Lunar Lander, required extremely optimized structural systems to increase the potential payload mass. A lightweight energy-absorbing system (LAGFEAS), which also acts as a landing load-limiter was designed to help achieve this optimized structure. Since the versatile and easily tailored system is a load-limiter, it allowed for the structure to be designed independently of the ever-changing landing energy predictions. This paper describes the LAGFEAS system and preliminary verification testing performed at NASA's Johnson Space Center for the Common Lunar Lander program.

Hansen, Chris; Tsai, Ted

1994-01-01

226

The KamLAND Full-Volume Calibration System  

SciTech Connect

We have successfully built and operated a source deployment system for the KamLAND detector. This system was used to position radioactive sources throughout the delicate 1-kton liquid scintillator volume, while meeting stringent material cleanliness, material compatibility, and safety requirements. The calibration data obtained with this device were used to fully characterize detector position and energy reconstruction biases. As a result, the uncertainty in the size of the detector fiducial volume was reduced by a factor of two. Prior to calibration with this system, the fiducial volume was the largest source of systematic uncertainty in measuring the number of antineutrinos detected by KamLAND. This paper describes the design, operation and performance of this unique calibration system.

KamLAND Collaboration; Berger, B. E.; Busenitz, J.; Classen, T.; Decowski, M. P.; Dwyer, D. A.; Elor, G.; Frank, A.; Freedman, S. J.; Fujikawa, B. K.; Galloway, M.; Gray, F.; Heeger, K. M.; Hsu, L.; Ichimura, K.; Kadel, R.; Keefer, G.; Lendvai, C.; McKee, D.; O'Donnell, T.; Piepke, A.; Steiner, H. M.; Syversrud, D.; Wallig, J.; Winslow, L. A.; Ebihara, T.; Enomoto, S.; Furuno, K.; Gando, Y.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Nakajima, K.; Nakajima, K.; Nakamura, K.; Owada, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Tamae, K.; Yoshida, S.; Kozlov, A.; Murayama, H.; Grant, C.; Leonard, D. S.; Luk, K.-B.; Jillings, C.; Mauger, C.; McKeown, R. D.; Zhang, C.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Pakvasa, S.; Foster, J.; Horton-Smith, G. A.; Tang, A.; Dazeley, S.; Downum, K. E.; Gratta, G.; Tolich, K.; Bugg, W.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Piquemal, F.; Ricol, J.-S.

2009-03-05

227

The development and application of a decision support system for land management in the Lake Tahoe Basin—The Land Use Simulation Model  

USGS Publications Warehouse

This report describes and applies the Land Use Simulation Model (LUSM), the final modeling product for the long-term decision support project funded by the Southern Nevada Public Land Management Act and developed by the U.S. Geological Survey’s Western Geographic Science Center for the Lake Tahoe Basin. Within the context of the natural-resource management and anthropogenic issues of the basin and in an effort to advance land-use and land-cover change science, this report addresses the problem of developing the LUSM as a decision support system. It includes consideration of land-use modeling theory, fire modeling and disturbance in the wildland-urban interface, historical land-use change and its relation to active land management, hydrologic modeling and the impact of urbanization as related to the Lahontan Regional Water Quality Control Board’s recently developed Total Maximum Daily Load report for the basin, and biodiversity in urbanizing areas. The LUSM strives to inform land-management decisions in a complex regulatory environment by simulating parcel-based, land-use transitions with a stochastic, spatially constrained, agent-based model. The tool is intended to be useful for multiple purposes, including the multiagency Pathway 2007 regional planning effort, the Tahoe Regional Planning Agency (TRPA) Regional Plan Update, and complementary research endeavors and natural-resource-management efforts. The LUSM is an Internet-based, scenario-generation decision support tool for allocating retired and developed parcels over the next 20 years. Because USGS staff worked closely with TRPA staff and their “Code of Ordinances” and analyzed datasets of historical management and land-use practices, this report accomplishes the task of providing reasonable default values for a baseline scenario that can be used in the LUSM. One result from the baseline scenario for the model suggests that all vacant parcels could be allocated within 12 years. Results also include: assessment of model functionality, brief descriptions of the 7 basic output tables, assessment of the rate of change in land-use allocation pools over time, locations and amounts of the spatially explicit probabilities of land-use transitions by real estate commodity, and analysis of the state change from today’s existing land cover to potential land uses in the future. Assumptions and limitations of the model are presented. This report concludes with suggested next steps to support the continued utility of the LUSM and additional research avenues.

Forney, William M.; Oldham, I. Benson; Crescenti, Neil

2013-01-01

228

Intersects between Land, Energy, Water and the Climate System  

NASA Astrophysics Data System (ADS)

Climate change affects water, and land resources, and with growing human activity, each of these sectors relies increasingly on the others for critical resources. Events such as drought across the South Central U.S. during 2011 demonstrate that climatic impacts within each of these sectors can cascade through interactions between sectors. Energy, water, and land resources are each vulnerable to impacts on either of the other two sectors. For example, energy systems inherently require land and water. Increased electricity demands to contend with climate change can impose additional burdens on overly subscribed water resources. Within this environment, energy systems compete for water with agriculture, human consumption, and other needs. In turn, climate driven changes in landscape attributes and land use affect water quality and availability as well as energy demands. Diminishing water quality and availability impose additional demands for energy to access and purify water, and for land to store and distribute water. In some situations, interactions between water, energy, and land resources make options for reducing greenhouse gas emissions vulnerable to climate change. Energy options such as solar power or biofuel use can reduce net greenhouse gas emissions as well as U.S. dependence on foreign resources. As a result, the U.S. is expanding renewable energy systems. Advanced technology such as carbon dioxide capture with biofuels may offer a means of removing CO2 from the atmosphere. But as with fossil fuels, renewable energy sources can impose significant demands for water and land. For example, solar power mayrequire significant land to site facilities and water for cooling or to produce steam. Raising crops to produce biofuels uses arable land and water that might otherwise be available for food production. Thus, warmer and drier climate can compromise these renewable energy resources, and drought can stress water supplies creating competition between energy production and agriculture. These kinds of stresses often initiate innovated technological developments, such as dry cooling to reduce water demands in the U.S. Southwest for utility-scalesolar development, however, the need for large areas of land remain, and often, large land tracts in this region are under Federal ownership and used as conservation or wildlife refuges. Conflicting stakeholder views, institutional commitments, and international concerns can constrain options for reducing vulnerability to climate change, and interactions among water, energy, and land resource sectors can intensify such constraints. While management decisions may focus primarily on one of these resource sectors, where the three sectors are tightly coupled, options for mitigating or adapting to climate change may be limited more than expected. For example, the Columbia River Treaty between Canada and the U.S. emphasizes hydroelectric power and flood control, but with warmer temperatures and drier summers projected for the Northwest, diminishing water supplies will result in increased pumping for resource production (i.e., deeper groundwater) and transmission. Finally, coordinated water management for agriculture, ecosystem services, and hydropower will be an important aspect of adaptation not necessarily accommodated by the Treaty.

Hibbard, K. A.; Skaggs, R.; Wilson, T.

2012-12-01

229

The Earth System's Missing Energy and Land Warming  

NASA Astrophysics Data System (ADS)

The energy content of the Earth system is determined by the balance or imbalance between the incoming energy from solar radiation and the outgoing energy of terrestrial long wavelength radiation. Change in the Earth system energy budget is the ultimate cause of global climate change. Satellite data show that there is a small yet persistent radiation imbalance at the top-of-atmosphere such that Earth has been steadily accumulating energy, consistent with the theory of greenhouse effect. It is commonly believed [IPCC, 2001; 2007] that up to 94% of the energy trapped by anthropogenic greenhouse gases is absorbed by the upper several hundred meter thick layer of global oceans, with the remaining to accomplish ice melting, atmosphere heating, and land warming, etc. However, the recent measurements from ocean monitoring system indicated that the rate of oceanic heat uptake has not kept pace with the greenhouse heat trapping rate over the past years [Trenberth and Fasullo, Science, 328: 316-317, 2010]. An increasing amount of energy added to the earth system has become unaccounted for, or is missing. A recent study [Loeb et al., Nature Geoscience, 5:110-113, 2012] suggests that the missing energy may be located in the deep ocean down to 1,800 m. Here we show that at least part of the missing energy can be alternatively explained by the land mass warming. We argue that the global continents alone should have a share greater than 10% of the global warming energy. Although the global lands reflect solar energy at a higher rate, they use less energy for evaporation than do the oceans. Taken into accounts the terrestrial/oceanic differences in albedo (34% vs. 28%) and latent heat (27% vs. 58% of net solar radiation at the surface), the radiative energy available per unit surface area for storage or other internal processes is more abundant on land than on ocean. Despite that the lands cover only about 29% of the globe, the portion of global warming energy stored in the lands is much greater than previously thought. The earth system is consisted of well-connected and interdependent atmosphere, hydrosphere, lithosphere, and biosphere. The lack of knowledge about or misrepresentation of the role of the heat capacity of the continental land masses will inevitably affect our ability to understand Earth's climate response to increasing concentrations of greenhouse gases in the atmosphere.

Huang, S.; Wang, H.; Duan, W.

2013-05-01

230

Automated On-board Terrain Analysis for Precision Landings  

NASA Technical Reports Server (NTRS)

Advances in space robotics technology hinge to a large extent upon the development and deployment of sophisticated new vision-based methods for automated in-space mission operations and scientific survey. To this end, we have developed a new concept for automated terrain analysis that is based upon a generic image enhancement platform-multi-scale Retinex (MSR) and visual servo (VS) processing. This pre-conditioning with the MSR and the VS produces a "canonical" visual representation that is largely independent of lighting variations, and exposure errors. Enhanced imagery is then processed with a biologically inspired two-channel edge detection process, followed by a smoothness based criteria for image segmentation. Landing sites can be automatically determined by examining the results of the smoothness-based segmentation which shows those areas in the image that surpass a minimum degree of smoothness. Though the MSR has proven to be a very strong enhancement engine, the other elements of the approach, the VS, terrain map generation, and smoothness-based segmentation, are in early stages of development. Experimental results on data from the Mars Global Surveyor show that the imagery can be processed to automatically obtain smooth landing sites. In this paper, we describe the method used to obtain these landing sites, and also examine the smoothness criteria in terms of the imager and scene characteristics. Several examples of applying this method to simulated and real imagery are shown.

Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.; Hines, Glenn D.

2006-01-01

231

Automated, on-board terrain analysis for precision landings  

NASA Technical Reports Server (NTRS)

Advances in space robotics technology hinge to a large extent upon the development and deployment of sophisticated new vision-based methods for automated in-space mission operations and scientific survey. To this end, we have developed a new concept for automated terrain analysis that is based upon a generic image enhancement platform|multi-scale retinex (MSR) and visual servo (VS) processing. This pre-conditioning with the MSR and the vs produces a "canonical" visual representation that is largely independent of lighting variations, and exposure errors. Enhanced imagery is then processed with a biologically inspired two-channel edge detection process, followed by a smoothness based criteria for image segmentation. Landing sites can be automatically determined by examining the results of the smoothness-based segmentation which shows those areas in the image that surpass a minimum degree of smoothness. Though the msr has proven to be a very strong enhancement engine, the other elements of the approach|the vs, terrain map generation, and smoothness-based segmentation|are in early stages of development. Experimental results on data from the Mars Global Surveyor show that the imagery can be processed to automatically obtain smooth landing sites. In this paper, we describe the method used to obtain these landing sites, and also examine the smoothness criteria in terms of the imager and scene characteristics. Several examples of applying this method to simulated and real imagery are shown.

Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.; Hines, Glenn D.

2006-01-01

232

VITS-A Vision System for Autonomous Land Vehicle Navigation  

Microsoft Academic Search

A description is given of VITS (for vision task sequencer), the vision system for the autonomous land vehicle (ALV) Alvin, addressing in particular the task of road-following. The ALV vision system builds symbolic descriptions of road and obstacle boundaries using both video and range sensors. The authors discuss various road segmentation methods for video-based road-following, along with approaches to boundary

MATTHEW A. TURK; David G. Morgenthaler; Keith D. Gremban; Martin Marra

1988-01-01

233

Assessing the Potential for Renewable Energy on National Forest System Lands  

SciTech Connect

This technical report and CD for the U.S. Department of Agriculture, Forest Service (USFS), evaluates the potential for renewable energy resource development on National Forest System (NFS) lands. USFS can use the report findings to consider potential for development of solar and wind energy resources on NFS lands, in land management decisions. The Geographical Information System (GIS) based analysis resulted in the following findings: (1) Ninety-nine National Forest Units have high potential for power production from one or more of these solar and wind energy sources; and (2) Twenty National Forest Units in nine states have high potential for power production from two or more of these solar and wind energy sources.

Not Available

2005-01-01

234

Land resource database based on multiple satellites sensors and geographical information systems  

NASA Astrophysics Data System (ADS)

Remote Sensing (RS) enables land cover investigation and earth surface environmental investigation from the global scale to several kilometer regional scale by multispectrum analysis of physical information on the basis of observation performance such as wavelengths and spatial resolution of observation. On the other hand, it is possible to graphically and statistically analyze using Geographical Information Systems (GIS) about the information that cannot be extracted from remote sensing, or the information of conventional socio-statistics. In addition, Computer Aided Design (CAD) for structure design enables automatic design processing. This study attempted construction of land resource database by means of integration of the above three systems that have different characteristics. The database provides a foundation for studying global light distribution, assessing land cover change resulting from human activities and planning infrastructure construction.

Suga, Y.; Tsuru, M.; Tanaka, S.; Nakayama, Y.

1994-03-01

235

Land Use Adaptation Strategies Analysis in Landslide Risk Region  

NASA Astrophysics Data System (ADS)

In order to respond to the impact of climate and environmental change on Taiwanese mountain region, this study used GTZ (2004) Risk analysis guidelines to assess the landslide risk for 178 Taiwanese mountain towns. This study used 7 indicators to assess landslide risk, which are rainfall distribution, natural environment vulnerability (e.g., rainfall threshold criterion for debris flow, historical disaster frequency, landslide ratio, and road density), physicality vulnerability (e.g., population density) and socio-economic vulnerability (e.g., population with higher education, death rate and income). The landslide risk map can be obtained by multiplying 7 indicators together and ranking the product. The map had 5 risk ranges, and towns within the range of 4 to 5, which are high landslide risk regions, and have high priority in reducing risk. This study collected the regions with high landslide risk regions and analyzed the difference after Typhoon Morakot (2009). The spatial distribution showed that after significant environmental damage high landslide risk regions moved from central to south Taiwan. The changeable pattern of risk regions pointed out the necessity of updating the risk map periodically. Based on the landslide risk map and the land use investigation data which was provided by the National Land Surveying and Mapping Center in 2007, this study calculated the size of the land use area with landslide disaster risk. According to the above results and discussion, this study can be used to suggest appropriate land use adaptation strategies provided for reducing landslide risk under the impact of climate and environmental change.

Lin, Yu-Ching; Chang, Chin-Hsin; Chen, Ying-Tung

2013-04-01

236

Land-mobile satellite communication system  

NASA Technical Reports Server (NTRS)

A satellite communications system includes an orbiting communications satellite for relaying communications to and from a plurality of ground stations, and a network management center for making connections via the satellite between the ground stations in response to connection requests received via the satellite from the ground stations, the network management center being configured to provide both open-end service and closed-end service. The network management center of one embodiment is configured to provides both types of service according to a predefined channel access protocol that enables the ground stations to request the type of service desired. The channel access protocol may be configured to adaptively allocate channels to open-end service and closed-end service according to changes in the traffic pattern and include a free-access tree algorithm that coordinates collision resolution among the ground stations.

Yan, Tsun-Yee (Inventor); Rafferty, William (Inventor); Dessouky, Khaled I. (Inventor); Wang, Charles C. (Inventor); Cheng, Unjeng (Inventor)

1993-01-01

237

Development of the Arab Land Data Assimilation System (ALDAS)  

NASA Astrophysics Data System (ADS)

The Arab region of the Middle East and Northern Africa (MENA) suffers from arid conditions, dense population, and inefficient use of fresh water resources. These factors have nearly exhausted the existing water resources in the region and have led to a re-evaluation of water management plans and budgeting schemes between nations. In order to utilize the existing resources more efficiently, it is necessary that all nations within the MENA have access to optimal estimates of hydrological states and fluxes relevant to water resources. However, the region is poorly monitored due to trans-boundary issues and sparse in situ networks. This presentation will introduce a methodology and implementation strategy envisaged to achieve these goals through the development of a Land Data Assimilation System designed specifically for the Arab region (ALDAS). The ALDAS optimally merges available in situ data with satellite-based estimates of meteorological variables including data from the Gravity Recovery and Climate Experiment (GRACE), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Tropical Rainfall Measuring Mission (TRMM) within a land surface modeling framework. As a result of this effort, a platform for data sharing among MENA nations is being prepared to provide timely regional estimates of hydrological states and fluxes at 1/8th degree resolution. To be discussed will be development and status of the land data assimilation system, and preliminary results from land surface model simulations over the region.

Bolten, J. D.; Rodell, M.; Zaitchik, B. F.; Toll, D. L.; Engman, E.; Habib, S.; Ozdogan, M.

2009-12-01

238

Multipath effect suppression for instrument landing system based on MUSIC  

NASA Astrophysics Data System (ADS)

The Decimeter-wavelength Instrument Landing System is designed to assure an exact and timely flight arrival on many airports. But its signal can often be distorted by reflections and scattering caused by objects which are illuminated by the radiating antennas, sometimes referred to be "multipath", which pose a great threat to the system's operation. In this paper, an improved receiver based on spatial spectrum estimation concepts is proposed for safer automatic landing procedures. The new approach is based on Direction of Arrival (DOA) estimation performed by the MUSIC algorithm and signal filter performed by beamforming algorithm. The superior performance of the proposed system with respect to currently employed techniques in the presence of unwanted interferences has been tested in extensive computer simulations.

Zhao, Xiubin; Wang, Yongsheng; Jiang, Hengle; Dai, Chuanjin

2005-11-01

239

Study of USGS/NASA land use classification system. [compatibility of land use classification system with computer processing techniques employed for land use mapping from ERTS data  

NASA Technical Reports Server (NTRS)

It is known from several previous investigations that many categories of land-use can be mapped via computer processing of Earth Resources Technology Satellite data. The results are presented of one such experiment using the USGS/NASA land-use classification system. Douglas County, Georgia, was chosen as the test site for this project. It was chosen primarily because of its recent rapid growth and future growth potential. Results of the investigation indicate an overall land-use mapping accuracy of 67% with higher accuracies in rural areas and lower accuracies in urban areas. It is estimated, however, that 95% of the State of Georgia could be mapped by these techniques with an accuracy of 80% to 90%.

Spann, G. W.; Faust, N. L.

1974-01-01

240

Vision-Aided Inertial Navigation for Precise Planetary Landing: Analysis and Experiments  

Microsoft Academic Search

In this paper, we present the analysis and experi- mental validation of a vision-aided inertial navigation algorithm for planetary landing applications. The system employs tight integration of inertial and visual feature measurements to com- pute accurate estimates of the lander's terrain-relative position, attitude, and velocity in real time. Two types of features are considered: mapped landmarks, i.e., features whose global

Anastasios I. Mourikis; Nikolas Trawny; Stergios I. Roumeliotis; Andrew Johnson; Larry Matthies

2007-01-01

241

Theoretical analysis of the global land carbon cycle: what determines the trajectory of future carbon uptake?  

NASA Astrophysics Data System (ADS)

The global land surface has taken up about 29% of anthropogenic CO2 emissions since preindustrial times. Yet it remains uncertain whether this significant buffer to the effects of anthropogenic climate change will continue in future. Some models predict that the global land biosphere will remain a carbon sink by the end of this century, but others predict it to become a major source. It is therefore important to understand what causes this divergence in predictions. In this presentation, we combined numerical and mathematical analysis to reveal general behaviour of global land models. Our analysis is based on the recognition that the terrestrial carbon cycle generally can be mathematically expressed by a system of first-order linear ordinary differential equations subject to an initial condition as follows: dC/dt = x(t)AC+BU(t) with C(t=0)=C0 where C(t) is the C pool size, A is the C transfer matrix, U is the photosynthetic input, B is a vector of partitioning coefficients, C0 is the initial value of the C pool, and x is an environmental scalar. In this equation, the linear carbon transfer among pools within one ecosystem is represented by matrix A and vector B, and the nonlinearity of environmental influences is represented by environmental scalar x(t) on carbon transfer and U(t) for carbon influx. We investigate how important variation in parameters controlling terrestrial carbon cycling are for three key predictions of the dynamics of future land carbon: the maximum carbon uptake, Fmax, the number of years it takes to reach Fmax, tmax, and the year in which the land biosphere changes from a carbon sink to a source, t1 (if it happens). The parameters included the sensitivity of net primary production to atmospheric [CO2], ?, the temperature sensitivity of soil carbon decomposition, Q10, and the sensitivity of global mean land surface to atmospheric [CO2],?. Our theoretical analyses reveal that a theoretical maximal amount carbon accumulated by land biosphere can be estimated from Fmax and the residence times of the different carbon pools, and that an estimate on the time it takes for the system to approach its new equilibrium can be obtained from the residence time of the slowest pool. Our numerical analyses reveal that a 3-D parameter space can bound the range of land carbon uptake trajectories from 1850 to 2100 predicted by all Earth System Models for the 5th assessment report of the IPCC. The maximal amount of carbon accumulated, tmax and t1 increases with ? and decreases with Q10 and ?. The sensitivities of all three model predictions to ? and Q10 increase with ? .

Wang, Y.; Smith, M. J.; Luo, Y.; Leite, M.; Agusto, F.; Chen, B.; Hoffman, F. M.; Medlyn, B. E.; Rasmussen, M.

2013-12-01

242

Assessing land-use impacts on biodiversity using an expert systems tool  

USGS Publications Warehouse

Habitat alteration, in the form of land-use development, is a leading cause of biodiversity loss in the U.S. and elsewhere. Although statutes in the U.S. may require consideration of biodiversity in local land-use planning and regulation, local governments lack the data, resources, and expertise to routinely consider biotic impacts that result from permitted land uses. We hypothesized that decision support systems could aid solution of this problem. We developed a pilot biodiversity expert systems tool (BEST) to test that hypothesis and learn what additional scientific and technological advancements are required for broad implementation of such a system. BEST uses data from the U.S. Geological Survey's Gap Analysis Program (GAP) and other data in a desktop GIS environment. The system provides predictions of conflict between proposed land uses and biotic elements and is intended for use at the start of the development review process. Key challenges were the development of categorization systems that relate named land-use types to ecological impacts, and relate sensitivities of biota to ecological impact levels. Although the advent of GAP and sophisticated desktop GIS make such a system feasible for broad implementation, considerable ongoing research is required to make the results of such a system scientifically sound, informative, and reliable for the regulatory process. We define a role for local government involvement in biodiversity impact assessment, the need for a biodiversity decision support system, the development of a prototype system, and scientific needs for broad implementation of a robust and reliable system.

