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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

Development of Land Analysis System display modules  

NASA Technical Reports Server (NTRS)

The Land Analysis System (LAS) display modules were developed to allow a user to interactively display, manipulate, and store image and image related data. To help accomplish this task, these modules utilize the Transportable Applications Executive and the Display Management System software to interact with the user and the display device. The basic characteristics of a display are outlined and some of the major modifications and additions made to the display management software are discussed. Finally, all available LAS display modules are listed along with a short description of each.

Gordon, Douglas; Hollaren, Douglas; Huewe, Laurie

1986-01-01

3

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

4

Dynamic heave-pitch analysis of air cushion landing systems  

NASA Technical Reports Server (NTRS)

A program to develop analytical tools for evaluating the dynamic performance of Air Cushion Landing Systems (ACLS) is described. The heave (vertical) motion of the ACLS was analyzed, and the analysis was extended to cover coupled heave-pitch motions. The mathematical models developed are based on a fundamental analysis of the body dynamics and fluid mechanics of the aircraft-cushion-runway interaction. The air source characteristics, flow losses in the feeding ducts, trunk and cushion, the effects of fluid compressibility, and dynamic trunk deflections, including ground contact are considered. A computer program, based on the heave-pitch analysis, was developed to simulate the dynamic behavior of an ACLS during landing impact and taxi over an irregular runway. The program outputs include ACLS motions, loadings, pressures, and flows as a function of time. To illustrate program use, three basic types of simulations were carried out. The results provide an initial indication of ACLS performance during (1) a static drop, (2) landing impact, and (3) taxi over a runway irregularity.

Captain, K. M.; Boghani, A. B.; Wormley, D. N.

1975-01-01

5

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

6

Pilot land data system  

NASA Technical Reports Server (NTRS)

During the fall of 1983, the Information Systems Office of NASA's Office of Space Science and Applications assembled a Working Group to develop initial plans for a Pilot Land Data System (PLDS). Workshops coordinated planning and concept development activities between land-related and computer science disciplines, and examined land research requirements, information science technology requirements, PLDS architecture, and methodologies for system evaluation. The PLDS will be a limited-scale distributed information system to explore scientific, technical and management approaches to satisfy land science research needs. PLDS will pave the way for a Land Data System to improve data access, processing, transfer and analysis, fostering an environment in which land science information synthesis can occur on a scale not previously possible owing to limits to data assembly and access and efficiency of processing.

Cressy, P. J.; Estes, J. E.

1984-01-01

7

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

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

Overview of the NASA Entry, Descent and Landing Systems Analysis Study  

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 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.

Zang, Thomas A.; Dwyer-Cianciolo, Alicia M.; Kinney, David J.; Howard, Austin R.; Chen, George T.; Ivanov, Mark C.; Sostaric, Ronald R.; Westhelle, Carlos H.

2010-01-01

10

The Improvements of Land Suitability Assessment for Sustainable Land Use Management through Multi-Criteria Analysis in Korea: Focused on Assessment System 2  

Microsoft Academic Search

This paper provides an appraisal of and proposes improvements to the Korean Land Suitability Assessment (LSA) System; a multi-criteria decision analysis procedure for land use planning that was introduced under the National Land Planning and Utilization Act (2002). This nationwide procedure was designed to protect the natural environment and reduce urban sprawl. It is used to assess the developmental or

Hang-Jib Kim

2010-01-01

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

Heave-pitch-roll analysis and testing of air cushion landing systems  

NASA Technical Reports Server (NTRS)

The analytical tools (analysis and computer simulation) needed to explain and predict the dynamic operation of air cushion landing systems (ACLS) is described. The following tasks were performed: the development of improved analytical models for the fan and the trunk; formulation of a heave pitch roll analysis for the complete ACLS; development of a general purpose computer simulation to evaluate landing and taxi performance of an ACLS equipped aircraft; and the verification and refinement of the analysis by comparison with test data obtained through lab testing of a prototype cushion. Demonstration of simulation capabilities through typical landing and taxi simulation of an ACLS aircraft are given. Initial results show that fan dynamics have a major effect on system performance. Comparison with lab test data (zero forward speed) indicates that the analysis can predict most of the key static and dynamic parameters (pressure, deflection, acceleration, etc.) within a margin of a 10 to 25 percent.

Boghani, A. B.; Captain, K. M.; Wormley, D. N.

1978-01-01

13

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

14

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...

15

Guidance and Control Algorithms for the Mars Entry, Descent and Landing Systems Analysis.  

National Technical Information Service (NTIS)

The purpose of the Mars Entry, Descent and Landing Systems Analysis (EDL-SA) study was to identify feasible technologies that will enable human exploration of Mars, specifically to deliver large payloads to the Martian surface. This paper focuses on the m...

A. M. CwyerCianciolo E. Garcia-Llama J. D. Shidner J. L. Davis R. W. Powell

2010-01-01

16

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

17

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

18

Tims Ford Land Analysis.  

National Technical Information Service (NTIS)

The Tims Ford Analysis was developed to aid TVA and the Tennessee Elk River Development Agency in making land use and land management decisions. Spatially located data were used to identify sensitive resource areas and to provide a basis for site specific...

E. E. Howard

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

Land suitability analysis for cereal production in Himachal Pradesh (India) using Geographical Information System  

Microsoft Academic Search

Land suitability analysis is prerequisite for sustainable agriculture and it plays a pivotal role in the niche based agricultural\\u000a planning in mountain regions. In this paper different parameters viz. climatic (precipitation and temperature), topographic\\u000a (elevation), soil type and land cover\\/land use have been used in order to perform land suitability evaluation for cereals\\u000a food-grain crops in Himachal Pradesh using Geographic

R. M. Bhagat; Sharda Singh; C. Sood; R. S. Rana; V. Kalia; S. Pradhan; W. Immerzeel; B. Shrestha

2009-01-01

21

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

22

Comparison of Boolean and fuzzy classification methods in land suitability analysis by using geographical information systems  

Microsoft Academic Search

In this paper the information content of Boolean and fuzzy-set-based approaches to the problem of analyzing land suitability for agriculture within a geographical information system (GIS) is assessed. First, the two approaches to this problem are stated and formalized in the context of land-suitability evaluation. A database comprising 642 unique areas, 7 land qualities, 13 land characteristcs, and 2 crop

G B Hall; F Wang; Subaryono

1992-01-01

23

Analysis of Army Operational Requirements for the Tactical Microwave Landing System.  

National Technical Information Service (NTIS)

A definitive set of test requirements are developed for the U.S. Army evaluation of the Microwave Landing System (MLS). The approach taken in to (1) access the Army operational requirements for an aircraft landing system in the 1980-1990 era, (2) compare ...

P. G. Stoltz J. H. Priedigkeit

1975-01-01

24

Decision analysis and risk models for land development affecting infrastructure systems.  

PubMed

Coordination and layering of models to identify risks in complex systems such as large-scale infrastructure of energy, water, and transportation is of current interest across application domains. Such infrastructures are increasingly vulnerable to adjacent commercial and residential land development. Land development can compromise the performance of essential infrastructure systems and increase the costs of maintaining or increasing performance. A risk-informed approach to this topic would be useful to avoid surprise, regret, and the need for costly remedies. This article develops a layering and coordination of models for risk management of land development affecting infrastructure systems. The layers are: system identification, expert elicitation, predictive modeling, comparison of investment alternatives, and implications of current decisions for future options. The modeling layers share a focus on observable factors that most contribute to volatility of land development and land use. The relevant data and expert evidence include current and forecasted growth in population and employment, conservation and preservation rules, land topography and geometries, real estate assessments, market and economic conditions, and other factors. The approach integrates to a decision framework of strategic considerations based on assessing risk, cost, and opportunity in order to prioritize needs and potential remedies that mitigate impacts of land development to the infrastructure systems. The approach is demonstrated for a 5,700-mile multimodal transportation system adjacent to 60,000 tracts of potential land development. PMID:22050390

Thekdi, Shital A; Lambert, James H

2012-07-01

25

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

NASA Technical Reports Server (NTRS)

A number of problems related to the design, construction and evaluation of an autonomous roving planetary vehicle and its control and operating systems intended for an unmanned exploration of Mars are studied. Vehicle configuration, dynamics, control, systems and propulsion; systems analysis; terrain sensing and modeling and path selection; and chemical analysis of samples are included.

1974-01-01

26

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

27

Revised Land Use Characteristic Dataset for Asia and Southwest Asia for the Navy Aerosol Analysis and Prediction System (NAAPS)  

Microsoft Academic Search

Presently, the Navy Aerosol Analysis and Prediction System (NAAPS) uses the U.S. Geological Survey (USGS) land use characteristic dataset to determine global dust emission areas. The USGS dataset was developed from Advanced Very High-Resolution Radiometer 1-km data from April 1992 to March 1993. In the past decade drastic changes in land and water use in Asia and Southwest Asia have

A. L. Walker; K. Richardson; D. L. Westphal

2002-01-01

28

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

29

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

30

Analysis of Summer Thunderstorms in Central Alabama Using the NASA Land Information System  

NASA Technical Reports Server (NTRS)

Forecasters have difficulty predicting "random" afternoon thunderstorms during the summer months. Differences in soil characteristics could be a contributing factor for storms. The NASA Land Information System (LIS) may assist forecasters in predicting summer convection by identifying boundaries in land characteristics. This project identified case dates during the summer of 2009 by analyzing synoptic weather maps, radar, and satellite data to look for weak atmospheric forcing and disorganized convective development. Boundaries in land characteristics that may have lead to convective initiation in central Alabama were then identified using LIS.

James, Robert; Case, Jonathan; Molthan, Andrew; Jedloved, Gary

2010-01-01

31

Parametric Mass Modeling for Mars Entry, Descent and Landing System Analysis Study  

NASA Technical Reports Server (NTRS)

This paper provides an overview of the parametric mass models used for the Entry, Descent, and Landing Systems Analysis study conducted by NASA in FY2009-2010. The study examined eight unique exploration class architectures that included elements such as a rigid mid-L/D aeroshell, a lifting hypersonic inflatable decelerator, a drag supersonic inflatable decelerator, a lifting supersonic inflatable decelerator implemented with a skirt, and subsonic/supersonic retro-propulsion. Parametric models used in this study relate the component mass to vehicle dimensions and mission key environmental parameters such as maximum deceleration and total heat load. The use of a parametric mass model allows the simultaneous optimization of trajectory and mass sizing parameters.

Samareh, Jamshid A.; Komar, D. R.

2011-01-01

32

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 control of a mobile planetary vehicle according to a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: (1) overall systems analysis; (2) vehicle configuration and dynamics; (3) toroidal wheel design and evaluation; (4) on-board navigation systems; (5) satellite-vehicle navigation systems; (6) obstacle detection systems; (7) terrain sensing, interpretation and modeling; (8) computer simulation of terrain sensor-path selection systems; and (9) chromatographic systems design concept studies. The specific tasks which have been undertaken are defined and the progress which has been achieved during the period July 1, 1971 to December 31, 1971 is summarized.

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

1971-01-01

33

Landsafe: Landing Site Risk Analysis Software Framework  

NASA Astrophysics Data System (ADS)

The European Space Agency (ESA) is planning a Lunar Lander mission in the 2018 timeframe that will demonstrate precise soft landing at the polar regions of the Moon. To ensure a safe and successful landing a careful risk analysis has to be carried out. This is comprised of identifying favorable target areas and evaluating the surface conditions in these areas. Features like craters, boulders, steep slopes, rough surfaces and shadow areas have to be identified in order to assess the risk associated to a landing site in terms of a successful touchdown and subsequent surface operation of the lander. In addition, global illumination conditions at the landing site have to be simulated and analyzed. The Landing Site Risk Analysis software framework (LandSAfe) is a system for the analysis, selection and certification of safe landing sites on the lunar surface. LandSAfe generates several data products including high resolution digital terrain models (DTMs), hazard maps, illumination maps, temperature maps and surface reflectance maps which assist the user in evaluating potential landing site candidates. This paper presents the LandSAfe system and describes the methods and products of the different modules. For one candidate landing site on the rim of Shackleton crater at the south pole of the Moon a high resolution DTM is showcased.

Schmidt, R.; Bostelmann, J.; Cornet, Y.; Heipke, C.; Philippe, C.; Poncelet, N.; de Rosa, D.; Vandeloise, Y.

2012-08-01

34

Cadastral surveying and land registration: A comparative analysis of the English and Tasmanian systems  

Microsoft Academic Search

The role of surveying is traced in the development of the land registration systems of Tasmania on the one hand and that of England and Wales on the other. The technical problems of cadastral surveying in these systems are examined and analysed in terms of the cadastral base, statutory requirements and professional practice.

K. N. Toms; S. Lewis

1974-01-01

35

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

36

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

37

Improving Land Title Registration Systems.  

National Technical Information Service (NTIS)

The land title recordation system, unique to the United States and Canada, maintains that title to land is registered with the government, and the government's determination of title is conclusive on all persons. However, title recordation is costly to co...

1979-01-01

38

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

39

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

40

An integrated land navigation system  

Microsoft Academic Search

An exploratory development model of an optimally integrated system for Artic land navigation has been designed, implemented, and tested. This system, called PLANS (Primary Land Arctic Navigation System) was designed and built to be a highly reliable, moderately accurate and moderately priced, nonradiating automatic navigation system for all-weather off-the-road use. It combines several self-contained sensors with two satellite receivers, using

J. C. McMillan

1988-01-01

41

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

NASA Technical Reports Server (NTRS)

A number of problems related to unmanned exploration of planets or other extraterrestrial bodies with Mars as a case in point were investigated. The design and evaluation of a prototype rover concept with emphasis on mobility, maneuverability, stability, control and propulsion is described along with the development of terrain sensor concepts and associated software for the autonomous control of any planetary rover. Results are applicable not only to the design of a mission rover but the vehicle is used as a test bed for the rigorous evaluation of alternative autonomous control systems.

Gisser, D. G.; Frederick, D. K.; Yerazunis, S. W.

1977-01-01

42

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

43

NASA Low Visibility Landing and Surface Operations (LVLASO) Atlanta Demonstration: Surveillance Systems Performance Analysis  

NASA Technical Reports Server (NTRS)

NASA conducted a series of flight experiments at Hartsfield Atlanta International Airport as part of the Low Visibility Landing and Surface Operations (LVLASO) Program. LVLASO is one of the subelements of the NASA Terminal Area Productivity (TAP) Program, which is focused on providing technology and operating procedures for achieving clear-weather airport capacity in instrument-weather conditions, while also improving safety. LVLASO is investigating various technologies to be applied to airport surface operations, including advanced flight deck displays and surveillance systems. The purpose of this report is to document the performance of the surveillance systems tested as part of the LVLASO flight experiment. There were three surveillance sensors tested: primary radar using Airport Surface Detection Equipment (ASDE-3) and the Airport Movement Area Safety System (AMASS), Multilateration using the Airport Surface Target Identification System (ATIDS), and Automatic Dependent Surveillance - Broadcast (ADS-B) operating at 1090 MHz. The performance was compared to the draft requirements of the ICAO Advanced Surface Movement Guidance and Control System (A-SMGCS). Performance parameters evaluated included coverage, position accuracy, and update rate. Each of the sensors was evaluated as a stand alone surveillance system.

Cassell, Rick; Evers, Carl; Hicok, Dan; Lee, Derrick

1999-01-01

44

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

45

Revised Land Use Characteristic Dataset for Asia and Southwest Asia for the Navy Aerosol Analysis and Prediction System (NAAPS)  

NASA Astrophysics Data System (ADS)

Presently, the Navy Aerosol Analysis and Prediction System (NAAPS) uses the U.S. Geological Survey (USGS) land use characteristic dataset to determine global dust emission areas. The USGS dataset was developed from Advanced Very High-Resolution Radiometer 1-km data from April 1992 to March 1993. In the past decade drastic changes in land and water use in Asia and Southwest Asia have quickly outdated this dataset. In China and Mongolia, age-old practices of farming and animal husbandry have been abandoned. Herders have too many animals in one location allowing the grassland to be eaten away and leaving vast areas of topsoil exposed and primed for removal by the wind. In the case of Southwest Asia, a four-year drought is in progress. Many of the wetlands and marshes in the river deltas are drying up from the lack of water runoff. To compound the problem several new dams were and are being built along the major watersheds. In particular, Iraq's dam building in the 1990's and politically driven draining of the Mesopotamian marshes between the Tigris and Euphrates rivers has lead to the near disappearance of this historical marshland. To incorporate these changes we are updating the USGS land use characteristic dataset using GIS-like software named ENVI (Environment for Visualizing Images), 1 km National Geophysical Data Center (NGDC) global topographical data, satellite imagery, and recently released governmental maps and reports. (For example, within the last two years the Chinese and Mongolian governments have released land degradation and desertification maps to satisfy the requirements set forth by United Nations Convention to Combat Desertification.) The steps taken to create the new land use characteristic database will be described in detail. Before (non-dust producing areas) and after (dust producing areas) examples will be shown.

Walker, A. L.; Richardson, K.; Westphal, D. L.

2002-12-01

46

Failure Modes, Effects and Criticality Analysis (FMECA) of Category III Instrument Landing System.  

National Technical Information Service (NTIS)

A Failure Modes, Effects and Criticality Analysis (FMECA) is used to optimize system performance by identification (and subsequent elimination) of all potentially hazardous failure modes affecting either personnel safety or operational mission success. Th...

P. Dvoracek

1972-01-01

47

Guidance and control for lunar landing system  

Microsoft Academic Search

Fundamental considerations on guidance and control problems are presented for the lunar landing system which will be developed in Japan in several years. The guidance and control system for the lunar landing system includes functions such as attitude and position control during descent, searching for optimum landing position, guidance to the landing position, and deceleration control for soft landing. Fundamental

Shohei Niwa; Masayuki Suzuki; Jun Zhou; Takahiro Kawasaki; Shunichiro Nakai; Kazuyuki Higashino

1992-01-01

48

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

49

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

50

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

51

Dual Heat Pulse, Dual Layer Thermal Protection System Sizing Analysis and Trade Studies for Human Mars Entry Descent and Landing  

NASA Technical Reports Server (NTRS)

NASA has been recently updating design reference missions for the human exploration of Mars and evaluating the technology investments required to do so. The first of these started in January 2007 and developed the Mars Design Reference Architecture 5.0 (DRA5). As part of DRA5, Thermal Protection System (TPS) sizing analysis was performed on a mid L/D rigid aeroshell undergoing a dual heat pulse (aerocapture and atmospheric entry) trajectory. The DRA5 TPS subteam determined that using traditional monolithic ablator systems would be mass expensive. They proposed a new dual-layer TPS concept utilizing an ablator atop a low thermal conductivity insulative substrate to address the issue. Using existing thermal response models for an ablator and insulative tile, preliminary hand analysis of the dual layer concept at a few key heating points indicated that the concept showed potential to reduce TPS masses and warranted further study. In FY09, the followon Entry, Descent and Landing Systems Analysis (EDL-SA) project continued by focusing on Exploration-class cargo or crewed missions requiring 10 to 50 metric tons of landed payload. The TPS subteam advanced the preliminary dual-layer TPS analysis by developing a new process and updated TPS sizing code to rapidly evaluate mass-optimized, full body sizing for a dual layer TPS that is capable of dual heat pulse performance. This paper describes the process and presents the results of the EDL-SA FY09 dual-layer TPS analyses on the rigid mid L/D aeroshell. Additionally, several trade studies were conducted with the sizing code to evaluate the impact of various design factors, assumptions and margins.

McGuire, Mary Kathleen

2011-01-01

52

Estimating Evapotranspiration with Land Data Assimilation Systems.  

National Technical Information Service (NTIS)

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...

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

2011-01-01

53

Design and Development of Land Resources Information System of Zibo area Based on Client\\/Server  

Microsoft Academic Search

SUMMARY Land resources information system has been developed to assess the land quality, to manage agricultural resource and to analysis the land use in Zibo area, China. Through analysis present situation of the development of the land resources, land resources information system based on MapObjects is designed this paper. Key technologies such as total database system structure, data organization and

Jianpeng Chu; Yunjun Yao

54

Integrating NASA's Land Analysis System (LAS) image processing software with an appropriate Geographic Information System (GIS): A review of candidates in the public domain  

NASA Technical Reports Server (NTRS)

A user requirements analysis (URA) was undertaken to determine and appropriate public domain Geographic Information System (GIS) software package for potential integration with NASA's LAS (Land Analysis System) 5.0 image processing system. The necessity for a public domain system was underscored due to the perceived need for source code access and flexibility in tailoring the GIS system to the needs of a heterogenous group of end-users, and to specific constraints imposed by LAS and its user interface, Transportable Applications Executive (TAE). Subsequently, a review was conducted of a variety of public domain GIS candidates, including GRASS 3.0, MOSS, IEMIS, and two university-based packages, IDRISI and KBGIS. The review method was a modified version of the GIS evaluation process, development by the Federal Interagency Coordinating Committee on Digital Cartography. One IEMIS-derivative product, the ALBE (AirLand Battlefield Environment) GIS, emerged as the most promising candidate for integration with LAS. IEMIS (Integrated Emergency Management Information System) was developed by the Federal Emergency Management Agency (FEMA). ALBE GIS is currently under development at the Pacific Northwest Laboratory under contract with the U.S. Army Corps of Engineers' Engineering Topographic Laboratory (ETL). Accordingly, recommendations are offered with respect to a potential LAS/ALBE GIS linkage and with respect to further system enhancements, including coordination with the development of the Spatial Analysis and Modeling System (SAMS) GIS in Goddard's IDM (Intelligent Data Management) developments in Goddard's National Space Science Data Center.

Rochon, Gilbert L.

1989-01-01

55

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

56

Automatic land and parcel valuation to support the land and buildings tax information system by developing the open source software  

Microsoft Academic Search

Summary The land valuation is to provide a credible, reliable, and cost-effective estimate of market value as of given point in time. Land valuation is one of most important activity for Service point of land & buildings taxation in Indonesia. Where the location became the strongest factor to land value. Geographical Information Systems Technology with spatial analysis capability can measure

Bambang-Edhi LEKSONO; Yuliana SUSILOWATI; Andriyan Bayu SUKMONO

57

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

58

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

59

Design and implementation of land reservation system  

NASA Astrophysics Data System (ADS)

Land reservation is defined as a land management policy for insuring the government to control primary land market. It requires the government to obtain the land first, according to plan, by purchase, confiscation and exchanging, and then exploit and consolidate the land for reservation. Underlying this policy, it is possible for the government to satisfy and manipulate the needs of land for urban development. The author designs and develops "Land Reservation System for Eastern Lake Development District" (LRSELDD), which deals with the realistic land requirement problems in Wuhan Eastern Lake Development Districts. The LRSELDD utilizes modern technologies and solutions of computer science and GIS to process multiple source data related with land. Based on experiments on the system, this paper will first analyze workflow land reservation system and design the system structure based on its principles, then illustrate the approach of organization and management of spatial data, describe the system functions according to the characteristics of land reservation and consolidation finally. The system is running to serve for current work in Eastern Lake Development Districts. It is able to scientifically manage both current and planning land information, as well as the information about land supplying. We use the LRSELDD in our routine work, and with such information, decisions on land confiscation and allocation will be made wisely and scientifically.

