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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Inventory estimation on the massively parallel processor

This paper describes algorithms for efficiently computing inventory estimates from satellite based images. The algorithms incorporate a one dimensional feature extraction which optimizes the pairwise sum of Fisher distances. Biases are eliminated with a premultiplication by the inverse of the analytically derived error matrix. The technique is demonstrated with a numerical example using statistics obtained from an actual Landsat scene. Attention was given to implementation of the Massively Parallel processor (MPP). A timing analysis demonstrates that the inventory estimation can be performed an order of magnitude faster on the MPP than on a conventional serial machine.

Argentiero, P. D.↗
NASA NTRS1981

Cooperative forestry inventory project for Nevada

A forest inventory project employing computerized classification of LANDSAT data to inventory vegetation types in western Nevada is described. The methodology and applicability of the resulting survey are summarized.

Thornhill, R.↗
NASA NTRS1981

FOCIS: A forest classification and inventory system using LANDSAT and digital terrain data

Accurate, cost-effective stratification of forest vegetation and timber inventory is the primary goal of a Forest Classification and Inventory System (FOCIS). Conventional timber stratification using photointerpretation can be time-consuming, costly, and inconsistent from analyst to analyst. FOCIS was designed to overcome these problems by using machine processing techniques to extract and process tonal, textural, and terrain information from registered LANDSAT multispectral and digital terrain data. Comparison of samples from timber strata identified by conventional procedures showed that both have about the same potential to reduce the variance of timber volume estimates over simple random sampling.

Strahler, A. H.↗
NASA NTRS1981

Performing and updating an inventory of Oregon's expanding irrigated agricultural lands utilizing remote sensing technology

An inventory technique based upon using remote sensing technology, interpreting both high altitude aerial photography and LANDSAT multispectral scanner imagery, is discussed. It is noted that once the final land use inventory maps of irrigated agricultural lands are available and approximately scaled they may be overlaid directly onto either multispectral scanner or return beam vidicon prints, thereby providing an inexpensive updating procedure.

Hall, M. J.↗
NASA NTRS1981

LANDSAT-D data format control book. Volume 6, appendix G: GSFC HDT-AM inventory tape (GHIT-AM)

The data format specifications of the Goddard HDT inventory tapes (GHITS), which accompany shipments of archival digital multispectral scanner image data (HDT-AM tapes), are defined. The GHIT is a nine-track, 1600-BPI tape which conforms to the ANSI standard and serves as an inventory and description of the image data included in the shipment. The archival MSS tapes (HDT-AMs) contain radiometrically corrected but geometrically uncorrected image data plus certain ancillary data necessary to perform the geometric corrections.

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NASA NTRS1982

Factors in the Effective Utilization of a LANDSAT Related Inventory in West Africa

A comprehensive LANDSAT related resource inventory was performed in parts of Ghana, Benin, and Upper Volta to determine resource development potential in areas freed of the disease onchocerciasis. The ultimate success of the project lies in the effective use of the data by host country personnel in resource development projects. This requires project follow-through, adequate training of regional counterparts, and integration of the data into an easily used framework. Present levels of support systems and technical expertise in West Africa indicate that an automated system for natural resource data is not currently appropriate. Suggestions for the greater implementation of such inventories are explored.

Hall, L.↗
NASA NTRS1982

The ABAG biogenic emissions inventory project

The ability to identify the role of biogenic hydrocarbon emissions in contributing to overall ozone production in the Bay Area, and to identify the significance of that role, were investigated in a joint project of the Association of Bay Area Governments (ABAG) and NASA/Ames Research Center. Ozone, which is produced when nitrogen oxides and hydrocarbons combine in the presence of sunlight, is a primary factor in air quality planning. In investigating the role of biogenic emissions, this project employed a pre-existing land cover classification to define areal extent of land cover types. Emission factors were then derived for those cover types. The land cover data and emission factors were integrated into an existing geographic information system, where they were combined to form a Biogenic Hydrocarbon Emissions Inventory. The emissions inventory information was then integrated into an existing photochemical dispersion model.