Crist, P.J.; Kohley, T.W.; Oakleaf, J.

2000-01-01

243

Implementation of pin point landing vision components in an FPGA system  

Microsoft Academic Search

Pin-point landing is required to enable missions to land close, typically within 10 meters, to scientifically important targets in generally hazardous terrain. In Pin Point Landing both high accuracy and high speed estimation of position and orientation is needed to provide input to the control system to safely choose and navigate to a safe landing site. A proposed algorithm called

Arin Morfopolous; Brandon Metz; Carlos Villalpando; Larry Matthies; Navid Serrano

2011-01-01

244

LAND REFORM IN NAMIBIA: AN ANALYSIS OF MEDIA COVERAGE  

E-print Network

were found on the Namibian media’s portrayal of land reform. In the years proximate to Namibia’s independence, some studies considered various options for land reform, however, interest quickly waned. During the ‘fast track’ land reform in Zimbabwe... immediately after Zimbabwe’s ‘fast track’ program, because it renewed the debate about land reform in Namibia. I analyzed the three daily newspapers’ coverage of land reform from early 2003, the earliest year that the available archives permit, until the end...

Engelbrecht, Petrus J.

2014-08-31

245

Land  

NSDL National Science Digital Library

The solid Earth is the foundation upon which the entire system rests, and provides the critical substrate and reservoir of raw materials the rest of the system. The solid Earth also records the past in the ...

246

Modeling and Simulation of the Second-Generation Orion Crew Module Air Bag Landing System  

NASA Technical Reports Server (NTRS)

Air bags were evaluated as the landing attenuation system for earth landing of the Orion Crew Module (CM). Analysis conducted to date shows that airbags are capable of providing a graceful landing of the CM in nominal and off-nominal conditions such as parachute failure, high horizontal winds, and unfavorable vehicle/ground angle combinations, while meeting crew and vehicle safety requirements. The analyses and associated testing presented here surround a second generation of the airbag design developed by ILC Dover, building off of relevant first-generation design, analysis, and testing efforts. In order to fully evaluate the second generation air bag design and correlate the dynamic simulations, a series of drop tests were carried out at NASA Langley s Landing and Impact Research (LandIR) facility in Hampton, Virginia. The tests consisted of a full-scale set of air bags attached to a full-scale test article representing the Orion Crew Module. The techniques used to collect experimental data, develop the simulations, and make comparisons to experimental data are discussed.

Timmers, Richard B.; Hardy, Robin C.; Willey, Cliff E.; Welch, Joseph V.

2009-01-01

247

78 FR 9883 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Implementation of the National Forest System Land Management Planning Rule AGENCY: Forest Service, USDA. ACTION: Notice...Implementation of the National Forest System Land Management Planning Rule will meet in Albuquerque, NM. The...

2013-02-12

248

77 FR 50985 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Implementation of the National Forest System Land Management Planning Rule AGENCY: Forest Service, USDA. ACTION: Notice...Implementation of the National Forest System Land Management Planning Rule will meet in Washington, DC. The...

2012-08-23

249

29 CFR 1915.507 - Land-side fire protection systems.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Land-side fire protection systems. 1915.507 Section...HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Fire Protection in Shipyard Employment § 1915.507 Land-side fire protection systems. (a) Employer...

2011-07-01

250

29 CFR 1915.507 - Land-side fire protection systems.  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Land-side fire protection systems. 1915.507 Section...HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Fire Protection in Shipyard Employment § 1915.507 Land-side fire protection systems. (a) Employer...

2014-07-01

251

29 CFR 1915.507 - Land-side fire protection systems.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Land-side fire protection systems. 1915.507 Section...HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Fire Protection in Shipyard Employment § 1915.507 Land-side fire protection systems. (a) Employer...

2012-07-01

252

29 CFR 1915.507 - Land-side fire protection systems.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Land-side fire protection systems. 1915.507 Section...HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Fire Protection in Shipyard Employment § 1915.507 Land-side fire protection systems. (a) Employer...

2010-07-01

253

29 CFR 1915.507 - Land-side fire protection systems.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Land-side fire protection systems. 1915.507 Section...HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Fire Protection in Shipyard Employment § 1915.507 Land-side fire protection systems. (a) Employer...

2013-07-01

254

75 FR 52713 - Nationwide Aerial Application of Fire Retardant on National Forest System Lands  

Federal Register 2010, 2011, 2012, 2013, 2014

...Service Nationwide Aerial Application of Fire Retardant on National Forest System Lands...continued nationwide aerial application of fire retardant on National Forest System lands...The Forest Service is working to restore fire-adapted ecosystems through...

2010-08-27

255

A Global Land System Framework for Integrated Climate-Change Assessments  

E-print Network

Land ecosystems play a major role in the global cycles of energy, water, carbon and nutrients. A Global Land System (GLS) framework has been developed for the Integrated Global Systems Model Version 2 (IGSM2) to simulate ...

Schlosser, C. Adam

256

Pervasive transition of the Brazilian land-use system  

NASA Astrophysics Data System (ADS)

Agriculture, deforestation, greenhouse gas emissions and local/regional climate change have been closely intertwined in Brazil. Recent studies show that this relationship has been changing since the mid 2000s, with the burgeoning intensification and commoditization of Brazilian agriculture. On one hand, this accrues considerable environmental dividends including a pronounced reduction in deforestation (which is becoming decoupled from agricultural production), resulting in a decrease of ~40% in nationwide greenhouse gas emissions since 2005, and a potential cooling of the climate at the local scale. On the other hand, these changes in the land-use system further reinforce the long-established inequality in land ownership, contributing to rural-urban migration that ultimately fuels haphazard expansion of urban areas. We argue that strong enforcement of sector-oriented policies and solving long-standing land tenure problems, rather than simply waiting for market self-regulation, are key steps to buffer the detrimental effects of agricultural intensification at the forefront of a sustainable pathway for land use in Brazil.

Lapola, David M.; Martinelli, Luiz A.; Peres, Carlos A.; Ometto, Jean P. H. B.; Ferreira, Manuel E.; Nobre, Carlos A.; Aguiar, Ana Paula D.; Bustamante, Mercedes M. C.; Cardoso, Manoel F.; Costa, Marcos H.; Joly, Carlos A.; Leite, Christiane C.; Moutinho, Paulo; Sampaio, Gilvan; Strassburg, Bernardo B. N.; Vieira, Ima C. G.

2014-01-01

257

LAnd surface remote sensing Products VAlidation System (LAPVAS) and its preliminary application  

NASA Astrophysics Data System (ADS)

The long term record of remote sensing product shows the land surface parameters with spatial and temporal change to support regional and global scientific research widely. Remote sensing product with different sensors and different algorithms is necessary to be validated to ensure the high quality remote sensing product. Investigation about the remote sensing product validation shows that it is a complex processing both the quality of in-situ data requirement and method of precision assessment. A comprehensive validation should be needed with long time series and multiple land surface types. So a system named as land surface remote sensing product is designed in this paper to assess the uncertainty information of the remote sensing products based on a amount of in situ data and the validation techniques. The designed validation system platform consists of three parts: Validation databases Precision analysis subsystem, Inter-external interface of system. These three parts are built by some essential service modules, such as Data-Read service modules, Data-Insert service modules, Data-Associated service modules, Precision-Analysis service modules, Scale-Change service modules and so on. To run the validation system platform, users could order these service modules and choreograph them by the user interactive and then compete the validation tasks of remote sensing products (such as LAI ,ALBEDO ,VI etc.) . Taking SOA-based architecture as the framework of this system. The benefit of this architecture is the good service modules which could be independent of any development environment by standards such as the Web-Service Description Language(WSDL). The standard language: C++ and java will used as the primary programming language to create service modules. One of the key land surface parameter, albedo, is selected as an example of the system application. It is illustrated that the LAPVAS has a good performance to implement the land surface remote sensing product validation.

Lin, Xingwen; Wen, Jianguang; Tang, Yong; Ma, Mingguo; Dou, Baocheng; Wu, Xiaodan; Meng, Lumin

2014-11-01

258

Models for estimating runway landing capacity with Microwave Landing System (MLS)  

NASA Technical Reports Server (NTRS)

A model is developed which is capable of computing the ultimate landing runway capacity, under ILS and MLS conditions, when aircraft population characteristics and air traffic control separation rules are given. This model can be applied in situations when only a horizontal separation between aircraft approaching a runway is allowed, as well as when both vertical and horizontal separations are possible. It is assumed that the system is free of errors, that is that aircraft arrive at specified points along the prescribed flight path precisely when the controllers intend for them to arrive at these points. Although in the real world there is no such thing as an error-free system, the assumption is adequate for a qualitative comparison of MLS with ILS. Results suggest that an increase in runway landing capacity, caused by introducing the MLS multiple approach paths, is to be expected only when an aircraft population consists of aircraft with significantly differing approach speeds and particularly in situations when vertical separation can be applied. Vertical separation can only be applied if one of the types of aircraft in the mix has a very steep descent angle.

Tosic, V.; Horonjeff, R.

1975-01-01

259

An investigation of an active landing gear system to reduce aircraft vibrations caused by landing impacts and runway excitations  

Microsoft Academic Search

A mathematical model is developed to control aircraft vibrations caused by runway excitation using an active landing gear system. Equations are derived to describe the integrated aircraft-active system. The nonlinear characteristics of the system are modelled and it is actively controlled using a Proportional Integral Derivative (PID) strategy. The performance of this system and its corresponding passive system are compared

Haitao Wang; J. T. Xing; W. G. Price; Weiji Li

2008-01-01

260

Improved Modeling of Land-Atmosphere Interactions using a Coupled Version of WRF with the Land Information System  

NASA Technical Reports Server (NTRS)

The exchange of energy and moisture between the Earth's surface and the atmospheric boundary layer plays a critical role in many hydrometeorological processes. Accurate and high-resolution representations of surface properties such as sea-surface temperature (SST), vegetation, soil temperature and moisture content, and ground fluxes are necessary to better understand the Earth-atmosphere interactions and improve numerical predictions of weather and climate phenomena. The NASA/NWS Short-term Prediction Research and Transition (SPORT) Center is currently investigating the potential benefits of assimilating high-resolution datasets derived from the NASA moderate resolution imaging spectroradiometer (MODIS) instruments using the Weather Research and Forecasting (WRF) model and the Goddard Space Flight Center Land Information System (LIS). The LIS is a software framework that integrates satellite and ground-based observational and modeled data along with multiple land surface models (LSMs) and advanced computing tools to accurately characterize land surface states and fluxes. The LIS can be run uncoupled to provide a high-resolution land surface initial condition, and can also be run in a coupled mode with WRF to integrate surface and soil quantities using any of the LSMs available in LIS. The LIS also includes the ability to optimize the initialization of surface and soil variables by tuning the spin-up time period and atmospheric forcing parameters, which cannot be done in the standard WRF. Among the datasets available from MODIS, a leaf-area index field and composite SST analysis are used to improve the lower boundary and initial conditions to the LIS/WRF coupled model over both land and water. Experiments will be conducted to measure the potential benefits from using the coupled LIS/WRF model over the Florida peninsula during May 2004. This month experienced relatively benign weather conditions, which will allow the experiments to focus on the local and mesoscale impacts of the high-resolution MODIS datasets and optimized soil and surface initial conditions. Follow-on experiments will examine the utility of such an optimized WRF configuration for more complex weather scenarios such as convective initiation. This paper will provide an overview of the experiment design and present preliminary results from selected cases in May 2004.

Case, Jonathan L.; LaCasse, Katherine M.; Santanello, Joseph A., Jr.; Lapenta, William M.; Petars-Lidard, Christa D.

2007-01-01

261

A satellite system for land-mobile communications in Europe  

NASA Technical Reports Server (NTRS)

There exists a great unsatisified demand for land mobile communications in Europe, particularly in sectors of business activity such as the road transport industry. This demand could best be satisfied by means of satellite-based private networks providing voice and data communications in a hub configuration. The potential market is estimated to encompass several hundred thousand road vehicles and the transmission capacity required would be several thousand channels. ESA is currently demonstrating the potential of satellite communications for this type of application, using a system called PRODAT. System studies are being performed with the aim of defining the architecture of a regional satellite system for Europe.

Bartholome, P.; Rogard, R.

1988-01-01

262

Alternative options of land consolidation in the mountains of Nepal: An analysis based on stakeholders’ opinions  

Microsoft Academic Search

In view of the adverse impact of land fragmentation on the mountain agriculture development in Nepal, this study begins with the intergenerational land fragmentation trend analysis and its causes. This is followed by an evaluation of alternative options of land consolidation from the perspectives of stakeholders surveyed. Required information was collected from the farmers, local elites, parliamentarians, top-level bureaucrats, and

Gopal B. Thapa; Gajendra S. Niroula

2008-01-01

263

Shortle and Jeddi 1 Probabilistic Analysis of Wake Vortex Hazards for Landing Aircraft Using Multilateration  

E-print Network

Shortle and Jeddi 1 Probabilistic Analysis of Wake Vortex Hazards for Landing Aircraft Using revised from original submittal. #12;Shortle and Jeddi 2 ABSTRACT Wake vortices are a safety hazard to landing aircraft. A landing aircraft that encounters a wake may roll, resulting in a fatal crash

264

43 CFR 2650.4-6 - National wildlife refuge system lands.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false National wildlife refuge system lands. 2650.4-6...Generally § 2650.4-6 National wildlife refuge system lands. (a) Every...which includes lands within the national wildlife refuge system shall, as to...

2013-10-01

265

43 CFR 2650.4-6 - National wildlife refuge system lands.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false National wildlife refuge system lands. 2650.4-6...Generally § 2650.4-6 National wildlife refuge system lands. (a) Every...which includes lands within the national wildlife refuge system shall, as to...

2014-10-01

266

43 CFR 2650.4-6 - National wildlife refuge system lands.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false National wildlife refuge system lands. 2650.4-6...Generally § 2650.4-6 National wildlife refuge system lands. (a) Every...which includes lands within the national wildlife refuge system shall, as to...

2012-10-01

267

43 CFR 2650.4-6 - National wildlife refuge system lands.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false National wildlife refuge system lands. 2650.4-6...Generally § 2650.4-6 National wildlife refuge system lands. (a) Every...which includes lands within the national wildlife refuge system shall, as to...

2011-10-01

268

Interior Secretary Formally Designates BLM Lands the National System of Public Lands  

Microsoft Academic Search

He also said that the designation will emphasize the interconnectedness and interdependence of the public lands and all who benefit from them; better convey the diversity of interests and values associated with the public lands and how these are served through balanced, comprehensive, management; and increase the critical importance of enlightened citizen stewardship to the preservation of these lands and

Frank Quimby

2009-01-01

269

EVALUATION OF A LANDING GEAR SEMIACTIVE CONTROL SYSTEM FOR COMPLETE AIRCRAFT LANDING  

Microsoft Academic Search

This paper deals with the simulation of landing gear semi-active control for a small trainer aircraft in a multibody framework. The behavior of single passive landing gear drop test simulation models and of a complete aircraft landing simulation model, developed and implemented in the commercial multibody code ADAMS in previous works, is compared to the that of analogous models equipped

Gian Luca Ghiringhelli; Stefania Gualdi

2004-01-01

270

The State, Land System, and Land Development Processes in Contemporary China  

Microsoft Academic Search

In the era of state socialism under Mao, land in China was treated as a means of production and was allocated administratively by the state free of charge. To accommodate the interests of foreign investors without violating the socialist principle of public ownership, the Chinese state has, since the 1980s, separated land use rights from land ownership and opened up

George C. S. Lin; Samuel P. S. Ho

2005-01-01

271

Land-use planning of Volyn region (Ukraine) using Geographic Information Systems (GIS) technologies  

NASA Astrophysics Data System (ADS)

Land-use development planning is carried out in order to create a favourable environment for human life, sustainable socioeconomic and spatial development. Landscape planning is an important part of land-use development that aims to meet the fundamental principles of sustainable development. Geographic Information Systems (GIS) is a fundamental tool to make a better landscape planning at different territorial levels, providing data and maps to support decision making. The objective of this work is to create spatio-temporal, territorial and ecological model of development of Volyn region (Ukraine). It is based on existing spatial raster and vector data and includes the analysis of territory dynamics as the aspects responsible for it. A spatial analyst tool was used to zone the areas according to their environmental components and economic activity. This analysis is fundamental to define the basic parameters of sustainability of Volyn region. To carry out this analysis, we determined the demographic capacity of districts and the analysis of spatial parameters of land use. On the basis of the existing natural resources, we observed that there is a need of landscape protection and integration of more are natural areas in the Pan-European Ecological Network. Using GIS technologies to landscape planning in Volyn region, allowed us to identify, natural areas of interest, contribute to a better resource management and conflict resolution. Geographic Information Systems will help to formulate and implement landscape policies, reform the existing administrative system of Volyn region and contribute to a better sustainable development.

Strielko, Irina; Pereira, Paulo

2014-05-01

272

Unmanned Aircraft Systems for Monitoring Department of the Interior Lands  

NASA Astrophysics Data System (ADS)

Unmanned Aircraft Systems (UAS) technology is quickly evolving and will have a significant impact on Earth science research. The U.S. Geological Survey (USGS) is conducting an operational test and evaluation of UAS to see how this technology supports the mission of the Department of the Interior (DOI). Over the last 4 years, the USGS, working with many partners, has been actively conducting proof of concept UAS operations, which are designed to evaluate the potential of UAS technology to support the mandated DOI scientific, resource and land management missions. UAS technology is being made available to monitor environmental conditions, analyze the impacts of climate change, respond to natural hazards, understand landscape change rates and consequences, conduct wildlife inventories and support related land management and law enforcement missions. Using small UAS (sUAS), the USGS is able to tailor solutions to meet project requirements by obtaining very high resolution video data, acquiring thermal imagery, detecting chemical plumes, and generating digital terrain models at a fraction of the cost of conventional surveying methods. UAS technology is providing a mechanism to collect timely remote sensing data at a low cost and at low risk over DOI lands that can be difficult to monitor and consequently enhances our ability to provide unbiased scientific information to better enable decision makers to make informed decisions. This presentation describes the UAS technology and infrastructure being employed, the application projects already accomplished, lessons learned and future of UAS within the DOI. We fully expect that by 2020 UAS will emerge as a primary platform for all DOI remote sensing applications. Much like the use of Internet technology, Geographic Information Systems (GIS) and Global Positioning Systems (GPS), UAS have the potential of enabling the DOI to be better stewards of the land.

Hutt, M. E.; Quirk, B.

2013-12-01

273

Analysis of continuous GPS measurements from southern Victoria Land, Antarctica  

USGS Publications Warehouse

Several years of continuous data have been collected at remote bedrock Global Positioning System (GPS) sites in southern Victoria Land, Antarctica. Annual to sub-annual variations are observed in the position time-series. An atmospheric pressure loading (APL) effect is calculated from pressure field anomalies supplied by the European Centre for Medium-Range Weather Forecasts (ECMWF) model loading an elastic Earth model. The predicted APL signal has a moderate correlation with the vertical position time-series at McMurdo, Ross Island (International Global Navigation Satellite System Service (IGS) station MCM4), produced using a global solution. In contrast, a local solution in which MCM4 is the fiducial site generates a vertical time series for a remote site in Victoria Land (Cape Roberts, ROB4) which exhibits a low, inverse correlation with the predicted atmospheric pressure loading signal. If, in the future, known and well modeled geophysical loads can be separated from the time-series, then local hydrological loading, of interest for glaciological and climate applications, can potentially be extracted from the GPS time-series.

Willis, Michael J.

2007-01-01

274

Landing impact studies of a 0.3-scale model air cushion landing system for a Navy fighter airplane  

NASA Technical Reports Server (NTRS)

An experimental study was conducted in order to determine the landing-impact behavior of a 0.3-scale, dynamically (but not physically) similar model of a high-density Navy fighter equipped with an air cushion landing system. The model was tested over a range of landing contact attitudes at high forward speeds and sink rates on a specialized test fixture at the Langley aircraft landing loads and traction facility. The investigation indicated that vertical acceleration at landing impact was highly dependent on the pitch angle at ground contact, the higher acceleration of approximately 5g occurring near zero body-pitch attitude. A limited number of low-speed taxi tests were made in order to determine model stability characteristics. The model was found to have good pitch-damping characteristics but stability in roll was marginal.

Leland, T. J. W.; Thompson, W. C.

1975-01-01

275

Human Planetary Landing System (HPLS) Capability Roadmap: Wrap Up  

NASA Technical Reports Server (NTRS)

When and how does the full scale system and subsystems need to be qualified & Human-rated for flight? Answer: No later than 29. Full scale AEDL Flight Tests can and should be done at Earth (need to get fast turn around between multiple tests). Do we need a Full Scale Validation Flight Test at Mars? Answer: Not, specifically, but the AEDL community is very uncomfortable with the notion of the very first full scale AEDL being piloted. The full scale unpiloted AEDL advance cargo mission that immediately precedes the human landing could do the trick. What kind of precursor AEDL Flight Tests are needed at Mars? Answer: We need to validate our performance & aerodynamic models by flying a scaled (1/10th?) version of the Full Scale Mission by 22. When and how do we decide on the AEDL system to fly? Answer: No later than 2015 (earlier is harder). We need to do multi-path full scale flight simulations and subscale / component development testing starting ASAP. If we find an AEDL for a landing mass of 40 MT, will this same architecture and technology paradigm extend to landing 80 MT? 120 MT? Is there another break point? Answer: We do not know yet.

Manning, Rob

2005-01-01

276

Precipitation, Recycling, and Land Memory: An Integrated Analysis  

E-print Network

A synthesis of several approaches to quantifying land–atmosphere interactions is presented. These approaches use data from observations or atmospheric reanalyses applied to atmospheric tracer models and stand-alone land ...

Dirmeyer, Paul A.