Gao, Yurong; Gao, Qingqiang

2009-10-01

60

Autonomous landing guidance system validation  

NASA Astrophysics Data System (ADS)

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 by potential revenue savings since today only 43 Type III and 80 Type II instrumented landing system (ILS) runway ends in the United States are equipped for lower minimum flight operations. Additionally, most of these ILS facilities are clustered at major gateway airports which further impacts on dispatch authority and general ATC regional delays. Infrastructure consists to upgrade additional runways must not only account for the high integrity ground instrumentation, but also the installation of lights and markers mandated for Cat III operations. The military services ability to train under realistic battlefield conditions, to project power globally in support of national interests, while providing humanitarian aid, is significantly impaired by the inability to conduct precision approaches and landings in low visibility conditions to either instrumented runways or to a more tactical environment with operations into and out of unprepared landing strips, particularly when time does not permit deployment of ground aids and the verification of their integrity. Recently, Lear Astronics, in cooperation with Consortium members of the ALG Program, concluded a flight test program which evaluated the utility of the ALG system in meeting both civil and military needs. Those results are the subject of this paper.

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

1997-06-01

61

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

62

Static error budget analysis for a land-based dual-camera mobile mapping system  

Microsoft Academic Search

A mobile mapping system (MMS) is developed based on a direct sensor orientation technique that integrates GPS\\/inertial measurement unit (IMU) and digital cameras. This system is capable of directly mapping geospatial information without the requirement of ground control. In this article, an MMS composed of two digital single-lens reflex cameras and an Applanix POS AV-510 is described. There are several

Jiann-Yeou Rau; Liang-Chien Chen; Cheng-Chang Hsieh; Ting-Ming Huang

2011-01-01

63

A Lunar Landing Guidance System for Soft-Precision Landings  

Microsoft Academic Search

A logical development of a novel, minimum-complexity guidance system for precise and soft lunar landing is presented together with an evaluation of predominant error sensitivities. Selection of this minimum-complexity system is influenced by its ability to handle a wide range of initial condition, sensor, propulsion and control system errors with minimum fuel and accuracy penalty. The trajectory control technique allows

J. E. Vaeth; M. D. Sarles

1964-01-01

64

Land mobile satellite system requirements  

NASA Astrophysics Data System (ADS)

A Land Mobile Satellite System (LMSS) provides voice, data and related communications services to moving vehicles and persons. Communications between the mobiles and satellite are in the 806-890 MHz band. The satellite translates these signals to a ""fixed services band'' such as 14/12 GHz band (Ku-band), and communicates in this band with fixed terminals called gateways. The gateways are located at convenient places such as telephone switches (which provide entry into the national telephone system), dispatcher headquarters, computer centers, etc. Communications are therefore principally mobile to fixed. A third communications link, also at Ku-band, is needed between the satellite and a single fixed ground station. This link provides satellite command, telemetry and ranging and also provides a network control function. The latter, through a common signalling system, receives requests and assigns channel slots, and otherwise controls, monitors and polices the network and collects billing information.

Kiesling, J. D.

1983-05-01

65

Land mobile satellite system requirements  

NASA Technical Reports Server (NTRS)

A Land Mobile Satellite System (LMSS) provides voice, data and related communications services to moving vehicles and persons. Communications between the mobiles and satellite are in the 806-890 MHz band. The satellite translates these signals to a ""fixed services band'' such as 14/12 GHz band (Ku-band), and communicates in this band with fixed terminals called gateways. The gateways are located at convenient places such as telephone switches (which provide entry into the national telephone system), dispatcher headquarters, computer centers, etc. Communications are therefore principally mobile to fixed. A third communications link, also at Ku-band, is needed between the satellite and a single fixed ground station. This link provides satellite command, telemetry and ranging and also provides a network control function. The latter, through a common signalling system, receives requests and assigns channel slots, and otherwise controls, monitors and polices the network and collects billing information.

Kiesling, J. D.

1983-01-01

66

Public Land Policy and the Environment. Volume 4. Part III: Environmental Quality and the Public Lands: A General System for Environmental Resource Analysis.  

National Technical Information Service (NTIS)

Volume four of the study on public land policy and the environment deals with the environmental effects of land use which cover a complex of biological and physical relationships, such as impacts on air and water quality, as well as those affecting aesthe...

P. H. Lewis C. Steinitz

1970-01-01

67

Land cover analysis along semi-arid transects in Asia  

NASA Astrophysics Data System (ADS)

Current estimates of land cover and land use are important aspects in understanding the flux of material and energy from terrestrial ecosystems into hydrological and atmospheric components of the earth system. These land use characteristics define the various dimensions of human impacts on ecosystem processes and resource use. The recent availability of global remote sensing data and agricultural census data from various regions of the world, including portions of Asia such as China and Mongolia, now makes it feasible to evaluate differences in the physical environment and land use patterns affecting land cover and land use changes. In addition, recent research involving transects studies along gradients of climate, soil, and land use intensity has been carried out during the past decade to allow more careful regional comparisons. Using the analysis of the Mongolian-North East China Transect (NECT), we can estimate the effect of land cover differences on ecosystem dynamics. The 30 m-Thematic Mapper data provides a way to identify fine scale features of the regional landscape patterns which are not captured by the 1-km AVHRR data. The focus of this paper is to evaluate the scale of land use and cover changes in the Asian region and the biogeochemical implications of these changes. The estimates of land cover and land use can vary depending on the spatial scale of the features represented across the land surface. Both physical and social factors influence the spatial extent these features represent. Therefore, the scale of land use intensification can affect the accuracy of land use area estimations. In particular, those regions of the world where land use practices are implemented via small individual holdings may be underestimated when using coarse scale remote sensing data such as AVHRR, where as the Thematic Mapper satellite data at 30 to 50 m resolution can provide a better estimate of land cover and land use area. The accuracy of the extrapolated fluxes of ecosystem dynamics and biogeochemical cycles are directly proportional to the accuracy associated with the land estimates. We will evaluate the land cover estimates in this region of Asia using these data sources. This region encompasses a broad set of precipitation and temperature regimes and includes characteristics of regional land cover and land use related to grazing systems and grain cultivation.

Ojima, Dennis; Gao, Zhiqiang; Liu, Jiyuan; Kneeland, Mary; Chuluun, Togtohyn

2003-07-01

68

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

69

Crew Office Evaluation of a Precision Lunar Landing System  

NASA Technical Reports Server (NTRS)

A representative Human System Interface for a precision lunar landing system, ALHAT, has been developed as a platform for prototype visualization and interaction concepts. This facilitates analysis of crew interaction with advanced sensors and AGNC systems. Human-in-the-loop evaluations with representatives from the Crew Office (i.e. astronauts) and Mission Operations Directorate (MOD) were performed to refine the crew role and information requirements during the final phases of landing. The results include a number of lessons learned from Shuttle that are applicable to the design of a human supervisory landing system and cockpit. Overall, the results provide a first order analysis of the tasks the crew will perform during lunar landing, an architecture for the Human System Interface based on these tasks, as well as details on the information needs to land safely.

Major, Laura M.; Duda, Kevin R.; Hirsh, Robert L.

2011-01-01

70

Mars Landing Site Analysis Lab  

NSDL National Science Digital Library

Brian Hynek, University of Colorado Summary Students use recent data acquired from Mars orbiters to assess the safety and scientific value of various proposed landing sites for a future Mars lander. Context Type ...

Hynek, Brian

71

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

72

Analysis of consistency of global net land-use change carbon emission scenario using offline vegetation model and earth system model  

NASA Astrophysics Data System (ADS)

For CMIP5 experiments, emissions scenarios data sets for climate models are prepared as Representative Concentration Pathways (RCPs) by the Integrated Assessment Models (IAMs). IAMs also have depicted regional land-use scenarios based on the socioeconomic assumption of the future scenarios of RCPs. In the land-use harmonization project, gridded land-use transition data has been constructed from the regional IAMs future land-use scenarios which smoothly connects historical reconstructions of land-use based on HYDE 3 data and FAO wood harvest data. In this study, using the gridded transition land-use scenario data, global net CO2 emission from land-use change for each RCPs scenarios is evaluated with a offline version of terrestrial biogeochemical model, VISIT (Vegetation Integrative SImulation Tool), utilizing a protocol to estimate carbon emission from deforested biomass considering delayed decomposition of product pools, and regrowth absorption from the secondary lands with abandoned agricultural lands. From the model output, effect of CO2 fertilization and land-use scenario itself on the emission is assessed to see the consistency of the scenarios. In addition, to see the effect of climate change and the climate-carbon feedback on terrestrial ecosystems, net land-use change CO2 emission is also evaluated with an earth system model, MIROC-ESM incorporating a DGVM with land-use change component. In the simulations with earth system model, RCP 6.0 scenario has been evaluated by model runs with and without land-use change forcing.

Kato, E.; Kawamiya, M.

2010-12-01

73

Sherpa moving mass entry descent landing system  

NASA Technical Reports Server (NTRS)

We describe Sherpa - a Strap-on High-altitude Entry Reconnaissance and Precision Aeromaneuver system that utilizes a moving mass system within an entry capsule to land a spacecraft precisely onto the surface of Mars.

Balaram, J.

2005-01-01

74

Future Landing Capabilities of the Mars 2020 Entry, Descent, and Landing System  

NASA Astrophysics Data System (ADS)

This study examines landing site elevation capability as a function of landing season, for a future mission using the heritage MSL/Mars 2020 EDL system. Results are presented for a 1200kg landed mass with different parachute technology assumptions.

Kipp, K. A.; Hines, E. K.; Chen, A.

2014-06-01

75

Preliminary Study of Marine Aircraft Landing Systems.  

National Technical Information Service (NTIS)

The requirement of the Navy to develop versatile, rugged, and transportable landing systems suited to Marine Corps Aircraft has created specific problems of a diverse, yet highly technical nature. The problems addressed in this report include those associ...

W. E. Sears R. P. Zimmer E. R. Flynt C. E. Ryan

1973-01-01

76

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

77

Land system architecture: Using land systems to adapt and mitigate global environmental change  

SciTech Connect

Land systems (mosaics of land use and cover) are human environment systems, the changes in which drive and respond to local to global environmental changes, climate to macro-economy (Foley et al., 2005). Changes in land systems have been the principal proximate cause in the loss of habitats and biota globally, long contributed to atmospheric greenhouse gases, and hypothesized to have triggered climate changes in the early Holocene (Ruddiman, 2003). Land use, foremost agriculture, is the largest source of biologically active nitrogen to the atmosphere, critical to sources and sinks of carbon, and a major component in the hydrologic cycle (e.g., Bouwman et al., 2011). Changes in land systems also affect regional climate (Feddema et al., 2005; Pielke, 2005), ecosystem functions, and the array of ecosystem services they provide. Land systems, therefore, are a central feature of how humankind manages its relationship with nature-intended or not, or whether this relationship proceeds sustainably or not.

Turner, B.L.; Janetos, Anthony C.; Verbug, Peter H.; Murray, Alan T.

2013-04-01

78

Autonomous precision approach and landing system (APALS)  

NASA Astrophysics Data System (ADS)

The APALSTM system is a precision approach and landing system designed to enable low visibility landings at many more airports than is now possible. It is an autonomous navigation system which uses standard avionics equipment to determine the aircraft position and altitude with respect to unique features over which the aircraft flies. The primary measurement is made with the aircraft's weather radar and provides the range and range rate information necessary to update the precision navigation system. The system makes use of stored terrain map data as references for map matching with Synthetic Aperture Radar maps.

Dieffenbach, Otto

1995-06-01

79

Crew procedures for microwave landing system operations  

NASA Technical Reports Server (NTRS)

The objective of this study was to identify crew procedures involved in Microwave Landing System (MLS) operations and to obtain a preliminary assessment of crew workload. The crew procedures were identified for three different complements of airborne equipment coupled to an autopilot. Using these three equipment complements, crew tasks were identified for MLS approaches and precision departures and compared to an ILS approach and a normal departure. Workload comparisons between the approaches and departures were made by using a task-timeline analysis program that obtained workload indexes, i.e., the radio of time required to complete the tasks to the time available. The results showed an increase in workload for the MLS scenario for one of the equipment complements. However, even this workload was within the capacity of two crew members.

Summers, Leland G.

1987-01-01

80

Geodetic GPS analysis of Land Victoria's GPSnet  

Microsoft Academic Search

The first published results of the geodetic GPS analysis of the data from the base stations that comprise Land Victoria's GPSnet are presented. Nineteen GPS base stations distributed across the state of Victoria (Australia) make up the network, whose principal purpose aims to reduce the reliance for positioning across the state on ground marks, and satisfy the ever increasing number

N. Penna; J. Lo; G. Luton

2005-01-01

81

Experimental Land Observing Data System Feasibility Study.  

National Technical Information Service (NTIS)

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 Prog...

J. L. Buckley H. Kraiman

1982-01-01

82

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

83

Land Use Analysis and Land Potential Study: Cumberland County, North Carolina.  

National Technical Information Service (NTIS)

The report contains an analysis of existing land uses in Cumberland County, North Carolina. Emphasis is placed upon patterns of land development and problems resulting therefrom. Major arterial development is examined. Physiographical and man-made factors...

1970-01-01

84

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

85

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

86

New Developments in Land Transportation [Transportation Systems  

Microsoft Academic Search

The paper discussed the new developments in land transportation system in different locations. Here are some of the developments discussed: In Vienna, train control system is ordered for Phase 4 extension of Wiener Linien. Sound transit extension to Sea Tac Airport in Seattle is operational. Nuovo Transporto Viaggiatori receives its first high speed trains from Alstom for testing on the

Harvey Glickenstein

2010-01-01

87

Land Mobile Satellite Data System.  

National Technical Information Service (NTIS)

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 capab...

J. D. B. Kent

1990-01-01

88

Data Acquisition and Analysis for Land Slide susceptibility mapping using Geographical Information System (GIS) at Nilgiris district, India  

Microsoft Academic Search

The purpose of this study is to develop technique for landslide susceptibility mapping using artificial neural networks and then to apply the technique to the selected study area at Nilgiris district in Tamil Nadu. Landslide locations are identified by interpreting the satellite images and field survey data, and a spatial database of the topography, soil, forest, and land use. Then

S. PRABU; S. S. RAMAKRISHNAN; R. VIDYA

89

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

90

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

NASA Technical Reports Server (NTRS)

The NASA developed Land Information System (LIS) is the Air Force Weather Agency's (AFWA) operational Land Data Assimilation System (LDAS) combining real time precipitation observations and analyses, global forecast model data, vegetation, terrain, and soil parameters with the community Noah land surface model, along with other hydrology module options, to generate profile analyses of global soil moisture, soil temperature, and other important land surface characteristics. (1) A range of satellite data products and surface observations used to generate the land analysis products (2) Global, 1/4 deg spatial resolution (3) Model analysis generated at 3 hours

Shaw, Michael; Kumar, Sujay V.; Peters-Lidard, Christa D.; Cetola, Jeffrey

2011-01-01

91

Land Use Analysis, Vigo County Area, Indiana.  

National Technical Information Service (NTIS)

The study concentrates upon 1960-1971 land use data. It provides the resources required to analyze the areas land usage and to develop a land use plan. This study concerns general land use trends and compilation and development of land use data relating t...

J. Sheehan

1972-01-01

92

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

93

Mars Exploration Rovers Landing Dispersion Analysis.  

National Technical Information Service (NTIS)

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 ...

P. C. Knocke G. G. Wawrzyniak B. M. Kennedy P. N. Desai T. I. J. Parker M. P. Golombek T. C. Duxbury D. M. Kass

2004-01-01

94

A land mobile satellite data system  

NASA Astrophysics Data System (ADS)

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.

95

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

96

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

97

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.

98

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

Federal Register 2010, 2011, 2012, 2013

...of Public and National Forest System Lands, Coconino...776 acres of public and National Forest System lands from location...exploration and mining: Gila and Salt River Meridian...776 acres public and National Forest System lands in...

2011-06-28

99

Mars Exploration Rover Mission: Entry, Descent, and Landing System Validation  

NASA Technical Reports Server (NTRS)

System validation for a Mars entry, descent, and landing system is not simply a demonstration that the electrical system functions in the associated environments. The function of this system is its interaction with the atmospheric and surface environment. Thus, in addition to traditional test-bed, hardware-in-the-loop, testing, a validation program that confirms the environmental interaction is required. Unfortunately, it is not possible to conduct a meaningful end-to-end test of a Mars landing system on Earth. The validation plan must be constructed from an interconnected combination of simulation, analysis and test. For the Mars Exploration Rover mission, this combination of activities and the logic of how they combined to the system's validation was explicitly stated, reviewed, and tracked as part of the development plan.

Mitcheltree, Robert A.; Lee, Wayne; Steltzner, Adam; SanMartin, Alejanhdro

2004-01-01

100

Guide to NASA's Pilot Land Data System (PLDS).  

National Technical Information Service (NTIS)

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 librar...

1991-01-01

101

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.

Li, Guiying; Moran, Emilio; Hetrick, Scott

2013-01-01

102

ILS/MLS (Instrument Landing System/Microwave Landing System) Comparison Tests at Miami/Tamiami, Florida Airport.  

National Technical Information Service (NTIS)

A series of flight tests were performed by the Federal Aviation Administration (FAA) Technical Center at the Miami/Tamiami, Florida Airport, to compare the course quality of an instrumented landing system (ILS) with a collected Microwave Landing System (M...

J. Townsend

1989-01-01

103

ILS/MLS (Instrumented Landing System/Microwave Landing System) Comparison Tests at Miami/Tamiami, Florida Airport.  

National Technical Information Service (NTIS)

A series of flight tests were performed by the Federal Aviation Administration (FAA) Technical Center at the Miami/Tamiami, Florida Airport, to compare the course quality of an instrumented landing system (ILS) with a collocated Microwave Landing System (...

J. Townsend

1989-01-01

104

Louisiana comprehensive planning information system. [computerized land use mapping system  

NASA Technical Reports Server (NTRS)

A statewide computerized land use mapping system is reported that uses polygons to identify inventories from aerial photography by employing the USGS classification system. In addition, the system provides soil, population, and housing census data as well as economic indicators that can be useful in relating to the overall system.

Ryan, P. W.; Schwertz, E.

1975-01-01

105

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

106

Sustainable land use evaluation spatialization analysis  

Microsoft Academic Search

This paper discussed about the process and method of sustainable land use spatialization. Divide the indicator into statistical indicator and geospatial indicator. Take Guyuan County, Kangbao County and Zhangbei County in Bashang region of Hebei province, China as examples, build a sustainable land use evaluation indicator. Evaluate the sustainable land use in Bashang region in 2003; the result can describe

Bin Zhao; Jia-cun Li; Wen-ji Zhao

2010-01-01

107

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

108

Satellite systems requirements for land mobile communications  

NASA Technical Reports Server (NTRS)

The system design objective is to provide a satellite link through a gateway station, connecting mobile users in areas not served by a terrestrial cellular system to the switched telephone network (STN). The proposed frequency allocation comprises a pair of 10-MHz bands in the 806-890 MHz range specified by the 1979 World Administrative Radio Conference (WARC) for land-mobile satellite service (LMSS). The satellite design is constrained by projected STS capability with an upper stage of the wide-body Centaur or Integral Propulsion System (IPS) type. For the latter (a TRW design), the payload is limited to approximately 10,400 lb. The design is to be based on 1990's technology, with initial operating capability scheduled for 1995. The satellite should be designed for a 7-year life. Mobile-unit compatibility with cellular system specifications is desirable, if consistent with other system requirements.

Horstein, M.

1983-01-01

109

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

110

AGFATL- ACTIVE GEAR FLEXIBLE AIRCRAFT TAKEOFF AND LANDING ANALYSIS  

NASA Technical Reports Server (NTRS)

The Active Gear, Flexible Aircraft Takeoff and Landing Analysis program, AGFATL, was developed to provide a complete simulation of the aircraft takeoff and landing dynamics problem. AGFATL can represent an airplane either as a rigid body with six degrees of freedom or as a flexible body with multiple degrees of freedom. The airframe flexibility is represented by the superposition of up to twenty free vibration modes on the rigid-body motions. The analysis includes maneuver logic and autopilots programmed to control the aircraft during glide slope, flare, landing, and takeoff. The program is modular so that performance of the aircraft in flight and during landing and ground maneuvers can be studied separately or in combination. A program restart capability is included in AGFATL. Effects simulated in the AGFATL program include: (1) flexible aircraft control and performance during glide slope, flare, landing roll, and takeoff roll under conditions of changing winds, engine failures, brake failures, control system failures, strut failures, restrictions due to runway length, and control variable limits and time lags; (2) landing gear loads and dynamics for up to five gears; (3) single and multiple engines (maximum of four) including selective engine reversing and failure; (4) drag chute and spoiler effects; (5) wheel braking (including skid-control) and selective brake failure; (6) aerodynamic ground effects; (7) aircraft carrier operations; (8) inclined runways and runway perturbations; (9) flexible or rigid airframes; 10) rudder and nose gear steering; and 11) actively controlled landing gear shock struts. Input to the AGFATL program includes data which describe runway roughness; vehicle geometry, flexibility and aerodynamic characteristics; landing gear(s); propulsion; and initial conditions such as attitude, attitude change rates, and velocities. AGFATL performs a time integration of the equations of motion and outputs comprehensive information on the airframe, state-of-maneuver logic, autopilots, control response, and aircraft loads from impact, runway roll-out, and ground operations. Flexible-body and total (elastic plus rigid-body) displacements, velocities, and accelerations are also output in the flexible-body option for up to twenty points on the aircraft. The AGFATL program is written in FORTRAN IV for batch execution and has been implemented on a CDC CYBER 170 series computer with an overlayed central memory requirement of approximately 141 (octal) of 60 bit words. The AGFATL program was last updated in 1984.

Mcgehee, J. R.

1994-01-01

111

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

112

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

113

Retinal Image of the Fresnel Lens Optical Landing System.  

National Technical Information Service (NTIS)

The theory and geometry by which the Fresnel Lens Optical Landing System (FLOLS) provides glideslope information to the pilot attempting a carrier landing is described. From the theory, geometry, and the linear spatial dimensions of the FLOLS, the image i...

L. A. Temme W. A. Monaco

1986-01-01

114

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

National Technical Information Service (NTIS)

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...