Carson-Henry, C.↗
NASA NTRS1982

AgRISTARS: Agriculture and resources inventory surveys through aerospace remote sensing

The rationale, objectives, participants, and approach of the AgRISTARS program are described. Progress is reported in activities related to early warning and crop condition assessment; inventory technology development (formerly foreign commodity production forecasting); yield model development; supporting research; soil moisture; renewable resources inventory; domestic crops and land cover; and conservation and pollution. Emphasis is on technological highlights.

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NASA NTRS1977

An Inventory of Ohio's Land Use/Land Cover as Seen by Landsat

LANDSAT 2 (Land Satellite) was launched at Vandenburg, AFB, California on January 22, 1975. The satellite orbits the earth at an altitude of about 920 km (570 miles) and scans the earth's surface in a continuous track 185 km (115 miles) wide. LANDSAT 2 passes over the same spot every 18 days transmitting scanned data to receiving stations scattered around the globe. LANDSAT's continuously-scanning sensors provide useful information about the earth, one of the most important categories being land use. The statistics contained in the appendices of this report represent acreage and percentage of seven types of land cover in Ohio as seen by LANDSAT. The inventory represents a trial effort at determining the Sate's land cover by a method which is inexpensive, reliable, accurate and rapid. Given a successful method, the inventory and periodic updates could provide information to land use decision-makers and, over a period of time, would reveal patterns of land use change. Technical aspects of the project (process, methodology, and verification) are discussed in Schaal (1977) and Schmidt (1976).

Schaal, Gary M.↗
NASA NTRS1984

Optimal maintenance center inventories for fault-tolerant repairable systems

A probabilistic approach is taken to determine the optimal repairable parts inventory for a maintenance center, servicing machines which contain several m-out-of-n systems of different parts, with a constraint on the total inventory investment. A model, based on the discrete Markov process, accounts for a typical ultrareliable avionics system, such as one presently being developed by NASA. The dynamic programming algorithm for minimizing the stockout and holding costs is applied to an exemplary maintenance center, and solutions for single-item and multi-item cases are given. The computational burden is noted to be reasonable and a computer program is used to generate optimal solutions.

Lawrence, S. H.↗
NASA NTRS1984

Optimal inventories for overhaul of repairable redundant systems - A Markov decision model

A Markovian decision model was developed to calculate the optimal inventory of repairable spare parts for an avionics control system for commercial aircraft. Total expected shortage costs, repair costs, and holding costs are minimized for a machine containing a single system of redundant parts. Transition probabilities are calculated for each repair state and repair rate, and optimal spare parts inventory and repair strategies are determined through linear programming. The linear programming solutions are given in a table.

Schaefer, M. K.↗
NASA NTRS1986

Calculations of cosmogenic nuclide production rates in the Earth's atmosphere and their inventories

The production rates of cosmogenic isotopes in the Earth's atmosphere and their resulting terrestrial abundances have been calculated, taking into account both geomagnetic and solar-modulatory effects. The local interstellar flux was assumed to be that of Garcia-Munoz, et al. Solar modulation was accounted for using the heliocentric potential model and expressed in terms of the Deep River neutron monitor count rates. The geomagnetic field was presented by vertical cutoffs calculated by Shea and Smart and the non-vertical cutoffs calculated using ANGRI. The local interstellar particle flux was first modulated using the heliocentric potential field. The modulated cosmic-ray fluxes reaching the earth's orbit then interacted with the geomagnetic field as though it were a high-pass filter. The interaction of the cosmic radiation with the Earth's atmosphere was calculated utilizing the Bolztmann transport equation. Spallation cross sections for isotope production were calculated using the formalism of Silberberg and Tsao and other cross sections were taken from standard sources. Inventories were calculated by accounting from the variation in solar modulation and geomagnetic field strength with time. Results for many isotope, including C-14, Be-7 and Be-10 are in generally good agreement with existing data. The C-14 inventory, for instance, amounts to 1.75/sq cm(e)/s, in excellent agreement with direct estimates.