277

Validation and Verification of the Operational Land Analysis Activities at the Air Force Weather Agency  

NASA Astrophysics Data System (ADS)

The importance of operational benchmarking and uncertainty characterization of land surface modeling can be clear upon considering the wide range of performance characteristics of numerical land surface models realizable through various combinations of factors. Such factors might include model physics and numerics, resolution, and forcing datasets used in operational implementation versus those that might have been involved in any prior development benchmarking. Of course, decisions concerning operational implementation may be better informed through more effective benchmarking of performance under various blends of such aforementioned operational factors. To facilitate this and other needs for land analysis activities at the Air Force Weather Agency (AFWA), the Model Evaluation Toolkit (MET) - a joint product of the National Center for Atmospheric Research Developmental Testbed Center (NCAR DTC), AFWA, and the user community - and the land information system (LIS) Verification Toolkit (LVT) - developed at the Goddard Space Flight Center (GSFC) - have been adapted to the operational benchmarking needs of AFWA's land characterization activities in order to compare the performance of new land modeling and related activities with that of previous activities as well as observational or analyzed datasets. In this talk, three examples of adaptations of MET and LVT to evaluation of LIS-related operations at AFWA will be presented. One example will include comparisons of new surface rainfall analysis capabilities, towards forcing of AFWA's LIS, with previous capabilities. Comparisons will be relative to retrieval-, model-, and measurement-based precipitation fields. Results generated via MET's grid-stat, neighborhood, wavelet, and object based evaluation (MODE) utilities adapted to AFWA's needs will be discussed. This example will be framed in the context of better informing optimal blends of land surface model (LSM) forcing data sources - namely precipitation data- under various atmospheric and land surface conditions through consideration of various metrics and their tradeoffs. A second example, conducted through both the adapted MET utilities and those of LVT, will involve comparisons of several of AFWA's LIS output surface flux and state variables with those of the Agricultural Meteorology (AGRMET) model and various retrieval- and measurement-based datasets towards judging relative performance. A third example will highlight LVT's capabilities towards data assimilation (DA) through LIS and LVT, and the benefits of LVT as both a benchmarking tool and facilitator of LIS DA. All examples will highlight benefits and lessons learned through operational, systematic benchmarking contexts.

Shaw, M.; Kumar, S.; Peters-Lidard, C. D.; Cetola, J.

2011-12-01

278

Optimum combination of leasing systems on public lands  

SciTech Connect

Bonus bidding for oil and gas leases on public lands has been a reasonably satisfactory system for capturing the average rent available while being neutral with respect to economic decisions such as abandonment. However, it places a heavy burden of risk and uncertainty on the lessee. There is some reason to believe that social gains are to be had from shifting some of the risk and uncertainty to the lessors (governmental units). Profit-share or royalty bidding tends to accomplish such a shift. However, optimality seems to call for a combination of bonus bidding and profit-share (or royalty) bidding, the latter on wildcat tracts and the former on drainage tracts. Profit-share bidding is somewhat superior to royalty bidding, and the best definition of ''profit'' for the purpose is profits in excess of a normal return on investment. The combination suggested above may be especially desirable in a program of accelerated leasing of public lands. 2 figs.

McDonald, S.L.

1984-12-01

279

Integrating land management into Earth system models: the importance of land use transitions at sub-grid-scale  

NASA Astrophysics Data System (ADS)

Recent studies indicate that changes in surface climate and carbon fluxes caused by land management (i.e., modifications of vegetation structure without changing the type of land cover) can be as large as those caused by land cover change. Further, such effects may occur on substantial areas: while about one quarter of the land surface has undergone land cover change, another fifty percent are managed. This calls for integration of management processes in Earth system models (ESMs). This integration increases the importance of awareness and agreement on how to diagnose effects of land use in ESMs to avoid additional model spread and thus unnecessary uncertainties in carbon budget estimates. Process understanding of management effects, their model implementation, as well as data availability on management type and extent pose challenges. In this respect, a significant step forward has been done in the framework of the current IPCC's CMIP5 simulations (Coupled Model Intercomparison Project Phase 5): The climate simulations were driven with the same harmonized land use dataset that, different from most datasets commonly used before, included information on two important types of management: wood harvest and shifting cultivation. However, these new aspects were employed by only part of the CMIP5 models, while most models continued to use the associated land cover maps. Here, we explore the consequences for the carbon cycle of including subgrid-scale land transformations ("gross transitions"), such as shifting cultivation, as example of the current state of implementation of land management in ESMs. Accounting for gross transitions is expected to increase land use emissions because it represents simultaneous clearing and regrowth of natural vegetation in different parts of the grid cell, reducing standing carbon stocks. This process cannot be captured by prescribing land cover maps ("net transitions"). Using the MPI-ESM we find that ignoring gross transitions underestimates emissions substantially, for historical times by about 40%. Implementation of land management such as gross transitions is a step forward in terms of comprehensiveness of simulated processes. However, it has increased model spread in carbon fluxes, because land management processes have been considered by only a subset of recent ESMs contributing to major projects such as IPCC or the Global Carbon Project. This model spread still causes the net land use flux to be the most uncertain component in the global carbon budget. Other causes have previously been identified as differences in land use datasets, differing types of vegetation model, accounting of nutrient limitation, the inclusion of land use feedbacks (increase in atmospheric CO2 due to land use emissions causing terrestrial carbon uptake), and a confusion of whether the net land use flux in ESMs should be reported as instantaneous emissions, or also account for delayed carbon responses and regrowth. These differences explain a factor 2-6 difference between model estimates and are expected to be further affected by interactions with land management. This highlights the importance of an accurate protocol for future model intercomparisons of carbon fluxes from land cover change and land management to ensure comparison of the same processes and fluxes.

Pongratz, Julia; Wilkenskjeld, Stiig; Kloster, Silvia; Reick, Christian

2014-05-01

280

Evolution of INMARSAT systems and applications: The land mobile experience  

NASA Technical Reports Server (NTRS)

Inmarsat has provided mobile satellite communication services for land mobile applications for well over a decade. Having started with the Inmarsat-A voice and telex system, Inmarsat is committed to the evolution of services towards a global personal, handheld satellite communicator. Over the years, users have benefitted from the evolution of technologies, increased user friendliness and portability of terminals and ever decreasing cost of operations. This paper describes the various present systems, their characteristics and applications, and outlines their contributions in the evolution towards the personal global communicator.

Staffa, Eugene; Subramaniam, Ram

1993-01-01

281

An investigation of an active landing gear system to reduce aircraft vibrations caused by landing impacts and runway excitations  

NASA Astrophysics Data System (ADS)

A mathematical model is developed to control aircraft vibrations caused by runway excitation using an active landing gear system. Equations are derived to describe the integrated aircraft-active system. The nonlinear characteristics of the system are modelled and it is actively controlled using a Proportional Integral Derivative (PID) strategy. The performance of this system and its corresponding passive system are compared using numerical simulations. It is demonstrated that the impact loads and the vertical displacement of the aircraft's centre of gravity caused by landing and runway excitations are greatly reduced using the active system, which result in improvements to the performance of the landing gear system, benefits the aircraft's fatigue life, taxiing performance, crew/passenger comfort and reduces requirements on the unevenness of runways.

Wang, Haitao; Xing, J. T.; Price, W. G.; Li, Weiji

2008-10-01

282

Using the Nordic Geodetic Observing System for land uplift studies  

NASA Astrophysics Data System (ADS)

Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the datasets. Globally, there is the IAG GGOS (Global Geodetic Observing System), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, NGOS (Nordic Geodetic Observing System) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss on general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravimeter, with the Nordic NKG2005LU land uplift model. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. It is also important to consider the relation between geodetic observing systems and specific projects like DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) or EPOS (European Plate Observing System). The natural aim of observing systems will be to produce data and other products needed by such multidisciplinary projects, but their needs may currently exceed the scope of an observing system. We discuss what requirements the projects pose to observing systems and their development.

Nordman, M.; Poutanen, M.; Kairus, A.; Virtanen, J.

2014-01-01

283

Integrated Display System for Low Visibility Landing and Surface Operations  

NASA Technical Reports Server (NTRS)

This report summarizes the software products and system architectures developed by Lockheed Martin in support of the Low Visibility Landing and Surface Operations (LVLASO) program at NASA Langley Research Center. It presents an overview of the technical aspects, capabilities, and system integration issues associated with an integrated display system (IDS) that collects, processes and presents information to an aircraft flight crew during all phases of landing, roll-out, turn-off, inbound taxi, outbound taxi and takeoff. Communications hardware, drivers, and software provide continuous real-time data at varying rates and from many different sources to the display programs for presentation on a head-down display (HDD) and/or a head-up display (HUD). An electronic moving map of the airport surface is implemented on the HDD which includes the taxi route assigned by air traffic control, a text messaging system, and surface traffic and runway status information. Typical HUD symbology for navigation and control of the aircraft is augmented to provide aircraft deceleration guidance after touchdown to a pilot selected exit and taxi guidance along the route assigned by ATC. HUD displays include scene-linked symbolic runways, runway exits and taxiways that are conformal with the actual locations on the airport surface. Display formats, system architectures, and the various IDS programs are discussed.

Beskenis, Sharon Otero; Green, David F., Jr.; Hyer, Paul V.; Johnson, Edward J., Jr.

1998-01-01

284

Variable structure approach power compensation system design of an automatic carrier landing system  

Microsoft Academic Search

The design problem of approach power compensation system via variable structure control theory is considered. The function of approach power compensation system in automatic carrier landing system is introduced, and its working principle is analyzed. The approach power compensation system is designed via variable structure control theory and the ability of this system that reduces the influence of air disturbance

Zhu Qi-dan; Wang Tong; Zhang Wen; Zhou Fang

2009-01-01

285

An Onboard Monocular Vision System for Autonomous Takeoff, Hovering and Landing of a Micro Aerial Vehicle  

E-print Network

An Onboard Monocular Vision System for Autonomous Takeoff, Hovering and Landing of a Micro Aerial monocular vision system for autonomous takeoff, hovering and landing of a Micro Aerial Vehicle (MAV). Since years. Takeoff, hovering and landing are three basic phases for autonomous flight of rotorcrafts. Among

Zell, Andreas

286

Passive Viscoelastic Constrained Layer Damping Application for a Small Aircraft Landing Gear System  

E-print Network

Passive Viscoelastic Constrained Layer Damping Application for a Small Aircraft Landing Gear System. Ferris 9/30/2008 Blacksburg, VA Keywords: Viscoelastic, Damping, Loss Factor, Landing Gear, Aircraft #12;Passive Viscoelastic Constrained Layer Damping Application for a Small Aircraft Landing Gear System

Kochersberger, Kevin

287

Using the Nordic Geodetic Observing System for land uplift studies  

NASA Astrophysics Data System (ADS)

Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the data sets. Globally, there is the International Association of Geodesy (IAG) Global Geodetic Observing System (GGOS), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, the Nordic Geodetic Observing System (NGOS) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss in general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such a database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravity, with the Nordic Geodetic Commission NKG2005LU land uplift model for Fennoscandia. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. The primary aim of observing systems will be to produce data and other products needed by multidisciplinary projects, such as Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas (DynaQlim) or the European Plate Observing System (EPOS), but their needs may currently exceed the scope of an existing observing system. We discuss what requirements the projects pose to observing systems and their development. To make comparisons between different studies possible and reliable, the researcher should document what they have in detail, either in appendixes, supplementary material or some other available format.

Nordman, M.; Poutanen, M.; Kairus, A.; Virtanen, J.

2014-07-01

288

Seasonal-scale Observational Data Analysis and Atmospheric Phenomenology for the Cold Land Processes Experiment  

NASA Technical Reports Server (NTRS)

The Cold Land Processes Experiment (CLPX) experiment emphasized the development of a strong synergism between process-oriented understanding, land surface models and microwave remote sensing. Our work sought to investigate which topographically- generated atmospheric phenomena are most relevant to the CLPX MSA's for the purpose of evaluating their climatic importance to net local moisture fluxes and snow transport through the use of high-resolution data assimilation/atmospheric numerical modeling techniques. Our task was to create three long-term, scientific quality atmospheric datasets for quantitative analysis (for all CLPX researchers) and provide a summary of the meteorologically-relevant phenomena of the three MSAs (see Figure) over northern Colorado. Our efforts required the ingest of a variety of CLPX datasets and the execution an atmospheric and land surface data assimilation system based on the Navier-Stokes equations (the Local Analysis and Prediction System, LAPS, and an atmospheric numerical weather prediction model, as required) at topographically- relevant grid spacing (approx. 500 m). The resulting dataset will be analyzed by the CLPX community as a part of their larger research goals to determine the relative influence of various atmospheric phenomena on processes relevant to CLPX scientific goals.

Poulos, Gregory S.; Stamus, Peter A.; Snook, John S.

2005-01-01

289

Surface Hydrology in Global River Basins in the Off-Line Land-Surface GEOS Assimilation (OLGA) System  

NASA Technical Reports Server (NTRS)

Land surface hydrology for the Off-line Land-surface GEOS Analysis (OLGA) system and Goddard Earth Observing System (GEOS-1) Data Assimilation System (DAS) has been examined using a river routing model. The GEOS-1 DAS land-surface parameterization is very simple, using an energy balance prediction of surface temperature and prescribed soil water. OLGA uses near-surface atmospheric data from the GEOS-1 DAS to drive a more comprehensive parameterization of the land-surface physics. The two global systems are evaluated using a global river routing model. The river routing model uses climatologic surface runoff from each system to simulate the river discharge from global river basins, which can be compared to climatologic river discharge. Due to the soil hydrology, the OLGA system shows a general improvement in the simulation of river discharge compared to the GEOS-1 DAS. Snowmelt processes included in OLGA also have a positive effect on the annual cycle of river discharge and source runoff. Preliminary tests of a coupled land-atmosphere model indicate improvements to the hydrologic cycle compared to the uncoupled system. The river routing model has provided a useful tool in the evaluation of the GCM hydrologic cycle, and has helped quantify the influence of the more advanced land surface model.

Bosilovich, Michael G.; Yang, Runhua; Houser, Paul R.

1998-01-01

290

Mars Science Laboratory: Entry, Descent, and Landing System Performance  

NASA Technical Reports Server (NTRS)

In 2010, the Mars Science Laboratory (MSL) mission will pioneer the next generation of robotic Entry, Descent, and Landing (EDL) systems, by delivering the largest and most capable rover to date to the surface of Mars. To do so, MSL will fly a guided lifting entry at a lift-to-drag ratio in excess of that ever flown at Mars, deploy the largest parachute ever at Mars, and perform a novel Sky Crane maneuver. Through improved altitude capability, increased latitude coverage, and more accurate payload delivery, MSL is allowing the science community to consider the exploration of previously inaccessible regions of the planet. The MSL EDL system is a new EDL architecture based on Viking heritage technologies and designed to meet the challenges of landing increasing massive payloads on Mars. In accordance with level-1 requirements, the MSL EDL system is being designed to land an 850 kg rover to altitudes as high as 1 km above the Mars Orbiter Laser Altimeter defined areoid within 10 km of the desired landing site. Accordingly, MSL will enter the largest entry mass, fly the largest 70 degree sphere-cone aeroshell, generate the largest hypersonic lift-to-drag ratio, and deploy the largest Disk-Gap-Band supersonic parachute of any previous mission to Mars. Major EDL events include a hypersonic guided entry, supersonic parachute deploy and inflation, subsonic heatshield jettison, terminal descent sensor acquisition, powered descent initiation, sky crane terminal descent, rover touchdown detection, and descent stage flyaway. Key performance metrics, derived from level-1 requirements and tracked by the EDL design team to indicate performance capability and timeline margins, include altitude and range at parachute deploy, time on radar, and propellant use. The MSL EDL system, which will continue to develop over the next three years, will enable a notable extension in the advancement of Mars surface science by delivering more science capability than ever before to the surface of Mars. This paper describes the current MSL EDL system performance as predicted by end-to-end EDL simulations, highlights the sensitivity of this baseline performance to several key environmental assumptions, and discusses some of the challenges faced in delivering such an unprecedented rover payload to the surface of Mars.

Way, David W.; Powell, Richard W.; Chen, Allen; SanMartin, A. Miguel; Burkhart, P. Daniel; Mendeck, Gavin F.

2007-01-01

291

Development of land based radar polarimeter processor system  

NASA Technical Reports Server (NTRS)

The processing subsystem of a land based radar polarimeter was designed and constructed. This subsystem is labeled the remote data acquisition and distribution system (RDADS). The radar polarimeter, an experimental remote sensor, incorporates the RDADS to control all operations of the sensor. The RDADS uses industrial standard components including an 8-bit microprocessor based single board computer, analog input/output boards, a dynamic random access memory board, and power supplis. A high-speed digital electronics board was specially designed and constructed to control range-gating for the radar. A complete system of software programs was developed to operate the RDADS. The software uses a powerful real time, multi-tasking, executive package as an operating system. The hardware and software used in the RDADS are detailed. Future system improvements are recommended.

Kronke, C. W.; Blanchard, A. J.

1983-01-01

292

Carbon balances during land conversion in early bioenergy systems  

NASA Astrophysics Data System (ADS)

In this study, we established a field experiment and deployed seven eddy-covariance towers to quantify the roles of land use change and the subsequent carbon (C) balances of three different bioenergy systems (corn, switchgrass, and mixed prairie species) that were developed from two historical land use types: monocultural grasslands dominated by smooth brome (Bromus inermis Leyss) and lands in the Conservation Reserve Program (CRP). Three CRP fields and three cropland fields were converted to soybean in 2009 (conversion year) before establishing the cellulosic biofuel cropping systems in 2010 (establishment year). A CRP perennial grassland site was kept undisturbed as a reference. Conversion of CRP to soybean induced net C emissions during the conversion year (134 -262 g C m-2 yr-1), while in the same year the net C balance at the CRP grassland reference was -35 g C m-2 yr-1 (i.e., net C sequestration). The establishment of switchgrass and mixed prairie induced a cumulative C balance of -113 g C m-2 (switchgrass from CRP), 250 g C m-2 (switchgrass from cropland), 706 g C m-2 (mixed prairie from CRP), and 59 g C m-2 (mixed prairie from cropland) over the three-year study period. The cumulative three-year C balance of corn converted from CRP and from cropland was -151 g C m-2 and -183 g C m-2, respectively. Eddy flux measurements during cellulosic biofuel crop establishment reveal annual changes in C balance that cannot be detected using conventional mass balance approaches. When end-use of harvested biomass was considered, the C balances for all studied systems, except the reference site, exhibited large C emissions ranging from 150 to 990 g C m-2 over the three-year conversion phase.

Zenone, T.; Chen, J.; Gelfand, I.; Robertson, G. P.; Hamilton, S. K.

2012-12-01

293

Shimmy analysis of a simple aircraft nose landing gear model using different mathematical methods  

Microsoft Academic Search

Shimmy oscillations are still a problem in design and operation of aircraft landing gears, and accurate and appropriate analysis is required to master the task. Based on a nonlinear model of the mechanics of the landing gear and tire elasticity according to elastic string theory, some well known linear and nonlinear mathematical methods are applied to the shimmy analysis of

Gerhard Somieski

1997-01-01

294

REDUCING STORMWATER RUNOFF THROUGH LAND SUITABILITY ANALYSIS AND LOW-IMPACT SUBDIVISION DESIGN  

Technology Transfer Automated Retrieval System (TEKTRAN)

We demonstrate an approach to reduce the anticipated increase in stormwater runoff from development under conventional subdivision design by incorporating hydrologic factors into a land suitability analysis and a low-impact subdivision design. A typical land suitability analysis assesses attributes ...

295

Involving Geospatial Information in the Analysis of Land-Cover Change along the Tanzania Coast  

E-print Network

Involving Geospatial Information in the Analysis of Land-Cover Change along the Tanzania Coast.1080/08920750590883132 Involving Geospatial Information in the Analysis of Land-Cover Change along the Tanzania Coast YEQIAO WANG, Rhode Island, USA VEDAST MAKOTA National Environment Management Council Dar es Salaam, Tanzania AMANI

Wang, Y.Q. "Yeqiao"

296

Design of Land-Use Planning Management Information System Base on ArcGIS  

Microsoft Academic Search

The traditional land-use planning (LUP) management is complicated and long-time cycle needed, which affected the implementation and management of land use planning in a certain extent. On the basis of analysis of the main content and features of land use planning management, and components of ArcGIS technical development, this paper discusses the technology and methods which realize the land use

Yuxiang Cao; Hongjiang Liu; Jianchun Xu

2009-01-01

297

Use of South American Land Data Assimilation System (SALDAS) to Assess Impacts of Biofuel Expansion on Water Resources in Brazil  

NASA Astrophysics Data System (ADS)

Large scale expansion of sugarcane production in Brazil is very positive in terms of biofuels and greenhouse gases; however, potential impacts on water resources are uncertain. The objective of this analysis is to assess potential impacts of biofuel expansion in Central South Brazil on water resources using the South American Land Data Assimilation System (SALDAS). SALDAS is driven by 3 hourly atmospheric forcing. Limited surface observations have resulted in use of remotely sensed data merged with surface observations to calculate precipitation and shortwave radiation fields. SALDAS simulates partitioning of water and energy in response to spatiotemporal variability in climate forcing and land use change related to biofuel expansion. The impacts of land use changes related to biofuel expansion will be examined by evaluating water and energy fluxes in areas of different land use and substituting space for time. Output from SALDAS will be compared with coarser resolution Global Land Data Assimilation System (GLDAS) and other more traditional modeling approaches, such as CROPWAT, to estimate changes in water use from biofuel expansion. Land surface models provide an excellent reconnaissance tool to better understand the hydrology of regional systems in response to climate and land use in data constrained regions.

Goncalves, L.; De Mattos, J. Z.; Scarpare, F.; Galdos, M. V.; Scanlon, B.; Long, D.

2013-12-01

298

Analysis of Links Positions in Landing Gear Mechanism  

NASA Astrophysics Data System (ADS)

This article contains a kinematic analysis of an aircraft chassis mechanism in a range of positions. The mechanism of the chassis is made up of several smaller subsystems with different functions. The first mechanism is used to eject the chassis before landing (touchdown) and fold it to hatchway after the lift off. The second mechanism is designed to perform rotation of the crossover with the wheel, in order to adjust the position of the wheel to fit it in the limited space in the hold. The third mechanism allows movement of the chassis resulting from the change in length of the damper. To determine the position of the following links of the mechanism calculus of vectors was applied in which unit vectors were used to represent the angular position of the links. The aim of the analysis is to determine the angle of convergence and the angle of heel wheels as a function of the variable length of hydraulic cylinder, length of the shock absorber, length of the regulations rods

Brewczy?ski, D.; Tora, G.