M. G. Bosilovich R. Yang P. R. Houser

1998-01-01

115

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

116

Soil Moisture Remote Sensing in the Canadian Land Data Assimilation System (CaLDAS)  

Microsoft Academic Search

For several years now, a major project has been underway at Environment Canada (EC) to improve the representation of land surface processes in operational environmental prediction systems. A foremost component of this effort is related to improving soil moisture analysis produced by the Canadian Land Data Assimilation System (CaLDAS). In its current operational state, CaLDAS assimilates observations from surface stations

S. Belair; M. Carrera; B. Bilodeau

2009-01-01

117

Analysis of land-use/land-cover change in the Carpathian region based on remote sensing techniques  

NASA Astrophysics Data System (ADS)

Human activities result in different significant environmental changes, these complex feedback processes may cause dramatic changes in our everyday life. Among others they include land-use and consequently land-cover changes. In order to study such complex variables full spatial coverage of the given area is one of the key issues. Rapid development of satellite use in different topics of research has provided an excellent tool to build agricultural monitoring systems and to improve our understanding of the complex links between air, water and land, including vegetation. In the last few years serious flood events occurred at the watershed of the river Tisza (both in Hungary and in Ukraine). One of the reasons of these floods is heavy precipitation at the region, which result in severe runoff consequences because of the significant change in land-use/land-cover. In this analysis both land-use change and Normalized Difference Vegetation Index (NDVI) values for the Carpathian Region have been statistically analysed for the last two decades. Remotely sensed datasets observed by NOAA and NASA satellites are available for this period. The spatial resolution of these measurements is 1 to 8 km. Tendencies in the change of natural and artificial land-cover types are investigated in the upper watershed of the river Tisza. According to our estimations the forest area on the Ukrainian part of the watershed decreased by about 10% in the last decade. Possible reasons include regional effects of the global climate change, deforestation in the region, etc.

Dezsõ, Zs.; Bartholy, J.; Pongrácz, R.; Barcza, Z.

2003-04-01

118

Evaluation of Noah land surface models in the FLUXNET sites using the Land Information System  

NASA Astrophysics Data System (ADS)

Land surface models (LSMs) are essential components of several current global data assimilation systems, run individually and in ensemble, which are used to reproduce surface components of the water and energy cycles (transpiration, evaporation, runoff, surface heat fluxes and radiation). The LSMs are expected to provide accurate understanding, to model and predict the local surface fluxes as part of a better land-atmosphere coupling scheme. However, the ability of LSMs to properly portion the water and energy budgets is still far from perfection. Many studies have been conducted to compare and benchmark LSMs. This study intends to contribute to the GEWEX benchmarking effort called PALS (Protocol for the Analysis of Land Surface models) using several recent versions of the Noah LSMs. We use the Noah LSMs, version 2.7.1, 3.2 and 3.3 included in NASA's Land Information System for this study. The models are run in offline mode for several FLUXNET station points located across the world using the forcings from in situ observations. A 2-year model spin-up is conducted for all stations. The simulated fluxes are compared against observed fluxes to evaluate model performance. Seasonal and diurnal analyses of the fluxes are investigated. Significant improvements are noted in sensible heat simulation in version 3.2 compared to version 2.7.1 at many locations. The summer-season improvement in sensible heat flux is notably significant. It is noted that systematic low bias problem in latent heat flux in version 2.7.1 are over-corrected in later versions of the Noah models, which has resulted high biases, particularly in summer season daytime fluxes. The results may be helpful in diagnosing the problems in the Noah LSM and improving it further.

Shrestha, R. K.; Dong, J.; Dirmeyer, P.; Ek, M. B.; Abramowitz, G.

2013-12-01

119

Trenton, Tennessee. Population, Economy, Land Use Survey, Land Use Standards, Land Use Analysis and Plan.  

National Technical Information Service (NTIS)

After a brief introduction, the site characteristics are discussed. The population trends, characteristics, change, projections and distribution are analyzed to aid the community in planning services and future land use requirements. The local economy is ...

1972-01-01

120

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

121

Remote sensing and GIS integration for land cover analysis, a case study: Bozcaada Island.  

PubMed

In this study, remote sensing and geographic information system (GIS) techniques were used in order to accomplish land cover change of Bozcaada Island, Turkey, by using multitemporal Landsat Thematic Mapper data. Digital image processing techniques were conducted for the processes of image enhancement, manipulation, registration and classification for land cover change analysis. The land cover changes between two different dates were visualized and analyzed by using Geographic Information System techniques. The results showed that remotely sensed data and GIS are effective and powerful tools for carrying out changes on land cover of the island and monitoring of its impact on the environment. PMID:16114638

Bektas, F; Goksel, C

2005-01-01

122

Comparison analysis of agricultural land gradation evaluation based on different weight making methods  

NASA Astrophysics Data System (ADS)

Agricultural land gradation links land classification and land appraisal. It indicates the difference in agricultural productivity resulted from differences in land's natural characteristics and/or the effectiveness and efficiency of agricultural production at present and in the future. Technically, agricultural land is graded based on the sum of weighted indices and further classified by equal-distance, or axis, or sum frequency curve. It is critical to define the system of weights in this process. In practice, a single or mixed weight system has been widely applied in agricultural land gradation. However, few studies put efforts in comparing outcomes in applying different systems of weights for a specific area. This research applied several popular systems of weights, such as AHP, factor analysis, grey relation analysis, entropy method, and etc., in gradating agricultural land in Jintan, Jiangsu province. Outcomes resulted from different systems of weights were compared. The result did illustrate the obvious differences among these outcomes, which in turn stood for differences among systems of weights. Considering biases inherent in different systems of weights, a system of combined weights is highly recommended for the general practice in agricultural land gradation.

Jin, Xiaobin; Zhang, Honghui; Zhou, Yinkang

2008-10-01

123

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

124

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

125

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

126

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

127

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.

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

2013-01-01

128

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

NASA Technical Reports Server (NTRS)

The NASA developed Land Information System (LIS) is the Air Force Weather Agency's (AFWA) operational Land Data Assimilation System (LDAS) combining real time precipitation observations and analyses, global forecast model data, vegetation, terrain, and soil parameters with the community Noah land surface model, along with other hydrology module options, to generate profile analyses of global soil moisture, soil temperature, and other important land surface characteristics. (1) A range of satellite data products and surface observations used to generate the land analysis products (2) Global, 1/4 deg spatial resolution (3) Model analysis generated at 3 hours. AFWA recognizes the importance of operational benchmarking and uncertainty characterization for land surface modeling and is developing standard methods, software, and metrics to verify and/or validate LIS output products. To facilitate this and other needs for land analysis activities at 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 surface Verification Toolkit (LVT), developed at the Goddard Space Flight Center (GSFC), have been adapted to operational benchmarking needs of AFWA's land characterization activities.

Shaw, Michael; Kumar, Sujay V.; Peters-Lidard, Christa D.; Cetola, Jeffrey

2012-01-01

129

Land Cover Analysis of Temperate Asia.  

National Technical Information Service (NTIS)

Satellite data from the advanced very high resolution radiometer (AVHRR) instrument were used to produce a general land cover distribution of temperate Asia (referred to hence as Central Asia) from 1982, starting with the NOAA-7 satellite, and continuing ...

C. Justice

1998-01-01

130

GNC system scheme for lunar soft landing spacecraft  

Microsoft Academic Search

A pinpoint autonomous GNC system scheme for lunar soft landing is proposed. First, the descriptions of the mission outline for lunar soft landing are provided. Second, the GNC system design of the spacecraft is proposed. The baseline is a 3-axis stabilized system during all the phases of the mission. Orbit maneuvers are achieved by an assembled constant thrust or a

Dayi Wang; Xiangyu Huang; Yifeng Guan

2008-01-01

131

Mars Exploration Rovers Entry, Descent, and Landing Trajectory Analysis  

NASA Technical Reports Server (NTRS)

The Mars Exploration Rover mission successfully landed two rovers "Spirit" and "Opportunity" on Mars on January 4th and 25th of 2004, respectively. The trajectory analysis performed to define the entry, descent, and landing (EDL) scenario is described. The entry requirements and constraints are presented, as well as uncertainties used in a Monte Carlo dispersion analysis to statistically assess the robustness of the entry design to off-nominal conditions. In the analysis, six-degree-of-freedom and three-degree-of-freedom trajectory results are compared to assess the entry characteristics of the capsule. Comparison of the preentry results to preliminary post-landing reconstruction data shows that all EDL parameters were within the requirements. In addition, the final landing position for both "Spirit" and "Opportunity" were within 15 km of the predicted landing location.

Desai, Prasun N.; Knocke, Philip C.

2004-01-01

132

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

133

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

134

Land Cover Analysis of Temperate Asia  

NASA Technical Reports Server (NTRS)

Satellite data from the advanced very high resolution radiometer (AVHRR) instrument were used to produce a general land cover distribution of temperate Asia (referred to hence as Central Asia) from 1982, starting with the NOAA-7 satellite, and continuing through 1991, ending with the NOAA-11 satellite. Emphasis was placed upon delineating the and and semi-arid zones of Central Asia (largely Mongolia and adjacent areas), mapping broad categories of aggregated land cover, and upon studying photosynthetic capacity increases in Central Asia from 1982 to 1991.

Justice, Chris

1998-01-01

135

Analysis of human spatial perception during lunar landing  

Microsoft Academic Search

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, vestibular limitations resulting from exposure to lunar gravity after short-term adaptation to weightlessness, combined with acceleration profiles unique to lunar landing trajectories may result in

Torin K. Clark; Alexander J. Stimpson; Laurence R. Young; Charles M. Oman; Kevin R. Duda

2010-01-01

136

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

137

Expert systems and GIS: an application of land suitability evaluation  

Microsoft Academic Search

In this paper expert systems and geographical information systems technologies are combined to help with an implementation of a land suitability evaluation model. The result is the LEIGIS software, which allows empirical work within the framework of this paper. The model used is based on the FAO land classification for crops, and data which describe an agricultural area in terms

S Kalogirou

2002-01-01

138

Assessment of land degradation using time series trend analysis of vegetation indictors in Otindag Sandy land  

NASA Astrophysics Data System (ADS)

Land condition assessment is a basic prerequisite for finding the degradation of a territory, which might lead to desertification under climatic and human pressures. The temporal change in vegetation productivity is a key indicator of land degradation. In this paper, taking the Otindag Sandy Land as a case, the mean normalized difference vegetation index (NDVI_a), net primary production (NPP) and vegetation rain use efficiency (RUE) dynamic trends during 2001–2010 were analysed. The Mann-Kendall test and the Correlation Analysis method were used and their sensitivities to land degradation were evaluated. The results showed that the three vegetation indicators (NDVI_a, NPP and RUE) showed a downward trend with the two methods in the past 10 years and the land was degraded. For the analysis of the three vegetation indicators (NDVI_a, NPP and RUE), it indicated a decreasing trend in 62.57%, 74.16% and 88.56% of the study area according to the Mann-Kendall test and in 57.85%, 68.38% and 85.29% according to the correlation analysis method. However, the change trends were not significant, the significant trends at the 95% confidence level only accounted for a small proportion. Analysis of NDVI_a, NPP and RUE series showed a significant decreasing trend in 9.21%, 4.81% and 6.51% with the Mann-Kendall test. The NPP change trends showed obvious positive link with the precipitation in the study area. While the effect of the inter-annual variation of the precipitation for RUE was small, the vegetation RUE can provide valuable insights into the status of land condition and had best sensitivity to land degradation.

Wang, H. Y.; Li, Z. Y.; Gao, Z. H.; Wu, J. J.; Sun, B.; Li, C. L.

2014-03-01

139

Impacts of Current and Previous Land Use on Greenhouse Gas Fluxes for Biofuel Cropping Systems  

NASA Astrophysics Data System (ADS)

Biofuel cropping systems are both a source and sink of greenhouse gases (GHG). Fertilizer and pesticide manufacture and transport, farm machinery operation, and processing of biomass into fuel all lead to carbon dioxide (CO2) emissions, but the largest GHG sources for biofuel systems are often soil nitrous oxide (N2O) emissions and loss of organic carbon as a result of land use change. However, improved land management can increase soil carbon levels and decrease N2O emissions, thus complementing the CO2 sink from displaced fossil fuel combustion. Previously cropped land, grazed land, and Conservation Reserve Program (CRP) land is being converted to biofuel cropping. We report results for the central US because most of the land used for biofuel cropping is in the central region of the country (corn/soy belt). The primary tool for this analysis is the DAYCENT ecosystem model. The ability of the model to simulate soil GHG fluxes and crop yields is demonstrated and results from simulations of different land management scenarios are presented. Our analyses suggest that conversion of CRP or grazed land to corn ethanol cropping under conventional management leads to a net source of GHG, but that converting these lands to perennial cellulosic biofuel cropping results in a GHG sink. Previously cropped land converted to corn ethanol under conventional management is a small GHG sink, but improved management and conversion to cellulosic based crops can greatly increase this sink strength.

Del Grosso, S.; Parton, W.; Adler, P.; Ogle, S.; West, T.

2008-12-01

140

Flight tests of the Digital Integrated Automatic Landing System (DIALS)  

NASA Technical Reports Server (NTRS)

The design, development, implementation and flight tests of the Digital Integrated Automatic Landing System (DIALS) are discussed. The system was implemented and flight tested on the Transport Systems Research Vehicle (TSRV), a Boeing 737-100. The design uses modern optimal control methods. The direct digital design obtained uses a 10 Hz rate for the sampling of sensors and the control commands. The basic structure of the control law consists of a steady state Kalman filter followed by a control gain matrix. The sensor information used includes Microwave Landing System (MLS) position, attitude, calibrated airspeed, and body accelerations. The phases of the final approach considered are localized and steep glideslope capture (which may be performed simultaneously or independently), localizer and glideslope track, crab/decrab, and flare to touchdown. The system can capture, track, and flare from conventional, as well as steep, glideslopes ranging from 2.5 deg to 5.5 deg. All of the modes of the control law including the Kalman filters were implemented on the TSRV flight computers which use fixed point arithmetic with 16 bit words. The implementation considerations are described as well as an analysis of the flight test results.

Halyo, N.

1984-01-01

141

Analysis of land use and cover change in Sichuan province, China  

NASA Astrophysics Data System (ADS)

A series of environmental policies in Sichuan province was executed to restore the grassland and forestland on some degraded lands after 2000. But the effectiveness on land use and cover change (LUCC) has not yet been systematically investigated. We undertook a detailed analysis about land use and cover change between 2000 and 2005 in Sichuan province. Our study mainly utilized remotely sensed data of 2005 China-Brazil Earth Resources Satellite II (CBERS II) and 2000 Landsat 5 thematic mapper (TM) data. Land use and cover change between 2000 and 2005 was visually interpreted by CBERS II with ArcInfo Workstation based on land use and cover database interpreted from TM. Then LUCC was validated by ground truth with global positioning system receivers. Our analysis illustrates that the conservation policies to restore the grassland and forestland were successful to a lesser extent. But more measures to restore the grassland and forestland of Sichuan province have to be taken further in the future.

Zheng, Zezhong; Yang, Wunian; Zhou, Guoqing; Wang, Xiaoting

2012-01-01

142

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

...SUPPLEMENTARY INFORMATION: The public and National Forest System lands described in this...following described public and National Forest System lands are hereby withdrawn...exploration and development: Gila and Salt River Meridian...

2012-01-18

143

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...

144

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.

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

2011-01-01

145

Computer-Assisted Land Information System for a Rural County - RAPLI-II.  

National Technical Information Service (NTIS)

Land information systems simultaneously serving real property taxation, land transfer, and land use planning functions in local government have been developed only in a few metropolitan areas. RAPLI-II is a simplified scheme providing land information com...

G. Wunderlich

1977-01-01

146

Neutron-based land mine detection system development  

SciTech Connect

This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to examine the feasibility of developing a land mine detection system that can detect nonmetallic (plastic) mines using the detection and analysis of prompt gamma neutron activation analysis (PGNAA). The authors approached this study by first carrying out a review of other nonmetallic land mine detection methods for comparison with the PGNAA concept. They reviewed issues associated with detecting and recording the return gamma signal resulting from neutrons interacting with high explosive in mines and they examined two neutron source technologies that have been under development at Los Alamos for the past several years for possible application to a PGNAA system. A major advantage of the PGNAA approach is it`s ability to discriminate detection speed and need for close proximity. The authors identified approaches to solving these problems through development of improved neutron sources and detection sensors.

Davis, H.A.; McDonald, T.E. Jr.; Nebel, R.A.; Pickrell, M.M.

1997-10-01

147

Biologically inspired enhanced vision system (EVS) for aircraft landing guidance  

Microsoft Academic Search

A useful enhanced vision system (EVS) for aircraft landing guidance not only has to provide the pilots a reliable image of the scene by fusing several sensor images in real time, but should also give them additional information such as attitude, navigation and hazard signals for safe landing in all weather conditions. Here, a biologically inspired EVS is proposed. The

Chiu Hung Luk; Changjian Gao; Dan Hammerstrom; M. Pavel; D. Kerr

2004-01-01

148

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

149

Development and evaluation of the mars pathfinder inflatable airbag landing system  

Microsoft Academic Search

The entry, descent, and landing system of the Mars Pathfinder spacecraft includes a unique subsystem of airbags for impact attenuation. The airbag geometric configuration and associated landing dynamic analysis was performed by the Jet Propulsion Laboratory and Sandia National Laboratories (Mars pathfinder airbag impact attenuation system, paper AIAA-95-1552; Mars pathfinder impact, paper AIAA-95-1553). ILC Dover performed detailed design and fabrication

D. Cadogan; C. Sandy; M. Grahne

2002-01-01

150

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

151

Multi-Scale Hydrometeorological Modeling, Land Data Assimilation and Parameter Estimation with the Land Information System  

NASA Technical Reports Server (NTRS)

The Land Information System (LIS; http://lis.gsfc.nasa.gov) is a flexible land surface modeling framework that has been developed 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. As such, LIS represents a step towards the next generation land component of an integrated Earth system model. In recognition of LIS object-oriented software design, use and impact in the land surface and hydrometeorological modeling community, the LIS software was selected as a co-winner of NASA?s 2005 Software of the Year award.LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has e volved from two earlier efforts -- North American Land Data Assimilation System (NLDAS) and Global Land Data Assimilation System (GLDAS) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of GLDAS and NLDAS now use specific configurations of the LIS software in their current implementations.In addition, LIS was recently transitioned into operations at the US Air Force Weather Agency (AFWA) to ultimately replace their Agricultural Meteorology (AGRMET) system, and is also used routinely by NOAA's National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC) for their land data assimilation systems to support weather and climate modeling. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through "plugins". LIS has been coupled to the Weather Research and Forecasting (WRF) model to support studies of land-atmosphere coupling be enabling ensembles of land surface states to be tested against multiple representations of the atmospheric boundary layer. LIS has also been demonstrated for parameter estimation, who showed that the use of sequential remotely sensed soil moisture products can be used to derive soil hydraulic and texture properties given a sufficient dynamic range in the soil moisture retrievals and accurate precipitation inputs.LIS has also recently been demonstrated for multi-model data assimilation using an Ensemble Kalman Filter for sequential assimilation of soil moisture, snow, and temperature.Ongoing work has demonstrated the value of bias correction as part of the filter, and also that of joint calibration and assimilation.Examples and case studies demonstrating the capabilities and impacts of LIS for hydrometeorological modeling, assimilation and parameter estimation will be presented as advancements towards the next generation of integrated observation and modeling systems

Peters-Lidard, Christa D.

2011-01-01

152

Multi-Scale Hydrometeorological Modeling, Land Data Assimilation and Parameter Estimation with the Land Information System  

NASA Technical Reports Server (NTRS)

The Land Information System (LIS; http://lis.gsfc.nasa.gov; Kumar et al., 2006; Peters- Lidard et al.,2007) is a flexible land surface modeling framework that has been developed 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. As such, LIS represents a step towards the next generation land component of an integrated Earth system model. In recognition of LIS object-oriented software design, use and impact in the land surface and hydrometeorological modeling community, the LIS software was selected ase co-winner of NASA's 2005 Software of the Year award. LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has evolved from two earlier efforts North American Land Data Assimilation System (NLDAS; Mitchell et al. 2004) and Global Land Data Assimilation System (GLDAS; Rodell al. 2004) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of GLDAS and NLDAS now use specific configurations of the LIS software in their current implementations. In addition, LIS was recently transitioned into operations at the US Air Force Weather Agency (AFWA) to ultimately replace their Agricultural Meteorology (AGRMET) system, and is also used routinely by NOAA's National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC) for their land data assimilation systems to support weather and climate modeling. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through "plugins,". As described in Kumar et al., 2007, and demonstrated in Case et al., 2008, and Santanello et al., 2009, LIS has been coupled to the Weather Research and Forecasting (WRF) model to support studies of land-atmosphere coupling the enabling ensembles of land surface states to be tested against multiple representations of the atmospheric boundary layer. LIS has also been demonstrated for parameter estimation as described in Peters-Lidard et al. (2008) and Santanello et al. (2007), who showed that the use of sequential remotely sensed soil moisture products can be used to derive soil hydraulic and texture properties given a sufficient dynamic range in the soil moisture retrievals and accurate precipitation inputs. LIS has also recently been demonstrated for multi-model data assimilation (Kumar et al., 2008) using an Ensemble Kalman Filter for sequential assimilation of soil moisture, snow, and temperature. Ongoing work has demonstrated the value of bias correction as part of the filter, and also that of joint calibration and assimilation. Examples and case studies demonstrating the capabilities and impacts of LIS for hydrometeoroogical modeling, assimilation and parameter estimation will be presented as advancements towards the next generation of integrated observation and modeling systems.

Peters-Lidard, Christa D.; Kumar, Sujay V.; Santanello, Joseph A., Jr.; Reichle, Rolf H.

2009-01-01

153

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

154

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). 971.214 Section 971...FEDERAL LANDS HIGHWAYS FOREST SERVICE MANAGEMENT SYSTEMS Forest Highway Program Management Systems § 971.214 Federal lands...

2013-04-01

155

23 CFR 970.214 - Federal lands congestion management system (CMS).  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Federal lands congestion management system (CMS). 970.214 Section 970...LANDS HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.214 Federal lands...

2013-04-01

156

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

Federal Register 2010, 2011, 2012, 2013

...Committee for Implementation of the National Forest System Land Management...Committee for Implementation of the National Forest System Land Management...recommendations on the implementation of the National Forest System Land...

2013-11-15

157

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

Federal Register 2010, 2011, 2012, 2013

...Committee for Implementation of the National Forest System Land Management...Committee for Implementation of the National Forest System Land Management...recommendations on the implementation of the National Forest System Land...

2011-12-29

158

Spatial Different Analysis of Land Use/Landcover Change And Human Impact In Typical Oasisin Arid Land  

NASA Astrophysics Data System (ADS)

With the current problem of population,resources and environment becoming increasingly intense day by day,the land use/land cover change (LUCC) is one of the core topics on the Present World Change Study.And with the worsening of the global environment,the exhausting of energy and the population explosion,the controversy between the development of oasis economy and the environment has become more and more sharp,which has formed a serious threat to the sustainable development the oasis economy.As a result,the reasonable,coordinate and continuous development is the experimental topic with great theoretical and practical significance in the world.Land use/land cover (LUCC) change has vital significance in environmental variation and the ecology monitoring in the arid and semi-arid areas.This article selects the typical oasis of Awat oasis,which is located in the upstream of Tarim River, where is a typical ecological fragile zone and environmental critical zone.Many effects are caused by the utilization of land and water resources.Along with further development and utilization,great changes of LUCC have been taken place.Based on the research on oasis-desert ecosystem,with the frontier theory of physical geography,LUCC of Awat oasis from 1990 to 2002 are analyzed through the technological train of 3S and statistics,and established the human impact index.Its influencing factors are also identified.First we take the farmland,the wood land,lawn,water,resident,wetland,salt alkali,sand land and naked land as a classification system.Based on the detailed analysis and pretreatment to the remote sensing imagery,we obtained reatively high precision classification result.By the quantification research of human impact to LUCC in Awat,it can be divided into the high human impact area and the low human impact area.The research shows that the changes of pattern are notable and human impact is continuously enhanced,and which is important for the sustainable development of Awat oasis.This research presents the evidence for harmonizing the relations between the land resource and the human activity and provides some methods and experiences for further study of LUCC in aridregion.

