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At least 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Bonanza project, 1971

Research on the application of remote sensing techniques to the mineral industry stresses photointerpretation by human interpreter experienced in the extraction of geological information from aerial color and multiband photographs and from thermal scanner imagery. Also considered are optical and digital image enhancement, multiband color additive projection, video image processing, and computer reduction and analysis of infrared spectrometry. Evaluation of those parameters which have the most contrast between adjacent rock formations and which can be remotely sensed establish the following most useful geological characteristics: Topographic landform, color, albedo, and surface temperature.

Lee, K.↗
NASA NTRS1973

Task 7: Image Enhancement and Advanced Information Extraction Techniques, 1385

The author has identified the following significant results. Atmospheric effects in satellite multispectral scanner data can influence results obtained with either manual image interpretation or computer information extraction techniques. The atmosphere attenuates radiation arriving from the surface and adds an extraneous path radiance component. Initial results of an investigation of atmospheric effects in ERTS-1 data are presented. Empirical analyses of ERTS-1 MSS data and simultaneous airborne MSS underflight data for one frame, along with theoretical calculations of atmospheric effects, are discussed. The effect of limited spatial resolution on the accuracy of information extracted from ERTS-1 data also is important. Problems occur when individual resolution elements contain two or more materials. Results from an initial application of Environmental Research Institute of Michigan techniques for estimating proportions of materials within individual elements are presented and discussed. Very accurate determination of surface areas of small lakes is achieved.

Malila, W. A.↗
NASA NTRS1973

Atmospheric effects in ERTS-1 data, and advanced information extraction techniques

Atmospheric effects in satellite multispectral scanner data can influence results obtained with either manual image interpretation or computer information extraction techniques. The atmosphere attenuates radiation arriving from the surface and adds an extraneous path radiance component. Initial results of an investigation of atmospheric effects in ERTS data are presented. Empirical analyses of ERTS MSS data and simultaneous airborne MSS underflight data for one frame, along with theoretical calculations of atmospheric effects, are discussed. The effect of limited spatial resolution on the accuracy of information extracted from ERTS data also is important. Problems occur when individual resolution elements contain two or more materials. Results from an initial application of ERIM techniques for estimating proportions of materials within individual elements are presented and discussed. Very accurate determination of surface areas of small lakes is achieved.

Malila, W. A.↗
NASA NTRS1974

Analysis of ERTS-1 linear features in New York State

The author has identified the following significant results. All ERTS-1 linears confirmed to date have topographic expression although they may appear as featureless tonal linears on the imagery. A bias is unavoidably introduced against any linears which may parallel raster lines, lithological trends, or the azimuth of solar illumination. Ground study of ERTS-1 topographic lineaments in the Adirondacks indicates: outcrops along linears are even more rare than expected, fault breccias are found along some NNE lineaments, chloritization and slickensiding without brecciation characterize one EW lineament whereas closely-spaced jointing plus a zone of plastic shear define another. Field work in the Catskills suggests that the prominent new NNE lineaments may be surface manifestations of normal faulting in the basement, and that it may become possible to map major joint sets over extensive plateau regions directly on the imagery. Fall and winter images each display some unique linears, and long linears on the fall image commonly appear as aligned segments on the winter scene. A computer-processed color composite image permitted the extraction or additional information on the shaded side of mountains.

Isachsen, Y. W.↗
NASA NTRS1975

Monterey Bay study

The multispectral scanner capabilities of LANDSAT 1 were tested over California's Monterey Bay area and portions of the San Joaquin Valley. Using both computer aided and image interpretive processing techniques, the LANDSAT 1 data were analyzed to determine their potential application in terms of land use and agriculture. Utilizing LANDSAT 1 data, analysts were able to provide the identifications and areal extent of the individual land use categories ranging from very general to highly specific levels (e.g., from agricultural lands to specific field crop types and even the different stages of growth). It is shown that the LANDSAT system is useful in the identification of major crop species and the delineation of numerous land use categories on a global basis and that repeated surveillance would permit the monitoring of changes in seasonal growth characteristics of crops as well as the assessment of various cultivation practices with a minimum of onsite observation. The LANDSAT system is demonstrated to be useful in the planning and development of resource programs on earth.

Bizzell, R. M.↗
NASA NTRS1975

Photographic image enhancement and processing

Image processing techniques (computer and photographic) are described which are used within the JSC Photographic Technology Division. Two purely photographic techniques used for specific subject isolation are discussed in detail. Sample imagery is included.