2014-08-01

299

Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis. Volume 2; Appendices  

NASA Technical Reports Server (NTRS)

The NASA Engineering and Safety Center (NESC) was requested to establish the Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis assessment, which involved development of an enhanced simulation architecture using the Program to Optimize Simulated Trajectories II (POST2) simulation tool. The assessment was requested to enhance the capability of the Agency to provide rapid evaluation of EDL characteristics in systems analysis studies, preliminary design, mission development and execution, and time-critical assessments. Many of the new simulation framework capabilities were developed to support the Agency EDL Systems Analysis (EDL-SA) team, that is conducting studies of the technologies and architectures that are required to enable higher mass robotic and human mission to Mars. The appendices to the original report are contained in this document.

Murri, Daniel G.

2010-01-01

300

Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis. Volume 1  

NASA Technical Reports Server (NTRS)

The NASA Engineering and Safety Center (NESC) was requested to establish the Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis assessment, which involved development of an enhanced simulation architecture using the Program to Optimize Simulated Trajectories II (POST2) simulation tool. The assessment was requested to enhance the capability of the Agency to provide rapid evaluation of EDL characteristics in systems analysis studies, preliminary design, mission development and execution, and time-critical assessments. Many of the new simulation framework capabilities were developed to support the Agency EDL Systems Analysis (EDL-SA) team, that is conducting studies of the technologies and architectures that are required to enable higher mass robotic and human mission to Mars. The findings of the assessment are contained in this report.

Murri, Daniel G.

2010-01-01

301

Navigation for space shuttle approach and landing using an inertial navigation system augmented by data from a precision ranging system or a microwave scan beam landing guidance system  

NASA Technical Reports Server (NTRS)

A preliminary study has been made of the navigation performance which might be achieved for the high cross-range space shuttle orbiter during final approach and landing by using an optimally augmented inertial navigation system. Computed navigation accuracies are presented for an on-board inertial navigation system augmented (by means of an optimal filter algorithm) with data from two different ground navigation aids; a precision ranging system and a microwave scanning beam landing guidance system. These results show that augmentation with either type of ground navigation aid is capable of providing a navigation performance at touchdown which should be adequate for the space shuttle. In addition, adequate navigation performance for space shuttle landing is obtainable from the precision ranging system even with a complete dropout of precision range measurements as much as 100 seconds before touchdown.

Mcgee, L. A.; Smith, G. L.; Hegarty, D. M.; Merrick, R. B.; Carson, T. M.; Schmidt, S. F.

1970-01-01

302

Land Data Assimilation of Satellite-Based Soil Moisture Products Using the Land Information System Over the NLDAS Domain  

NASA Technical Reports Server (NTRS)

This presentation will include results from data assimilation simulations using the NASA-developed Land Information System (LIS). Using the ensemble Kalman filter in LIS, two satellite-based soil moisture products from the AMSR-E instrument were assimilated, one a NASA-based product and the other from the Land Parameter Retrieval Model (LPRM). The domain and land-surface forcing data from these simulations were from the North American Land Data Assimilation System Phase-2, over the period 2002-2008. The Noah land-surface model, version 3.2, was used during the simulations. Changes to estimates of land surface states, such as soil moisture, as well as changes to simulated runoff/streamflow will be presented. Comparisons over the NLDAS domain will also be made to two global reference evapotranspiration (ET) products, one an interpolated product based on FLUXNET tower data and the other a satellite- based algorithm from the MODIS instrument. Results of an improvement metric show that assimilating the LPRM product improved simulated ET estimates while the NASA-based soil moisture product did not.

Mocko, David M.; Kumar, S. V.; Peters-Lidard, C. D.; Tian, Y.

2011-01-01

303

Application of scenario analysis and multiagent technique in land-use planning: a case study on Sanjiang wetlands.  

PubMed

Land-use planning has triggered debates on social and environmental values, in which two key questions will be faced: one is how to see different planning simulation results instantaneously and apply the results back to interactively assist planning work; the other is how to ensure that the planning simulation result is scientific and accurate. To answer these questions, the objective of this paper is to analyze whether and how a bridge can be built between qualitative and quantitative approaches for land-use planning work and to find out a way to overcome the gap that exists between the ability to construct computer simulation models to aid integrated land-use plan making and the demand for them by planning professionals. The study presented a theoretical framework of land-use planning based on scenario analysis (SA) method and multiagent system (MAS) simulation integration and selected freshwater wetlands in the Sanjiang Plain of China as a case study area. Study results showed that MAS simulation technique emphasizing quantitative process effectively compensated for the SA method emphasizing qualitative process, which realized the organic combination of qualitative and quantitative land-use planning work, and then provided a new idea and method for the land-use planning and sustainable managements of land resources. PMID:23818816

Yu, Huan; Ni, Shi-Jun; Kong, Bo; He, Zheng-Wei; Zhang, Cheng-Jiang; Zhang, Shu-Qing; Pan, Xin; Xia, Chao-Xu; Li, Xuan-Qiong

2013-01-01

304

Application of Calspan pitch rate control system to the Space Shuttle for approach and landing  

NASA Technical Reports Server (NTRS)

A pitch rate control system designed for use in the shuttle during approach and landing was analyzed and compared with a revised control system developed by NASA and the existing OFT control system. The design concept control system uses filtered pitch rate feedback with proportional plus integral paths in the forward loop. Control system parameters were designed as a function of flight configuration. Analysis included time and frequency domain techniques. Results indicate that both the Calspan and NASA systems significantly improve the flying qualities of the shuttle over the OFT. Better attitude and flight path control and less time delay are the primary reasons. The Calspan system is preferred because of reduced time delay and simpler mechanization. Further testing of the improved flight control systems in an in-flight simulator is recommended.

Weingarten, N. C.; Chalk, C. R.

1983-01-01

305

Nitrogen leaching losses from a wastewater land application system.  

PubMed

Potential contamination of groundwater because of nitrogen leaching has been an important concern in municipal wastewater land application systems; however, few efforts have made to measure nitrogen leaching (total N, NO(3-)-N, and NH(4+)-N) under field conditions. This research successfully developed a conceptual nitrogen mass balance model and quantified its components at a wastewater land application system located at the City of Littlefield, Texas, from October 2005 to September 2007. The concentrations of total nitrogen and nitrate-nitrogen in the leachate were significantly less than 10 mg/L, therefore, there was no potential nitrogen contamination to groundwater found at this site during the research period. Linear regression models were analyzed and resulted in R2 values of 0.918, 0.966, and 0.833 between cumulative applied total nitrogen mass and cumulative leached total nitrogen mass, cumulative applied nitrate-nitrogen mass and cumulative leached nitrate-nitrogen mass, and cumulative applied ammonia-nitrogen mass and cumulative leached ammonia-nitrogen mass, respectively. The nitrogen mass balance design approach for this site resulted in significant nitrogen removal. Organic nitrogen may leach with other forms of nitrogen, and denitrification plays an important role in nitrogen removal during the winter and spring seasons when the grass is dry. PMID:20369566

Duan, Runbin; Fedler, Clifford B; Sheppard, Christopher D

2010-03-01

306

A land-potential knowledge system (LandPKS) based on local and scientific knowledge of land productivity and resilience  

Technology Transfer Automated Retrieval System (TEKTRAN)

Economic assessment of land use change in drylands depends on understanding potential productivity, degradation resistance and resilience, all of which vary widely and are often ignored. Rapidly increasing demand, together with new technologies, migration and global capital mobility are driving dram...

307

Drivers of land use change and household determinants of sustainability in smallholder farming systems of Eastern Uganda  

PubMed Central

Smallholder farming systems in sub-Saharan Africa have undergone changes in land use, productivity and sustainability. Understanding of the drivers that have led to changes in land use in these systems and factors that influence the systems’ sustainability is useful to guide appropriate targeting of intervention strategies for improvement. We studied low input Teso farming systems in eastern Uganda from 1960 to 2001 in a place-based analysis combined with a comparative analysis of similar low input systems in southern Mali. This study showed that policy-institutional factors next to population growth have driven land use changes in the Teso systems, and that nutrient balances of farm households are useful indicators to identify their sustainability. During the period of analysis, the fraction of land under cultivation increased from 46 to 78%, and communal grazing lands nearly completely disappeared. Cropping diversified over time; cassava overtook cotton and millet in importance, and rice emerged as an alternative cash crop. Impacts of political instability, such as the collapse of cotton marketing and land management institutions, of communal labour arrangements and aggravation of cattle rustling were linked to the changes. Crop productivity in the farming systems is poor and nutrient balances differed between farm types. Balances of N, P and K were all positive for larger farms (LF) that had more cattle and derived a larger proportion of their income from off-farm activities, whereas on the medium farms (MF), small farms with cattle (SF1) and without cattle (SF2) balances were mostly negative. Sustainability of the farming system is driven by livestock, crop production, labour and access to off-farm income. Building private public partnerships around market-oriented crops can be an entry point for encouraging investment in use of external nutrient inputs to boost productivity in such African farming systems. However, intervention strategies should recognise the diversity and heterogeneity between farms to ensure efficient use of these external inputs. PMID:20628448

de Ridder, Nico; de Jager, Andre; Delve, Robert J.; Bekunda, Mateete A.; Giller, Ken E.

2010-01-01

308

Drivers of land use change and household determinants of sustainability in smallholder farming systems of Eastern Uganda.  

PubMed

Smallholder farming systems in sub-Saharan Africa have undergone changes in land use, productivity and sustainability. Understanding of the drivers that have led to changes in land use in these systems and factors that influence the systems' sustainability is useful to guide appropriate targeting of intervention strategies for improvement. We studied low input Teso farming systems in eastern Uganda from 1960 to 2001 in a place-based analysis combined with a comparative analysis of similar low input systems in southern Mali. This study showed that policy-institutional factors next to population growth have driven land use changes in the Teso systems, and that nutrient balances of farm households are useful indicators to identify their sustainability. During the period of analysis, the fraction of land under cultivation increased from 46 to 78%, and communal grazing lands nearly completely disappeared. Cropping diversified over time; cassava overtook cotton and millet in importance, and rice emerged as an alternative cash crop. Impacts of political instability, such as the collapse of cotton marketing and land management institutions, of communal labour arrangements and aggravation of cattle rustling were linked to the changes. Crop productivity in the farming systems is poor and nutrient balances differed between farm types. Balances of N, P and K were all positive for larger farms (LF) that had more cattle and derived a larger proportion of their income from off-farm activities, whereas on the medium farms (MF), small farms with cattle (SF1) and without cattle (SF2) balances were mostly negative. Sustainability of the farming system is driven by livestock, crop production, labour and access to off-farm income. Building private public partnerships around market-oriented crops can be an entry point for encouraging investment in use of external nutrient inputs to boost productivity in such African farming systems. However, intervention strategies should recognise the diversity and heterogeneity between farms to ensure efficient use of these external inputs. PMID:20628448

Ebanyat, Peter; de Ridder, Nico; de Jager, Andre; Delve, Robert J; Bekunda, Mateete A; Giller, Ken E

2010-07-01

309

Geospatial Analysis of Renewable Energy Technical Potential on Tribal Lands  

SciTech Connect

This technical report uses an established geospatial methodology to estimate the technical potential for renewable energy on tribal lands for the purpose of allowing Tribes to prioritize the development of renewable energy resources either for community scale on-tribal land use or for revenue generating electricity sales.

Doris, E.; Lopez, A.; Beckley, D.

2013-02-01

310

Independent Orbiter Assessment (IOA): Analysis of the landing/deceleration subsystem  

NASA Technical Reports Server (NTRS)

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Landing/Deceleration Subsystem hardware. The Landing/Deceleration Subsystem is utilized to allow the Orbiter to perform a safe landing, allowing for landing-gear deploy activities, steering and braking control throughout the landing rollout to wheel-stop, and to allow for ground-handling capability during the ground-processing phase of the flight cycle. Specifically, the Landing/Deceleration hardware consists of the following components: Nose Landing Gear (NLG); Main Landing Gear (MLG); Brake and Antiskid (B and AS) Electrical Power Distribution and Controls (EPD and C); Nose Wheel Steering (NWS); and Hydraulics Actuators. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the lack of redundancy in the Landing/Deceleration Subsystems there is a high number of critical items.

Compton, J. M.; Beaird, H. G.; Weissinger, W. D.

1987-01-01

311

Analysis of land use/land cover changes using remote sensing data and GIS at an urban area, Tirupati, India.  

PubMed

Land use/land cover (LU/LC) changes were determined in an urban area, Tirupati, from 1976 to 2003 by using Geographical Information Systems (GISs) and remote sensing technology. These studies were employed by using the Survey of India topographic map 57 O/6 and the remote sensing data of LISS III and PAN of IRS ID of 2003. The study area was classified into eight categories on the basis of field study, geographical conditions, and remote sensing data. The comparison of LU/LC in 1976 and 2003 derived from toposheet and satellite imagery interpretation indicates that there is a significant increase in built-up area, open forest, plantation, and other lands. It is also noted that substantial amount of agriculture land, water spread area, and dense forest area vanished during the period of study which may be due to rapid urbanization of the study area. No mining activities were found in the study area in 1976, but a small addition of mining land was found in 2003. PMID:23781152

Mallupattu, Praveen Kumar; Sreenivasula Reddy, Jayarama Reddy

2013-01-01

312

A mini/microcomputer-based land use information system  

NASA Technical Reports Server (NTRS)

The paper describes the Multipurpose Interactive NASA Information System (MINIS), a data management system for land-use applications. MINIS is written nearly entirely in FORTRAN IV, and has a full range of conditional, Boolean and arithmetic commands, as well as extensive format control and the capability of interactive file creation and updating. It requires a mini or microcomputer with at least 64 K of core or semiconductor memory. MINIS has its own equation-oriented query language for retrieval from different kinds of data bases. It features a graphics output which permits output of overlay maps. Some experience of the U.S. Department of Agriculture and the Tennessee State Planning Office with MINIS is discussed.

Seitz, R. N.; Keefer, R. L.; Britton, L. J.; Wilson, J. M.

1977-01-01

313

A Summary of the Development of a Nominal Land Landing Airbag Impact Attenuation System for the Orion Crew Module  

NASA Technical Reports Server (NTRS)

Airborne Systems North America (formally Irvin Aerospace Inc) has developed an Airbag Landing System for the Orion Crew Module of the Crew Exploration Vehicle. This work is in support of the NASA Langley Research Center Landing System Advanced Development Project. Orion is part of the Constellation Program to send human explorers back to the moon, and then onwards to Mars and other destinations in the Solar System. A component of the Vision for Space Exploration, Orion is being developed to also enable access to space following the retirement of the Space Shuttle in the next decade. This paper documents the development of a conceptual design, fabrication of prototype assemblies, component level testing and two generations of airbag landing system testing. The airbag system has been designed and analyzed using the transient dynamic finite element code LS-DYNA(RegisteredTradeMark). The landing system consists of six airbag assemblies; each assembly comprising a primary impact venting airbag and a non-venting anti-bottoming airbag. The anti-bottoming airbag provides ground clearance following the initial impact attenuation sequence. Incorporated into each primary impact airbag is an active vent that allows the entrapped gas to exit the control volume. The size of the vent is tailored to control the flow-rate of the exiting gas. An internal shaping structure is utilized to control the shape of the primary or main airbags prior to ground impact; this significantly improves stroke efficiency and performance.

Tutt, Ben; Gill, Susannah; Wilson, Aaron; Johnson, Keith

2009-01-01

314

Identification and Analysis of Landing sites for the ESA ExoMars Rover (2018)  

NASA Astrophysics Data System (ADS)

The exploration and search for life on Mars forms a cornerstone of international solar system exploration. In 2018, the European Space agency will launch the ExoMars Rover and Lander to further this exploration. The key science objectives of the ExoMars Rover are to: 1) search for signs of past and present life on Mars; 2) investigate the water/geochemical environment as a function of depth in the shallow subsurface; and 3) to characterise the surface environment. To meet these objectives ExoMars will drill into the sub-surface to look for indicators of past life using a range of complementary techniques, including assessment of morphology (potential fossil organisms), mineralogy (past environments) and a search for organic molecules and their chirality (biomarkers). The choice of landing site is vital if ExoMars' scientific objectives are to be met. The landing site must: (i) be ancient (?3.6 Ga); (ii) show abundant morphological and mineral evidence for long-term, or frequently reoccurring, aqueous activity; (iii) include numerous sedimentary outcrops that (iv) are distributed over the landing region (the typical Rover traverse range is only a few km, but the uncertainty in the location of the landing site forms an elliptical of size ~ 100 by 15 km); and (v) have little dust coverage. In addition, in order to land and operate safely, various 'engineering constraints' apply, including: (i) latitude limited to 5º S to 25º N; (ii) maximum altitude of the landing site 2 km below Mars's datum, (iii) few steep slopes within the uncertainty ellipse. These constraints are onerous. In particular, the objective to drill into sediments, the requirement for distributed targets within the ellipse, and the ellipse size, make ExoMars site selection extremely challenging. To meet these challenges, we have begun an intensive study of the martian landscape to identify as many possible ExoMars landing sites as possible. We have converted the current engineering constraints into spatial filters in a GIS (Geographical Information systems) to define regions of Mars where landing could be possible. We have used published geological maps of Mars to define areas that are of the appropriate age and integrated published catalogues of morphological indicators of standing water (e.g. delta-like landforms) and of layered terrains, and of the locations and spectral characteristics of minerals indicative of the action of water. Using this GIS we identified ~25 study areas that held promise scientifically, and into which one or more landing 'uncertainty ellipses' could be fitted without breaching the engineering constraints. For each of these, we obtained and processed imaging data (from the NASA Mars Reconnaissance Orbiter 'CTX' instrument and the ESA Mars Express Orbiter 'HRSC' instrument), high resolution topographic data (again, from ESA's HRSC), and mineralogical data (based on infrared spectrometry data obtained by ESA's OMEGA instrument and NASA's CRISM instrument. Using these data we down-selected to five sites that had the highest potential and which, in some cases, had not been well-described previously in the peer-reviewed literature. At the time of writing, we are undertaking further geomorphological and mineralogical mapping of these sites, with the expectation of submitting 1-3 sites to ESA's ExoMars Landing Site Selection Working Group by the deadline set at end of February 2014. In this presentation we detail the GIS and terrain analysis element of the work we have done, and describe how the diverse data types and team abilities were harnessed to solve the challenging problem created by ExoMars' stringent scientific and engineering constraints.

Balme, Matthew; Bridges, John; Fawdon, Peter; Grindrod, Peter; Gupta, Sanjeev; Michalski, Joe; Conway, Susan

2014-05-01

315

The NASA-Goddard Multi-Scale Modeling Framework - Land Information System: Global Land/atmosphere Interaction with Resolved Convection  

NASA Technical Reports Server (NTRS)

The present generation of general circulation models (GCM) use parameterized cumulus schemes and run at hydrostatic grid resolutions. To improve the representation of cloud-scale moist processes and landeatmosphere interactions, a global, Multi-scale Modeling Framework (MMF) coupled to the Land Information System (LIS) has been developed at NASA-Goddard Space Flight Center. The MMFeLIS has three components, a finite-volume (fv) GCM (Goddard Earth Observing System Ver. 4, GEOS-4), a 2D cloud-resolving model (Goddard Cumulus Ensemble, GCE), and the LIS, representing the large-scale atmospheric circulation, cloud processes, and land surface processes, respectively. The non-hydrostatic GCE model replaces the single-column cumulus parameterization of fvGCM. The model grid is composed of an array of fvGCM gridcells each with a series of embedded GCE models. A horizontal coupling strategy, GCE4fvGCM4Coupler4LIS, offered significant computational efficiency, with the scalability and I/O capabilities of LIS permitting landeatmosphere interactions at cloud-scale. Global simulations of 2007e2008 and comparisons to observations and reanalysis products were conducted. Using two different versions of the same land surface model but the same initial conditions, divergence in regional, synoptic-scale surface pressure patterns emerged within two weeks. The sensitivity of largescale circulations to land surface model physics revealed significant functional value to using a scalable, multi-model land surface modeling system in global weather and climate prediction.

Mohr, Karen Irene; Tao, Wei-Kuo; Chern, Jiun-Dar; Kumar, Sujay V.; Peters-Lidard, Christa D.

2013-01-01

316

A comparative analysis of two land surface heterogeneity representations  

NASA Technical Reports Server (NTRS)

Two contrasting representations of land surface variability used in general circulation models (GCMs) are compared through an analysis of their corresponding surface energy balance equations. In one representation (the 'mixture' approach), different vegetation types are assumed to be homogeneously mixed over a grid square, so that the GCM atmosphere sees near-surface conditions pertaining to the mixture only. In the second representation (the 'mosaic' approach), different vegetation types are viewed as separate 'tiles' of a grid-square 'mosaic', and each tile interacts with the atmosphere independently. The mosaic approach is computationally simpler and in many ways more flexible than the mixture approach. Analytical solutions to the linearized energy balance equations and numerical solutions to the nonlinear equations both demonstrate that the mixture strategy, when applied to two coexisting vegetation types that differ only in canopy transpiration resistance, promotes both total turbulent flux and latent heat flux relative to the mosaic strategy. The effective differences between the strategies, however, are small over a wide range of conditions. In particular, the strategies are effectively equivalent when the transpiration resistances of the different vegetation types are of the same order of magnitude.

Koster, Randal D.; Suarez, Max J.

1992-01-01

317

A Comparative Analysis of Two Land Surface Heterogeneity Representations.  

NASA Astrophysics Data System (ADS)

Two contrasting representations of land surface variability used in general circulation models (GCMS) are compared through an analysis of their corresponding surface energy balance equations. In one representation (the `mixture' approach), different vegetation types are assumed to be homogeneously mixed over a grid square, so that the GCM atmosphere sees near-surface conditions pertaining to the mixture only. In the second representation (the `mosaic' approach), different vegetation types are viewed as separate `tiles' of a grid-square `mosaic,' and each tile interacts with the atmosphere independently. The mosaic approach is computationally simpler and in many ways more flexible than the mixture approach.Analytical solutions to the linearized energy balance equations and numerical solutions to the nonlinear equations both demonstrate that the mixture strategy, when applied to two coexisting vegetation types that differ only in canopy transpiration resistance, promotes both total turbulent flux and latent beat flux relative to the mosaic strategy. The effective differences between the strategies, however, are small over a wide range of conditions. In particular, the strategies are effectively equivalent when the transpiration resistances of the different vegetation types are of the saint order of magnitude.