Wang, Hongwei; Tiyip, Tash Polat; Ding, Jianli; Luo, Jiangyan

159

Microwave Landing Systems: Additional Systems Should Not Be Procured Unless Benefits Proven.  

National Technical Information Service (NTIS)

Important parts of the national airspace system (NAS) are the precision landing systems which allow aircraft equipped with the necessary electronic hardware (avionics) to land in conditions of limited visibility, thereby increasing the time an airport can...

1988-01-01

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

Global and regional ensemble land-atmosphere modeling with the Land Information System  

NASA Astrophysics Data System (ADS)

NASA, Goddard Space Flight Center has developed a global Land Information System (LIS; http://lis.gsfc.nasa.gov) capable of modeling land-atmosphere interactions at spatial resolutions down to 1km. LIS consists of an ensemble of land surface models (e.g., CLM, Noah, VIC) run offline using satellite-based precipitation (SSM/I; TRMM), radiation and surface parameters, in addition to model-derived surface meteorology. Satellite-based surface parameters include AVHRR-based or MODIS-based land cover and Leaf Area Index (LAI), and MODIS-based albedo and emissivity. The high spatial resolution of LIS, enabled by the use of high performance computing and communications technologies, is capable of resolving mesoscale features, including urban areas, lakes, and agricultural fields. We will present results demonstrating LIS applied at degree, 5km and 1km resolutions. Several validation case studies conducted with LIS, including Houston, Texas, the Southern Great Plains, and the Coordinated Enhanced Observing Period (CEOP) reference sites, demonstrate that using current land cover and LAI products from MODIS, rather than AVHRR-based climatologies, has significant impacts on predicted land surface temperatures and surface water and energy fluxes.

Peters-Lidard, C.; Lis Team

162

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

163

Maneuver analysis methodology to predict vehicle impacts on training lands  

Microsoft Academic Search

Tactical mobility analysis techniques were merged with land management strategies to assess potential impacts of vehicle operations on training areas for rangeland planning and management. A vehicle mobility analysis was performed for a suite of vehicle types using the NATO Reference Mobility Model (NRMM II). Input parameters include terrain information (soil type, slope, vegetation, surface roughness, soil strength), terrain surface

S. Shoop; R. Affleck; C. Collins; G. Larsen; L. Barna; P. Sullivan

2005-01-01

164

Land Information System (LIS) Development Plan: FY13-FY17.  

National Technical Information Service (NTIS)

In 2007, the Air Force Weather Agency (AFWA) approved a plan, collaborative with NASA Goddard Space Flight Center (GSFC), to partner on development of the Land Information System (LIS), an advanced software framework capable of supporting an operational a...

J. B. Eylander

2013-01-01

165

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

166

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

167

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

168

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

169

Application of ERTS-1 imagery to state wide land information system in Minnesota  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. To update and refine existing state-wide land resource information systems, the Minnesota State Planning Agency is assessing the feasibility of extracting resource information from ERTS-1 imagery. Work has centered on a comparative analysis of Minnesota Land Management Information System (MLMIS) and ERTS-1 land use classes. The associated problems of determining appropriate data cell size and optimal seasonal timing have also been addressed. Using ERTS-1 images, dominant land use is classified as follows: urban, forest, agriculture, extractive, transportation, water, and wetlands. Preliminary analysis suggests that with appropriate changes in operational definitions these general classes can be further refined for the benefit of MLMIS users. Additional detail appears most feasible extractive classes.

Sizer, J. E.; Borchert, J. R. (principal investigators)

1973-01-01

170

Control systems for platform landings cushioned by air bags  

NASA Astrophysics Data System (ADS)

This report presents an exploratory mathematical study of control systems for airdrop platform landings cushioned by airbags. The basic theory of airbags is reviewed and solutions to special cases are noted. A computer program is presented, which calculates the time-dependence of the principal variables during a landing under the action of various control systems. Two existing control systems of open-loop type are compared with a conceptual feedback (closed-loop) system for a fairly typical set of landing conditions. The feedback controller is shown to have performance much superior to the other systems. The feedback system undergoes an interesting oscillation not present in the other systems, the source of which is investigated. Recommendations for future work are included.

Ross, Edward W.

1987-07-01

171

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

172

Hydro-ecological analysis of a sacred lake watershed system in relation to land-use\\/cover change from Sikkim Himalaya  

Microsoft Academic Search

The hydrology and ecological linkages between Khecheopalri lake and its surrounding watershed (area: 12 km2) in Sikkim were investigated to assess the long-term impacts of land-use\\/cover change on the hydrology of the lake ecosystem and bog formation around the glaciated lake. Significant land-use\\/cover change occurred in the past 4 decades. The bog area expanded by 67%, while the area under

Alka Jain; S. C. Rai; E. Sharma

2000-01-01

173

The analysis of land use spatial patterns responded to different geomorphology type: two case studies in Hubei Province, China  

NASA Astrophysics Data System (ADS)

Land use spatial pattern reflects both the impact of human activities on the process of ecological system and the human activities response to natural condition. Geomorphology condition, which has a close relationship with land use spatial pattern, is a direct and key factor influencing human to use land at the local level. This paper analyses two cases of land use spatial patterns in Hubei province China, Zigui County and Jiayu County, which are exemplary for two different geomorphology conditions, respectively the mountain area and plain model. The land use spatial pattern is analyzed using geographical information system (ArcGIS) and landscape-pattern analysis software (FRAGSTATS 3.3). The results indicate that different land use type has different landscape characteristics. Simultaneity, the same land use type forms different landscape pattern in the dissimilar geomorphology region. Terrain feature, which restrains the possible land use type, is the base for people to decide how to use the land. It is the most direct factor influencing people behavior for land using. Cultivated land is the substratum of landscape class in Plain, while in Mountain area is forestland. Patches of different landscape classes are inlaid the substratum. Comparing with mountain area, there are fewer land use types and inconspicuous substratum of landscape class in plain because of human intensive disturbance. Meanwhile patches in plain possess higher geometrical similarity and lower landscape fragment than in mountain area.

He, Yu; Liu, Yaolin; Zhao, Haiyun; Chen, Xuewen

2009-10-01

174

How progressive land titling could foster new surveying practices and land information systems--based on case studies in Namibia  

Microsoft Academic Search

Under the premise that land administration is one of the necessary components of sustainable development and better land management, this article reviews how progressive titling could foster new land administration procedures and associated information systems. This review is based on the objectives of progressive titling as they are developed or currently implemented in various regions in the world. These objectives

W. T. De Vries

2004-01-01

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

Ongoing Development of NASA's Global Land Data Assimilation System  

NASA Astrophysics Data System (ADS)

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, M.; Kato, H.; Zaitchik, B. F.

2008-05-01

177

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

178

Mobile robotic system for detection and location of antipersonnel land mines: field tests  

Microsoft Academic Search

Purpose – The purpose of this paper is to present the results obtained in the field tests of a new system for detection and location of antipersonnel land mines. Design\\/methodology\\/approach – The paper presents briefly the overall system and then it focuses on the description and analysis of the results obtained in three basic experiments: accuracy for following trajectories, mine

J. A. Cobano; R. Ponticelli; P. Gonzalez de Santos

2008-01-01

179

Research priorities in land use and land-cover change for the Earth system and integrated assessment modelling  

SciTech Connect

This special issue has highlighted recent and innovative methods and results that integrate observations and AQ3 modelling analyses of regional to global aspect of biophysical and biogeochemical interactions of land-cover change with the climate system. Both the Earth System and the Integrated Assessment modeling communities recognize the importance of an accurate representation of land use and land-cover change to understand and quantify the interactions and feedbacks with the climate and socio-economic systems, respectively. To date, cooperation between these communities has been limited. Based on common interests, this work discusses research priorities in representing land use and land-cover change for improved collaboration across modelling, observing and measurement communities. Major research topics in land use and land-cover change are those that help us better understand (1) the interaction of land use and land cover with the climate system (e.g. carbon cycle feedbacks), (2) the provision of goods and ecosystem services by terrestrial (natural and anthropogenic) land-cover types (e.g. food production), (3) land use and management decisions and (4) opportunities and limitations for managing climate change (for both mitigation and adaptation strategies).

Hibbard, Kathleen A.; Janetos, Anthony C.; Van Vuuren, Detlef; Pongratz, Julia; Rose, Steven K.; Betts, Richard; Herold, Martin; Feddema, Johannes J.

2010-11-15

180

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

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

Improved inflatable landing systems for low cost planetary landers  

NASA Astrophysics Data System (ADS)

Inflatable landing systems have been traditionally perceived as a cost-effective solution to the problem of landing a spacecraft on a planetary surface. To date the systems used have all employed the approach of surrounding the lander with non-vented airbags where the lander bounces on impact a number of times until the impact energy is dissipated. However the reliability record of such systems is not at all good. This paper examines the problems involved in the use of non-vented airbags, and how these problems have been overcome by the use of vented airbags in terrestrial systems. Using a specific case study, it is shown that even the basic passive type of venting can give significant mass reductions. It is also shown that actively controlling the venting based on the landing scenario can further enhance the performance of vented airbags.

Northey, Dave; Morgan, Chris

2003-11-01

183

Improved inflatable landing systems for low cost planetary landers  

NASA Astrophysics Data System (ADS)

Inflatable landing systems have been traditionally perceived as a cost-effective solution to the problem of landing a spacecraft on a planetary surface. To date, the systems used have all employed the approach of surrounding the lander with non-vented airbags where the lander on impact bounces a number of times until the impact energy is dissipated. However, the reliability record of such systems is not at all good. This paper examines the problems involved in the use of non-vented airbags, and how these problems have been overcome by the use of vented airbags in terrestrial systems. Using a specific case study, it is shown that even the basic passive type of venting can give significant mass reductions. It is also shown that actively controlling the venting based on the landing scenario can further enhance the performance of vented airbags.

Northey, Dave; Morgan, Chris

2006-10-01

184

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

185

Policy-oriented integrated analysis of land-use change: an analysis of data needs.  

PubMed

Integrated analysis of land-use change in support of informed policy-making for sustainable land use at various spatial levels makes heavy requirements for quality data. This paper aims to structure the principal methodological and practical issues of data needs for this task. The data needs for local level analyses of land-use change are given special attention. The paper adopts an integrated economic-environmental modeling framework and suggests the main types of data needed. Four main data dimensions are distinguished: system of spatial reference, system of temporal reference, definitions, and data collection procedures (sources, collection instruments and techniques, recording and retrieval systems, data format, frequency of data collection). To evaluate the suitability of current data sets as well as to guide the collection of new ones, a scheme based on substantive and practical criteria is employed. The former include compatibility, consistency, and reliability of data, while the latter include availability, ease and cost of data collection/retrieval, and transferability of data. The evaluation indicates the broad gaps in current data sets along the four main data dimensions. Based on this evaluation, the paper suggests framework guidelines to address the main data issues identified. PMID:11083904

Briassoulis, H

2001-01-01

186

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

187

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

188

An analysis of metropolitan land-use by machine processing of earth resources technology satellite data  

NASA Technical Reports Server (NTRS)

A successful application of state-of-the-art remote sensing technology in classifying an urban area into its broad land use classes is reported. This research proves that numerous urban features are amenable to classification using ERTS multispectral data automatically processed by computer. Furthermore, such automatic data processing (ADP) techniques permit areal analysis on an unprecedented scale with a minimum expenditure of time. Also, classification results obtained using ADP procedures are consistent, comparable, and replicable. The results of classification are compared with the proposed U. S. G. S. land use classification system in order to determine the level of classification that is feasible to obtain through ERTS analysis of metropolitan areas.

Mausel, P. W.; Todd, W. J.; Baumgardner, M. F.

1976-01-01

189

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

190

RITD - Adapting Mars Entry, Descent and Landing System for Earth  

NASA Astrophysics Data System (ADS)

A new generation of inflatable Entry, Descent and Landing System (EDLS) for Mars has been developed. It is used in both the initial atmospheric entry and atmospheric descent before the semi-hard impact of the penetrator into Martian surface. The EDLS applicability to Earth's atmosphere is studied by the EU/RITD [1] project. Project focuses to the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry. 1. EDLS for Earth The dynamical stability of the craft is analysed, concentrating on the most critical part of the atmospheric re-entry, the transonic phase. In Martian atmosphere the MetNet vehicle stability during the transonic phase is understood. However, in the more dense Earth's atmosphere, the transonic phase is shorter and turbulence more violent. Therefore, the EDLS has to be sufficiently dynamically stable to overcome the forces tending to deflect the craft from its nominal trajectory and attitude. The preliminary design of the inflatable EDLS for Earth will be commenced once the scaling of the re-entry system and the dynamical stability analysis have been performed. The RITD-project concentrates on mission and applications achievable with the current MetNet-type (i.e. 'Mini-1' category) of lander, and on requirements posed by other type Earth re-entry concepts. 2. Entry Angle Determination for Mini-1 - lander For successful Earth landing, the suitable re-entry angle and velocity with specific descent vehicle (DV) mass and heat flux parameters need to be determined. These key parameters in determining the Earth re-entry for DV are: qmax (kW/m2): maximal specific heat flux, Q (MJ/m2): specific integral heat flux to DV front shield, m (kg): descent vehicle (DV) mass, V (m/s): re-entry velocity and ? (deg.): flight-path angle at Earth re-entry For Earth re-entry, the calculation results in the optimal value of entry velocity for MetNet ('Mini-1' category) -type lander, with mass of 22kg, being VSOL = 5268 m/s. Using the basic pre-defined parameters for MetNet-type of lander in Earth atmosphere, we get the optimal angle of ? = -3.06 degrees for Earth re-entry. 3. Payload Mass for Earth Entry DV One of the key elements in Earth entry lander is the amount of available payload mass. The payload mass depends on, e.g., the lander size, landing type (soil or water), heat shield durability and additional landing gear. The payload mass will have an impact to the center of gravity of the lander. The payload with a 'low' CoG (compared the the lander structure) has a larger tolerance than the payload with 'high' CoG. In cases where payload CoG causes instability, the extra balance mass can be used to adjust CoG. This balance mass will reduce the available payload mass. A major limitation for payload mass is the heat shielding. Acknowledgements The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 263255. References [1] http://ritd.fmi.fi

Heilimo, Jyri; Harri, Ari-Matti; Aleksashkin, Sergey; Koryanov, Vsevolod; Arruego, Ignacio; Schmidt, Walter; Haukka, Harri; Finchenko, Valery; Martynov, Maxim; Ostresko, Boris; Ponomarenko, Andrey; Kazakovtsev, Viktor; Martin, Susanna; Siili, Tero

2014-05-01

191

A Stochastic Model for the Landing Dispersion of Hazard Detection and Avoidance Capable Flight Systems  

NASA Astrophysics Data System (ADS)

To support landing site assessments for HDA-capable flight systems and to facilitate trade studies between the potential HDA architectures versus the yielded probability of safe landing a stochastic landing dispersion model has been developed.

Witte, L.

2014-06-01

192

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.

193

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

194

An analysis of human-induced land transformations in the San Francisco Bay/Sacramento area  

SciTech Connect

Part of the US Geological Survey's Global Change Research Program involves studying the area from the Pacific Ocean to the Sierra foothills to enhance understanding of the role that human activities play in global change. The study investigates the ways that humans transform the land and the effects that changing the landscape may have on regional and global systems. To accomplish this research, scientists are compiling records of historical transformations in the region's land cover over the last 140 years, developing a simulation model to predict land cover change, and assembling a digital data set to analyze and describe land transformations. The historical data regarding urban growth focus attention on the significant change the region underwent from 1850 to 1990. The historical change is being used to calibrate a prototype cellular automata model, developed to predict changes in urban land cover 100 years into the future. These data aid in documenting and understanding human-induced land transformations from both historical and predictive perspectives. A descriptive analysis of the region is used to investigate the relationships among data characteristic of the region. These data consist of multilayer topography, climate, vegetation, and population data for a 256-km[sup 2] region of central California. A variety of multivariate analysis tools are used to integrate the data in raster format from map contours, interpolated climate observations, satellite observations, and population estimates.

Kirtland, D.; DeCola, L. (Geological Survey, Reston, VA (United States)); Gaydos, L.; Acevedo, W. (Geological Survey, Moffett Field, CA (United States)); Clarke, K. (Hunter Coll., New York, NY (United States). Dept. of Geology and Geography); Bell, C. (Johnson Controls World Services, Moffett Field, CA (United States))

1994-06-01

195

Improving institutional incentives for public land management: an econometric analysis of school trust land leases  

Microsoft Academic Search

There is considerable interest in the proper management of public lands in the United States, but questions arise over what institutional arrangements may ensure proper land stewardship. Recently, the trust doctrine has been heralded as a way to motivate prudent decision making by land managers. School trust lands, which are managed to generate revenues for public schools, represent a long-standing

MATTHEW H. BONDS; JEFFREY J. POMPE

2005-01-01

196

Estimation of Land Surface States and Fluxes using a Land Surface Model Considering Different Irrigation Systems  

NASA Astrophysics Data System (ADS)

Food security can be improved by increasing the extent of agricultural land or by increasing agricultural productivity, including through intensive management such as irrigation. The objectives of this study were to incorporate practical irrigation schemes into land surface models of the NASA Land Information System (LIS) and to apply the tool to estimate the impact of irrigation on land surface states and fluxes—including evapotranspiration, soil moisture, and runoff—in the Murray-Darling basin in Australia. Here we present results obtained using Noah Land Surface Model v3.2 within LIS without simulated irrigation (IR0) and with three irrigation simulation routines: flood irrigation (IR1), drip irrigation (IR2), and sprinkler irrigation (IR3). Moderate Resolution Imaging Spectrometer (MODIS) vegetation index was used to define crop growing seasons. Simulations were performed for a full year (July 2002 to June 2003) and evaluated against hydrologic flux estimates obtained in previous studies. Irrigation amounts during the growing season (August 2002 to March 2003) were simulated as 104.6, 24.6, and 188.1 GL for IR1, IR2, and IR3, respectively. These preliminary results showed water use efficiency from a drip irrigation scheme would be highest and lowest from a sprinkler irrigation scheme, with a highly optimized version of flood irrigation falling in between. Irrigation water contributed to a combination of increased evapotranspiration, runoff, and soil moisture storage in the irrigation simulations relative to IR0. Implications for water management applications and for further model development will be discussed.

Chun, J. A.; Zaitchik, B. F.; Evans, J. P.; Beaudoing, H. K.

2012-12-01

197

Knowledge-based decision support system on land suitability evaluation: A case of Hangzhou city  

Microsoft Academic Search

The researches combined land suitability evaluation and decision support system need to be improved. For the existed problems that land suitability evaluation systems based on GIS are lack of spatial decision support capabilities and the poor communication among urban planners, land managers and geological experts, a knowledge-based decision support system on land suitability evaluation is developed in this study, and

Weiming Xu; Jiangfeng Li

2011-01-01

198

75 FR 11154 - Marseilles Land and Water Company; Notice of Application Ready for Environmental Analysis and...  

Federal Register 2010, 2011, 2012, 2013

...Marseilles Land and Water Company; Notice of Application...Ready for Environmental Analysis and Soliciting Comments...Marseilles Land and Water Company. e. Name of...ready for environmental analysis. l. Project Description...tailrace discharging water back to the...

2010-03-10

199

Equivalent System Verification and Evaluation of Augmentation Effects on Fighter Approach and Landing Flying Qualities. Volume 1. Summary.  

National Technical Information Service (NTIS)

This executive summary reports an analysis of an approach and landing evaluation program using the AFWAL/Calspan NT-33 variable stability aircraft to test the suitability of representing aircraft with complex flight control systems by an equivalent simpli...

J. Hodgkinson R. C. Snyder R. E. Smith

1981-01-01

200

GIS-based fuzzy membership model for crop-land suitability analysis  

Microsoft Academic Search

Crop-land suitability analysis is a prerequisite to achieve optimum utilisation of the available land resources for sustainable agricultural production. The Food and Agricultural Organisation [FAO, 1976. A framework for land evaluation (Soils Bulletin No. 32). FAO, Rome.] recommended an approach for land suitability evaluation for crops in terms of suitability ratings from highly suitable to not suitable based on climatic

T. R. Nisar Ahamed; K. Gopal Rao; J. S. R. Murthy

2000-01-01

201

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

202

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

203

TOXIC AND PRIORITY ORGANICS IN MUNICIPAL SLUDGE LAND TREATMENT SYSTEMS  

EPA Science Inventory

The goal of the research reported herein was to begin a methodical investigation of organic priority pollutants applied to plant-soil systems at rates characteristic of municipal sludge land treatment. A single chemical was applied at rates of 0.1, 10, and 100-fold of the expecte...

204

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

205

Optimum Combination of Leasing Systems on Public Lands.  

National Technical Information Service (NTIS)

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 a...

S. L. McDonald

1984-01-01

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

Modeling BMPs to optimize municipal wastewater land treatment system  

Microsoft Academic Search

Nitrogen contamination of ground water is recognized as a widespread and persistent problem throughout the nation. As recently as 1996, a US Geological Survey report indicated that significant portions of the United States are susceptible to nitrate contamination of ground water. Nutrient simulations of a municipal wastewater land treatment system were performed using the ground-water loading effects of agricultural management

Michael D. Dukes; William F. Ritter

1998-01-01

208

INS\\/GPS navigation systems for land applications  

Microsoft Academic Search

Kearfott has developed a family of ring laser gyroscope (RLG) angular displacement and linear acceleration sensors which have been integrated with GPS in various configurations to address the operational requirements and cost of ownership constraints for tactical applications. This paper discusses the considerations in developing a military land navigation system which meets the rigid performance criteria and makes uses of

R. Tranfield

1996-01-01

209

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

210

A DEMONSTRATION PROJECT OF NGH LAND TRANSPORTATION SYSTEM  

Microsoft Academic Search

Joint project by Chugoku Electric Power Co., Inc. (CEP) and Mitsui Engineering & Shipbuilding Co. Ltd. (MES) has focused on a demonstration of land transportation system of Natural Gas Hydrate (NGH). The project started in summer of 2006 supported by New Energy and Industrial Technology Development Organization (NEDO). The construction of production plant is scheduled to be completed in spring

Shigeru Watanabe; Shinji Takahashi; Hiroshi Mizubayashi; Shinji Murata; Hideyuki Murakami

211

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...