Lockwood, H. E.↗
NASA NTRS1974

The ERTS-1 investigation (ER-600). Volume 4: ERTS-1 range analysis

The Range Analysis Team conducted an investigation to determine the utility of using LANDSAT 1 data for mapping vegetation-type information on range and related grazing lands. Two study areas within the Houston Area Test Site (HATS) were mapped to the highest classification level possible using manual image interpretation and computer aided classification techniques. Rangeland was distinguished from nonrangeland (water, urban area, and cropland) and was further classified as woodland versus nonwoodland. Finer classification of coastal features was attempted with some success in differentiating the lowland zone from the drier upland zone. Computer aided temporal analysis techniques enhanced discrimination among nearly all the vegetation types found in this investigation.

Erb, R. B.↗
NASA NTRS1975

Exploration for fossil and nuclear fuels from orbital altitudes

A review of satellite-based photographic (optical and infrared) and microwave exploration and large-area mapping of the earth's surface in the ERTS program. Synoptic cloud-free coverage of large areas has been achieved with planimetric vertical views of the earth's surface useful in compiling close-to-orthographic mosaics. Radar penetration of cloud cover and infrared penetration of forest cover have been successful to some extent. Geological applications include map editing (with corrections in scale and computer processing of images), landforms analysis, structural geology studies, lithological identification, and exploration for minerals and fuels. Limitations of the method are noted.

Short, N. M.↗
NASA NTRS1976

The Mount Wilson solar magnetograph - Scanning and data system

The paper describes a computer-operated image-scanning and data-collection system for the magnetograph at the Mt. Wilson 150-foot Tower telescope. The system is based on a minicomputer with a 32K word core memory and a generalized interface unit for controlling image motion, a keyboard, and an associated television screen. Operation of the solar image guider and the data-collection assembly is outlined along with the observation and data-reduction procedures. Advantages of the system include the ability to move the image in almost any conceivable fashion, a wide choice of integration times, and increased accuracy in magnetic and Doppler calibrations as well as in setting of the magnetic zero level.

Howard, R.↗
NASA NTRS1977

A low-cost system for reception and processing of line-scan data from LANDSAT and other sources

A low-cost transportable earth resources ground station was built in Canada and installed to operational status at Shoe Cove, Newfoundland. The system concepts developed for this station provide timely availability of data in both photographic and digital form. The system was designed with several objectives in mind: (1) to provide a system which could receive, store and process line-scan image data from a wide variety of satellites, most especially the LANDSAT and NOAA (VHRR) series, as well as aircraft scanner data, and data from future remote sensing and meteorological satellites; (2) the system has been designed to be operated by a small staff and to produce black and white images and computer-compatible tapes (CCT's) of all relevant data; (3) the system is compact in its physical design so that it is possible to configure it as a self-contained ground station, housed in a 3 x 12 meter trailer; (4) the system is designed to process all data at real-time rates or better and is designed in a modular fashion so that it can be easily upgraded to do further processing of the data, and/or to handle new satellites and sensors.

Sloan, D. S.↗
NASA NTRS1977

Usefulness of LANDSAT data for monitoring plant development and range conditions in California's annual grassland

A network of sampling sites throughout the annual grassland region was established to correlate plant growth in stages and forage production to climatic and other environmental factors. Plant growth and range conditions were further related to geographic location and seasonal variations. A sequence of LANDSAT data was obtained covering critical periods in the growth cycle. Data were analyzed by both photointerpretation and computer aided techniques. Image characteristics and spectral reflectance data were then related to forage production, range condition, range site, and changing growth conditions.

Carneggie, D. M.↗
NASA NTRS1978

Effects of uncertainty on manual tracking performance

Transient phenomena and target acquisition modes associated with interrupted observations during ground-to-air AA tracking were investigated. Using a two-axes control stick, the subjects tracked a computer-generated airplane image on a CRT display. The airplane image excuted a low-level straight pass. At certain pseudo-random times during each 25-second run, the screen was blanked for a period of one second. When the target image reappeared, the subjects reacquired it and continued tracking, attempting to minimize vector RMS error for the entire run (including the blanked period). The results reveal an increase both in tracking error and in error variance during the blanked period, only when the target disappears while in the crossover region. Blanking at other times effected increased variance but had no effect on the mean error. A blanking period just before crossover produced an increase lag while a blanking just after crossover resulted in a lead and thus made the error curve more symmetric.