Koster, Randal D.; Suarez, Max J.

1992-12-01

318

Analysis of coastal change in Marie Byrd Land and Ellsworth Land, West Antarctica, using Landsat imagery  

USGS Publications Warehouse

The U.S. Geological Survey is using Landsat imagery from the early 1970s and mid- to late 1980s/early 1990s to analyze glaciological features, compile a glacier inventory, measure surface velocities of outlet glaciers, ice streams and ice shelves, determine coastline change and calculate the area and volume of iceberg calving in Antarctica. Ice-surface velocities in Marie Byrd and Ellsworth Lands, West Antarctica, range from the fast-moving Thwaites, Pine Island, Land and DeVicq Glaciers to the slower-moving ice shelves. The average ice-front velocity during the time interval of Landsat imagery, for the faster-moving outlet glaciers, was 2.9 km a-1 for Thwaites Glacier, 2.4 km a-1 for Pine Island Glacier, 2.0 km a-1 for Land Glacier and 1.4 km a-1 for DeVicq Glacier. Evaluation of coastal change from the early 1970s to the early 1990s shows advance of the floating ice front in some coastal areas and recession in others, with an overall small average advance in the entire coastal study area, but no major trend towards advance or retreat. Comparison of average ice-surface velocities with changes in the ice front has yielded estimates of iceberg calving. The total iceberg calving from the Marie Byrd Land and Ellsworth Land coasts during the study period was greater than 8500 km2 (estimated volume of about 2400 km3) or an average of about 550 km2 a-1 (more than 150 km3 a-1). Almost 70% of this discharge is contributed by Thwaites and Pine Island Glaciers.

Ferrigno, J.G.; Williams, R.S., Jr.; Rosanova, C.E.; Lucchitta, B.K.; Swithinbank, C.

1998-01-01

319

Land use and land cover classification, changes and analysis in gum Arabic belt in North Kordofan, Sudan  

NASA Astrophysics Data System (ADS)

The gum arabic belt in Sudan plays a significant role in environmental, social and economical aspects. This research was conducted in North Kordofan State, which is affected by modifications in conditions and composition of vegetation cover trends in the gum arabic belt as in the rest of the Sahelian Sudan zone. The objective of the paper is to study the classification, changes and analysis of the land use and land cover in the gum arabic belt in North Kordofan State in Sudan. The study used imageries from different satellites (Landsat and ASTER) and multi-temporal dates (MSS 1972, TM 1985, ETM+ 1999 and ASTER 2007) acquired in dry season. The imageries were geo-referenced and radiometrically corrected by using ENVI-FLAASH software. Image classification (pixel-based) and accuracy assessment were applied. Application of multi-temporal remote sensing data demonstrated successfully the identification and mapping of land use and land cover into five main classes. Forest dominated by Acacia senegal class was separated covering an area of 21% in the year 2007. The obvious changes and reciprocal conversions in the land use and land cover structure indicate the trends and conditions caused by the human interventions as well as ecological impacts on Acacia senegal trees. Also the study revealed that a drastic loss of forest resources occurred in the gum arabic belt in North Kordofan during 1972 to 2007 (25% for Acacia senegal trees). The study concluded that, using of traditional Acacia senegal-based agro-forestry as one of the most successful form in the gum belt.

Adam, Hassan E.; Csaplovics, Elmar; Elhaja, Mohamed E.; El Abbas, Mustafa M.

2013-10-01

320

Surface Temperature Assimilation in the Global Land Data Assimilation System (GLDAS)  

NASA Technical Reports Server (NTRS)

The Global Land Data Assimilation System (GLDAS) is a global land parameterization that uses prescribed meteorology as forcing in order to determine regular gridded land surface states (temperature and moisture) and other properties (e.g. water and heat fluxes). In the present experiment, the assimilation of surface skin temperature is incorporated into the land parameterizations. The meteorological forcing was derived from the Goddard Earth Observing System (GEOS-3) Data Assimilation System (DAS) for the full year of 1998 GLDAS can use several land parameterizations, but here we use the Mosaic land surface model and the Common Land Model (CLM). TOVS surface temperature observations are assimilated into GLDAS. The TOVS observations are less frequent that observations used in previous experiments (ISCCP). The purpose of this presentation is to evaluate the impact of the TOVS assimilation on both Mosaic and CLM. We will especially consider the impact of coarse temporal observations on the assimilation and bias correction.

Bosilovich, Michael G.; Radakovich, Jon D.; daSilva, Arlindo; Houser, Paul R.; Atlas, Robert M. (Technical Monitor)

2002-01-01

321

Active RF seeker analysis for land combat seekers  

NASA Astrophysics Data System (ADS)

This report discusses some analysis techniques which apply to all-weather/day-night missile guidance systems against tank type targets using an RF seeker. Those techniques are examined that may be applied to obtain the proper s/c ratio and terminal accuracy, including squint, polarization and frequency discrimination.

Russell, R. F.; Garlough, R. H.

1981-04-01

322

Lake Michigan Diversion Accounting land cover change estimation by use of the National Land Cover Dataset and raingage network partitioning analysis  

USGS Publications Warehouse

This study used the National Land Cover Dataset (NLCD) and developed an automated process for determining the area of the three land cover types, thereby allowing faster updating of future models, and for evaluating land cover changes by use of historical NLCD datasets. The study also carried out a raingage partitioning analysis so that the segmentation of land cover and rainfall in each modeled unit is directly applicable to the HSPF modeling. Historical and existing impervious, grass, and forest land acreages partitioned by percentages covered by two sets of raingages for the Lake Michigan diversion SCAs, gaged basins, and ungaged basins are presented.

Sharpe, Jennifer B.; Soong, David

2015-01-01

323

Detection of land use/land cover changes through the comparative analysis of NDVI-MODIS phenological clusters  

NASA Astrophysics Data System (ADS)

The use of satellite time series provides precious information to understand vegetation dynamics. In particular, they can be profitably used for studying magnitudo and spatial extent of the Earth's land cover alterations, which affect directly biodiversity, can contribute to land degradation, and are linked to climate change by feedback mechanisms. In the framework of PRO-LAND project (PO-FESR Basilicata 2007-2013), we used NDVI-MODIS satellite time series (250 m), available as 16-day composite from the NASA LPDAAC dataset, to analyze land cover changes occurred in Basilicata region (Southern Italy) during the period 2000-2010. We performed a phenological clustering for the years 2000 and 2010 by means of the unsupervised classification fuzzy k-means which is able to identify gradual differences among phenological patterns. The time domain considered is from April to October in order to reduce disturbances due to the presence of clouds, which can distort actual vegetation phenological profiles. The optimal number of clusters to capture the heterogeneity of the examined area was fixed at ten, because it seemed to be a good trade-off between the need of an efficient representation of ecosystems and the ability to detect local fragmentation effects. Results show that the temporal patterns of the ten clusters can be organised in a continuum of phenological curves. They can be sorted unambiguously according to increasing percentage of man-made areas (decreasing percentage of natural areas) and allow us to well discriminate different land cover compositions by looking not only at differences in mean NDVI values but also at differences in the seasonal timing. The cluster sequence for both the examined years mostly follows the spatial arrangement of the land cover classes, and the complex orography of the investigated region. In general, results show that a slight variability characterize the arrangement of cluster cores, particularly for the clusters with a dominance of natural or anthropic covers, whereas a slightly higher variability appears at the cluster borders (especially for clusters where anthropic and natural covers are mixed). Overall, this study puts into evidence a fair decrease in the number of patches (~ -10%) accompanied by the increase of the mean patch area (~ +10%), which means that there is a tendency to compaction of the areas that are classified in the same phenological cluster. This phenomenon is particularly interesting for mountainous natural areas. A coupled analysis of meteo-climatic conditions and implemented land cover management policies can enable to identify the causes behind the observed phenomena, allowing for a more complete picture and a better interpretation of the occurred land cover changes.

Simoniello, Tiziana; Imbrenda, Vito; Lanfredi, Maria

2013-04-01

324

Numerical Analysis of Steady Flow around a Landing Gear Noise Measurement Model  

NASA Astrophysics Data System (ADS)

It is well known that landing-gear noise is one of the dominant noise sources during the approach phase of a civil airplane. Therefore, it is important to understand the noise generation mechanism and reduce the noise from a landing gear. In this study, steady-state flow analysis around a landing gear model is reported using unstructured-mesh method. To predict the landing gear noise directly, unsteady flow analysis is necessary. However, even from the steady-state analysis, information related with the noise generation could be gained by focusing on the accelerated region or wake interference. From these preliminary results, basic flow field information is obtained to understand the flow physics around the complicated landing gear geometry.

Imamura, Taro; Hirai, Tohru; Yokokawa, Yuzuru; Murayama, Mitsuhiro; Yamamoto, Kazuomi

325

Elemental analysis in environmental land samples by stand-off laser-induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

The stand-off detection and analysis of environmental land samples have been demonstrated using laser-induced breakdown spectrometry. The samples of interest have included soils and vegetation powder. Elements Hg, As, Pb, Zn, Cd and Cr have been spectrally analysed with a focus on Hg as a trace contaminant in the samples. It is found that element Fe, usually contained in land samples, is a main source of spectral interference for Hg detection due to its ever present iron emission line at 253.68 nm that is closely adjacent to the strongest Hg emission line at 253.65 nm, and hence, a high resolution of spectral detection is necessary. The strong spectral signals from Bremsstrahlung emission in laser-induced plasma and atomic emission of Fe of high concentration caused a significant reduction in detection resolution in the use of image intensifier of an ICCD. The limit of detection at ~8 ppm for Hg detection in soil samples with iron as a minor constituent has been achieved, using an optical chopper and a CCD detector for laser-induced breakdown spectroscopy (LIBS) signal detection. Such detection method in LIBS system has shown a great advantage in determining trace elements from interfering elemental constituents in land sample matrixes.

Fang, Xiao; Ahmad, S. R.

2014-06-01

326

Analysis of arable land loss and its impact on rural sustainability in Southern Jiangsu Province of China  

Microsoft Academic Search

Rapid urbanization and industrialization in southern Jiangsu Province have consumed a huge amount of arable land. Through comparative analysis of land cover maps derived from TM images in 1990, 2000 and 2006, we identified the trend of arable land loss. It is found that most arable land is lost to urbanization and rural settlements development. Urban settlements, rural settlements, and

Y. S. Liu; J. Y. Wang; H. L. Long

2010-01-01

327

Transaction cost analysis in redeveloping indigenous lands in Malaysia Analiza costurilor de tranzacie în reamenajarea terenurilor indigene în Malaezia  

Microsoft Academic Search

Land supply constraints restrict the flow of land supply onto the land market for development purposes. It disturbs the effectiveness of the land market. As a result, the underutilized area may become derelict and needs regeneration as part of urban renewal programs. The study begins with discussion on transaction costs within institutional economics analysis. In particular, the review on literature

N. D. PRIJONO

2009-01-01

328

Green Infrastructure & Sustainable Urban Land Use Decision Analysis Workshop  

EPA Science Inventory

Introduce green infrastructure, concepts and land use alternatives, to City of Cleveland operations staff. Discuss potential of green alternatives to impact daily operations and routine maintenance activities. Tie in sustainability concepts to long-term City planning and discu...

329

Manifesting Destiny: A Land Education Analysis of Settler Colonialism in Jamestown, Virginia, USA  

ERIC Educational Resources Information Center

Globally, colonization has been and continues to be enacted in the take-over of Indigenous land and the subsequent conversion of agriculture from diverse food and useful crops to large-scale monoculture and cash crops. This article uses a land education analysis to map the rise of the ideology and practices of Manifest Destiny in Virginia.…

McCoy, Kate

2014-01-01

330

Land disposal of water treatment plant sludge -- A feasibility analysis  

SciTech Connect

In this study, the following alternative disposal methods for the Buffalo Pound Water Treatment Sludge were evaluated: landfilling, discharge into sanitary sewers, long-term lagooning, use in manufacturing, co-composting, alum recovery and land application. Land application was chosen at the best disposal alternative. Preliminary design resulted in a 1% dry alum sludge loading rate (25 tonnes/ha), requiring 35 ha over a nine-year period and a phosphorus fertilizer supplement of about 50kg/ha.

Viraraghavan, T.; Multon, L.M.; Wasylenchuk, E.J.

1998-07-01

331

Estimating impacts of land use on groundwater quality using trilinear analysis.  

PubMed

Groundwater is connected to the landscape above and is thus affected by the overlaying land uses. This study evaluated the impacts of land uses upon groundwater quality using trilinear analysis. Trilinear analysis is a display of experimental data in a triangular graph. Groundwater quality data collected from agricultural, septic tank, forest, and wastewater land uses for a 6-year period were used for the analysis. Results showed that among the three nitrogen species (i.e., nitrate and nitrite (NO(x)), dissolved organic nitrogen (DON), and total organic nitrogen (TON)), NO(x) had a high percentage and was a dominant species in the groundwater beneath the septic tank lands, whereas TON was a major species in groundwater beneath the forest lands. Among the three phosphorus species, namely the particulate phosphorus (PP), dissolved ortho phosphorus (PO4(3-)) and dissolved organic phosphorus (DOP), there was a high percentage of PP in the groundwater beneath the septic tank, forest, and agricultural lands. In general, Ca was a dominant cation in the groundwater beneath the septic tank lands, whereas Na was a dominant cation in the groundwater beneath the forest lands. For the three major anions (i.e., F(-), Cl(-), and SO4(2-)), F(-) accounted for <1% of the total anions in the groundwater beneath the forest, wastewater, and agricultural lands. Impacts of land uses on groundwater Cd and Cr distributions were not profound. This study suggests that trilinear analysis is a useful technique to characterize the relationship between land use and groundwater quality. PMID:24802588

Ouyang, Ying; Zhang, Jia En; Cui, Lihua

2014-09-01

332

Architecture of the global land acquisition system: applying the tools of network science to identify key vulnerabilities  

NASA Astrophysics Data System (ADS)

Global land acquisitions, often dubbed ‘land grabbing’ are increasingly becoming drivers of land change. We use the tools of network science to describe the connectivity of the global acquisition system. We find that 126 countries participate in this form of global land trade. Importers are concentrated in the Global North, the emerging economies of Asia, and the Middle East, while exporters are confined to the Global South and Eastern Europe. A small handful of countries account for the majority of land acquisitions (particularly China, the UK, and the US), the cumulative distribution of which is best described by a power law. We also find that countries with many land trading partners play a disproportionately central role in providing connectivity across the network with the shortest trading path between any two countries traversing either China, the US, or the UK over a third of the time. The land acquisition network is characterized by very few trading cliques and therefore characterized by a low degree of preferential trading or regionalization. We also show that countries with many export partners trade land with countries with few import partners, and vice versa, meaning that less developed countries have a large array of export partnerships with developed countries, but very few import partnerships (dissassortative relationship). Finally, we find that the structure of the network is potentially prone to propagating crises (e.g., if importing countries become dependent on crops exported from their land trading partners). This network analysis approach can be used to quantitatively analyze and understand telecoupled systems as well as to anticipate and diagnose the potential effects of telecoupling.

Seaquist, J. W.; Li Johansson, Emma; Nicholas, Kimberly A.

2014-11-01

333

Assessing sustainable land-use practices using geographic information systems  

NASA Astrophysics Data System (ADS)

Many prominent scientists have claimed that we need to develop environmentally sustainable practices otherwise societies may collapse. The use of Geographic Information Systems allows detailed studies that can cross disciplinary boundaries and lead to quantifiable statements as to the change of land use practices that took place in the past and those that may occur in the future. This dissertation focuses on two research topics. One that attempts to quantify the environmental consequences of parking lots located in the Midwest, USA. The other research topic focuses on the land area needed to support ethanol in the United States. In Tippecanoe County, Indiana, it was determined that parking lots occupied approximately 6.6% of the urban areas, that the area devoted to parking lots exceeded the area devoted to urban parks by a factor of 3, and that these parking lots contributed to increased runoff of pollutants. The parking lots of Tippecanoe County were estimated to be responsible for 46.5 thousand pounds of oil and grease released annually in runoff, as well as an increase of 240.6 thousand pounds of suspended solids, and 65.7 pounds of lead released when compared to pre-development conditions. A method that scales up the county wide study was also developed to determine the areal footprint of parking lots with the states of Illinois, Indiana, Michigan and Wisconsin. It was estimated that these four states allocate approximately 1260 square km of their land to parking lots and that this accounts for 4.97% of urban land use and over 43 million parking spaces, whereas the number of individuals in age of driving (adults over 18 years old) amounted to just over 25 million. Within the four states studied, states where urban sprawl was considered more prevalent were also states that had a higher proportion of their urban land devoted to parking lots. The second dissertation topic focused on using GIS to locate suitable sites for corn or cellulosic based ethanol production facilities. Since a valuable byproduct of corn ethanol production is Distiller's Grain Solubles (DGS), siting of ethanol plants was considered with regard to both corn production by county within the conterminous United States and head of cattle available to use this output as feed. We found that many counties outside the Midwest could sustain smaller sized ethanol plants, especially when considering that most large production facilities need to redistribute their DGS in dried form sometimes as far as California which has negative impacts on the Net Energy Value of corn based ethanol. The future of ethanol expansion however lies with cellulosic feedstock which is bulkier and thus more costly to transport than corn. Our results indicate that cellulosic ethanol plants should be smaller in capacity, especially when compared to corn ethanol plants where 100 million gallons a year (mgy) plants are more the norm. Only 7 out of 3109 counties in the conterminous United States contain enough wood, switchgrass or crop residue feedstock to sustain plants that produce greater than 40 mgy of biofuel, meaning that larger plants would need to import feedstock from considerable distances and thus incur greater feedstock transport costs. The last section explored co-location options for siting lignocellulosic ethanol plant production facilities.

Davis, Amelie Y.

334

Using GIS and outranking multicriteria analysis for land-use suitability assessment  

Microsoft Academic Search

Land-useplanners oftenmake complexdecisionswithin a shortperiod of time when they must take into account sustainable developmentand economic competitiveness. A set of land-use suitability maps would be very useful in this respect.Ideally, thesemapsshouldincorporatecomplexcriteriaintegratingseveral stakeholders' points of view. To illustrate the feasibility of this approach, a land suitability map for housing was realised for a small region of Switzerland. Geographical Information System technology

Florent Joerin; Marius Thériault; André Musy

2001-01-01

335

23 CFR 971.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Federal lands bridge management system (BMS). 971.210...Systems § 971.210 Federal lands bridge management system (BMS). In addition...partnership shall have a BMS for the FH bridges funded under the FLHP and required...

2010-04-01

336

23 CFR 973.210 - Indian lands bridge management system (BMS).  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Indian lands bridge management system (BMS). 973.210...Management Systems § 973.210 Indian lands bridge management system (BMS). In addition...for the federally and tribally owned IRR bridges that are funded under the FLHP and...

2010-04-01

337

Land Tenure and the Cadastral System of Mali University of Maine, Department of Spatial Information Engineering  

E-print Network

is an introduction to the history of land tenure and cadastral systems in the sub-Saharan country of Mali in West Africa. Mali is today one of the poorest of the developing countries and has been the frequent recipient systems are adequate. This report surveys the existing land tenure and cadastral system in the sub

Onsrud, Harlan J.

338

Application of Adaptive Type2 Fuzzy CMAC to Automatic Landing System  

Microsoft Academic Search

Computational intelligence that utilizes adaptive fuzzy cerebellar model articulation controller (FCMAC) to aircraft automatic landing system is proposed in this paper. The proposed intelligent scheme uses CMAC and type-2 fuzzy system. Current flight control law is adopted in the controller design. Lyapunov stability theory is applied to obtain adaptive learning rule and to guarantee stability of the automatic landing system.

Teng-Chieh Yang; Jih-Gau Juang

2010-01-01

339

Results from Assimilating AMSR-E Soil Moisture Estimates into a Land Surface Model Using an Ensemble Kalman Filter in the Land Information System  

NASA Technical Reports Server (NTRS)

Improve simulations of soil moisture/temperature, and consequently boundary layer states and processes, by assimilating AMSR-E soil moisture estimates into a coupled land surface-mesoscale model Provide a new land surface model as an option in the Land Information System (LIS)

Blankenship, Clay B.; Crosson, William L.; Case, Jonathan L.; Hale, Robert

2010-01-01

340

Analysis of Renewable Energy Potential on U. S. National Forest Lands  

SciTech Connect

In 2005, the National Renewable Energy Laboratory (NREL) completed an assessment of the potential for solar and wind energy development on National Forest System (NFS) public lands managed by the US Department of Agriculture, U.S. Forest Service (USFS). This report provides an update of the analysis in the NREL report, and extends the analysis with additional siting factors for solar and wind energy. It also expands the scope to biomass and geothermal energy resources. Hydropower is acknowledged as another major renewable energy source on NFS lands; however, it was not analyzed in this project primarily because of the substantially different analysis that would be needed to identify suitable locations. Details about each renewable energy production technology included in the study are provided following the report introduction, including how each resource is converted to electrical power, and examples of existing power plants. The analysis approach was to use current and available Geographic Information System (GIS) data to map the distribution of the subject renewable energy resources, major siting factors, and NFS lands. For each major category of renewable energy power production, a set of siting factors were determined, including minimum levels for the renewable energy resources, and details for each of the other siting factors. Phase 1 of the analysis focused on replicating and updating the 2005 NREL analysis, and Phase 2 introduced additional siting factors and energy resources. Source data were converted to a cell?based format that helped create composite maps of locations meeting all the siting criteria. Acreages and potential power production levels for NFS units were tabulated and are presented throughout this report and the accompanying files. NFS units in the southwest United States were found to have the most potentially suitable land for concentrating solar power (CSP), especially in Arizona and New Mexico. In total, about 136,032 acres of NFS lands were found potentially suitable for CSP development, potentially yielding as much as 13,603 megawatts (MW) of electricity, assuming 10 acres per MW. For photovoltaic solar power (PV), the top NFS units were more widely distributed than CSP. Notably, more than 150,000 acres in Comanche National Grassland in Colorado were found to be potentially suitable for PV development, accounting for more than 25% of the potentially suitable NFS lands combined. In total, about 564,698 acres of NFS lands were found potentially suitable for PV development, potentially yielding as much as 56,469 MW of electricity, assuming 10 acres per MW. NFS units most suitable for wind power are concentrated in the northern Great Plains. In total, about 3,357,792 acres of NFS lands were found potentially suitable for wind development, potentially yielding as much as 67,156 MW of electricity, assuming 50 acres per MW. Of that area, 571,431 acres (11,429 MW) are located within the Bankhead?Jones Farm Tenant Act Land in Montana. NFS lands in Alaska have considerable wind resources, but other siting factors eliminated almost the entire area. The southwest coast of Chugach National Forest, near Seward, Alaska, maintains the majority of the remaining acreage. NFS units with highly suitable biomass resources are located from Idaho to Louisiana. In total, about 13,967,077 acres of NFS lands are potentially highly suitable for biomass from logging and thinning residue development. Of that, 1,542,247 acres is located in Fremont?Winema National Forest in Oregon. Not surprisingly, most NFS units have at least some level of potentially suitable biomass resources. In general, biomass resources such as these could significantly offset consumption of coal and petroleum?based fuels. NFS units deemed potentially highly suitable for enhanced geothermal system (EGS) development were distributed widely from California to Virginia, accounting for some 6,475,459 acres. Mark Twain National Forest in Missouri has the largest area of all the NFS units, with 900,637 acres. While more rigorous studies are needed

Zvolanek, E. [Environmental Science Division] [Environmental Science Division; Kuiper, J. [Environmental Science Division] [Environmental Science Division; Carr, A. [Environmental Science Division] [Environmental Science Division; Hlava, K.