212

Preliminary Assessment of Lower Landing Minima Capabilities in the Small Aircraft Transportation System Program  

Microsoft Academic Search

A preliminary assessment is presented of the required lower landing minima (LLM) capabilities needed to support the Small Aircraft Trans- portation System (SATS) Program. The goal of this analysis is to under- stand the number of potentially challenged SATS airports and to identify methods to remove obstacles by using technology solutions. Four obsta- cle removal methods are considered to assess

Yue Xu; Antonio A. Trani; Hojong Baik

2005-01-01

213

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

Microsoft Academic Search

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

A. D. Kotin

1978-01-01

214

Helical helicopter approaches with microwave landing system guidance  

NASA Technical Reports Server (NTRS)

It is desirable that the landing approach of helicopters and V/STOL aircraft into a congested airport equipped with a microwave landing system (MLS) can take place essentially independent of CTOL traffic. The helical approach has been proposed as one way to provide aircraft separation while requiring minimum airspace. A helical descent makes it possible for the helicopter to lose altitude in a confined airspace without descending along an excessively steep glide slope. This avoids helicopter handling problems which occur at slow airspeeds. Preliminary flight-test data are presented regarding the operational feasibility of the helical approach under IFR conditions where the primary guidance information is from an MLS.

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

1981-01-01

215

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

216

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

217

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

218

STRATEGIC MANAGEMENT INFORMATION SYSTEM APPROACH FOR MALAYSIA LAND ADMINISTRATION INFORMATION SYSTEM WITH SPATIAL DATA INFRASTRUCTURE  

Microsoft Academic Search

The Strategic Management Information System (SMIS) with integrated approach as a one of method to achieve the capability information system for organization such land administration. However, must concern several issue such as integrate legal and institutional infrastructures; governance & cross-government collaboration; structure and cultural management; and information security; from implementation of spatial data infrastructure for land administration information system at

Halim Hamzah; Abdul Rashid Mohamed Shariff; Ahmad Rodzi Mahmud

219

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

220

A hedonic model comparison for residential land value analysis  

NASA Astrophysics Data System (ADS)

Distantial attenuation is a significant characteristic of the urban environment. In this paper we explore the relative contributions of different land uses to the urban residential environment according to distances with an analysis on the most significant scope of these factors. Two types of models are developed. One employs the distance to city center, main road, public facilities and environment factors as the variables for macro environment analysis, and the another one includes all factors to analyze the influences of the micro environment. In the models of the latter type, the contributions of the neighboring land uses are magnified with a specially designed variable measurement scheme in which variables are evaluated specially for each model so that the contributions of the variables become comparable from model to model. With an application to the case study of Danyang, China, we measure the distantial functions of the urban environment (e.g. the surrounding land uses) including both the most influential scopes and the relative contributions by means of model summary and regression coefficient comparisons. Finally, case comparison on the samples is introduced to figure out the difference of the functions under micro environment.

Liu, Yaolin; Zheng, Bin; Turkstra, Jan; Huang, Lina

221

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

222

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

223

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

224

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

Code of Federal Regulations, 2013 CFR

...false Indian lands congestion management system (CMS). 973.214 Section... FEDERAL LANDS HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO THE BUREAU OF... Bureau of Indian Affairs Management Systems § 973.214 Indian...

2013-04-01

225

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

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Federal lands pavement management system (PMS). 970.208...Systems § 970.208 Federal lands pavement management system (PMS). In addition... (i) An inventory of the physical pavement features including the number of...

2009-04-01

226

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Federal lands pavement management system (PMS). 970.208...Systems § 970.208 Federal lands pavement management system (PMS). In addition... (i) An inventory of the physical pavement features including the number of...

2010-04-01

227

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

228

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

229

94 GHz FMCW radar for low visibility aircraft landing system  

Microsoft Academic Search

The authors describe a 94 GHz bistatic FMCW (frequency-modulation continuous-wave) radar under development for an aircraft landing system. Using a narrow vertical fan beam antenna, the system scans the runaway rapidly in azimuth, processes the radar returns, and obtains a realistic real-time runway image with sufficient information and resolution to enable a pilot to operate in and out of the

L. Q. Bui; Y. Alon; T. Morton

1991-01-01

230

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

231

Land control and monitoring system for fire prevention  

Microsoft Academic Search

Abstract—This paper describes the project: “Study and development of a real-time land control and monitoring system for fire prevention” co-funded ,by the ,Italian Ministry for Instruction, University, and Research (MIUR) within the framework of the PRIN 2004. This project has been devoted to study and develop a system for the territory control in order to prevent and mange natural disasters.

G. Buttazzo; G. Chiandussi; C. Demartini; G. Iannizzotto; F. Quagliotti

2006-01-01

232

Video Guidance, Landing, and Imaging system (VGLIS) for space missions  

NASA Technical Reports Server (NTRS)

The feasibility of an autonomous video guidance system that is capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was demonstrated. The system was breadboarded and "flown" on a physical simulator consisting of a control panel and monitor, a dynamic simulator, and a PDP-9 computer. The breadboard VGLIS consisted of an image dissector camera and the appropriate processing logic. Results are reported.

Schappell, R. T.; Knickerbocker, R. L.; Tietz, J. C.; Grant, C.; Flemming, J. C.

1975-01-01

233

Satellite-aided land mobile communications system implementation considerations  

NASA Technical Reports Server (NTRS)

It was proposed that a satellite-based land mobile radio system could effectively extend the terrestrial cellular mobile system into rural and remote areas. The market, technical and economic feasibility for such a system is studied. Some of the aspects of implementing an operational mobile-satellite system are discussed. In particular, two key factors in implementation are examined: (1) bandwidth requirements; and (2) frequency sharing. Bandwidth requirements are derived based on the satellite antenna requirements, modulation characteristics and numbers of subscribers. Design trade-offs for the satellite system and potential implementation scenarios are identified. Frequency sharing is examined from a power flux density and modulation viewpoint.

Leroy, B. E.

1982-01-01

234

Videometric terminal guidance method and system for UAV accurate landing  

NASA Astrophysics Data System (ADS)

We present a videometric method and system to implement terminal guidance for Unmanned Aerial Vehicle(UAV) accurate landing. In the videometric system, two calibrated cameras attached to the ground are used, and a calibration method in which at least 5 control points are applied is developed to calibrate the inner and exterior parameters of the cameras. Cameras with 850nm spectral filter are used to recognize a 850nm LED target fixed on the UAV which can highlight itself in images with complicated background. NNLOG (normalized negative laplacian of gaussian) operator is developed for automatic target detection and tracking. Finally, 3-D position of the UAV with high accuracy can be calculated and transfered to control system to direct UAV accurate landing. The videometric system can work in the rate of 50Hz. Many real flight and static accuracy experiments demonstrate the correctness and veracity of the method proposed in this paper, and they also indicate the reliability and robustness of the system proposed in this paper. The static accuracy experiment results show that the deviation is less-than 10cm when target is far from the cameras and lessthan 2cm in 100m region. The real flight experiment results show that the deviation from DGPS is less-than 20cm. The system implement in this paper won the first prize in the AVIC Cup-International UAV Innovation Grand Prix, and it is the only one that achieved UAV accurate landing without GPS or DGPS.

Zhou, Xiang; Lei, Zhihui; Yu, Qifeng; Zhang, Hongliang; Shang, Yang; Du, Jing; Gui, Yang; Guo, Pengyu

2012-05-01

235

Land use change analysis of Beykoz-Istanbul by means of satellite images and GIS.  

PubMed

Management and planning of the natural environment requires spatially accurate and timely information on land use patterns. With repetitive satellite coverage, the rapid evolution of computer technology and the integration of satellite and spatial data, the development of land use applications have become ubiquitous. The integration of Remote Sensing (RS) and Geographic Information Systems (GIS) has been widely applied and recognized as a powerful and effective tool in detecting land use change in urban areas. This paper presents the land use change analysis of the Beykoz region, which is the second largest administrative district of Istanbul. Land use changes and their impacts are monitored using Landsat (MSS - TM) and Spot 5 satellite data in the period of 1975-2001. The independent classification of each satellite image was used as a change analysis method and the resulting images were analyzed with GIS techniques. The results showed that forest area of Beykoz decreased from 80.55% to 70.5% between 1975 and 1984 and during the 1984-2001 periods, the forested area decreased from 70.5% to 68.86% and the urban growth rate was 4.65%. PMID:16114639

Musaoglu, N; Coskun, M; Kocabas, V

2005-01-01

236

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

237

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

238

Orion crew module landing system simulation and verification  

Microsoft Academic Search

NASA Langley Research Center (LaRC) has developed a comprehensive test and analysis program to evaluate the ability of LS-DYNA to model the materials and the phenomena involved in soil and water landing impacts of the Orion crew module. 12 Elemental, scale boilerplate, and full-scale prototype testing is being conducted in support of the simulation verification and validation approach. Aspects of

Gregory J. Vassilakos; David E. Stegall; Robin C. Hardy; Richard L. Boitnott; Mercedes Reaves; Stephen D. Mark; Martin S. Annett

2011-01-01

239

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

240

Automated, on-board terrain analysis for precision landings  

NASA Astrophysics Data System (ADS)

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.

2006-06-01

241

High Performance Hydrometeorological Modeling, Land Data Assimilation and Parameter Estimation with the Land Information System at NASA/GSFC  

NASA Astrophysics Data System (ADS)

The Land Information System (LIS; http://lis.gsfc.nasa.gov; Kumar et al., 2006; Peters-Lidard et al., 2007) is a flexible land surface modeling framework that has been developed 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. The LIS software was the co-winner of NASA's 2005 Software of the Year award. LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has evolved from two earlier efforts - North American Land Data Assimilation System (NLDAS; Mitchell et al. 2004) and Global Land Data Assimilation System (GLDAS; Rodell et al. 2004) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of these systems, now use specific configurations of the LIS software in their current implementations. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through 'plugins'. In addition to these capabilities, LIS has also been demonstrated for parameter estimation (Peters-Lidard et al., 2008; Santanello et al., 2007) and data assimilation (Kumar et al., 2008). Examples and case studies demonstrating the capabilities and impacts of LIS for hydrometeorological modeling, land data assimilation and parameter estimation will be presented.

Peters-Lidard, C. D.; Kumar, S. V.; Santanello, J. A.; Tian, Y.; Rodell, M.; Mocko, D.; Reichle, R.

2008-12-01

242

GIS-based planning support system for rural land-use allocation  

Microsoft Academic Search

This article describes a planning support system for rural land-use allocation. The system is called RULES (RUral Land-use Exploration System) and is based on a geographic information system (GIS). Other software components have been incorporated into the GIS to link external analytical models to the system. These analytical techniques support three basic stages in a rural land-use planning model: land

Inés Santé-Riveira; Rafael Crecente-Maseda; David Miranda-Barrós

2008-01-01

243

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

244

Assessing improvements to Land Data Assimilation System (LDAS) water and energy flux data  

Microsoft Academic Search

Accurate assessment of the spatial and temporal variation of land surface energy and water balance is essential for understanding climate variability. A Land Data Assimilation System (LDAS) is under development which uses various satellite and ground based observations within a land surface modeling and data assimilation framework to produce optimal output fields of land surface states and fluxes. The goal

D. Toll; P. Houser; J. Gottschalck; B. Cosgrove; A. Wilhelm

2003-01-01

245

Autonomous rendezvous, docking, and landing system using cruise missile technologies  

NASA Astrophysics Data System (ADS)

General Dynamics has been developing an Autonomous Rendezvous Docking and Landing (ARD&L) system that utilizes cruise missile technologies. In November 1990 the Autonomous Rendezvous and Docking (AR&D) system was first demonstrated for members of NASA's Strategic Avionics Technology Working Group (SATWG). This simulation utilized prototype hardware from the Cruise Missile and Advanced Centaur Avionics systems. The objective was to show that all the accuracy, reliability, and operational requirements established for a spacecraft to dock with Space Station Freedom could be met by the proposed system. Rapid prototyping techniques were used to evaluate the proposed system in a real time, hardware in the loop simulation of the rendezvous and docking reference mission. The simulation is currently being upgraded to test an Autonomous Approach and Landing (AA&L) system. Both systems use inertial guidance and control systems supplemented by the Global Positioning System (GPS) and an Image Processing System (IPS), for target recognition and tracking. The IPS includes a general purpose multiprocessor computer and a selected suite of sensors that will provide the required relative position and orientation data. Graphic displays can provide the astronaut/operator with realtime guidance and navigation data with enhanced video or sensor imagery.

Jones, Ruel E.

1992-07-01

246

Digital simulation of continuous error models with application to an instrument landing system error  

NASA Technical Reports Server (NTRS)

A digital simulation of the continuous error of the localized beam of a conventional instrument landing system is discussed. The digital simulation was developed during the analysis of space shuttle navigation capabilities. A discrete mathematical model for use on a digital computer is described. The model generates an output random sequence which is equivalent, for simulation purposes, to the desired random process. The model is a system of difference equations driven by a zero-mean Gaussian random sequence.

Merrick, R. B.; Smith, G. L.

1972-01-01

247

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

Federal Register 2010, 2011, 2012, 2013

...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

248

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

Federal Register 2010, 2011, 2012, 2013

...Implementation of the National Forest System Land Management Planning...implementation of the National Forest System Land Management Rule...discuss findings from smaller working groups, and (3) administrative...comments must be sent to USDA Forest Service, Ecosystem...

2013-02-12

249

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

Federal Register 2010, 2011, 2012, 2013

...Implementation of the National Forest System Land Management Planning...implementation of the National Forest System Land Management Rule...discuss findings from committee working groups, and (3) administrative...comments must be sent to USDA Forest Service, Ecosystem...

2013-04-18

250

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

Federal Register 2010, 2011, 2012, 2013

...Implementation of the National Forest System Land Management Planning...implementation of the National Forest System Land Management Rule...Discuss findings from Committee working groups, and (3) Administrative...comments must be sent to USDA Forest Service, Ecosystem...

2013-06-06

251

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

252

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

253

Airborne antenna polarization study for the microwave landing system  

NASA Technical Reports Server (NTRS)

The feasibility of the microwave landing system (MLS) airborne antenna pattern coverage requirements are investigated for a large commercial aircraft using a single omnidirectional antenna. Omnidirectional antennas having vertical and horizontal polarizations were evaluated at several different station locations on a one-eleventh scale model Boeing 737 aircraft. The results obtained during this experimental program are presented which include principal plane antenna patterns and complete volumetric coverage plots.

Gilreath, M. C.

1976-01-01

254

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

255

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

256

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

257

The Land Lease System in the People's Republic of China: Its Development, Performance and Reform1  

Microsoft Academic Search

On the basis of a theoretical expression of the influence of the system of land ownership and use on economic development, by building up a mathematical model to analyse the shape and development of the land lease system in the People's Republic of China (PRC), this paper analyses the contributions of the operation of the land lease system on China's

Huang Xianjin; Lulu Li; Zhigang Chen; Lijun Zhang; Taiyang Zhong

258

Developing a land capability system for the Western Plains of New South Wales  

Microsoft Academic Search

Land capability is a system that is used for classifying landscapes according to the risk of soil degradation, particularly soil erosion. The system helps contribute to land use planning at property, catchment and regional scales. It has conventionally been determined by a combination of attributes including climate, soil, slope, terrain and existing soil degradation. The land capability system has mostly

Paul Smith; John Lawrie; Alan Welch; Daniel Wiecek

259

An innovative land use regression model incorporating meteorology for exposure analysis  

Microsoft Academic Search

The advent of spatial analysis and geographic information systems (GIS) has led to studies of chronic exposure and health effects based on the rationale that intra-urban variations in ambient air pollution concentrations are as great as inter-urban differences. Such studies typically rely on local spatial covariates (e.g., traffic, land use type) derived from circular areas (buffers) to predict concentrations\\/exposures at

Jason G. Su; Michael Brauer; Bruce Ainslie; Douw Steyn; Timothy Larson; Michael Buzzelli

2008-01-01

260

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

261

Microwave landing system modeling with application to air traffic control  

NASA Technical Reports Server (NTRS)

Compared to the current instrument landing system, the microwave landing system (MLS), which is in the advanced stage of implementation, can potentially provide significant fuel and time savings as well as more flexibility in approach and landing functions. However, the expanded coverage and increased accuracy requirements of the MLS make it more susceptible to the features of the site in which it is located. An analytical approach is presented for evaluating the multipath effects of scatterers that are commonly found in airport environments. The approach combines a multiplane model with a ray-tracing technique and a formulation for estimating the electromagnetic fields caused by the antenna array in the presence of scatterers. The model is applied to several airport scenarios. The reduced computational burden enables the scattering effects on MLS position information to be evaluated in near real time. Evaluation in near real time would permit the incorporation of the modeling scheme into air traffic control automation; it would adaptively delineate zones of reduced accuracy within the MLS coverage volume, and help establish safe approach and takeoff trajectories in the presence of uneven terrain and other scatterers.

Poulose, M. M.

1991-01-01

262

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

263

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

264

Developing Lunar Landing Vehicle Display Requirements Through Content Analysis of Apollo Lunar Landing Voice Communications  

Microsoft Academic Search

The lengthy period since the Apollo landings limits present-day engineers attempts to draw from the experiences of veteran Apollo engineers and astronauts in the design of a new lunar lander. To circumvent these limitations, content analyses were performed on the voice transcripts of the Apollo lunar landing missions. The analyses highlighted numerous inefficiencies in the design of the Apollo Lunar

Cristin A. Smith; Mary L. Cummings; Liang Sim

2008-01-01

265

LAND SUITABILITY ASSESSMENT FOR DATE PALM CULTIVATION IN THE EASTERN NILE DELTA, EGYPT USING AN AUTOMATED LAND EVALUATION SYSTEM AND GIS  

Microsoft Academic Search

A physical land suitability assessment for irrigated date palm in the Eastern Nile Delta was performed using the DATE PALM-EGYPT model built in the Automated Land Evaluation System (ALES) computer program. Selection of the best land for irrigated date palm cultivation and determination of the production limiting factors are done through matching land characteristics with the date palm requirements using

A. Salah; E. Van Ranst

266

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

267

Matrix Land Use Analysis - a Case Study of Landscape Changes in Israeli Carmel Area  

Microsoft Academic Search

The spatial redistribution of the land uses can be measured by remote sensing conventional methods in the form of the matrices of the land uses redistributions within a given set of regions in a given time period. Two new methods of analysis of such land uses redistribution matrices are proposed. The first method represent the geometric and analytical algorithm of

Michael Sonis; Maxim Shoshany; Naftali Goldschlager

2005-01-01

268

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

269

Satellite-aided land mobile communications system implementation considerations  

NASA Technical Reports Server (NTRS)

It was proposed that a satellite-based land mobile radio system could effectively extend the terrestrial cellular mobile system into rural and remote areas. The market, technical and economic feasibility for such a system is studied. Some of the aspects of implementing an operational mobile-satellite system are discussed. In particular, two key factors in implementation are examined: (1) bandwidth requirements; and (2) frequency sharing. Bandwidth requirements are derived based on the satellite antenna requirements, modulation characteristics and numbers of subscribers. Design trade-offs for the satellite system and potential implementation scenarios are identified. Frequency sharing is examined from a power flux density and modulation viewpoint. Previously announced in STAR as N82-25290

Leroy, B. E.

1982-01-01

270

Digital photogrammetric analysis of the IMP camera images: Mapping the Mars Pathfinder landing site in three dimensions  

Microsoft Academic Search

This paper describes our photogrammetric analysis of the Imager for Mars Pathfinder data, part of a broader program of mapping the Mars Pathfinder landing site in support of geoscience investigations. This analysis, carried out primarily with a commercial digital photogrammetric system, supported by our in-house Integrated Software for Imagers and Spectrometers (ISIS), consists of three steps: (1) geometric control: simultaneous

R. L. Kirk; E. Howington-Kraus; T. Hare; E. Dorrer; D. Cook; K. Becker; K. Thompson; B. Redding; J. Blue; D. Galuszka; E. M. Lee; L. R. Gaddis; J. R. Johnson; L. A. Soderblom; A. W. Ward; P. H. Smith; D. T. Britt

1999-01-01

271

Topographic Analysis of the Proposed Landing Area of Sinus Iridum  

NASA Astrophysics Data System (ADS)

The Chinese first lunar lander/rover Chang'E-3 is planned to land on the Sinus Iridum landing area in 2013. Using the Chang'E-2 CCD image data, we analyzed the topographic features of the proposed landing area.

Zou, X. D.; Liu, J. J.; Mou, L. L.; Ren, X.; Li, K.; Zhao, J. J.; Liu, Y. X.; Li, C. L.

2012-09-01

272

Technical system of land survey and monitoring and its future schemes in China  

NASA Astrophysics Data System (ADS)

China's land resources are extremely scarce. There is a pressing need for building the technical system of land survey and monitoring for detail knowledge about the current situation of land use, land value and land property right of each piece of land in the whole country for land use and management. Many works of land survey and monitoring in China have been finished for providing references directly for the macro decision-making and making the national economic and social development planning. However, there were limits in integrity, systemization, and standardization, and some of works about survey and monitoring were carried out in the early period and their results were not updated in time. The purpose of the paper is to establish the framework of systemized technical system of land survey and monitoring for guidance of future national work of land survey and monitoring. The study was through comparing and analyzing the past and ongoing projects of land survey and monitoring. Results indicated that the technical system is constituted by 5 sub-systems. The system will integrate land survey and monitoring, land evaluation, and information sharing service into a whole. The regional arrangement of land survey and monitoring was proposed. Seven implementation regions of land survey and monitoring were divided, including the northeastern region, eastern coastal region, central region, southwestern region, northwestern region, Xinjiang Urgur region, and Qinghai-Tibetan region. The survey and monitoring objectives and contents in each region are different. The zoning is for guidance of the future project arrangement about national land survey and monitoring in China based on land resources background and economic development demands.

Wang, Jing; Liu, Aixia; Li, Shuangcheng; Chen, Yongqi

2010-04-01

273

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

274

Development of a New Geospatial Data Sharing/overlay System for Land Environmental Studies - Ceres GAIA -  

NASA Astrophysics Data System (ADS)

A new geospatial data sharing/overlay system, CEReS Gaia, has developed. The purpose of the system development is to promote land surface environmental studies. The system has developed to meet the requirements by academic users who wish easy data analysis by using his/her own data with existing other data. The system has the following features; a) internationally unlimited expansion of servers, b) multi-language capability (currently, only English), c) free access without user registration, d) data upload/download by registered users, e) capability to overlay user's data on other registered data, f) option of open or selective data distribution.

Tateishi, R.; Sri Sumantyo, J. T.; Miyazaki, A.; Sumitani, H.

2012-07-01

275

43 CFR 3503.31 - How should I describe lands in states which are part of the Public Land Survey System but have...  

Code of Federal Regulations, 2010 CFR

...states which are part of the Public Land Survey System but have not been surveyed...states which are part of the Public Land Survey System but have not been surveyed...an official corner of the public land survey system or, for accreted...

2010-10-01

276

43 CFR 3503.31 - How should I describe lands in states which are part of the Public Land Survey System but have...  

Code of Federal Regulations, 2010 CFR

...states which are part of the Public Land Survey System but have not been surveyed...states which are part of the Public Land Survey System but have not been surveyed...an official corner of the public land survey system or, for accreted...