Obrien, K.↗
NASA NTRS1987

Inventory behavior at remote sites

An operations research study was conducted concerning inventory behavior on the space station. Historical data from the Space Shuttle was used. The results demonstrated a high logistics burden if Space Shuttle reliability technology were to be applied without modification to space station design (which it was not). Effects of rapid resupply and on board repair capabilities on inventory behavior were investigated.

Lewis, William C., Jr.↗
NASA NTRS1987

Using Enviro-Pod low altitude imagery to inventory building surface materials for an acid rain study - A Baltimore example

Low altitude, oblique and vertical color photography taken from EPA's Enviro-Pod Ka 85 camera system has provided the data for taking an inventory of building surface materials in a test area of downtown Baltimore. Photography was acquired from a gridded flight plan to provide views of all sides of buildings. Color, texture, and linear detail are employed in the photo interpretation aided by contextual reference to a classification of building construction type developed in an earlier study. The work could potentially support a materials inventory initiated by the National Acid Precipitation Assessment Program (NAPAP) by scientists from EPA, Geological Survey, and the Department of Energy. Initial results show the method to be viable. Discrete surface materials such as brick, both bare and painted, stone, and metal are identified.

Ellefsen, Richard↗
NASA NTRS1987

Volatile inventory of Mars-2: Primordial sources and fractionating processes

The total volatile inventory of Mars has been modeled using meteoritic and presumed primordial abundances in the early solar system. Evidence is presented which indicates that the elemental abundances of the noble gases on Earth and Mars are similar, and their ratios are comparable to those in average carbonaceous chondrites with the exception of xenon and krypton. In order to account for presently observed variations in gas abundances, two primordial sources were used. One was the solar composition similar to the solar wind, and the other of carbonaceous grains that were the source for trace exotic components. For Mars, a model in which the early, high solar EUV flux with continued hydrogen production by differentiation results in mass fractionation of the primordial atmosphere, early depletion of xenon, and later depletion of gases lighter than krypton. The result is that the primordial Mars water inventory may have been on the order of 20 to 30 km if spread over the planet.

Pepin, R. O.↗
NASA NTRS1992

The 1985 chlorine and fluorine inventories in the stratosphere based on ATMOS observations at 30 deg North latitude

Results are presented of an investigation of the Cl and F inventories derived from the concentrations of eleven Cl- and F-bearing organic and inorganic species throughout the atmosphere, based on observations with the Atmospheric Trace Molecule Spectroscopy instrument aboard the Space Shuttle during the Spacelab 3 mission of April 29 to May 6, 1985. It was found that, in April-May 1985, near 30 deg N, the mean total stratospheric concentrations of Cl and F were 2.58 +/-0.10 ppbv and 1.15 +/-0.12 ppbv, respectively. Partitioning among the source, sink, and reservoir species was consistent with the conservation of the F and Cl budgets throughout the stratosphere. It is shown that the budgets of Cl and F above about 45 km altitude can be determined accurately by measuring only HCl, HF, and CF4 and provide a straightforward timely reference point for future inventories and trends evaluations.

Zander, R.↗
NASA NTRS1992

NASA's Education Program Inventory FY 91

In 1988, the Education Division produced an inventory of NASA-supported education programs. Since then, mathematics, science, and technology education has taken on a more visible role, not only as part of NASA's mission, but as part of the National Education Goals and other Federal initiatives. Therefore, it became important to update the 1988 inventory in order to achieve a more accurate and comprehensive look at NASA's educational programs. The data collected is summarized and descriptions of each program are provided.

Source record↗
NASA NTRS1994

Three dimensional inventories of aircraft emissions

Three dimensional inventories of fuel burned and emissions (NO(x), CO, and hydrocarbons) have been developed on a 1 deg latitude by 1 deg longitude by 1 km altitude grid for scheduled commercial air traffic (passenger jet, cargo, and turboprop aircraft) for 1990 and projected to the year 2015. Emission scenarios have also been calculated for projected fleets of Mach 2 and Mach 2.4 high speed civil transports. The methodology and results are discussed. These emission inventories are now in use in the assessment of aircraft emissions impact by NASA.

Baughcum, Steven L.↗