Ephrath, A. R.↗
NASA NTRS1978

Multiple-frame, full resolution Landsat mosaicking to standard map projections

Landsat digital data are presently available by frames whose size and location are determined by satellite orbit. The utility of Landsat data was increased by the image processing support for JPL's planetary program which provided the basic software and procedures necessary for image mosaicking. The computer software has been extended to perform this task on Landsat Multi-spectral scanner imagery and a ten frame digital mosaic of the Southern California desert has been completed. Major processing steps include location of geographic points in the digital frame and of common geographic points in adjacent frames, conversion to a map projection, lateral 'rubber sheet' correction of the digital frames, brightness correction of adjacent frames, and mosaicking of the frames to eliminate overlap and produce a single large frame.

Zobrist, A. L.↗
NASA NTRS1980

The use of radar and LANDSAT data for mineral and petroleum exploration in the Los Andes region, Venezuela

A geological study of a 27,500 sq km area in the Los Andes region of northwestern Venezuela was performed which employed both X-band radar mosaics and computer processed Landsat images. The 3.12 cm wavelength radar data were collected with horizontal-horizontal polarization and 10 meter spatial resolution by an Aeroservices SAR system at an altitude of 12,000 meters. The radar images increased the number of observable suspected fractures by 27 percent over what could be mapped by LANDSAT alone, owing mostly to the cloud cover penetration capabilities of radar. The approximate eight fold greater spatial resolution of the radar images made possible the identification of shorter, narrower fractures than could be detected with LANDSAT data alone, resulting in the discovery of a low relief anticline that could not be observed in LANDSAT data. Exploration targets for petroleum, copper, and uranium were identified for further geophysical work.

Vincent, R. K.↗
NASA NTRS1981

The Control Point Library Building System

The Earth Resources Observation System (EROS) Data Center in Sioux Falls, South Dakota distributes precision corrected Landsat MSS and RBV data. These data are derived from master data tapes produced by the Master Data Processor (MDP), NASA's system for computing and applying corrections to the data. Included in the MDP is the Control Point Library Building System (CPLBS), an interactive, menu-driven system which permits a user to build and maintain libraries of control points. The control points are required to achieve the high geometric accuracy desired in the output MSS and RBV data. This paper describes the processing performed by CPLBS, the accuracy of the system, and the host computer and special image viewing equipment employed.

Niblack, W.↗
NASA NTRS1983

High resolution bone mineral densitometry with a gamma camera

A technique by which the regional distribution of bone mineral can be determined in bone samples from small animals is described. The technique employs an Anger camera interfaced to a medical computer. High resolution imaging is possible by producing magnified images of the bone samples. Regional densitometry of femurs from oophorectomised and bone mineral loss.

Leblanc, A.↗
NASA NTRS1984

Assessment of Computer-based Geologic Mapping of Rock Units in the LANDSAT-4 Scene of Northern Death Valley, California

Results from a series of geologic classifications conducted on a thematic mapper subscene of the northern Death Valley, California are reported. Measurements of accuracy are made through comparison with the 1977 edition of the Death Valley geologic sheet. This employs a simplified map version which is registered by computer to the image data base, allowing a pixel by pixel match with the classified scene. The results show accuracy ranges from 36 to 79% depending on the type of classifier used and the statistical adjustments made to the data. Accuracy values in identifying geologic units were 2 to 3 times higher for those in the relatively flat valleys than for units in the rugged mountainous terrain. Improvements in accuracy will be sought by correcting for slope/aspect variations in mountainous terrain using topographic data recorded in Defense Mapping Agency (DMA) tapes. The above classification results will also be compared with ratio and principal component image classifications made from the same scene.

Short, N. M.↗
NASA NTRS1984

Thematic mapping of likely target areas for the occurence of cassiterite in the Serra do Mocambo (GO) granitic massifs using LANDSAT 2 digital imaging

The applicability of LANDSAT/MSS images, enhanced by computer derived techniques, as essential tools in mineral research was investigated and the Serra do Mocambo granitic massif was used as illustration. Given the peculiar factors founded in this area, orbital imagery permitted the delineation of potential target areas of mineralization occurrences, associated to albitized/greisenized types. Follow up prospection for primary tin deposits in this granitic massif should be restricted to the delineated areas which are less than 5% of the total superficial area of the massif.

Almeidofilho, R.↗