2013-12-13

341

77 FR 8895 - Public Land Order No. 7788; Withdrawal of National Forest System Land for the Red Cloud...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Withdrawal of National Forest System Land for the Red Cloud Campground; New Mexico AGENCY: Bureau...historical interpretive integrity of the Red Cloud Campground within the Cibola National...capital investment expended to develop the Red Cloud Campground facility and the...

2012-02-15

342

78 FR 58555 - Public Land Order No. 7821; Withdrawal of National Forest System Land for Steamboat Rock Picnic...  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Forest System Land for Steamboat Rock Picnic Grounds; South Dakota AGENCY...uses and improvements at the Steamboat Rock Picnic Grounds within the Black Hills National...uses and improvements within the Steamboat Rock Picnic Grounds. Order By virtue of...

2013-09-24

343

A prototype Global Drought Information System based on multiple land surface models  

NASA Astrophysics Data System (ADS)

Droughts are pervasive natural hazards, which cause large economic losses and human suffering. While the absolute magnitude of these losses is greatest in the developed world, the relative impact is much higher in the developing world. Nonetheless, our ability to monitor and predict the development and occurrence of droughts at a global scale in near real-time is limited. This ability is of particular importance in estimating regional crop production and thus current and future prices of agricultural commodities, as well as the implementation of emergency measures in areas where the effects of drought threaten lives and livelihoods. We describe the implementation of a multi-model drought monitoring system, which provides near real-time estimates of soil moisture conditions for the global land areas between 50S and 50N with a latency of about one day. The system is an extension of similar systems developed by both the University of Washington and the National Centers for Environmental Prediction for use in the U.S. Drought Monitor. Global application of the protocols used in the U.S. systems poses new challenges, particularly with respect to the generation of meteorological forcings with which to drive the land surface models used in such a system. The global system we describe uses satellite-based precipitation (as contrasted with gridded station data in the U.S. systems) as well as temperature estimates based on global weather model analysis fields to track the evolution of soil moisture in near real-time at a spatial resolution of 0.5 degree using multiple land surface models. By comparing the modeled, near real-time soil moisture values with the results from long-term retrospective simulations, the model estimates can be placed in historic context (as soil moisture percentiles) and used to monitor the development of droughts around the world. We evaluate the performance of our system for historic droughts, and compare with other drought analyses and analytical data.

Nijssen, Bart; Shukla, Shrad; Lin, Chi-Yu; Lettenmaier, Dennis

2013-04-01

344

Some findings on the applications of ERTS and Skylab imagery for metropolitan land use analysis  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Work undertaken on a three-sensor land use data evaluation for a portion of the Phoenix area is reported. Analyses between land use data generated from 1970 high altitude photography and that detectable from ERTS and Skylab, especially in terms of changes in land use indicate that ERTS and Skylab imagery can be used effectively to detect and identify areas of post-1970 land use change, especially those documenting urban expansion at the rural-urban fringe. Significant preliminary findings on the utility of ERTS and Skylab data for metropolitan land use analysis, substantiated by evaluation with 1970 and 1972 ground control land use data are reported.

Alexander, R. H. (principal investigator); Milazzo, V. A.

1974-01-01

345

[GIS-based analysis of the land suitability for manure application in the northeastern provinces].  

PubMed

As an important industrial and grain production base of China, livestock and poultry industry have been rapidly developed in the northeastern provinces. With the rapid increasing amount of animal production, how to handle the huge amount of animal manure has become a critical issue for local government. A quantitative analysis based on geographic information system (GIS) combining the biophysical, environmental, social and economic factors was applied to determine the land suitability for manure application in the northeastern provinces. The results show that a farmland area of 211942.7 km2, accounting for 78.9% of the cultivated land in three northeastern provinces, is estimated to be suitable for manure application. The suitable farmlands are mostly distributed in Heilongjiang and Jilin provinces. Proximity to residential area, water body and roads are identified as the primary factors influencing the manure application, while rainfall is the main factor to generate discrepancies in different areas. Furthermore, the future potential capacity for animal production in three provinces was forecasted based on the areas of suitable land and the population of existing livestock production. Among 36 cities of three provinces, the big variation is observed, Siping City is overproducing 1.813 million heads of pig unit at present, but Qiqihaer City still has the potential to rear 11.203 million heads of pig unit. Overall, eastern region of the study area holds the high potential for animal production with a surplus capacity of 2.842 million heads of pig unit, the potential of the typical mountain and forest areas is only 10% of eastern region, however. In contrast, in half of western region (central Liaoning province and central Jilin Province), their animal populations have exceeded the land carrying capacity. Therefore, we strongly suggest a site-specific animal production and manure application guide to achieve a sustainable development of livestock production in the northeastern provinces. PMID:20527197

Li, Yan-xia; Li, Wei; Han, Wei; Yang, Ming; Dong, Yun-she; Lin, Chun-ye; Zhang, Feng-song; Xiong, Xiong

2010-04-01

346

Simulating feedbacks in land use and land cover change models  

Microsoft Academic Search

In spite of the many advances in land use and land cover change modelling over the past decade many challenges remain. One\\u000a of these challenges relates to the explicit treatment of feedback mechanisms in descriptive models of the land use system.\\u000a This paper argues for model-based analysis to explore the role of feedback mechanisms as determinants of land use dynamics

Peter H. Verburg

2006-01-01

347

23 CFR 970.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2010 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.212 Federal lands safety management system (SMS). In addition...location, description of event, severity, weather and...

2010-04-01

348

23 CFR 973.212 - Indian lands safety management system (SMS).  

Code of Federal Regulations, 2011 CFR

...212 Indian lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.” 3 3 “Safety Management Systems: Good Practices...framework for an SMS: (1) A database and an ongoing program...

2011-04-01

349

23 CFR 972.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2013 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance and reporting of a database that includes:...

2013-04-01

350

23 CFR 972.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2011 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance and reporting of a database that includes:...

2011-04-01

351

23 CFR 972.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2011 CFR

... FISH AND WILDLIFE SERVICE MANAGEMENT SYSTEMS Fish and Wildlife Service Management Systems § 972.210 Federal lands bridge management system (BMS). In addition...framework for a BMS: (1) A database and an ongoing program...

2011-04-01

352

23 CFR 973.212 - Indian lands safety management system (SMS).  

Code of Federal Regulations, 2014 CFR

...212 Indian lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.” 3 3 “Safety Management Systems: Good Practices...framework for an SMS: (1) A database and an ongoing program...

2014-04-01

353

23 CFR 970.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2012 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.210 Federal lands bridge management system (BMS). In addition...following components: (1) A database and an ongoing program...

2012-04-01

354

23 CFR 971.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2013 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance, and reporting of a database that includes:...

2013-04-01

355

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2013 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition...framework for a PMS: (1) A database and an ongoing program...

2013-04-01

356

23 CFR 970.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2014 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.210 Federal lands bridge management system (BMS). In addition...following components: (1) A database and an ongoing program...

2014-04-01

357

23 CFR 972.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2014 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance and reporting of a database that includes:...

2014-04-01

358

23 CFR 973.212 - Indian lands safety management system (SMS).  

Code of Federal Regulations, 2013 CFR

...212 Indian lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.” 3 3 “Safety Management Systems: Good Practices...framework for an SMS: (1) A database and an ongoing program...

2013-04-01

359

23 CFR 971.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2014 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance, and reporting of a database that includes:...

2014-04-01

360

23 CFR 970.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2011 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.210 Federal lands bridge management system (BMS). In addition...following components: (1) A database and an ongoing program...

2011-04-01

361

23 CFR 972.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2013 CFR

... FISH AND WILDLIFE SERVICE MANAGEMENT SYSTEMS Fish and Wildlife Service Management Systems § 972.210 Federal lands bridge management system (BMS). In addition...framework for a BMS: (1) A database and an ongoing program...

2013-04-01

362

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2011 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition...framework for a PMS: (1) A database and an ongoing program...

2011-04-01

363

23 CFR 970.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2013 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.210 Federal lands bridge management system (BMS). In addition...following components: (1) A database and an ongoing program...

2013-04-01

364

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2012 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition...framework for a PMS: (1) A database and an ongoing program...

2012-04-01

365

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2014 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition...framework for a PMS: (1) A database and an ongoing program...

2014-04-01

366

23 CFR 972.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2014 CFR

... FISH AND WILDLIFE SERVICE MANAGEMENT SYSTEMS Fish and Wildlife Service Management Systems § 972.210 Federal lands bridge management system (BMS). In addition...framework for a BMS: (1) A database and an ongoing program...

2014-04-01

367

23 CFR 971.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2012 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance, and reporting of a database that includes:...

2012-04-01

368

23 CFR 973.212 - Indian lands safety management system (SMS).  

Code of Federal Regulations, 2012 CFR

...212 Indian lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.” 3 3 “Safety Management Systems: Good Practices...framework for an SMS: (1) A database and an ongoing program...

2012-04-01

369

23 CFR 972.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2012 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance and reporting of a database that includes:...

2012-04-01

370

23 CFR 971.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2011 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance, and reporting of a database that includes:...

2011-04-01

371

23 CFR 972.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2012 CFR

... FISH AND WILDLIFE SERVICE MANAGEMENT SYSTEMS Fish and Wildlife Service Management Systems § 972.210 Federal lands bridge management system (BMS). In addition...framework for a BMS: (1) A database and an ongoing program...

2012-04-01

372

23 CFR 971.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2010 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance, and reporting of a database that includes:...

2010-04-01

373

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition...framework for a PMS: (1) A database and an ongoing program...

2010-04-01

374

23 CFR 970.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2010 CFR

...HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.210 Federal lands bridge management system (BMS). In addition...following components: (1) A database and an ongoing program...

2010-04-01

375

23 CFR 972.210 - Federal lands bridge management system (BMS).  

Code of Federal Regulations, 2010 CFR

... FISH AND WILDLIFE SERVICE MANAGEMENT SYSTEMS Fish and Wildlife Service Management Systems § 972.210 Federal lands bridge management system (BMS). In addition...framework for a BMS: (1) A database and an ongoing program...

2010-04-01

376

23 CFR 973.212 - Indian lands safety management system (SMS).  

Code of Federal Regulations, 2010 CFR

...212 Indian lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.” 3 3 “Safety Management Systems: Good Practices...framework for an SMS: (1) A database and an ongoing program...

2010-04-01

377

23 CFR 972.212 - Federal lands safety management system (SMS).  

Code of Federal Regulations, 2010 CFR

...212 Federal lands safety management system (SMS). In addition...the guidance in “Safety Management Systems: Good Practices for...Implementation.”3 3 “Safety Management Systems: Good Practices...maintenance and reporting of a database that includes:...

2010-04-01

378

Flight test evaluation of the Stanford University/United Airlines differential GPS Category 3 automatic landing system  

NASA Technical Reports Server (NTRS)

Test flights were conducted to evaluate the capability of Differential Global Positioning System (DGPS) to provide the accuracy and integrity required for International Civil Aviation Organization (ICAO) Category (CAT) 3 precision approach and landings. These test flights were part of a Federal Aviation Administration (FAA) program to evaluate the technical feasibility of using DGPS based technology for CAT 3 precision approach and landing applications. A United Airlines Boeing 737-300 (N304UA) was equipped with DGPS receiving equipment and additional computing capability provided by Stanford University. The test flights were conducted at NASA Ames Research Center's Crows Landing Flight Facility, Crows Landing, California. The flight test evaluation was based on completing 100 approaches and autolandings; 90 touch and go, and 10 terminating with a full stop. Two types of accuracy requirements were evaluated: 1) Total system error, based on the Required Navigation Performance (RNP), and 2) Navigation sensor error, based on ICAO requirements for the Microwave Landing System (MLS). All of the approaches and autolandings were evaluated against ground truth reference data provided by a laser tracker. Analysis of these approaches and autolandings shows that the Stanford University/United Airlines system met the requirements for a successful approach and autolanding 98 out of 100 approaches and autolandings, based on the total system error requirements as specified in the FAA CAT 3 Level 2 Flight Test Plan.

Kaufmann, David N.; Ncnally, B. David

1995-01-01

379

Integrated dynamic landscape analysis and modeling system (IDLAMS) : installation manual.  

SciTech Connect

The Integrated Dynamic Landscape Analysis and Modeling System (IDLAMS) is a prototype, integrated land management technology developed through a joint effort between Argonne National Laboratory (ANL) and the US Army Corps of Engineers Construction Engineering Research Laboratories (USACERL). Dr. Ronald C. Sundell, Ms. Pamela J. Sydelko, and Ms. Kimberly A. Majerus were the principal investigators (PIs) for this project. Dr. Zhian Li was the primary software developer. Dr. Jeffrey M. Keisler, Mr. Christopher M. Klaus, and Mr. Michael C. Vogt developed the decision analysis component of this project. It was developed with funding support from the Strategic Environmental Research and Development Program (SERDP), a land/environmental stewardship research program with participation from the US Department of Defense (DoD), the US Department of Energy (DOE), and the US Environmental Protection Agency (EPA). IDLAMS predicts land conditions (e.g., vegetation, wildlife habitats, and erosion status) by simulating changes in military land ecosystems for given training intensities and land management practices. It can be used by military land managers to help predict the future ecological condition for a given land use based on land management scenarios of various levels of training intensity. It also can be used as a tool to help land managers compare different land management practices and further determine a set of land management activities and prescriptions that best suit the needs of a specific military installation.

Li, Z.; Majerus, K. A.; Sundell, R. C.; Sydelko, P. J.; Vogt, M. C.

1999-02-24

380

Integrated dynamic landscape analysis and modeling system (IDLAMS) : programmer's manual.  

SciTech Connect

The Integrated Dynamic Landscape Analysis and Modeling System (IDLAMS) is a prototype, integrated land management technology developed through a joint effort between Argonne National Laboratory (ANL) and the US Army Corps of Engineers Construction Engineering Research Laboratories (USACERL). Dr. Ronald C. Sundell, Ms. Pamela J. Sydelko, and Ms. Kimberly A. Majerus were the principal investigators (PIs) for this project. Dr. Zhian Li was the primary software developer. Dr. Jeffrey M. Keisler, Mr. Christopher M. Klaus, and Mr. Michael C. Vogt developed the decision analysis component of this project. It was developed with funding support from the Strategic Environmental Research and Development Program (SERDP), a land/environmental stewardship research program with participation from the US Department of Defense (DoD), the US Department of Energy (DOE), and the US Environmental Protection Agency (EPA). IDLAMS predicts land conditions (e.g., vegetation, wildlife habitats, and erosion status) by simulating changes in military land ecosystems for given training intensities and land management practices. It can be used by military land managers to help predict the future ecological condition for a given land use based on land management scenarios of various levels of training intensity. It also can be used as a tool to help land managers compare different land management practices and further determine a set of land management activities and prescriptions that best suit the needs of a specific military installation.

Klaus, C. M.; Li, Z.; Majerus, K. A.; Sundell, R. C.; Sydelko, P. J.; Vogt, M. C.

1999-02-24

381

Derivative hyperspectral image analysis for land use classification  

NASA Astrophysics Data System (ADS)

As hyperspectral remote sensing data become commonly available, researchers need an effective tool specifically designed for analyzing this new type of data. Derivative analysis has been proved a useful tool capable of detecting subtle information from hyperspectral data sets. However, there are no systematic procedures for effectively applying derivative analysis to remote sensing hyperspectral images yet. This research developed a systematic procedure for using derivative analysis to help improve supervised classification of hyperspectral images. The algorithm allows investigators to identify derivative features better separating target classes according to the Jeffries-Matusita distances between classes. These features can be added into the classification image in order to improve the classification result. A maximum likelihood classification for vegetation was used as an example in this research. It demonstrated the effectiveness of using derivatives to detect useful information that might be lost during feature reduction operations. Classification accuracies of classes that were poorly classified in a 10-band principal component image gradually improved as more appropriate derivative features were extracted from the original image and appended to the base image. With the data set used in this study, derivative analysis did not generally provide a better performance than principal component analysis, but it may be suitable for some data sets and applications. The procedure developed in this research can be used as a starting point for subsequently designing an advanced system to systematically analyze hyperspectral images for remote sensing applications.

Tsai, Fu-An

382

Anticipating forest and range land development in central Oregon (USA) for landscape analysis, with an example application involving mule deer.  

PubMed

Forest policymakers, public lands managers, and scientists in the Pacific Northwest (USA) seek ways to evaluate the landscape-level effects of policies and management through the multidisciplinary development and application of spatially explicit methods and models. The Interagency Mapping and Analysis Project (IMAP) is an ongoing effort to generate landscape-wide vegetation data and models to evaluate the integrated effects of disturbances and management activities on natural resource conditions in Oregon and Washington (USA). In this initial analysis, we characterized the spatial distribution of forest and range land development in a four-county pilot study region in central Oregon. The empirical model describes the spatial distribution of buildings and new building construction as a function of population growth, existing development, topography, land-use zoning, and other factors. We used the model to create geographic information system maps of likely future development based on human population projections to inform complementary landscape analyses underway involving vegetation, habitat, and wildfire interactions. In an example application, we use the model and resulting maps to show the potential impacts of future forest and range land development on mule deer (Odocoileus hemionus) winter range. Results indicate significant development encroachment and habitat loss already in 2000 with development located along key migration routes and increasing through the projection period to 2040. The example application illustrates a simple way for policymakers and public lands managers to combine existing data and preliminary model outputs to begin to consider the potential effects of development on future landscape conditions. PMID:20300934

Kline, Jeffrey D; Moses, Alissa; Burcsu, Theresa

2010-05-01

383

Anticipating Forest and Range Land Development in Central Oregon (USA) for Landscape Analysis, with an Example Application Involving Mule Deer  

NASA Astrophysics Data System (ADS)

Forest policymakers, public lands managers, and scientists in the Pacific Northwest (USA) seek ways to evaluate the landscape-level effects of policies and management through the multidisciplinary development and application of spatially explicit methods and models. The Interagency Mapping and Analysis Project (IMAP) is an ongoing effort to generate landscape-wide vegetation data and models to evaluate the integrated effects of disturbances and management activities on natural resource conditions in Oregon and Washington (USA). In this initial analysis, we characterized the spatial distribution of forest and range land development in a four-county pilot study region in central Oregon. The empirical model describes the spatial distribution of buildings and new building construction as a function of population growth, existing development, topography, land-use zoning, and other factors. We used the model to create geographic information system maps of likely future development based on human population projections to inform complementary landscape analyses underway involving vegetation, habitat, and wildfire interactions. In an example application, we use the model and resulting maps to show the potential impacts of future forest and range land development on mule deer ( Odocoileus hemionus) winter range. Results indicate significant development encroachment and habitat loss already in 2000 with development located along key migration routes and increasing through the projection period to 2040. The example application illustrates a simple way for policymakers and public lands managers to combine existing data and preliminary model outputs to begin to consider the potential effects of development on future landscape conditions.

Kline, Jeffrey D.; Moses, Alissa; Burcsu, Theresa

2010-05-01

384

Land reclamation information system of mining area based on GIS  

Microsoft Academic Search

Land reclamation of mining area is an interdisciplinary. The data to be dealt with involves the fields of mining, geology, geography, soil, agriculture and forest, biology, society, economy, etc, with the characteristic of plenty of data and complicated relationship. The traditional data processing cannot meet the demand of land reclamation. The research is based on the result of prevenient scholars

Quiji Chen; Zhenqi Hu; Chuanghua Liu; Jianghua Gu; Yongping Wang

2007-01-01

385

Annual Report 2008 / 2009 Faculty of Land and Food Systems  

E-print Network

, water shortages, and famine. These are issues that affect every single person on the planet. We are all day, all around us, we see evidence of the havoc that has been wreaked upon the earth. Global warming, a sustainable food supply and the responsible use of finite land and water resources. #12;Faculty of Land

Farrell, Anthony P.