2009-10-01

277

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

278

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

Microsoft Academic Search

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

Chandra Giri; Zhiliang Zhu; Bradley Reed

2005-01-01

279

Development and application of a benchmarking system for land models (Invited)  

NASA Astrophysics Data System (ADS)

There is a widely understood need for improved assessment of terrestrial system models that are utilized in climate, weather, and ecosystem modeling. A more comprehensive and more systematic land model ';benchmarking' process should help speed the development of new parameterizations, improve the design of new measurement campaigns, and reduce uncertainties associated with key land surface processes. However, the development of informative metrics is non-trivial. Past data-model intercomparisons have certainly strengthened the representation of key processes in land models, but often this information has not been easily accessible for use by other modeling teams or in future intercomparisons. Further, the development of sophisticated model diagnostics programs--that can fully exploit the richness of large Earth System data sets like satellite or Fluxnet measurements--are outside the scope of any single investigator. Here, we will describe progress in the development of a comprehensive (and extensible) land model analysis system that spans water, energy, carbon, and vegetation dynamics metrics. Several classes of metrics are employed including (1) large-scale state and flux estimates (e.g., soil C, atmospheric CO2 cycle, surface temperatures, GRACE water budget estimates, river discharge); (2) functional responses of explicitly modeled and emergent processes (e.g., stomatal responses to VPD, near-surface soil moisture responses to precipitation); and (3) experimental manipulation responses (e.g., N additions, FACE, warming). We will demonstrate the application of selected metrics to several versions of the Community Land Model (principally CLM4 and CLM4.5 and variants therein). Additionally, we will discuss how the analysis package, which is open source and modular, is designed to be extensible and improved by many different modeling and measurement teams.

Lawrence, D. M.; Randerson, J. T.; Mu, M.; Hoffman, F. M.; Riley, W. J.; Koven, C. D.; Todd-Brown, K. E.; Keppel-Aleks, G.

2013-12-01

280

76 FR 62694 - Appeal of Decisions Relating to Occupancy or Use of National Forest System Lands and Resources  

Federal Register 2010, 2011, 2012, 2013

...Use of National Forest System Lands and Resources AGENCY: USDA, Forest Service. ACTION...National Forest System (NFS) lands and resources. The appeal process for decisions related to occupancy or use of NFS lands and resources has remained substantially...

2011-10-11

281

Development and flight test of a deployable precision landing system  

NASA Technical Reports Server (NTRS)

A joint NASA Dryden Flight Research Facility and Johnson Space Center program was conducted to determine the feasibility of the autonomous recovery of a spacecraft using a ram-air parafoil system for the final stages of entry from space that included a precision landing. The feasibility of this system was studied using a flight model of a spacecraft in the generic shape of a flattened biconic that weighed approximately 150 lb and was flown under a commercially available, ram-air parachute. Key elements of the vehicle included the Global Positioning System guidance for navigation, flight control computer, ultrasonic sensing for terminal altitude, electronic compass, and onboard data recording. A flight test program was used to develop and refine the vehicle. This vehicle completed an autonomous flight from an altitude of 10,000 ft and a lateral offset of 1.7 miles that resulted in a precision flare and landing into the wind at a predetermined location. At times, the autonomous flight was conducted in the presence of winds approximately equal to vehicle airspeed. Several novel techniques for computing the winds postflight were evaluated. Future program objectives are also presented.

Sim, Alex G.; Murray, James E.; Neufeld, David C.; Reed, R. Dale

1994-01-01

282

The future of olive plantation systems on sloping and mountainous land; scenarios for production and natural resource conservation, First Annual Report. EU project Olivero  

Microsoft Academic Search

The project will devote itself to the future of olive plantation systems on sloping and mountainous land in southern Europe. These systems have been affected by emigration of local populations and fierce competition from low land plantations and from non-EU countries, and are currently neither productive nor sustainable. The project will undertake a thorough analysis of production, ecological and socio-economic

L. Fleskens; L. Stroosnijder; Graaff de J

2004-01-01

283

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

284

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

285

An innovative land use regression model incorporating meteorology for exposure analysis.  

PubMed

The advent of spatial analysis and geographic information systems (GIS) has led to studies of chronic exposure and health effects based on the rationale that intra-urban variations in ambient air pollution concentrations are as great as inter-urban differences. Such studies typically rely on local spatial covariates (e.g., traffic, land use type) derived from circular areas (buffers) to predict concentrations/exposures at receptor sites, as a means of averaging the annual net effect of meteorological influences (i.e., wind speed, wind direction and insolation). This is the approach taken in the now popular land use regression (LUR) method. However spatial studies of chronic exposures and temporal studies of acute exposures have not been adequately integrated. This paper presents an innovative LUR method implemented in a GIS environment that reflects both temporal and spatial variability and considers the role of meteorology. The new source area LUR integrates wind speed, wind direction and cloud cover/insolation to estimate hourly nitric oxide (NO) and nitrogen dioxide (NO(2)) concentrations from land use types (i.e., road network, commercial land use) and these concentrations are then used as covariates to regress against NO and NO(2) measurements at various receptor sites across the Vancouver region and compared directly with estimates from a regular LUR. The results show that, when variability in seasonal concentration measurements is present, the source area LUR or SA-LUR model is a better option for concentration estimation. PMID:18048083

Su, Jason G; Brauer, Michael; Ainslie, Bruce; Steyn, Douw; Larson, Timothy; Buzzelli, Michael

2008-02-15

286

Entry, Descent, and Landing Operations Analysis for the Stardust Re-Entry Capsule  

NASA Technical Reports Server (NTRS)

On the morning of January 15, 2006, the Stardust capsule successfully landed at the Utah Test and Training range in northwest Utah returning cometary samples from the comet Wild-2. An overview of the entry, descent, and landing (EDL) trajectory analysis that was performed for targeting during the Stardust Mission Navigation Operations Phase upon final approach to Earth is described. In addition, how the predicted landing location and the resulting overall 99 percentile landing footprint ellipse obtained from a Monte Carlo analysis changed over the final days and hours prior to entry is also presented. The navigation and EDL operations effort accurately delivered the entry capsule to the desired landing site. The final landing location was 8.1 km from the target, which was well within the allowable landing area.

Desao, Prasun N.; Lyons, Dan T.; Tooley, Jeff; Kangas, Julie

2006-01-01

287

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

288

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

289

The phylogeny of land plants: A cladistic analysis based on male gametogenesis  

Microsoft Academic Search

A cladistic analysis was carried out to resolve phylogenetic pattern among bryophytes and other land plants. The analysis used 22 taxa of land plants and 90 characters relating to male gametogenesis.Coleochaete orChara\\/Nitella were the outgroups in various analyses using HENNIG86, PAUP, and MacClade, and the land plant phylogeny was unchanged regardless of outgroup utilized. The most parsimonious cladograms from HENNIG86

David J. Garbary; Karen S. Renzaglia; Jeffrey G. Duckett

1993-01-01

290

76 FR 8479 - National Forest System Land Management Planning  

Federal Register 2010, 2011, 2012, 2013

...sustainable multiple uses, including ecosystem services, so that NFS lands continuously...uses of NFS lands, including ecosystem services and sustainable recreation...of multiple uses, including ecosystem services, energy, minerals,...

2011-02-14

291

The value of ground resolution, spectral range and stereoscopy of satellite imagery for land system and land-use mapping of the humid tropics  

Microsoft Academic Search

The quality of SPOT imagery of the humid tropics is variable: frequently only the infrared band is usable. The following statistical conclusions were drawn from a comparison of SPOT and Landsat-TM imagery of Belize: (1) land systems, but not often land facets, can be demarcated; (2) where the quality is good, stereoscopic imagery is preferred for demarcating land systems; (3)

R. BRUCE KING

1994-01-01

292

Determination of the controlled landing trajectory of Chang’E-1 satellite and the coordinate analysis of the landing point on the Moon  

Microsoft Academic Search

Based on the tracking observations of radio ranges and VLBI delays of Chang’E-1 (CE-1) satellite during the controlled landing\\u000a on the Moon on March 1, 2009, the landing trajectory and the coordinates of the landing point are determined by positioning\\u000a analysis. It is shown that the landing epoch (the emission epoch of the last signal) of CE-1 satellite on the

JinLing Li; Li Guo; ZhiHan Qian; DongRong Jiang; WeiMin Zheng; XiaoYu Hong

2010-01-01

293

Study of Millimeter-Wave Radar for Helicopter Assisted-Landing System  

Microsoft Academic Search

Landing helicopters on rough unprepared terrain has always been considered hazardous, since the massive dust cloud generated by wind drafts from the helicopter's rotors completely obstructs the pilot's view of the landing area. This article presents a performance assessment of a proposed millimeter-wave (MMW) three-dimensional imaging radar system, specifically meant for helicopter assisted landing. The assessment includes simulation of radar

M. Rangwala; Feinian Wang; Kamal Sarabandi

2008-01-01

294

A Decision Support System Based on Support Vector Machine for Hard Landing of Civil Aircraft  

Microsoft Academic Search

Hard landing event affect the flight safety seriously. In this paper, a decision support system that classifiers the hard landing signals of the civil aircraft to two classes (normal and abnormal) is presented to support fault diagnosis. As our previous paper where ANN is used as a classifier for event detection from measured hard landing signals. In this paper, our

Wang Xu-hui; Shu Ping; Rong Xiang; Nie Lei

2009-01-01

295

Combining Land Capability Evaluation, Geographic Information Systems, and Indigenous Technologies for Soil Conservation in Northern Ethiopia  

Microsoft Academic Search

A framework for soil conservation planning is proposed by combining land capability evaluation, geographic information systems (GIS), and indigenous conservation technologies for use in the northern Ethiopian highlands. The applicability of the framework was tested in a typical agricultural micro-watershed, i.e., the Gido watershed of South Welo. Land capability and land use status were established following the procedures of a

Belay Tegene

2003-01-01

296

Including Land Use and Land Cover Change in Earth System Models  

Microsoft Academic Search

The Millennium Ecosystem Assessment provided the most recent well-documented global view of recent, rapid land-cover and land-use change. These results coincided with its review of the structure of the major proximate and ultimate drivers of global changes and changes in the provision and sustainability of ecosystem services. This review is now supplemented by the recent findings of the IPCC Fourth

A. C. Janetos

2007-01-01

297

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

298

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

299

BAE systems brownout landing aid system technology (BLAST) system overview and flight test results  

NASA Astrophysics Data System (ADS)

Rotary wing aircraft continue to experience mishaps caused by the loss of visual situational awareness and spatial disorientation due to brownout or whiteout in dusty, sandy or snowy conditions as the downwash of the rotor blades creates obscurant clouds that completely engulf the helicopter during approaches to land. BAE Systems has developed a "see-through" brownout landing aid system technology (BLAST) based on a small and light weight 94GHz radar with proven ability to penetrate dust, coupled with proprietary antenna tracking, signal processing and digital terrain morphing algorithms to produce a cognitive real-time 3D synthetic image of the ground and proximate surface hazards in and around the landing zone. A series of ground and flight tests have been conducted at the United States Army's Yuma Proving Ground in Arizona that reflect operational scenarios in relevant environments to progressively mature the technology. A description of the BLAST solution developed by BAE Systems and results from recent flight tests is provided.

Sykora, Brian

2012-05-01

300

Integrated land-use systems: Assessment of promising agroforest and alternative land-use practices to enhance carbon conservation and sequestration  

Microsoft Academic Search

Degraded or sub-standard soils and marginal lands occupy a significant proportion of boreal, temperate and tropical biomes. Management of these lands with a wide range of existing, site-specific, integrated, agroforest systems represents a significant global opportunity to reduce the accumulation of greenhouse gases in the atmosphere. Establishment of extensive agricultural, agroforest, and alternative land-use systems on marginal or degraded lands

Robert K. Dixon; Jack K. Winjum; Kenneth J. Andrasko; Jeffrey J. Lee; Paul E. Schroeder

1994-01-01

301

Assimilation of remotely sensed snow data in CALDAS land assimilation system  

NASA Astrophysics Data System (ADS)

Snow cover and terrestrial snow processes have a crucial influence on heat fluxes between the land and atmosphere because of its high albedo and insulating thermal properties, which impact the energy and water balance on land. For this reason, special emphasis is put on the modeling of snow processes and on the application of initial conditions for these processes in environmental prediction system (weather and hydrology). The snow water equivalent (SWE) and snow cover fraction (SCF) are of particular importance for accurate representation of sensible and latent heat fluxes in atmospheric model and of water availability in hydrological model. To account for this, a high resolution ensemble Kalman filter (EnKF) analysis scheme has been developed to include observed SWE and SCF into the Canadian Land Data Assimilation System (CaLDAS), to be proposed for operational implementation at the Canadian Meteorological Service in the next year or so. Ultimately, CaLDAS will be integrated into the coupled land-atmosphere system. The main objective of this study is to include the following space-based remote sensing data in CaLDAS for the assimilation of terrestrial snow. Snow remote sensing data by the Advanced Microwave Scanning Radiometer (AMSR-E) produces daily coarse-resolution (25 km) SWE products. The Moderate Resolution Imaging Spectro radiometer (MODIS) provides global snow cover products on a daily basis at a spatial resolution of 4 km, but the SCF only contains partial information about the SWE state. The Interactive Multi sensor Snow and Ice Mapping System (IMS, from NOAA) data are also available on a polar stereographic projection at 4 km resolution which classifies data points as either land, sea, sea ice or snow. As a first step, daily and 5-day average (pentad) passive microwave SWE data for a period from November 2006 to April 2007 will be compared to snow water equivalent data derived from the GEM land surface model through Western Canada (500 - 650 N latitude, 2400 - 2650 longitude) with 10 km resolution covering of the study area (forest, tundra and prairie). A subsequent modeling study to compare the daily MODIS SCF and IMS imageries for spring 2007 with the land surface model output will also be carried out for the same region.

Solomon, S. J.; Belair, S.; Derksen, C.; Wang, L.; Carrera, M. L.; Bilodeau, B.

2010-12-01

302

Analysis of Land Use/Land Cover Changes Using Remote Sensing Data and GIS at an Urban Area, Tirupati, India  

PubMed Central

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.

Mallupattu, Praveen Kumar; Sreenivasula Reddy, Jayarama Reddy

2013-01-01

303

Orion Crew Module Landing System Simulation and Verification  

NASA Technical Reports Server (NTRS)

NASA Langley Research Center (LaRC) has developed a comprehensive test and analysis program to evaluate the ability of LS-DYNA to model the materials and the phenomena involved in soil and water landing impacts of the Orion crew module. Elemental, scale boilerplate, and full-scale prototype testing is being conducted in support of the simulation verification and validation approach. Aspects of the simulations evaluated against test data include soil constitutive properties, water equations of state, and contact algorithms. Subsystems tested include airbags, crushable energy absorbing honeycomb materials, and energy absorbing seat support struts. The procedures, instrumentation, and general observations from each test series are presented. Plans for a series of swing tests of a full-scale boilerplate into a purpose-built water basin are described. Further plans for swing tests of flight-like prototypes into the water basin are noted.

Vassilakos, Gregory J.; Stegall, David E.; Hardy, Robin C.; Boitnott, Richard L.; Reaves, Mercedes; Mark, Stephen D.; Annett, Martin S.

2011-01-01

304

Linking Land-Use Projections and Forest Fragmentation Analysis.  

National Technical Information Service (NTIS)

An econometric model of private land-use decisions is used to project land use to 2030 for each county in the continental United States. On a national scale, forest area is projected to increase overall between 0.1 and 0.2 percent per year between now and...

A. J. Plantinga D. J. Lewis H. Eichman R. J. Alig

2007-01-01

305

Tool for Statistical Analysis and Display of Landing Sites  

NASA Technical Reports Server (NTRS)

MarsLS is a software tool for analyzing statistical dispersion of spacecraft-landing sites and displaying the results of its analyses. Originally intended for the Mars Explorer Rover (MER) mission, MarsLS is also applicable to landing sites on Earth and non-MER sites on Mars. MarsLS is a collection of interdependent MATLAB scripts that utilize the MATLAB graphical-user-interface software environment to display landing-site data (see figure) on calibrated image-maps of the Martian or other terrain. The landing-site data comprise latitude/longitude pairs generated by Monte Carlo runs of other computer programs that simulate entry, descent, and landing. Using these data, MarsLS can compute a landing-site ellipse a standard means of depicting the area within which the spacecraft can be expected to land with a given probability. MarsLS incorporates several features for the user s convenience, including capabilities for drawing lines and ellipses, overlaying kilometer or latitude/longitude grids, drawing and/or specifying lines and/or points, entering notes, defining and/or displaying polygons to indicate hazards or areas of interest, and evaluating hazardous and/or scientifically interesting areas. As part of such an evaluation, MarsLS can compute the probability of landing in a specified polygonal area.

Wawrzyniak, Geoffrey; Kennedy, Brian; Knocke, Philip; Michel, John

2006-01-01

306

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

307

Application of Scenario Analysis and Multiagent Technique in Land-Use Planning: A Case Study on Sanjiang Wetlands  

PubMed Central

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.

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

2013-01-01

308

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

309

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.

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

2010-01-01

310

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

311

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

312

Normalising impacts in an environmental systems analysis of wastewater systems  

Microsoft Academic Search

In an environmental systems analysis of four wastewater systems, the environmental aspects were prioritised by normalisation of predicted impacts from the studied systems to the total impacts from society. Priority Group 1 (highest priority) consisted of discharges (flows) of nitrogen, cadmium, lead and mercury to water, recycling of nitrogen and phosphorus to arable land and flows of heavy metals to

E. Kärrman; H. Jönsson

313

Activities of the Pilot Land Data System project  

NASA Technical Reports Server (NTRS)

The University of Maryland's Remote Sensing Systems Laboratory submitted to NASA/Goddard an interim progress report on the work being conducted within its Pilot Land Data System IPLDS project. The Remote Sensing Systems Laboratory addressed the following tasks: (1) identify data types and data sources needed to describe the selected test sites in collaboration with Goddard's Hydrological Sciences Branch; (2) define the procedures necessary to access/acquire this data; (3) conduct meetings with the PLDS Systems Engineering Group to identify functional specification priorities for PLDS development; (4) assemble documentation on historical remotely sensed imagery and transfer of such information to the PLDS Data Management Group; (5) collect data identified by Goodard's Hydrological Sciences Branch for data set inventory in PLD; (6) develop a Workstation-PLDS system interface over high speed lines, (7) develop and test through a Phase 1 demonstration of a micro workstation to access PLDS; and (8) establish interdepartmental agreement of development of computer link for electronic access of water resources data from USGS.

Sircar, J. K. (principal investigator)

1985-01-01

314

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

315

Simulation Framework for Rapid Entry, Descent, and Landing (EDL) Analysis, Phase 2 Results  

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 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 (SA) team that is conducting studies of the technologies and architectures that are required to enable human and higher mass robotic missions to Mars. The findings, observations, and recommendations from the NESC are provided in this report.

Murri, Daniel G.

2011-01-01

316

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

317

Land cover analysis of James City County, Virginia  

NASA Technical Reports Server (NTRS)

The approach used to obtain reliable countywide forest resource data, including statistics and a forest cover distribution map from LANDSAT data is described. Comparison of results of the LANDSAT anlysis and U.S. Forestry Survey data is presented in a table. Pine, oak/pine, and oak/hickory accounted for 22.3%, 32.6% and 45.2% respectively of the total forest area in the LANDSAT analysis, compared to 22.8%, 30.1%. and 47.1% in the Forest Survey. The corresponding figures for each forest type differ at most 2.5% for the mixed forest. The total county area in forest land measured using LANDSAT was underestimated by 1,409 acres, a 2.2% error based on the Forest Survey statistics. However, the estimate of 61,242 acres fell well within the known 4% uncertainty of the estimate for the Forest Survey figures (62,651 acres + or - 2,544 acres).

Copony, J. A.; Middleton, E. M.; Bly, B. G.

1981-01-01

318

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

319

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

Federal Register 2010, 2011, 2012, 2013

...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

320

DEVELOPING A FIFTY-ATTRIBUTE FRAMEWORK FOR MINED LAND SUITABILITY ANALYSIS USING AHP-TOPSIS APPROACH  

Microsoft Academic Search

Suitability of a mined land for alternative post-mining land-uses should be assessed through an analytic process. This process is typically a Multi-Attribute Decision-Making (MADM) problem. Analytical Hierarchy Process (AHP) method which is an MADM technique has been addressed more or less in literature on the field of Mined Land Suitability Analysis (MLSA). Almost in all of those cases, maximum emphasis

SOLTANMOHAMMADI Hossein; OSANLOO Morteza; AGHAJANI BAZZAZI

2008-01-01

321

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

322

Normalising impacts in an environmental systems analysis of wastewater systems.  

PubMed

In an environmental systems analysis of four wasterwater systems, the environmental aspects were prioritised by normalisation of predicted impacts from the studied systems to the total impacts from society. Priority Group 1 (highest priority) consisted of discharges (flows) of nitrogen, cadmium, lead and mercury to water, recycling of nitrogen and phosphorus to arable land and flows of heavy metals to arable land. A conventional wastewater system (A) was compared to irrigation of energy forest with biologically treated wastewater (B), liquid composting of toilet wastewater (C) and a conventional system supplemented with urine separation (D). Analysing the aspects in priority group one, systems B-D improved the management of plant nutrients and decreased the flow of heavy metals to water, while the flow to arable land increased, especially for system B. The suggested method is useful in municipal environmental planning and when choosing a wastewater system. PMID:11379144

Kärrman, E; Jönsson, H

2001-01-01

323

Application of analytical hierarchy process and geographic information systems in land-use suitability evaluation: a case study of Dümrek village (Çanakkale, Turkey)  

Microsoft Academic Search

This study used both analytical hierarchy process (AHP) and geographic information systems (GIS) to make a land-use suitability analysis for the village of Dümrek, NW Turkey. Primarily, alternative land uses for agriculture, meadow–pasture and forest were determined along with criteria for these alternatives and a hierarchical structure was produced and used to determine the weights of the criteria. Spatial data

Tülay Cengiz; Cengiz Akbulak

2009-01-01

324

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Federal lands bridge management system (BMS). 970.210...Systems § 970.210 Federal lands bridge management system (BMS). In addition...a) The NPS shall have a BMS for the bridges which are under the NPS...

2013-04-01

325

23 CFR 971.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Federal lands pavement management system (PMS). 971.208...Systems § 971.208 Federal lands pavement management system (PMS). In addition...concepts described in the AASHTO's âPavement Management Guide.â 1 1...

2009-04-01

326

23 CFR 972.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Federal lands pavement management system (PMS). 972.208...Systems § 972.208 Federal lands pavement management system (PMS). In addition...concepts described in the AASHTO's âPavement Management Guide.â2 2...

2009-04-01

327

23 CFR 973.208 - Indian lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Indian lands pavement management system (PMS). 973.208...Systems § 973.208 Indian lands pavement management system (PMS). In addition...concepts described in the AASHTO's âPavement Management Guide.â 1 1...

2009-04-01

328

23 CFR 973.208 - Indian lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Indian lands pavement management system (PMS). 973.208...Systems § 973.208 Indian lands pavement management system (PMS). In addition...concepts described in the AASHTO's âPavement Management Guide.â 1 1...

2010-04-01

329

23 CFR 971.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Federal lands pavement management system (PMS). 971.208...Systems § 971.208 Federal lands pavement management system (PMS). In addition...concepts described in the AASHTO's âPavement Management Guide.â 1 1...