386

Landing Characteristics of the Apollo Spacecraft with Deployed Heat Shield Impact Attenuation System  

NASA Technical Reports Server (NTRS)

Landing Characteristics of the Apollo Spacecraft with Deployed Heat Shield Impact Attenuation Systems. An experimental investigation was made to determine the landing characteristics of a 1/4-scale dynamic model of the Apollo spacecraft command module using two different active (heat shield deployed prior to landing) landing systems for impact attenuation. One landing system (configuration 1) consisted of six hydraulic struts and eight crushable honeycomb struts. The other landing system (configuration 2), consisted of four hydraulic struts and six strain straps. Tests made on water and the hard clay-gravel composite landing surfaces simulated parachute letdown (vertical) velocities of 23 ft/sec (7.0 m/s) (full scale). Landings made on the sand landing surface simulated vertical velocities of 30 ft/sec (9.1 m/s). Horizontal velocities of from 0 to 50 ft/sec (15 m/s) were simulated. Landing attitudes ranged from -30'degrees to 20 degrees, and the roll attitudes were O degrees, 90 degrees, and 180 degrees. For configuration 1, maximum normal accelerations at the vehicle center of gravity for landings on water, sand, and the hard clay-gravel composite surface were 9g, 20g, and 18g, respectively. The maximum normal center-of-gravity acceleration for configuration 2 which was landed only on the hard clay-gravel landing surface was approximately 19g. Accelerations for configuration 2 were generally equal to or lower than accelerations for configuration 1 and normal. [Entire movie available on DVD from CASI as Doc ID 20070030975. Contact help@sti.nasa.gov

1965-01-01

387

Experimental and analytical studies of advanced air cushion landing systems  

NASA Technical Reports Server (NTRS)

Several concepts are developed for air cushion landing systems (ACLS) which have the potential for improving performance characteristics (roll stiffness, heave damping, and trunk flutter), and reducing fabrication cost and complexity. After an initial screening, the following five concepts were evaluated in detail: damped trunk, filled trunk, compartmented trunk, segmented trunk, and roll feedback control. The evaluation was based on tests performed on scale models. An ACLS dynamic simulation developed earlier is updated so that it can be used to predict the performance of full-scale ACLS incorporating these refinements. The simulation was validated through scale-model tests. A full-scale ACLS based on the segmented trunk concept was fabricated and installed on the NASA ACLS test vehicle, where it is used to support advanced system development. A geometrically-scaled model (one third full scale) of the NASA test vehicle was fabricated and tested. This model, evaluated by means of a series of static and dynamic tests, is used to investigate scaling relationships between reduced and full-scale models. The analytical model developed earlier is applied to simulate both the one third scale and the full scale response.

Lee, E. G. S.; Boghani, A. B.; Captain, K. M.; Rutishauser, H. J.; Farley, H. L.; Fish, R. B.; Jeffcoat, R. L.

1981-01-01

388

Development of automatic and manual flight director landing systems for the XV-15 tilt rotor aircraft in helicopter mode  

NASA Technical Reports Server (NTRS)

The objective of this effort is to determine IFR approach path and touchdown dispersions for manual and automatic XV-15 tilt rotor landings, and to develop missed approach criteria. Only helicopter mode XV-15 operation is considered. The analysis and design sections develop the automatic and flight director guidance equations for decelerating curved and straight-in approaches into a typical VTOL landing site equipped with an MLS navigation aid. These system designs satisfy all known pilot-centered, guidance and control requirements for this flying task. Performance data, obtained from nonstationary covariance propagation dispersion analysis for the system, are used to develop the approach monitoring criteria. The autoland and flight director guidance equations are programmed for the VSTOLAND 1819B digital computer. The system design dispersion data developed through analysis and the 1819B digital computer program are verified and refined using the fixed-base, man-in-the-loop XV-15 VSTOLAND simulation.

Hofmann, L. G.; Hoh, R. H.; Jewell, W. F.; Teper, G. L.; Patel, P. D.

1978-01-01

389

Model-Checking Real-Time Properties of an Aircraft Landing Gear System  

E-print Network

Model-Checking Real-Time Properties of an Aircraft Landing Gear System Using Fiacre Bernard with modeling the landing gear system of an aircraft using the formal specification language Fiacre. Our model but also to find a safe bound on the maximal time needed for all gears to be down and locked (assuming

Paris-Sud XI, Université de

390

Research Article: A GIS-embedded system to support land consolidation plans in Galicia  

Microsoft Academic Search

Land consolidation is a strategic instrument for rural planning and thus economic development in the Spanish region of Galicia. This paper describes an experimental system embedded in a GIS environment to aid rural engineers to develop land consolidation plans. The system supports all the stages of the plan and many functionalities are implemented as heuristic processes based on expert knowledge

Juan Touriño; Jorge Parapar; Ramon Doallo; Marcos Boullón; Francisco F. Rivera; Javier D. Bruguera; Xesús P. González; Rafael Crecente; Carlos Álvarez

2003-01-01

391

IMPLEMENTATION AND APPLICATION OF THE KALMAN FILTER DATA ASSIMILATION APPROACHES IN NASA'S LAND INFORMATION SYSTEM INFRASTRUCTURE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Building on the North-American and Global Land Data Assimilation Systems (LDAS), a Land Information System (LIS) infrastructure has been developed at NASA Goddard Space Flight Center jointly with NOAA-NCEP, NWS and university collaborators. In the context of numerical weather prediction applications...

392

A Generic, Interoperable, Hydrologic Data Assimilation Framework using the Land Information System  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land Information System (LIS; http://lis.gsfc.nasa.gov) is a hydrologic modeling system that integrates the use of various community land surface models, use of ground and satellite-based observations, and high performance computing and data management tools to enable hydrologic prediction at variou...

393

Cross-Site Comparison of Land-Use Decision-Making and Its Consequences across Land Systems with a Generalized Agent-Based Model  

PubMed Central

Local changes in land use result from the decisions and actions of land-users within land systems, which are structured by local and global environmental, economic, political, and cultural contexts. Such cross-scale causation presents a major challenge for developing a general understanding of how local decision-making shapes land-use changes at the global scale. This paper implements a generalized agent-based model (ABM) as a virtual laboratory to explore how global and local processes influence the land-use and livelihood decisions of local land-users, operationalized as settlement-level agents, across the landscapes of six real-world test sites. Test sites were chosen in USA, Laos, and China to capture globally-significant variation in population density, market influence, and environmental conditions, with land systems ranging from swidden to commercial agriculture. Publicly available global data were integrated into the ABM to model cross-scale effects of economic globalization on local land-use decisions. A suite of statistics was developed to assess the accuracy of model-predicted land-use outcomes relative to observed and random (i.e. null model) landscapes. At four of six sites, where environmental and demographic forces were important constraints on land-use choices, modeled land-use outcomes were more similar to those observed across sites than the null model. At the two sites in which market forces significantly influenced land-use and livelihood decisions, the model was a poorer predictor of land-use outcomes than the null model. Model successes and failures in simulating real-world land-use patterns enabled the testing of hypotheses on land-use decision-making and yielded insights on the importance of missing mechanisms. The virtual laboratory approach provides a practical framework for systematic improvement of both theory and predictive skill in land change science based on a continual process of experimentation and model enhancement. PMID:24489696

Magliocca, Nicholas R.; Brown, Daniel G.; Ellis, Erle C.

2014-01-01

394

Cross-site comparison of land-use decision-making and its consequences across land systems with a generalized agent-based model.  

PubMed

Local changes in land use result from the decisions and actions of land-users within land systems, which are structured by local and global environmental, economic, political, and cultural contexts. Such cross-scale causation presents a major challenge for developing a general understanding of how local decision-making shapes land-use changes at the global scale. This paper implements a generalized agent-based model (ABM) as a virtual laboratory to explore how global and local processes influence the land-use and livelihood decisions of local land-users, operationalized as settlement-level agents, across the landscapes of six real-world test sites. Test sites were chosen in USA, Laos, and China to capture globally-significant variation in population density, market influence, and environmental conditions, with land systems ranging from swidden to commercial agriculture. Publicly available global data were integrated into the ABM to model cross-scale effects of economic globalization on local land-use decisions. A suite of statistics was developed to assess the accuracy of model-predicted land-use outcomes relative to observed and random (i.e. null model) landscapes. At four of six sites, where environmental and demographic forces were important constraints on land-use choices, modeled land-use outcomes were more similar to those observed across sites than the null model. At the two sites in which market forces significantly influenced land-use and livelihood decisions, the model was a poorer predictor of land-use outcomes than the null model. Model successes and failures in simulating real-world land-use patterns enabled the testing of hypotheses on land-use decision-making and yielded insights on the importance of missing mechanisms. The virtual laboratory approach provides a practical framework for systematic improvement of both theory and predictive skill in land change science based on a continual process of experimentation and model enhancement. PMID:24489696

Magliocca, Nicholas R; Brown, Daniel G; Ellis, Erle C

2014-01-01

395

Analysis of the geomorphology surrounding the Chang'e-3 landing site  

NASA Astrophysics Data System (ADS)

Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4 km×4 km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration.

Li, Chun-Lai; Mu, Ling-Li; Zou, Xiao-Duan; Liu, Jian-Jun; Ren, Xin; Zeng, Xing-Guo; Yang, Yi-Man; Zhang, Zhou-Bin; Liu, Yu-Xuan; Zuo, Wei; Li, Han

2014-12-01

396

Bioenergy costs and potentials with special attention to implications for the land system  

NASA Astrophysics Data System (ADS)

In the coming decades, an increasing competition for global land and water resources can be expected, due to rising demand for agricultural products, goals of nature conservation, and changing production conditions due to climate change. Especially biomass from cellulosic bioenergy crops, such as Miscanthus or poplar, is being proposed to play a substantial role in future energy systems if climate policy aims at stabilizing greenhouse gas (GHG) concentration at low levels. However, the potential of bioenergy for climate change mitigation remains unclear due to large uncertainties about future agricultural yield improvements, land availability for biomass plantations, and implications for the land system. In order to explore the cost-effective contribution of bioenergy to a low carbon transition with special attention to implications for the land system, we present a modeling framework with detailed biophysical and economic representation of the land and energy sector: We have linked the global dynamic vegetation and water balance model LPJmL (Bondeau et al. 2007, Rost et al. 2008), the global land and water use model MAgPIE (Lotze-Campen et al. 2008, Popp et al. 2010), and the global energy-economy-climate model ReMIND (Leimbach et al. 2009). In this modeling framework LPJmL supplies spatially explicit (0.5° resolution) agricultural yields as well as carbon and water stocks and fluxes. Based on this biophysical input MAgPIE delivers cost-optimized land use patterns (0.5° resolution), associated GHG emissions and rates of future yield increases in agricultural production. Moreover, shadow prices are calculated for irrigation water (as an indicator for water scarcity), food commodities, and bioenergy (as an indicator for changes in production costs) under different land use constraints such as forest conservation for climate change mitigation and as a contribution to biodiversity conservation. The energy-economy-climate model ReMIND generates the demand for bioenergy, taking into account the direct competition with other energy technology options for GHG mitigation, based on economic costs of bioenergy production. As a result, we find that bioenergy from specialized grassy and woody bioenergy crops can contribute approximately 100 EJ in 2055 and up to 300 EJ of primary energy in 2095. Protecting natural forests decreases biomass availability for energy production in the medium run, but not in the long run. Reducing the land available for agricultural use can partially be compensated for by higher rates of technological change in agriculture; however, bioenergy crops will occupy large shares of available cropland in both scenarios. In addition, our trade-off analysis indicates that forest protection combined with large-scale cultivation of dedicated bioenergy is likely to affect bioenergy potentials, but also to increase global food prices and increase water scarcity.

Popp, A.; Lotze-Campen, H.; Dietrich, J.; Klein, D.; Bauer, N.; Krause, M.; Beringer, T.; Gerten, D.

2011-12-01

397

Development and Flight Testing of an Autonomous Landing Gear Health-Monitoring System  

NASA Technical Reports Server (NTRS)

Development and testing of an adaptable vehicle health-monitoring architecture is presented. The architecture is being developed for a fleet of vehicles. It has three operational levels: one or more remote data acquisition units located throughout the vehicle; a command and control unit located within the vehicle; and, a terminal collection unit to collect analysis results from all vehicles. Each level is capable of performing autonomous analysis with a trained expert system. Communication between all levels is done with wireless radio frequency interfaces. The remote data acquisition unit has an eight channel programmable digital interface that allows the user discretion for choosing type of sensors; number of sensors, sensor sampling rate and sampling duration for each sensor. The architecture provides framework for a tributary analysis. All measurements at the lowest operational level are reduced to provide analysis results necessary to gauge changes from established baselines. These are then collected at the next level to identify any global trends or common features from the prior level. This process is repeated until the results are reduced at the highest operational level. In the framework, only analysis results are forwarded to the next level to reduce telemetry congestion. The system's remote data acquisition hardware and non-analysis software have been flight tested on the NASA Langley B757's main landing gear. The flight tests were performed to validate the following: the wireless radio frequency communication capabilities of the system, the hardware design, command and control; software operation; and, data acquisition, storage and retrieval.

Woodard, Stanley E.; Coffey, Neil C.; Gonzalez, Guillermo A.; Taylor, B. Douglas; Brett, Rube R.; Woodman, Keith L.; Weathered, Brenton W.; Rollins, Courtney H.

2003-01-01

398

Multi-Terrain Earth Landing Systems Applicable for Manned Space Capsules  

NASA Technical Reports Server (NTRS)

A key element of the President's Vision for Space Exploration is the development of a new space transportation system to replace the Shuttle that will enable manned exploration of the moon, Mars, and beyond. NASA has tasked the Constellation Program with the development of this architecture, which includes the Ares launch vehicle and Orion manned spacecraft. The Orion spacecraft must carry six astronauts and its primary structure should be reusable, if practical. These requirements led the Constellation Program to consider a baseline land landing on return to earth. To assess the landing system options for Orion, a review of current operational parachute landing systems such as those used for the F-111 escape module and the Soyuz is performed. In particular, landing systems with airbags and retrorockets that would enable reusability of the Orion capsule are investigated. In addition, Apollo tests and analyses conducted in the 1960's for both water and land landings are reviewed. Finally, tests and dynamic finite element simulations to understand land landings for the Orion spacecraft are also presented.

Fasanella, Edwin L.

2008-01-01

399

Multi-Terrain Earth Landing Systems Applicable for Manned Space Capsules  

NASA Technical Reports Server (NTRS)

A key element of the President's Vision for Space Exploration is the development of a new space transportation system to replace Shuttle that will enable manned exploration of the moon, Mars, and beyond. NASA has tasked the Constellation Program with the development of this architecture, which includes the Ares launch vehicle and Orion manned spacecraft. The Orion spacecraft must carry six astronauts and its primary structure should be reusable, if practical. These requirements led the Constellation Program to consider a baseline land landing on return to earth. To assess the landing system options for Orion, a review of current operational parachute landing systems such as those used for the F-111 escape module and the Soyuz is performed. In particular, landing systems with airbags and retrorockets that would enable reusability of the Orion capsule are investigated. In addition, Apollo tests and analyses conducted in the 1960's for both water and land landings are reviewed. Finally, tests and dynamic finite element simulations to understand land landings for the Orion spacecraft are also presented.

Fasanella, Edwin L.

2008-01-01

400

Preliminary Analysis of the efficacy of Artificial neural Network (ANN) and Cellular Automaton (CA) based Land Use Models in Urban Land-Use Planning  

NASA Astrophysics Data System (ADS)

This research provides an opportunity of collaboration between urban planners and modellers by providing a clear theoretical foundations on the two most widely used urban land use models, and assessing the effectiveness of applying the models in urban planning context. Understanding urban land cover change is an essential element for sustainable urban development as it affects ecological functioning in urban ecosystem. Rapid urbanization due to growing inclination of people to settle in urban areas has increased the complexities in predicting that at what shape and size cities will grow. The dynamic changes in the spatial pattern of urban landscapes has exposed the policy makers and environmental scientists to great challenge. But geographic science has grown in symmetry to the advancements in computer science. Models and tools are developed to support urban planning by analyzing the causes and consequences of land use changes and project the future. Of all the different types of land use models available in recent days, it has been found by researchers that the most frequently used models are Cellular Automaton (CA) and Artificial Neural Networks (ANN) models. But studies have demonstrated that the existing land use models have not been able to meet the needs of planners and policy makers. There are two primary causes identified behind this prologue. First, there is inadequate understanding of the fundamental theories and application of the models in urban planning context i.e., there is a gap in communication between modellers and urban planners. Second, the existing models exclude many key drivers in the process of simplification of the complex urban system that guide urban spatial pattern. Thus the models end up being effective in assessing the impacts of certain land use policies, but cannot contribute in new policy formulation. This paper is an attempt to increase the knowledge base of planners on the most frequently used land use model and also assess the relative effectiveness of the two models, ANN and CA, in urban planning. The questions that are addressed in this research are: a) What makes ANN models different from CA models?; b) Which model has higher accuracy in predicting future urban land use change?; and c) Are the models effective enough in guiding urban land use policies and strategies? The models that are used for this research are Multilayer Perceptron (MLP) and CA model, available in IDRISI Taiga. Since, the objective is to perform a comparative analysis and draw general inferences irrespective of specific urban policies, the availability of data was given more emphasis over the selection of particular location. Urban area in Massachusetts was chosen to conduct the study due to data availability. Extensive literature review was performed to understand the functionality of the two models. The models were applied to predict future changes and the accuracy assessment was performed using standard matrix. Inferences were drawn about the applicability of the models in urban planning context along with recommendations. This research will not only develop understanding of land use models among urban planners, but also will create an environment of coupled research between planners and modellers.

Harun, R.

2013-05-01

401

Land Use and Land Cover Baseline Report  

E-print Network

high-priority development and conservation zones. Land management tools that center sustainable land management on areas with slopes greater than 15%. #12Land Use and Land Cover Baseline Report September 2012 Data and analysis of land use and land cover

Columbia University

402

Management of land use land cover through the application of remote sensing, geographic information systems and simulation  

NASA Astrophysics Data System (ADS)

Deforestation and degradation of forest areas, including those in the Protected Areas (PAs), are major concerns in India. There were 2 broad objectives of the study: the technological objective pertained to the development of state-of-art programs that could serve as Decision Support Systems while finalizing plans and policy interventions, while the other objective aimed at generating geo-spatial data in 2 PAs. A part of the Eastern Himalaya biodiversity hotspot, Manas Tiger Reserve (MTR), Assam, India having an area of 2837.12 sq km and an important part of Rajaji-Corbett Tiger Conservation Unit, Rajaji National Park (RNP), Uttarakhand, India, having an area of 820.42 sq km, were taken for the assessment of land use and land cover (LULC) change during 1990--2004. Simulation was undertaken in a smaller area of 1.2 km * 1.2 km right on the fringe of RNP. Three advanced geo-spatial programs---Multi-Algorithm Automation Program (MAAP), Data Automatic Modification Program (DAMP) and Multi-Stage Simulation Program (MUSSIP)---developed by the author were used extensively. Based on the satellite data, MAAP was used for the rapid assessments of LULC of 2004 and 1990; DAMP was used for the spectral modification of the satellite data of the adjacent scenes of 2004 and of 1990; and MUSSIP was used to simulate LULC maps for the future periods (till 2018). These programs produced very high accuracy levels: 91.12% in 2004 and 89.67% in 1990 were obtained for MTR; and 94.87% in 2004 and 94.10% in 1990 were obtained for RNP; 93.40% pixel-to-pixel accuracy and 0.7904 for kappa were achieved for simulation. The annual rate of loss of forests (0.41% in MTR and 1.20% in RNP) and loss of water (1.79% in MTR and 1.69% in RNP) during 1990-2004 is a matter of serious concern. The scenario analysis in the study area for simulation revealed that the deforestation rate of 1.27% per year during 2004--2018 would increase to 2.04% if the human population growth rate is enhanced by 10%. Hence these PAs need urgent restoration measures and effective conservation planning to address the problems of deforestation, severe degradation and immense loss of water.

Jha, Praveen

403

Space shuttle navigation analysis. Volume 2: Baseline system navigation  

NASA Technical Reports Server (NTRS)

Studies related to the baseline navigation system for the orbiter are presented. The baseline navigation system studies include a covariance analysis of the Inertial Measurement Unit calibration and alignment procedures, postflight IMU error recovery for the approach and landing phases, on-orbit calibration of IMU instrument biases, and a covariance analysis of entry and prelaunch navigation system performance.

Jones, H. L.; Luders, G.; Matchett, G. A.; Rains, R. G.

1980-01-01

404

Towards decision-based global land use models for improved understanding of the Earth system  

NASA Astrophysics Data System (ADS)

A primary goal of Earth system modelling is to improve understanding of the interactions and feedbacks between human decision making and biophysical processes. The nexus of land use and land cover change (LULCC) and the climate system is an important example. LULCC contributes to global and regional climate change, while climate affects the functioning of terrestrial ecosystems and LULCC. However, at present, LULCC is poorly represented in global circulation models (GCMs). LULCC models that are explicit about human behaviour and decision-making processes have been developed at local to regional scales, but the principles of these approaches have not yet been applied to the global scale level in ways that deal adequately with both direct and indirect feedbacks from the climate system. In this article, we explore current knowledge about LULCC modelling and the interactions between LULCC, GCMs and dynamic global vegetation models (DGVMs). In doing so, we propose new ways forward for improving LULCC representations in Earth system models. We conclude that LULCC models need to better conceptualise the alternatives for upscaling from the local to global scale. This involves better representation of human agency, including processes such as learning, adaptation and agent evolution, formalising the role and emergence of governance structures, institutional arrangements and policy as endogenous processes and better theorising about the role of teleconnections and connectivity across global networks. Our analysis underlines the importance of observational data in global-scale assessments and the need for coordination in synthesising and assimilating available data.

Rounsevell, M. D. A.; Arneth, A.; Alexander, P.; Brown, D. G.; de Noblet-Ducoudré, N.; Ellis, E.; Finnigan, J.; Galvin, K.; Grigg, N.; Harman, I.; Lennox, J.; Magliocca, N.; Parker, D.; O'Neill, B. C.; Verburg, P. H.; Young, O.

2014-02-01

405

77 FR 472 - National Advisory Committee for Implementation of the National Forest System Land Management...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Implementation of the National Forest System Land Management Planning Rule; Correction AGENCY: USDA Forest Service...Forest Service, National Forest System, Ecosystem Management Coordination; telephone: (202) 205-0830,...

2012-01-05

406

System architecture and market aspects of an European Land Mobile Satellite System via EMS  

NASA Astrophysics Data System (ADS)

The paper describes an implementation scenario of a Land Mobile Satellite System via the EMS (European Mobile System) payload embarked on Italsat F-2. Some emphasis is given on market issues aiming at singling out business niches of Land Mobile Satellite Services (LMSS) in Europe. Other crucial issues exist such as: the alternate/competitive systems, the problems of interworking with other existing and/or planned systems, the definition of network architecture that better fits the user requirements, the marketing strategy and, last but not least, the financial evaluation of the project. The paper, on the basis of a study performed by Telespazio on behalf of ESA, discusses some of these issues with emphasis on competitive market aspects.

Ananasso, F.; Mistretta, I.

1992-03-01

407

AGROFORESTRY SYSTEMS: INTEGRATED LAND USE TO STORE AND CONSERVE CARBON  

EPA Science Inventory

Agroforestry is a promising land use practice to maintain or increase agricultural productivity while preserving or improving fertility. n extensive literature survey was conducted to evaluate the carbon dynamics of agroforestry practices and to assess their potential to store ca...