2010-04-01

330

23 CFR 972.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Federal lands pavement management system (PMS). 972.208...Systems § 972.208 Federal lands pavement management system (PMS). In addition...concepts described in the AASHTO's âPavement Management Guide.â2 2...

2010-04-01

331

SPATIAL AND TEMPORAL DYNAMICS OF LAND USE IMPACTS ON WATER QUALITY IN WATERSHED SYSTEMS  

Microsoft Academic Search

SPATIAL AND TEMPORAL DYNAMICS OF LAND USE IMPACTS ON WATER QUALITY IN WATERSHED SYSTEMS SEPTEMBER 2007 OLGA TSVETKOVA, B.S., NOVGOROD STATE UNIVERSITY, RUSSIA M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Timothy O. Randhir Predicting land use change and assessing watershed tradeoffs between the watershed system components through system simulation helps to determine future nutrient and sediment load reductions needed

Olga Tsvetkova

2007-01-01

332

The landing flare: An analysis and flight-test investigation  

NASA Technical Reports Server (NTRS)

Results are given of an extensive investigation of conventional landing flares in general aviation type airplanes. A wide range of parameters influencing flare behavior are simulated in experimental landings in a variable-stability Navion. The most important feature of the flare is found to be the airplane's deceleration in the flare. Various effects on this are correlated in terms of the average flare load factor. Piloting technique is extensively discussed. Design criteria are presented.

Seckel, E.

1975-01-01

333

A Study of Persistence in the Land-Atmosphere System with a Fourth-Order Analytical Model.  

NASA Astrophysics Data System (ADS)

In a companion paper, Y. Liu and R. Avissar analyzed the features of persistence in the land-atmosphere system simulated with the National Center for Atmospheric Research Community Climate Model Version 2 coupled with the Biosphere-Atmosphere Transfer Scheme (CCM2-BATS). To interpret the results obtained in that study, a fourth-order land-atmosphere analytical model is developed and used to investigate the timescales of disturbances in the land-atmosphere system, and the major parameters and processes affecting them. This analytical model has four damping timescales, namely seasonal, monthly, weekly, and daily. It is found that the seasonal scale is caused by self-feedback of soil moisture, and its length increases significantly due to the interactions between soil moisture and the other system variables. A sensitivity analysis performed with the Fourier amplitude sensitivity test indicates that the seasonal timescale is mostly affected by the physical parameters related to hydrological processes (namely, evaporation, runoff, and soil moisture diffusion), while the thermal characteristics of the land-atmosphere system mostly affect the monthly timescale. Thus, the results of this analytical study indicate that the persistence obtained in the CCM2-BATS simulation is an inherent property of the land-atmosphere system. They also emphasize the importance of soil moisture disturbances on persistence in the climatic system.

Liu, Yongqiang; Avissar, Roni

1999-08-01

334

Environmental impacts of land use and land cover change in the Zhujiang Delta, China: An analysis using an integrated GIS, remote sensing, and spatial modeling approach  

Microsoft Academic Search

This dissertation attempts to apply an integrated approach of remote sensing, GIS, and spatial modeling for environmental studies. The feasibility, advantages, and disadvantages of this integrated approach are investigated through land use and land cover change modeling, environmental impact analysis, and stochastic analysis. By applying this approach to the Zhujiang Delta, this dissertation also attempts to examine the environmental implications

Qihao Weng

1999-01-01

335

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

336

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

337

Landing and Population Hazard Analysis for Stardust Entry in Operations and Entry Planning  

NASA Technical Reports Server (NTRS)

Stardust is a comet sample return mission that successfully returned to Earth on January 15, 2006. Stardust's targeted landing area was the Utah Test and Training Range in the Northwest corner of Utah. Requirements for the risks associated with landing were levied on Stardust by the Utah Test and Training Range and NASA. This paper describes the analysis to verify that these requirements were met and and includes calculation of debris survivability, generation of landing site selection plots, and identification of keep-out zones, as well as appropriate selection of the landing site. Operationally the risk requirements were all met for both of the GOMO-GO polls, so entry was authorized.

Tooley, Jeffrey; Desai, Prasun N.; Lynos, Daniel T.; Hirst, Edward A.; Wahl, Tom E.; Wawrzyniak, Georffery G.

2006-01-01

338

Land suitability analysis for Tabriz County, Iran: a multi-criteria evaluation approach using GIS  

Microsoft Academic Search

In our research we investigated the optimal utilization of land resources for agricultural production in Tabriz County, Iran. A GIS-based Multi Criteria Decision Making land suitability analysis was performed. Hereby, several suitability factors including soils, climatic conditions, and water availability were evaluated, based on expert knowledge from stakeholders at various levels. An Analytical Hierarchical Process was used to rank the

Bakhtiar Feizizadeh; Thomas Blaschke

2012-01-01

339

On the Impact of Future Land Use Assumptions on Risk Analysis for Superfund Sites  

Microsoft Academic Search

In this paper, assumptions regarding future land use as a key uncertainty is considered and its impact on risk analysis for contaminated sites is assessed. Risks are assessed for two land use scenarios (current-use industrial and future-use residential) using probabilistic models that incorporate uncertainty and variability in the exposure parameters. Residual risks are calculated for both industrial and residential cleanup

Peter T. Katsumata; William E. Kastenberg

1997-01-01

340

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

341

Restriction Analysis of Residual Capacity of Intersection on Land Development Intensity  

Microsoft Academic Search

At present, the common existing problem of Traffic Impact Analysis (TIA) is that there is no control on land development intensity on the stage of approval. This paper evaluates the restriction of residual capacity of intersection on land development intensity. Intersection is frequently a bottleneck of urban road network. With estimation of the proportion of turning flow and consideration of

Zhiqiang LIU; Jie CHEN; Jie NI; Li ZHANG

2011-01-01

342

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

343

Uncertainty in Multi-Criteria Evaluation Techniques When Used for Land Suitability Analysis  

Microsoft Academic Search

\\u000a Uncertainty analysis is rarely considered in the application of predictive models in agriculture, resource planning and land\\u000a suitability analysis. Uncertainty in modeling land suitability for agricultural production arises from a variety of sources.\\u000a An important source of error is due to uncertainty in model inputs and parameters, especially in the case of multi-criteria\\u000a analysis requiring data from physical measurements or

K. K. Benke; C. Pelizaro; K. E. Lowell

344

Land Cover and Landscape Diversity Analysis in the West Polesie Biosphere Reserve  

NASA Astrophysics Data System (ADS)

The aim of this research was to present the land cover structure and landscape diversity in the West Polesie Biosphere Reserve. The land cover classification was performed using Object Based Image Analysis in Trimble eCognition Developer 8 software. The retrospective land cover changes analysis in 3 lake catchments (Kleszczów, Moszne, Bia³eW³odawskie Lakes)was performed on the basis of archival aerial photos taken in 1952, 1971, 1984, 1992, 2007 and one satellite scene from 2003 (IKONOS).On the basis of land cover map structure, Shannon diversity index was estimated with the moving window approach enabled in Fragstats software. The conducted research has shown that the land cover structure of the West Polesie Biosphere Reserve is diverse and can be simply described by selected landscape metrics. The highest level of land cover diversity, as showed by Shannon Diversity Index, was identified in the western part of the West Polesie Biosphere Reserve, which is closely related to the agricultural character of land cover structure in those regions. The examples of three regional retrospective land cover analyses demonstrated that the character of land cover structure has changed dramatically over the last 40 years.

Chmielewski, Szymon; Chmielewski, Tadeusz J.; Tompalski, Piotr

2014-04-01

345

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

346

An equilibrium analysis of the land use structure in the Yunnan Province, China  

NASA Astrophysics Data System (ADS)

Global land use structure is changing rapidly due to unceasing population growth and accelerated urbanization, which leads to fierce competition between the rigid demand for built-up area and the protection of cultivated land, forest, and grassland. It has been a great challenge to realize the sustainable development of land resources. Based on a computable general equilibrium model of land use change with a social accounting matrix dataset, this study implemented an equilibrium analysis of the land use structure in the Yunnan Province during the period of 2008-2020 under three scenarios, the baseline scenario, low TFP (total factor productivity) scenario, and high TFP scenario. The results indicated that under all three scenarios, area of cultivated land declined significantly along with a remarkable expansion of built-up area, while areas of forest, grassland, and unused land increased slightly. The growth rate of TFP had first negative and then positive effects on the expansion of built-up area and decline of cultivated land as it increased. Moreover, the simulated changes of both cultivated land and built-up area were the biggest under the low TFP scenario, and far exceeded the limit in the Overall Plan for Land Utilization in the Yunnan Province in 2020. The scenario-based simulation results are of important reference value for policy-makers in making land use decisions, balancing the fierce competition between the protection of cultivated land and the increasing demand for built-up area, and guaranteeing food security, ecological security, and the sustainable development of land resources.

van Aken, H. M.; van Veldhoven, A. K.; Veth, C.; de Ruijter, W. P. M.; van Leeuwen, P. J.; Drijfhout, S. S.; Whittle, C. P.; Rouault, M.

2014-06-01

347

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

348

Definition and testing of the hydrologic component of the pilot land data system  

NASA Technical Reports Server (NTRS)

The specific aim was to develop within the Pilot Land Data System (PLDS) software design environment, an easily implementable and user friendly geometric correction procedure to readily enable the georeferencing of imagery data from the Advanced Very High Resolution Radiometer (AVHRR) onboard the NOAA series spacecraft. A software subsystem was developed within the guidelines set by the PLDS development environment utilizing NASA Goddard Space Flight Center (GSFC) Image Analysis Facility's (IAF's) Land Analysis Software (LAS) coding standards. The IAS current program development environment, the Transportable Applications Executive (TAE), operates under a VAX VMS operating system and was used as the user interface. A brief overview of the ICARUS algorithm that was implemented in the set of functions developed, is provided. The functional specifications decription is provided, and a list of the individual programs and directory names containing the source and executables installed in the IAF system are listed. A user guide is provided for the LAS system documentation format for the three functions developed.

Ragan, Robert M.; Sircar, Jayanta K.

1987-01-01

349

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

350

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

351

A Terminal Descent Sensor Trade Study Overview for the Orion Landing and Recovery System  

NASA Technical Reports Server (NTRS)

This trade study was conducted as a part of the Orion Landing System Advanced Development Project to determine possible Terminal Descent Sensor (TDS) architectures that could be used for a rocket assisted landing system. Several technologies were considered for the Orion TDS including radar, lidar, GPS applications, mechanical sensors, and gamma ray altimetry.

Dunn, Catherine; Prakash, Ravi

2008-01-01

352

A role for AVIRIS in the Landsat and Advanced Land Remote Sensing Systems program  

NASA Technical Reports Server (NTRS)

As a calibrated imaging spectrometer flying at a 20 km altitude, AVIRIS may contribute to the Landsat and the Advanced Land Remote Sensing System efforts. These contributions come in the areas of: (1) on-orbit calibration, (2) specification of new spectral bands, (3) validation of algorithms, and (4) investigation of an imaging spectrometer of the Advanced Land Remote Sensing System.

Green, Robert O.; Simmonds, John J.

1993-01-01

353

A comparison of different methodologies for designing land application systems: Case study at the Redueña WWTP  

Microsoft Academic Search

The conventional treatment of wastewater in small populations is unfeasible. Therefore, nonconventional methods have to be applied in these cases, including land application systems (LAS) also called “filtros verdes” in Spanish. Nowadays, there are many methodologies applicable to the design and sizing of land application systems: the flow\\/EH, the hydraulic load based on the permeability of the ground, the hydraulic

Irene de Bustamante; Francisco Javier Lillo; Juana María Sanza; Ángel de Miguel; Eloy García; Francisco Carreño; David Gómez; Tomás Martín; Francisco Martínez; José Luis Corvea

2009-01-01

354

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

Microsoft Academic Search

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

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

2008-01-01

355

Assessment on EXPERT Descent and Landing System Aerodynamics  

NASA Astrophysics Data System (ADS)

EXPERT is a re-entry vehicle designed for validation of aero-thermodynamic models, numerical schemes in Computational Fluid Dynamics codes and test facilities for measuring flight data under an Earth re-entry environment. This paper addresses the design for the descent and landing sequence for EXPERT. It includes the descent sequence, the choice of drogue and main parachutes, and the parachute deployment condition, which can be supersonic or subsonic. The analysis is based mainly on an engineering tool, PASDA, together with some hand calculations for parachute sizing and design. The tool consists of a detailed 6-DoF simulation performed with the aerodynamics database of the vehicle, an empirical wakes model and the International Standard Atmosphere database. The aerodynamics database for the vehicle is generated by DNW experimental data and CFD codes within the framework of an ESA contract to CIRA. The analysis will be presented in terms of altitude, velocity, accelerations, angle-of- attack, pitch angle and angle of rigging line. Discussion on the advantages and disadvantages of each parachute deployment condition is included in addition to some comparison with the available data based on a Monte-Carlo method from a Russian company, FSUE NIIPS. Sensitivity on wind speed to the performance of EXPERT is shown to be strong. Supersonic deployment of drogue shows a better performance in stability at the expense of a larger G-load than those from the subsonic deployment of drogue. Further optimization on the parachute design is necessary in order to fulfill all the EXPERT specifications.

Wong, H.; Muylaert, J.; Northey, D.; Riley, D.

2009-01-01

356

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

357

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

358

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

359

Global land information system (GLIS) access to worldwide Landsat data  

USGS Publications Warehouse

The Landsat Technical Working Group (LTWG) and the Landsat Ground Station Operations Working Group (LGSOWG) have encouraged Landsat receiving stations around the world to share information about their data holdings through the exchange of metadata records. Receiving stations forward their metadata records to the U.S. Geological Survey's EROS Data Center (EDC) on a quarterly basis. The EDC maintains the records for each station, coordinates changes to the database, and provides metadata to the stations as requested. The result is a comprehensive international database listing most of the world's Landsat data acquisitions This exchange of information began in the early 1980's with the inclusion in the EDC database os scenes acquired by a receiving station in Italy. Through the years other stations have agreed to participate; currently ten of the seventeen stations actively share their metadata records. Coverage maps have been generated to depict the status of the database. The Worldwide Landsat database is also available though the Global Land Information System (GLIS).

Smith, Timothy B.; Goodale, Katherine L.

1993-01-01

360

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...

361

78 FR 13316 - National Forest System Land Management Planning Directives  

Federal Register 2010, 2011, 2012, 2013

...adaptively manage the NFS to maintain and restore NFS land and water ecosystems and protect species while providing for ecosystem services and multiple uses. The proposed directives are intended to guide the development, revision, and amendment...

2013-02-27

362

Analysis of subsurface drainage for land use planning  

Microsoft Academic Search

The trend of increasing agricultural output in recent decades has been noted. To some extent this increase has been due to a myopic view on growth and development that involved an unabated exploitation of land and water resources with intensive use of complex technology. In this process, for the past few decades, man has influenced the natural state of the

H. Jorjani

1990-01-01

363

Geologic-morphological analysis of the Luna24 landing site  

Microsoft Academic Search

Luna 24 landed on the moon in the southeast region of Mare Crisium, 12 deg 45 min S, 62 deg 12 min E. Photogeologic mapping results show that the material forming the plain of Mare Crisium is fairly homogeneous. Only one complex of soils is detected here, which, depending on the stratigraphic scale used, belongs to Procellarian, Upper Imbrian, or

K. P. Florenskii; A. T. Bazilevskii; G. A. Burba

1977-01-01

364

Methodological Advances in the Spatial Analysis of Land Fragmentation  

Microsoft Academic Search

This article evaluates the effect of moving window (MW) size on observed fragmentation spatial patterns and proposes a method to identify an effective MW size using Simpson's diversity index. To test the robustness of the proposed method, we demonstrate its use in six cities in the Phoenix metropolitan area that have substantial variation in land composition and configuration. Next we

Sainan Zhang; Abigail M. York; Christopher G. Boone; Milan Shrestha

2012-01-01

365

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

366

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

367

Application of spatial features to satellite land-use analysis. [spectral signature variations  

NASA Technical Reports Server (NTRS)

A Level I land-use analysis of selected training areas of the Colorado Front Range was carried out using digital ERTS-A satellite imagery. Level I land-use categories included urban, agriculture (irrigated and dryland farming), rangeland, and forests. The spatial variations in spectral response for these land-use classes were analyzed using discrete two-dimensional Fourier transforms to isolate and extract spatial features. Analysis was performed on ERTS frame 1352-17134 (July 10, 1973) and frame number 1388-17131 (August 15, 1973). On training sets, spatial features yielded 80 to 100 percent classification accuracies with commission errors ranging from 0 to 20 percent.

Smith, J.; Hornung, R.; Berry, J.

1975-01-01

368

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

369

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

370

RITD — Adapting Mars Entry, Descent and Landing System for Earth  

NASA Astrophysics Data System (ADS)

The EDLS applicability to Earth’s atmosphere is studied by the EU/RITD project. Project focuses to the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry.

Heilimo, J.; Harri, A.-M.; Aleksashkin, S.; Koryanov, V.; Arruego, I.; Schmidt, W.; Haukka, H.; Finchenko, V.; Martynov, M.; Ostresko, B.; Ponomarenko, A.; Kazakovtsev, V.; Martin, S.; Siili, T.

2014-06-01

371

Definition of All Weather Landing System Requirements for Category III Operation in Corvair 880 n 112.  

National Technical Information Service (NTIS)

Studies were made to define an All-Weather Landing System (AWLS) to be used to establish requirements for operation in Category III weather minimums. Initially a limited (Category II) system will be installed with automatic VFR touchdown capability which ...

1966-01-01

372

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

Federal Register 2010, 2011, 2012, 2013

...implementation of the National Forest System Land Management Planning...comments must be sent to USDA Forest Service, Ecosystem Management...Directives, 2. Discuss Committee working groups findings, and 3. Administrative...Associate Deputy Chief, National Forest System. [FR Doc....

2013-08-01

373

Entry, Descent, and Landing Operations Analysis for the Genesis Re-Entry Capsule  

NASA Technical Reports Server (NTRS)

On September 8, 2004, the Genesis spacecraft returned to Earth after spending 29 months about the sun-Earth libration point collecting solar wind particles. Four hours prior to Earth arrival, the entry capsule containing the samples was released for entry and subsequent landing at the Utah Test and Training Range. This paper provides an overview of the entry, descent, and landing trajectory analysis that was performed during the Mission Operations Phase leading up to final approach to Earth. The operations effort accurately delivered the entry capsule to the desired landing site. The final landing location was 8.3 km from the target, and was well within the allowable landing area. Preliminary reconstruction analyses indicate that the actual entry trajectory was very close to the pre-entry prediction.

Desai, Prasun N.; Lyons, Dan T.

2005-01-01

374

Combined analysis of land cover change and NDVI trends in the Northern Eurasian grain belt  

NASA Astrophysics Data System (ADS)

We present an approach to regional environmental monitoring in the Northern Eurasian grain belt combining time series analysis of MODIS normalized difference vegetation index (NDVI) data over the period 2001-2008 and land cover change (LCC) analysis of the 2001 and 2008 MODIS Global Land Cover product (MCD12Q1). NDVI trends were overwhelmingly negative across the grain belt with statistically significant ( p?0.05) positive trends covering only 1% of the land surface. LCC was dominated by transitions between three classes; cropland, grassland, and a mixed cropland/natural vegetation mosaic. Combining our analyses of NDVI trends and LCC, we found a pattern of agricultural abandonment (cropland to grassland) in the southern range of the grain belt coinciding with statistically significant ( p?0.05) negative NDVI trends and likely driven by regional drought. In the northern range of the grain belt we found an opposite tendency toward agricultural intensification; in this case, represented by LCC from cropland mosaic to pure cropland, and also associated with statistically significant ( p?0.05) negative NDVI trends. Relatively small clusters of statistically significant ( p?0.05) positive NDVI trends corresponding with both localized land abandonment and localized agricultural intensification show that land use decision making is not uniform across the region. Land surface change in the Northern Eurasian grain belt is part of a larger pattern of land cover land use change (LCLUC) in Eastern Europe, Russia, and former territories of the Soviet Union following realignment of socialist land tenure and agricultural markets. Here, we show that a combined analysis of LCC and NDVI trends provides a more complete picture of the complexities of LCLUC in the Northern Eurasian grain belt, involving both broader climatic forcing, and narrower anthropogenic impacts, than might be obtained from either analysis alone.

Wright, Christopher K.; de Beurs, Kirsten M.; Henebry, Geoffrey M.

2012-06-01

375

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...

376

Management control of soil organic matter dynamics in tropical land-use systems  

Microsoft Academic Search

Given the rapid conversion of tropical forests to crop and pasture land, the economic constraints to widespread fertilizer use, and the potentially negative ecological impacts of fertilizer misuse, there is an urgent need to improve the management of organic inputs and soil organic matter (SOM) dynamics in tropical land-use systems. One desirable goal is the ability to be able to

Erick C. M. Fernandes; Peter P. Motavalli; Carlos Castilla; Linus Mukurumbira

1997-01-01

377

RECONSTRUCTION OF LAND ADMINISTRATION SYSTEM IN NANGGROE ACEH DARUSSALAM (NAD) AND NIAS  

Microsoft Academic Search

SUMMARY: Indeed the earthquakes and tsunami that thoroughly shattered part of Aceh and Nias in North Sumatra brought particular damage to property rights marks and to the land administration system in general. Land rights recovery and protection, therefore, are necessary and should be recovered as soon as soon as possible. In this situation the role of BPN, as an organization

Joyo WINOTO

378

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

379

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

380

Spatio-temporal analysis of changes in land use through remotely sensed imagery  

NASA Astrophysics Data System (ADS)

Over the last decades Spanish rural and littoral areas have undergone a significant transformation. This process, affecting the use of land mainly, is even more obvious in periurban areas. It is along these areas where the process of urban expansion makes it difficult to combine the use of land in these regions, which, being basically agricultural in nature, become deeply influenced by neighbouring urban spaces. Remote sensing appears as an invaluable resource in this context of territory transformation processes. Monitoring techniques based on multispectral satellite-acquired data have demonstrated potential as a means to detect, identify, and map changes in land use. We have developed a methodology to map and monitor land cover change using multitemporal Landsat Thematic Mapper (TM) data in the are of Granada for 1998 and 2002. Various types of techniques have been used, both quantitative and of image comparison: difference between images, multitemporal quotients, main component analysis (MCA), multitemporal vectors, and multitemporal analysis of classified images. The results quantify the land cover change patterns in the metropolitan area and demonstrate the potential of multitemporal Landsat data to provide an accurate, economical means to map and analyze changes in land cover over time that can be used as inputs to land management and policy decisions.

Rodríguez-Galiano, Víctor; Chica-Olmo, Mario; Garcia-Soldado, Maria José

381

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

382

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

383

Construction of aided design system of land consolidation planning on platform extended graph-element  

NASA Astrophysics Data System (ADS)

According to the actual situation of aided design system of land consolidation, the shortcomings of the traditional aided design software of land consolidation are concluded in the paper. And with the development of the technology of the computer aided design and software, the aided design system of land consolidation on the platform extended graph-element, which adopts the mature and advanced technologies of extended graph-element as well as parametric design, and displays geospatial phenomenon to the users by the interactive design technology with CAD, is constructed to improve the speed and quality of the design. Considering about the main problems of the current land consolidation aided design, following the practical and systematic design idea, functional modules of the land consolidation aided design are constructed, and the composition and the working process of each function module is described in details.