408

Multi-Agent Systems for the Simulation of Land-Use and Land-Cover Change: A Review  

Microsoft Academic Search

This article presents an overview of multi-agent system models of land-use\\/cover change (MAS\\/LUCC models). This special class of LUCC models combines a cellular landscape model with agent-based representations of decision making, integrating the two components through specification of interdependencies and feedbacks between agents and their environment. The authors review alternative LUCC modeling techniques and discuss the ways in which MAS\\/LUCC

Dawn C. Parker; Steven M. Manson; Marco A. Janssen; Matthew J. Hoffmann; Peter Deadman

2003-01-01

409

Modeling the influences of land reclamation on groundwater systems: A case study in Shekou peninsula, Shenzhen, China  

E-print Network

Modeling the influences of land reclamation on groundwater systems: A case study in Shekou form 16 February 2010 Accepted 18 April 2010 Available online 24 April 2010 Keywords: Land reclamation of land has been reclaimed around the Shekou peninsula, Shenzhen, China. Land reclamation may have

Jiao, Jiu Jimmy

410

A Monte Carlo analysis of the Viking lander dynamics at touchdown. [soft landing simulation  

NASA Technical Reports Server (NTRS)

The performance of the Viking lander has been evaluated by using a Monte Carlo simulation, and all results are presented in statistical form. The primary objectives of this analysis were as follows: (1) to determine the three sigma design values of maximum rigid body accelerations and the minimum clearance of the lander body during landing; (2) to determine the probability of an unstable landing; and (3) to determine the probability of the lander body striking a rock. Two configurations were analyzed with the only difference being in the ability of the primary landing gear struts to carry tension loads.

Muraca, R. J.; Campbell, J. W.; King, C. A.

1975-01-01

411

Women, Wives and Land Rights in Africa: Situating Gender Beyond the Household in the Debate Over Land Policy and Changing Tenure Systems  

Microsoft Academic Search

The debate over land reform in Africa is embedded in evolutionary models, in which it is assumed landholding systems are evolving into individualized systems of ownership with greater market integration. This process is seen to be occurring even without state protection of private land rights through titling. Gender as an analytical category is excluded in evolutionary models. Women are accommodated

Ingrid Yngstrom

2002-01-01

412

Applying physical input–output analysis to estimate land appropriation (ecological footprints) of international trade activities  

Microsoft Academic Search

In the last few years some studies have been presented, which link land use accounting and input–output analysis (based on monetary input–output tables (MIOTs)) for the calculation of direct and indirect land appropriation of production and consumption activities. The compilation of the first comprehensive physical input–output tables (PIOTs) for some western European countries in the 1990s opened new possibilities for

Klaus Hubacek; Stefan Giljum

2003-01-01

413

Detecting Changes in Natural Resources Using Land Condition Trend Analysis Data  

Microsoft Academic Search

The Land Condition Trend Analysis (LCTA) program is the US Army's standard for land inventory and monitoring, employing standardized\\u000a methods of natural resources data collection, analyses, and reporting designed to meet multiple goals and objectives. Critical\\u000a to using LCTA data in natural resources management decisions is the ability of the LCTA protocols to detect changes in natural\\u000a resources. To quantify

ALAN B. ANDERSON

2002-01-01

414

A System for Integrated Management and Assessment of East African Pastoral Lands  

E-print Network

for Integrated Management andAssessment of EastAfrican Pastoral Lands: Balancing Food Security, WildlifeA System for Integrated Management and Assessment of East African Pastoral Lands Balancing Food Threats to Food Security, Wildlife Conservation, and Ecosystem Integrity in Northern Tanzania

Boone, Randall B.

415

GIS-based spatial and temporal prediction system development for regional land subsidence hazard mitigation  

Microsoft Academic Search

An integrated GIS-based approach for establishing a spatial and temporal prediction system for groundwater flow and land subsidence is proposed and applied to a subsidence-progressed Japanese coastal plain. Various kinds of fundamental data relating to groundwater flow and land subsidence are digitized and entered into a GIS database. A surface water hydrological cycle simulation is performed using a GIS spatial

Guoyun Zhou; Tetsuro Esaki; Jiro Mori

2003-01-01

416

Snow process modeling in the North American Land Data Assimilation System (NLDAS)  

E-print Network

Snow process modeling in the North American Land Data Assimilation System (NLDAS): 1. Evaluation of model-simulated snow cover extent Justin Sheffield,1 Ming Pan,1 Eric F. Wood,1 Kenneth E. Mitchell,2) and consists of two parts: (1) assessment of land surface model simulations of snow cover extent and (2

Robock, Alan

417

Representation of heterogeneity effects in Earth system modeling: Experience from land surface modeling  

Microsoft Academic Search

The land surface is characterized by pronounced spatial heterogeneity that spans a wide range of scales. This heterogeneity affects the surface energy and water budgets, as well as the land-atmosphere exchanges of momentum, heat, water and other constituents, through a number of highly nonlinear processes. The resolution of present-day Earth (or climate) system models is still too coarse to explicitly

Filippo Giorgi; Roni Avissar

1997-01-01

418

Representation of heterogeneity effects in earth system modeling: Experience from land surface modeling  

Microsoft Academic Search

The land surface is characterized by pronounced spatial heterogeneity that spans a wide range of scales. This heterogeneity affects the surface energy and water budgets, as well as the land-atmosphere exchanges of momentum, heat, water and other constituents, through a number of highly nonlinear processes. The resolution of present-day Earth (or climate) system models is still too coarse to explicitly

Filippo Giorgi; Roni Avissar

1997-01-01

419

REPRESENTATION OF HETEROGENEITY EFFECTS IN EARTH SYSTEM MODELING: EXPERIENCE FROM LAND SURFACE MODELING  

Microsoft Academic Search

The land surface is characterized by pro- nounced spatial heterogeneity that spans a wide range of scales. This heterogeneity affects the surface energy and water budgets, as well as the land-atmosphere exchanges of momentum, heat, water and other constituents, through a number of highly nonlinear processes. The resolution of present-day Earth (or climate) system models is still too coarse to

Filippo Giorgi

420

Impact of agricultural land management systems on soil microbial diversity and plant disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increased diversity of fungal rDNA ITS-1 amplicons, as measured by the Shannon-Weiner index, was associated with land management practices that minimise soil disturbance (bahiagrass pasture and undisturbed weed fallow) when compared with organic or conventional land management systems. Diversity de...

421

A Virtual Sensor Web Study Based on the Land Information System (LIS)  

Microsoft Academic Search

Land Surface Models (LSMs) are being developed within frameworks such as the Land Information System (LIS) to enable them to assimilate currently-available observations. With the development of intelligent sensors and communication in the next generation satellite constellations that provides an opportunity to enhance information retrieval via 2-way information flow between the LSMs and the sensors. In this presentation, recent progress

H. Su; P. Houser; Y. Tian; S. Kumar; J. Geiger; D. Belvedere

2008-01-01

422

FORT HOOD LAND MANAGEMENT SYSTEM (LMS) MILITARY FIELD APPLICATION SITE FY99 IN-PROGRESS REVIEW  

EPA Science Inventory

The purpose of the Land Management System (LMS) is to provide relevant science, tools, and information to land and water resource managers and decision makers with the goal of enhancing their ability to understand and communicate past, current, and potential impacts of management...

423

Energy and resource consumption of land-based hatchery systems for finfish  

Technology Transfer Automated Retrieval System (TEKTRAN)

The early rearing of most marine species will be land-based because of the need for precise control of the rearing environment. This chapter evaluates the resource and energy requirements of six different types of land-based, hatchery production systems: flow-through with a gravity water supply, flo...

424

Cartography and Information Systems for the Luna-Glob Landing Sites  

NASA Astrophysics Data System (ADS)

We provide cartography and information system support to the LUNA-GLOB mission and assess candidate landing sites [1] on the basis of different available remote sensing data sets. The main goal of our work is to identify science opportunities in the sub-polar areas and to detect possible hazards for any landing spacecraft.

Kokhanov, A.; Karachevtseva, I.; Oberst, J.; Zubarev, A.; Robinson, M. S.

2012-09-01

425

Land degradation and Poverty in maize producing areas of Kenya - Development of an interdisciplinary analysis framework using GIS and remote sensing  

NASA Astrophysics Data System (ADS)

Land degradation causes poverty and vice versa. But both processes are highly complex, hard to predict and to mitigate, and need insights from different perspectives. Therefore an interdisciplinary framework for the understanding of land degradation processes by linking biophysical data with socio-economic trends is necessary. Agricultural systems in Kenya are affected by land degradation and especially recent developments such as agricultural innovations including the use of hybrid seeds and chemical fertilizer have an impact on the environment. Vegetation analysis, used as a proxy indicator for the status of land is carried out to monitor environmental changes in maize producing areas of western Kenya. One of the methods used in this study includes time series analysis of vegetation data from 2001 to 2010 based on MODIS NDVI data with 250m and 500m resolution. Occurring trends are linked to rainfall estimation data and annually classified land use cover data with 500m resolution based on MODIS within the same time period. Analysis of significant trends in combination with land cover information show recent land change dynamics. As these changes are not solely biophysically driven, socio-economic variables representing marginality - defined as the root cause of poverty- are also considered. The most poor are primarily facing the most vulnerable and thereby less fertile soils. Moreover they are lacking access to information to eventually use existing potential. This makes the analysis of changing environmental processes and household characteristics in the interplay important to understand in order to highlight the most influencing variables. Within the new interdisciplinary analysis framework the concept of marginality includes different dimensions referring to certain livelihood characteristics such as health and education which describe a more diverse picture of poverty than the known economic perspective. Household surveys and census data from different time periods allow the analysis of socio-economic trends and link this information to biophysical factors. If relationships between certain variables are understood, adapted land management strategies can be developed. This study aims at linking pixel-level information with established remote sensing methods to the socio-economic concept of marginality based on household surveys and census data on administrative levels. Besides remote sensing and statistical analysis of socio-economic data a GIS is used for geospatial analysis. As most studies on land degradation focus on biophysical aspects such as vegetation or soil degradation this study uses an innovative approach by integrating biophysical analysis without neglecting a human oriented approach which plays a key role in environmental systems nowadays. This interdisciplinary research helps to get closer to the right and adapted policies and land management strategies as land degradation processes do not stick to administrative boundaries but policy advice does.

Graw, Valerie; Nkonya, Ephraim; Menz, Gunter

2014-05-01

426

Editing ERTS-1 data to exclude land aids cluster analysis of water targets  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. It has been determined that an increase in the number of spectrally distinct coastal water types is achieved when data values over the adjacent land areas are excluded from the processing routine. This finding resulted from an automatic clustering analysis of ERTS-1 system corrected MSS scene 1002-18134 of 25 July 1972 over Monterey Bay, California. When the entire study area data set was submitted to the clustering only two distinct water classes were extracted. However, when the land area data points were removed from the data set and resubmitted to the clustering routine, four distinct groupings of water features were identified. Additionally, unlike the previous separation, the four types could be correlated to features observable in the associated ERTS-1 imagery. This exercise demonstrates that by proper selection of data submitted to the processing routine, based upon the specific application of study, additional information may be extracted from the ERTS-1 MSS data.

Erb, R. B. (principal investigator)

1973-01-01

427

A Virtual Sensor Web Study Based on the Land Information System (LIS)  

NASA Astrophysics Data System (ADS)

Land Surface Models (LSMs) are being developed within frameworks such as the Land Information System (LIS) to enable them to assimilate currently-available observations. With the development of intelligent sensors and communication in the next generation satellite constellations that provides an opportunity to enhance information retrieval via 2-way information flow between the LSMs and the sensors. In this presentation, recent progress on developing a prototype Land Information Sensor Web (LISW), which integrates the Land Information System (LIS) and a sensor web framework, will be presented. The overall goal is to minimize the system uncertainty through sensor web reconfiguration. All the experiments were done synthetically. These synthetic experiments provide a controlled environment in which to examine the end-to-end system performance of the prototype, the impact of various sensor web design trade-offs and the eventual value of sensor webs for a particular prediction or decision support objective. The Common Land Model (CLM2.0) was used to produce a "virtual land truth". The Noah land model was employed to simulate the "virtual land truth" by assimilating observations from the reconfigurable sensor web which observes the "virtual land truth". The LISW is composed of three central components: the Sensor Web Framework, the Sensor Web Simulator and the Land Information System. The first layer soil moisture is studied in our experiment. Seasonal variation of the data assimilation performance is found, which may be caused by the different physics of the CLM and Noah in a particular season. That suggests a constant frequency or accuracy of observations is not optimal to minimize the overall system uncertainty. A dynamical adjustment of the observing frequency or accuracy is necessary. The study area is the conterminous US and the period is from 2003 through 2005. Because of the intensive computation required by different configurations of the data assimilation, the experiment was done on the Columbia NASA supercomputer.

Su, H.; Houser, P.; Tian, Y.; Kumar, S.; Geiger, J.; Belvedere, D.

2008-05-01

428

Integration of the NASA Land Information System as an Application Framework into the MRC Rapid Prototyping Capabilities Infrastructure  

NASA Astrophysics Data System (ADS)

The Mississippi Research Consortium (MRC) is implementing a computational Rapid Prototyping Capabilities (RPC) infrastructure, based on a systems engineering concept, advocated by the NASA Applied Sciences Program, in order to identify, evaluate, and integrate research results for applications. The NASA Land Information System (LIS) is a "functional Land Data Assimilation System (LDAS)" that incorporates a suite of land models in an interoperable computational framework. LIS currently is comprised of a LIS core, a number of community land models, data servers, and visualization systems - integrated in a high-performance computing environment. LIS uses model independent software frameworks, such as the Earth Systems Modeling Framework (ESMF) and Assistance for Land Modeling Activities (ALMA), in order to enable interactions with other earth system model and decision support systems (DSS). The LIS user interface (UI) can be used to query, browse, and download LIS derived products. Besides, any clients that support OpenDAP can be used to access the model results. NASA LIS has been identified to be integrated into the RPC infrastructure as a cross-cutting applications framework (AF). The land models in LIS incorporate surface and atmospheric parameters of temperature, snow/water, vegetation, albedo, soil conditions, topography, and radiation. Many of these parameters are available from in- situ observations, numerical model analysis, and from NASA, NOAA, and other remote sensing satellite platforms at various spatial and temporal resolutions. Since the land models in LIS require normal spin-up times of 5 years or more for most experiments, the necessary multi-year retrospective initialization and forcing fields (estimated to grow to 10 TB in size) are also stored and managed in the RPC infrastructure. The computational resources, available to LIS via the RPC infrastructure, support e-Science experiments involving the global modeling of land-atmosphere studies at 1km spatial resolutions as well as regional studies at finer resolutions. Thus the LIS AF with-in RPC can be used to rapidly prototype experiments in order to evaluate the viability of basic research results toward applications of societal benefits. Besides, use case scenarios developed using LIS are also used to specify and refine the system requirements for RPC. The approach used for the integration of LIS as an applications framework into RPC and the lessons learned will be shared during the presentation.

Anantharaj, V.; Peters-Lidard, C.; Houser, P.; Mostovoy, G.; Haupt, T.; Moorhead, R.; Kumar, S.

2006-12-01

429

Message handling system concepts and services in a land mobile satellite system  

NASA Technical Reports Server (NTRS)

A network architecture containing the capabilities offered by the Message Handling System (MHS) to the PRODAT Land Mobile Satellite System (LMSS) is described taking into account the constraints of a preexisting satellite system which is going to become operational. The mapping between MHS services and PRODAT requirements is also reported and shows that the supplied performance can be significantly enhanced to both fixed and mobile users. The impact of the insertion of additional features on the system structure, especially on the centralized control unit, are also addressed.

Barberis, S.; Settimo, F.; Giralda, A.; Mistretta, I.; Loisy, C.; Parmentier, J. L.

1990-01-01

430

A digital head-up display system as part of an integrated autonomous landing system concept  

NASA Astrophysics Data System (ADS)

Considerable interest continues both in the aerospace industry and the military in the concept of autonomous landing guidance, and as previously reported, BAE Systems has been engaged for some time on an internally funded program to replace the high voltage power supply, tube and deflection amplifiers of its head up displays with an all digital solid state illuminated image system, based on research into the requirements for such a display as part of an integrated Enhanced Vision System. This paper describes the progress made to date in realising and testing a weather penetrating system incorporating an all digital head up display as its pilot-machine interface.

Wisely, Paul L.

2008-04-01

431

An econometric analysis of changes in arable land utilization using multinomial logit model in Pinggu district, Beijing, China.  

PubMed

Arable land in China has been decreasing as a result of rapid population growth and economic development as well as urban expansion, especially in developed regions around cities where quality farmland quickly disappears. This paper analyzed changes in arable land utilization during 1993-2008 in the Pinggu district, Beijing, China, developed a multinomial logit (MNL) model to determine spatial driving factors influencing arable land-use change, and simulated arable land transition probabilities. Land-use maps, as well as social-economic and geographical data were used in the study. The results indicated that arable land decreased significantly between 1993 and 2008. Lost arable land shifted into orchard, forestland, settlement, and transportation land. Significant differences existed for arable land transitions among different landform areas. Slope, elevation, population density, urbanization rate, distance to settlements, and distance to roadways were strong drivers influencing arable land transition to other uses. The MNL model was proved effective for predicting transition probabilities in land use from arable land to other land-use types, thus can be used for scenario analysis to develop land-use policies and land-management measures in this metropolitan area. PMID:23774750

Xu, Yueqing; McNamara, Paul; Wu, Yanfang; Dong, Yue

2013-10-15

432

Indigenous Land Rights Systems in Sub-Saharan Africa: A Constraint on Productivity?  

Microsoft Academic Search

This article uses cross-sectional evidence from Ghana, Kenya, and Rwanda in 1987-88 to examine the question, Are indigenous land rights systems in sub-Saharan Africa a constraint on productivity? The evidence supports the hypothesis suggested by historical studies, that African indigenous land rights systems have spontaneously evolved from systems of communal control toward individual sized rights in response to increases in

Peter Hazell; Benoît Blarel

1991-01-01

433

Direct Sensor Orientation of a Land-Based Mobile Mapping System  

PubMed Central

A land-based mobile mapping system (MMS) is flexible and useful for the acquisition of road environment geospatial information. It integrates a set of imaging sensors and a position and orientation system (POS). The positioning quality of such systems is highly dependent on the accuracy of the utilized POS. This limitation is the major drawback due to the elevated cost associated with high-end GPS/INS units, particularly the inertial system. The potential accuracy of the direct sensor orientation depends on the architecture and quality of the GPS/INS integration process as well as the validity of the system calibration (i.e., calibration of the individual sensors as well as the system mounting parameters). In this paper, a novel single-step procedure using integrated sensor orientation with relative orientation constraint for the estimation of the mounting parameters is introduced. A comparative analysis between the proposed single-step and the traditional two-step procedure is carried out. Moreover, the estimated mounting parameters using the different methods are used in a direct geo-referencing procedure to evaluate their performance and the feasibility of the implemented system. Experimental results show that the proposed system using single-step system calibration method can achieve high 3D positioning accuracy. PMID:22164015

Rau, Jiann-Yeou; Habib, Ayman F.; Kersting, Ana P.; Chiang, Kai-Wei; Bang, Ki-In; Tseng, Yi-Hsing; Li, Yu-Hua

2011-01-01

434

BATSE spectroscopy analysis system  

NASA Technical Reports Server (NTRS)

The Burst and Transient Source Experiment (BATSE) Spectroscopy Analysis System (BSAS) is the software system which is the primary tool for the analysis of spectral data from BATSE. As such, Guest Investigators and the community as a whole need to know its basic properties and characteristics. Described here are the characteristics of the BATSE spectroscopy detectors and the BSAS.

Schaefer, Bradley E.; Bansal, Sandhia; Basu, Anju; Brisco, Phil; Cline, Thomas L.; Friend, Elliott; Laubenthal, Nancy; Panduranga, E. S.; Parkar, Nuru; Rust, Brad

1992-01-01

435

Inertial navigation systems analysis.  

NASA Technical Reports Server (NTRS)

This volume offers the avionic systems engineer a fundamental exposition of the mechanization and error analysis of inertial navigation systems. While the material is applicable to spacecraft and undersea navigation, emphasis is placed upon terrestrial applications on or slightly above the earth's surface. As a result, practical considerations are geared toward those aircraft navigation systems of particular current interest. Extensive use is made of perturbation techniques to develop linearized system equations, whose solutions closely approximate those obtained by nonlinear differential equations. A unified error analysis technique is developed that is applicable to virtually all system configurations. The technique provides a greatly simplified method for comparing the performance of competing system configurations.

Britting, K. R.

1971-01-01

436

Analysis of land use and land cover change in a coastal area of Rio de Janeiro using high-resolution remotely sensed data  

NASA Astrophysics Data System (ADS)

Coastal areas offer great recreational and economic opportunities, but require intensive resource management and environmental protection. Land use and land cover information provides a rapid and cost-effective means for monitoring and planning coastal area development. This study quantitatively describes spatiotemporal changes of land use and land cover over the last four decades in a coastal area of the state of Rio de Janeiro, Brazil. Historical aerial photographs from 1976 and satellite images from 1990 and 2012 were classified and analyzed. We used supervised classification and machine learning techniques to classify the images. An accuracy assessment of results was performed. Land use change statistics for the period indicate that urban areas have increased to the detriment of dense vegetation, salines, and bare soil. The analysis provides a basis for better control of anthropogenic impacts and geoconservation activities in this coastal area of Rio de Janeiro.

Avelar, Silvania; Tokarczyk, Piotr

2014-01-01

437

Land Subsidence of Jakarta (Indonesia) and its Geodetic Monitoring System  

Microsoft Academic Search

Jakarta is the capital city of Indonesia with a population of about 10 million people, inhabiting an area of about 25 × 25 km. It has been reported for sometime that locations in Jakarta are subsiding at different rates. Up to the present, there has been no comprehensive information about the characteristics and pattern of land subsidence in the Jakarta

Hasanuddin Z. Abidin; Rochman Djaja; Dudy Darmawan; Samsul Hadi; Arifin Akbar; H. Rajiyowiryono; Y. Sudibyo; I. Meilano; M. A. Kasuma; J. Kahar; Cecep Subarya

2001-01-01