Liu, Li; Zou, Fengya; Zhou, Yu

2009-10-01

384

Atmosphere, ocean, and land: Critical gaps in Earth system models  

NASA Technical Reports Server (NTRS)

We briefly review current knowledge and pinpoint some of the major areas of uncertainty for the following fundamental processes: (1) convection, condensation nuclei, and cloud formation; (2) oceanic circulation and its coupling to the atmosphere and cryosphere; (3) land surface hydrology and hydrology-vegetation coupling; (4) biogeochemistry of greenhouse gases; and (5) upper atmospheric chemistry and circulation.

Prinn, Ronald G.; Hartley, Dana

1992-01-01

385

Ground-operated energy recovery system for landing aircraft  

Microsoft Academic Search

In this paper, an innovative concept to convert the huge kinetic energy stored in landing aircraft into electricity is identified and presented. An appropriate technical route involving linear machines to implement this concept is proposed. Some challenges and possible applications are discussed. Simulation results on feeding the electricity generated back to the power grid are given.

Qing-Chang Zhong

2009-01-01

386

Ground-operated Energy Recovery System for Landing Aircraft  

Microsoft Academic Search

In this paper, an innovative concept to convert the huge kinetic energy stored in landing aircraft into electricity is identified and presented. An appropriate technical route involving linear machines to implement this concept is proposed. Some challenges and possible applications are discussed. Simulation results on feeding the electricity generated back to the power grid are given.

Qing-Chang Zhong

2010-01-01

387

Early surveys, land systems and settlement in South Australia  

Microsoft Academic Search

In 1828, while in prison, E. G. Wakefield issued pamphlets on “Sketch of a Proposal for Colonising Australia.” This created much interest, and in 1830 Wakefield formed a “National Colonisation Society,” of which Robert Gouger was appointed the first secretary. The Society made rapid progress, resulting in the abolishing of free grants in Australia, and the substitution of land sales

W. A. Winton

1931-01-01

388

A Graphical System for Introducing Estates in Land.  

ERIC Educational Resources Information Center

A method for introducing estates in land to first-year law students is presented in detail. A key element is its use of transparencies to graphically represent crucial concepts and appropriate language. The concepts are introduced in a systematic fashion to allow students to build an understanding gradually. (JMD)

Laurence, Robert T.; And Others

1980-01-01

389

Application of learning management system (LMS) to the learning of land evaluation  

NASA Astrophysics Data System (ADS)

The adaptation of the Universities to European Higher Education Area (EHEA) is producing changes in the learning system. One of the new learning system is the use of Moodle which is an Open Source Course Management System (CMS), also known as a Learning Management System (LMS) or a Virtual Learning Environment (VLE). It has become very popular among educators around the world as a tool for creating online dynamic web sites for their students. Professors of Soil Science Department of Universidad Politécnica de Madrid are introducing the use of moodle combined with the portfolio development in the learning of the subject of Land Evaluation. The objective of this subject is the application of the land capability system to the land evaluation of an specific area. The aim of this work is to evaluate the influence of the application of LMS in the teaching of Land Evaluation at University level.

Gascó, G.; Guerrero, F.; Gallardo, J.; Gascó, J. M.; Saa, A.

2010-05-01

390

Assessing regional land-use\\/cover influences on New Jersey Pinelands streamflow through hydrograph analysis  

Microsoft Academic Search

Relative baseflow volume and streamflow flashiness indices were used to assess relationships between land use\\/cover and streamflow regime in nine New Jersey (NJ) Pinelands streams. Baseflow index (BFI) and Richards-Baker flashiness index (RBI) were estimated on an October-September water year, with period-of-record changes assessed by trend analysis and differences between watersheds assessed by examining index versus land-use\\/cover relationships using a

Charles L. Dow

2007-01-01

391

Landscape level analysis of the spatial and temporal complexity of land-use change  

NASA Astrophysics Data System (ADS)

For understanding the causes and effects of changes in land use it is critical to study the interaction between the temporal dynamics and the spatial pattern of land use. Interactions arise from feedbacks in the human-environment system, heterogeneity in the biophysical and human environment and the influence of land-use history. Land-use simulation models can serve as a tool to understand these dynamics in more detail and assess the impact on ecosystem functioning. This chapter presents a spatially explicit modelling approach to explore the spatial and temporal changes in land-use patterns as a function of the specific characteristics of cropping systems and feedbacks between land use and the environment. A case study for Bac Kan province in northern Vietnam is used to test and illustrate the capacity of the model. The results indicate that the model can be used to assess changes in land-use pressure and pattern under different development pathways or scenario conditions. The potential of further developing this approach is discussed.

Verburg, Peter H.; Veldkamp, A.; Willemen, Louise; Overmars, Koen P.; Castella, Jean-Christophe

392

Land use information extraction and spatio-temporal variation analysis of Poyang Lake Basin based on remote sensing  

NASA Astrophysics Data System (ADS)

Poyang Lake Basin is the biggest freshwater lake in China and a significant wetland of the world. The study of the land use changes on there is a great significance for regional sustainable development. In this paper, using the RS image as the main data source, the study area was divided into six land use types. With the acquired land use data of three periods, the spatio-temporal dynamic variation characteristics were analyzed with the area changes and land use dynamic index (LUDI). The analysis shows that the largest land use type is woodland, followed by cultivated land and grassland, and area of the rest types all account for less than 10%. Through the analysis of the area transfer matrix of LUCC, it shows that woodland and construction land increased in each period while cultivated land reduced. Unused land increased a lot during 1990 to 2000 before decreased dramatically during 2000 to 2008, grassland and water experienced a significant increase after an obvious decline and came out to increase finally. The analysis of LUDI indicates that construction land changed the most quickly, followed by unused land and cultivated land, yet the other land use types changed slowly.

Liu, Hai; Xia, Huiqiong; Zhou, Bo

2013-10-01

393

GPS (Global Position System) Vertical Axis Performance Enhancement for Helicopter Precision Landing Approach.  

National Technical Information Service (NTIS)

Several areas were investigated for improving vertical accuracy for a rotorcraft using the differential Global Positioning System (GPS) during a landing approach. Continuous deltaranging was studied and the potential improvement achieved by estimating acc...

R. P. Denaro J. Beser

1986-01-01

394

Coming Soon to a Theater Near You...the Microwave Landing System.  

National Technical Information Service (NTIS)

This informational handbook has been prepared in response to a requirement levied by the SAC Instrument Flight Course (SIFC), Castle AFB, California. The Microwave Landing System (MLS) is projected for worldwide installation and use by both civilian and m...

K. S. C. Hamilton

1985-01-01

395

A low-cost inertial smoothing system for landing approach guidance  

NASA Technical Reports Server (NTRS)

Accurate position and velocity information with low noise content for instrument approaches and landings is required for both control and display applications. In a current VTOL automatic instrument approach and landing research program, radar-derived landing guidance position reference signals, which are noisy, have been mixed with acceleration information derived from low-cost onboard sensors to provide high-quality position and velocity information. An in-flight comparison of signal quality and accuracy has shown good agreement between the low-cost inertial smoothing system and an aided inertial navigation system. Furthermore, the low-cost inertial smoothing system has been proven to be satisfactory in control and display system applications for both automatic and pilot-in-the-loop instrument approaches and landings.

Niessen, F. R.

1973-01-01

396

FAA Lightning Protection Study: Lightning Protection Requirements for AN/GRN-27(V) Instrument Landing System.  

National Technical Information Service (NTIS)

The withstand capabilities and protection requirements for solid state circuits of the AN/GRN-27 (V) Instrument Landing System susceptible to lightning-induced transients on buried control cables are presented. Susceptible circuits and components were ide...

G. K. Huddleston J. D. Nordgard R. W. Larson

1974-01-01

397

77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...  

Federal Register 2010, 2011, 2012, 2013

...Systems: Backup Power Private Land Mobile Radio Services: Selection and Assignment of Frequencies, and Transition of the Upper...collection burden for small business concerns with fewer than 25 employees,'' pursuant to the Small Business Paperwork Relief...

2012-05-16

398

INTEGRATED LAND-USE SYSTEMS: ASSESSMENT OF PROMISING AGROFOREST AND ALTERNATIVE LAND-USE PRACTICES TO ENHANCE CARBON CONSERVATION AND SEQUESTRATION  

EPA Science Inventory

Degraded or sub-standard soils and marginal lands occupy a significant proportion of boreal, temperate and tropical biomes. anagement of these lands with a wide range of existing, site-specific, integrated, agroforest systems represents a significant global opportunity to reduce ...

399

Spatial Analysis and Present Situation Evaluation of Urban Residential Land Suitability Based on GIS: A Case Study in Changchun, China  

Microsoft Academic Search

Analysis and evaluation of urban residential land suitability plays an important role in the overall plan of urban land and coordination subsystem, and has important significance in improving the quality of urban inhabited environment. This paper discussed how to analyze and evaluate the suitability of urban residential land qualitatively and efficiently, taking Changchun, China as study area by GIS technology.

Jianxia Sun; Zhiming Liu; Ye Wei

2009-01-01

400

A Monte Carlo approach to Beryllium-7 solar neutrino analysis with KamLAND  

NASA Astrophysics Data System (ADS)

Terrestrial measurements of neutrinos produced by the Sun have been of great interest for over half a century because of their ability to test the accuracy of solar models. The first solar neutrinos detected with KamLAND provided a measurement of the 8B solar neutrino interaction rate above an analysis threshold of 5.5 MeV. This work describes efforts to extend KamLAND's detection sensitivity to solar neutrinos below 1 MeV, more specifically, those produced with an energy of 0.862 MeV from the 7Be electron-capture decay. Many of the difficulties in measuring solar neutrinos below 1 MeV arise from backgrounds caused abundantly by both naturally occurring, and man-made, radioactive nuclides. The primary nuclides of concern were 210Bi, 85Kr, and 39Ar. Since May of 2007, the KamLAND experiment has undergone two separate purification campaigns. During both campaigns a total of 5.4 ktons (about 6440 m3) of scintillator was circulated through a purification system, which utilized fractional distillation and nitrogen purging. After the purification campaign, reduction factors of 1.5 x 103 for 210Bi and 6.5 x 10 4 for 85Kr were observed. The reduction of the backgrounds provided a unique opportunity to observe the 7Be solar neutrino rate in KamLAND. An observation required detailed knowledge of the detector response at low energies, and to accomplish this, a full detector Monte Carlo simulation, called KLG4sim, was utilized. The optical model of the simulation was tuned to match the detector response observed in data after purification, and the software was optimized for the simulation of internal backgrounds used in the 7Be solar neutrino analysis. The results of this tuning and estimates from simulations of the internal backgrounds and external backgrounds caused by radioactivity on the detector components are presented. The first KamLAND analysis based on Monte Carlo simulations in the energy region below 2 MeV is shown here. The comparison of the chi2 between the null hypothesis and the existence of the 7Be solar neutrino signal in the data shows a change of 27.9 units, providing evidence that the signal is statistically favored. This analysis reports a measured interaction rate from 7Be solar neutrinos of R = 343.3 +/- 65.0(stat) +/- 99.2(syst) events/(kton·day), which corresponds to a total flux of phi = (3.41 +/- 1.18) x 109 cm-2s-1. The 7Be solar neutrino flux reported in this work is only the second measurement made of this quantity worldwide. It provides an important cross-check of the Borexino experiment. The flux measurement reported here agrees within 1sigma with the standard solar model predictions thus validating our basic understanding of solar fusion reaction processes.

Grant, Christopher Peter

401

Enhanced Flight Vision Systems and Synthetic Vision Systems for NextGen Approach and Landing Operations  

NASA Technical Reports Server (NTRS)

Synthetic Vision Systems and Enhanced Flight Vision System (SVS/EFVS) technologies have the potential to provide additional margins of safety for aircrew performance and enable operational improvements for low visibility operations in the terminal area environment with equivalent efficiency as visual operations. To meet this potential, research is needed for effective technology development and implementation of regulatory standards and design guidance to support introduction and use of SVS/EFVS advanced cockpit vision technologies in Next Generation Air Transportation System (NextGen) operations. A fixed-base pilot-in-the-loop simulation test was conducted at NASA Langley Research Center that evaluated the use of SVS/EFVS in NextGen low visibility approach and landing operations. Twelve crews flew approach and landing operations in a simulated NextGen Chicago O'Hare environment. Various scenarios tested the potential for using EFVS to conduct approach, landing, and roll-out operations in visibility as low as 1000 feet runway visual range (RVR). Also, SVS was tested to evaluate the potential for lowering decision heights (DH) on certain instrument approach procedures below what can be flown today. Expanding the portion of the visual segment in which EFVS can be used in lieu of natural vision from 100 feet above the touchdown zone elevation to touchdown and rollout in visibilities as low as 1000 feet RVR appears to be viable as touchdown performance was acceptable without any apparent workload penalties. A lower DH of 150 feet and/or possibly reduced visibility minima using SVS appears to be viable when implemented on a Head-Up Display, but the landing data suggests further study for head-down implementations.

Kramer, Lynda J.; Bailey, Randall E.; Ellis, Kyle K. E.; Williams, Steven P.; Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Shelton, Kevin J.

2013-01-01

402

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

403

Fuzzy Logic Based Approach to Design of Autonomous Landing System for Unmanned Aerial Vehicles  

Microsoft Academic Search

This paper is concerned with autonomous flight of UAVs and proposes a fuzzy logic based autonomous flight and landing system\\u000a controller. Besides three fuzzy logic controllers which are developed for autonomous navigation for UAVs in a previous work\\u000a as fuzzy logic based autonomous mission control blocks, three more fuzzy logic modules are developed under the main landing\\u000a system for the

Omer Cetin; Sefer Kurnaz; Okyay Kaynak

2011-01-01

404

Decision-support systems for natural-hazards and land-management issues  

USGS Publications Warehouse

Scientists at the USGS Western Geographic Science Center are developing decision-support systems (DSSs) for natural-hazards and land-management issues. DSSs are interactive computer-based tools that use data and models to help identify and solve problems. These systems can provide crucial support to policymakers, planners, and communities for making better decisions about long-term natural hazards mitigation and land-use planning.

Dinitz, Laura; Forney, William; Byrd, Kristin

2012-01-01

405

Relations Among Geology, Physiography, Land Use, and Stream Habitat Conditions in the Buffalo and Current River Systems, Missouri and Arkansas  

USGS Publications Warehouse

This study investigated links between drainage-basin characteristics and stream habitat conditions in the Buffalo National River, Arkansas and the Ozark National Scenic Riverways, Missouri. It was designed as an associative study - the two parks were divided into their principle tributary drainage basins and then basin-scale and stream-habitat data sets were gathered and compared between them. Analyses explored the relative influence of different drainage-basin characteristics on stream habitat conditions. They also investigated whether a relation between land use and stream characteristics could be detected after accounting for geologic and physiographic differences among drainage basins. Data were collected for three spatial scales: tributary drainage basins, tributary stream reaches, and main-stem river segments of the Current and Buffalo Rivers. Tributary drainage-basin characteristics were inventoried using a Geographic Information System (GIS) and included aspects of drainage-basin physiography, geology, and land use. Reach-scale habitat surveys measured channel longitudinal and cross-sectional geometry, substrate particle size and embeddedness, and indicators of channel stability. Segment-scale aerial-photo based inventories measured gravel-bar area, an indicator of coarse sediment load, along main-stem rivers. Relations within and among data sets from each spatial scale were investigated using correlation analysis and multiple linear regression. Study basins encompassed physiographically distinct regions of the Ozarks. The Buffalo River system drains parts of the sandstone-dominated Boston Mountains and of the carbonate-dominated Springfield and Salem Plateaus. The Current River system is within the Salem Plateau. Analyses of drainage-basin variables highlighted the importance of these physiographic differences and demonstrated links among geology, physiography, and land-use patterns. Buffalo River tributaries have greater relief, steeper slopes, and more streamside bluffs than the Current River tributaries. Land use patterns in both river systems correlate with physiography - cleared land area is negatively associated with drainage-basin average slope. Both river systems are dominantly forested (0-35 per-cent cleared land), however, the potential for landscape disturbance may be greater in the Buffalo River system where a larger proportion of cleared land occurs on steep slopes (>15 degrees). When all drainage basins are grouped together, reach-scale channel characteristics show the strongest relations with drainage-basin physiography. Bankfull channel geometry and residual pool dimensions are positively correlated with drainage area and topographic relief variables. After accounting for differences in drainage area, channel dimensions in Buffalo River tributaries tend to be larger than in Current River tributaries. This trend is consistent with the flashy runoff and large storm flows that can be generated in rugged, sandstone-dominate terrain. Substrate particle size is also most strongly associated with physiography; particle size is positively correlated with topographic relief variables. When tributaries are subset by river system, relations with geology and land use variables become apparent. Buffalo River tributaries with larger proportions of carbonate bedrock and cleared land area have shallower channels, better-sorted, gravel-rich substrate, and more eroding banks than those with little cleared land and abundant sandstone bedrock. Gravel-bar area on the Buffalo River main stem was also larger within 1-km of carbonate-rich tributary junctions. Because geology and cleared land are themselves correlated, relations with anthropogenic and natural factors could often not be separated. Channel characteristics in the Current River system show stronger associations with physiography than with land use. Channels are shallower and have finer substrates in the less rugged, karst-rich, western basins than in the

Panfil, Maria S.; Jacobson, Robert B.

2001-01-01

406

Capturing interactions between nitrogen and hydrological cycles under historical climate and land use: Susquehanna watershed analysis with the GFDL Land Model LM3-TAN  

NASA Astrophysics Data System (ADS)

We developed a~process model LM3-TAN to assess the combined effects of direct human influences and climate change on Terrestrial and Aquatic Nitrogen (TAN) cycling. The model was developed by expanding NOAA's Geophysical Fluid Dynamics Laboratory land model LM3V-N of coupled terrestrial carbon and nitrogen (C-N) cycling and including new N cycling processes and inputs such as a~soil denitrification, point N sources to streams (i.e. sewage), and stream transport and microbial processes. Because the model integrates ecological, hydrological, and biogeochemical processes, it captures key controls of transport and fate of N in the vegetation-soil-river system in a comprehensive and consistent framework which is responsive to climatic variations and land use changes. We applied the model at 1/8° resolution for a study of the Susquehanna River basin. We simulated with LM3-TAN stream dissolved organic-N, ammonium-N, and nitrate-N loads throughout the river network, and we evaluated the modeled loads for 1986-2005 using data from 15 monitoring stations as well as a reported budget for the entire basin. By accounting for inter-annual hydrologic variability, the model was able to capture inter-annual variations of stream N loadings. While the model was calibrated with the stream N loads only at the last downstream station Marietta (40.02° N, 76.32° W), it captured the N loads well at multiple locations within the basin with different climate regimes, land use types, and associated N sources and transformations in the sub-basins. Furthermore, the calculated and previously reported N budgets agreed well at the level of the whole Susquehanna watershed. Here we illustrate how point and non-point N sources contribute to the various ecosystems are stored, lost, and exported via the river. Local analysis for 6 sub-basins showed combined effects of land use and climate on the soil denitrification rates, with the highest rates in the Lower Susquehanna sub-basin (extensive agriculture; Atlantic coastal climate) and the lowest rates in the West Branch Susquehanna sub-basin (mostly forest; Great Lakes and Midwest climate). In the re-growing secondary forests, most of the N from non-point sources was stored in the vegetation and soil, but in the agricultural lands most N inputs were removed by soil denitrification indicating that anthropogenic N applications could drive substantial increase of N2O emission, an intermediate of the denitrification process.

Lee, M.; Malyshev, S.; Shevliakova, E.; Jaffé, P. R.

2014-04-01

407

Simulating the conversion of rural settlements to town land based on multi-agent systems and cellular automata.  

PubMed

Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans. PMID:24244472

Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

2013-01-01

408

Simulating the Conversion of Rural Settlements to Town Land Based on Multi-Agent Systems and Cellular Automata  

PubMed Central

Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans.

Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

2013-01-01

409

Geospatial-temporal analysis of land-use changes in the Yellow River Delta during the last 40 years  

Microsoft Academic Search

Comprehensive study on land-use change of spatial pattern and temporal process is the key component in land use\\/land cover\\u000a changes (LUCC) study nowadays. According to the theories and methods of Geo-information Tupu (Carto-methodology in Geo-information,\\u000a CMGI) for geospatial and temporal analysis and integration models of spatial pattern and temporal processes in GIS, the paper\\u000a puts forward Tupu methodology of land-use

Qinghua Ye; Gaohuan Liu; Guoliang Tian; Shenliang Chen; Chong Huang; Shupeng Chen; Qingshen Liu; Jun Chang; Yanan Shi

2004-01-01

410

Towards a public, standardized, diagnostic benchmarking system for land surface models  

NASA Astrophysics Data System (ADS)

We examine different conceptions of land surface model benchmarking and illustrate the importance of internationally standardized evaluation experiments that specify data sets, variables, metrics and model resolutions. We additionally show how essential the definition of a priori expectations of model performance can be, based on the complexity of a model and the amount of information being provided to it, and give an example of how these expectations might be quantified. Finally, we introduce the Protocol for the Analysis of Land Surface models (PALS), a free, online land surface model benchmarking application, and show how it is structured to meet both of these goals.

Abramowitz, G.

2012-02-01

411

Towards a public, standardized, diagnostic benchmarking system for land surface models  

NASA Astrophysics Data System (ADS)

This work examines different conceptions of land surface model benchmarking and the importance of internationally standardized evaluation experiments that specify data sets, variables, metrics and model resolutions. It additionally demonstrates how essential the definition of a priori expectations of model performance can be, based on the complexity of a model and the amount of information being provided to it, and gives an example of how these expectations might be quantified. Finally, the Protocol for the Analysis of Land Surface models (PALS) is introduced - a free, online land surface model benchmarking application that is structured to meet both of these goals.

Abramowitz, G.

2012-06-01

412

Application of Calspan Pitch Rate Control System to the Space Shuttle for Approach and Landing.  

National Technical Information Service (NTIS)

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 ra...

C. R. Chalk N. C. Weingarten

1983-01-01

413

Tracing the source and fate of nitrate in contemporary mixed land-use surface water systems  

NASA Astrophysics Data System (ADS)

Nitrogenous fertilizers increase agricultural productivity, ultimately feeding the planet. Yet, it is possible to have too much of a good thing, and nitrogen is no exception. When in excess nitrogen has been shown to accelerate eutrophication of water bodies, and act as a chronic toxin (e.g. methemoglobinemia). As land-use intensity continues to rise in response to increases in agricultural productivity, the risk of adverse effects of nitrogen loading on surface water bodies will also increase. Stable isotope proxies are potential tracers of nitrate, the most common nitrogenous phase in surface waters. Applying stable isotope proxies therefore presents an opportunity to identify and manage sources of excess nitrogen before aquatic systems are severely degraded. However, the heterogeneous nature of potential pollution sources themselves, and their distribution