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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Extensive summer upwelling on Lake Michigan during 1973 observed by NOAA-2 and ERTS-1 satellites

Two studies are presented that utilize data from the NOAA-2 and ERTS-1 satellites. The studies are concentrated on two summer upwelling episodes in Lake Michigan when considerable contrast was observed in both surface water temperature as observed by NOAA-2 and surface water color as observed by ERTS-1. Physical, biological and chemical processes support the hypothesis that much of the observed 'whitening' is calcium carbonate precipitating as an immediate result of the upwelling.

Strong, A. E.↗
NASA NTRS1974

Coastal wetlands analysis from ERTS MSS digital data and field spectral measurements

Classification, delineation and evaluation of coastal wetlands can be made on the basis of major vegetative associations. To produce wetland maps, two vegetation-analysis look-up tables were developed for use in the ERTS ANALYSIS System. These look-up tables are based on Earth Resources Technology Satellite (ERTS) digital values in Multispectral Scanner (MSS) bands 4, 5, and 7 and were developed using seasonal spectral reflectance measurements from field observations. Computer-generated maps at an approximate scale of 1:20,000 were produced for the primary test site, Chincoteague Marsh, Virginia. There is a high degree of accuracy in the identification of wetland features and plant associations. The classification was also tested on other Atlantic coast salt marshes and a brackish marsh in the Chesapeake Bay.

Carter, V.↗
NASA NTRS1974

California nearshore processes - ERTS 1

The detectability of many nearshore processes from ERTS is made possible due to the suspended sediment present in the coastal waters. From viewing and analyzing the California coastal imagery collected during the last year and a half, the overall current patterns and their changes have become evident. It is now possible to map monthly and seasonal changes that occur throughout the year. The original objectives of detecting currents, sediment transport, estuaries and river discharge have now been expanded to include the use of ERTS information in operational problems of the U.S. Army Corps of Engineers. This incorporates the detected nearshore features into planning and organizing shore protection facilities.

Steller, D. D.↗
NASA NTRS1974

A summary of ERTS data applications in Alaska

ERTS has proven to be an exceedingly useful tool for the preparation of urgently needed resource surveys in Alaska. For this reason the wide utilization of ERTS data by federal, state and industrial agencies in Alaska is increasingly directed toward the solution of operational problems in resource inventories, environmental surveys, and land use planning. Examples of some applications are discussed in connection with surveys of potential agricultural lands; mapping of predicted archaeological sites; permafrost terrain and aufeis mapping; snow melt enhancement from Prudhoe Bay roads; geologic interpretations correlated ith possible new petroleum fields, with earthquake activity, and with plate tectonic motion along the Denali fault system; hydrology in monitoring surging glaciers and the break-up characteristics of the Chena River watershed; sea-ice morphology correlated with marine mammal distribution; and coastal sediment plume circulation patterns.

Miller, J. M.↗
NASA NTRS1974

Wheat - Its growth and disease severity as deduced from ERTS-1

The spectral reflectance of a cropped surface changes as the plant develops. An indicator of crop growth is leaf area index (ratio of green leaf area to soil area). The leaf area index, disease severity, and yield were determined for several winter wheat fields in Kansas during the 1973 growing season. Multispectral scanner (MSS) data from Earth Resources Technology Satellite-1 (ERTS-1) showed a high correlation (r greater than or equal to 0.90) between crop growth and MSS4/MSS5, and crop growth and MSS5/MSS6. Wheat disease severity and yields were significantly correlated at the 5% level with MSS4/MSS6 and with MSS4/MSS7. Further investigation is required before ERTS imagery can be routinely used detecting and estimating disease severity and yield reduction.

Kanemasu, E. T.↗
NASA NTRS1974

The uses of ERTS-I imagery in the analysis of landscape change

Analysis of ERTS-I imagery to delimit, map, and monitor photomorphic regions of landscape dynamics is illustrated. Satellite observations were made over strip mining areas on the Cumberland Plateau of Tennessee; agricultural regions in Tennessee, Kentucky, and portions of northern Alabama and Mississippi; urban-suburban growth areas in Knoxville; and flooded areas within the Mississippi River floodplain. Production and analysis of maps of these areas made from ERTS imagery and RB-57 high altitude aircraft imagery are described and compared. The difficulties encountered in analyzing landscape change in or near urban areas are enumerated (small area size, extreme density of settlement, high reflectance characteristics), and the significance of the results of this investigation is noted.

Rehder, J. B.↗
NASA NTRS1974

The Penn State ORSER system for processing and analyzing ERTS and other MSS data

The Office for Remote Sensing of Earth Resources (ORSER) of the Space Science and Engineering Laboratory (SSEL) at the Pennsylvania State University has developed an extensive operational system for processing and analyzing ERTS-1 and similar multispectral data. The ORSER system was developed for use by a wide variety of researchers working in remote sensing. Both photointerpretive techniques and automatic computer processing methods have been developed and used, separately and in a combined approach. A Remote Job Entry (RJE) system permits use of an IBM 370/168 computer from any compatible remote terminal, including equipment tied in by long-distance telephone connections. An elementary cost analysis has been prepared for the processing of ERTS data.

Mcmurtry, G. J.↗
NASA NTRS1974

Quality and use of ERTS radiometric information in geologic applications

Some techniques are described for making full use of the data contained in an ERTS MSS image. Only about one-fourth of the data in a single band can be displayed at one time on a black and white image; therefore, when all four bands are considered, only about 7% of the available data can be used by the interpreter. Selecting the proper subset of information for the photointerpreter is therefore a necessity. Ratio methods exclude the brightness information from the display. A field study in one area using a portable spectrometer has shown only fair correlation with ERTS radiometry after one normalization procedure. Plots of brightness of test areas with sun angle show discrepancies. Plots of ratios show discrepancies of lesser magnitude, although the error limits are large.

Goetz, A. F. H.↗
NASA NTRS1975

Classification of physiography from ERTS imagery

The potential application of optical data processing to ERTS imagery as a means for automatic identification of large-scale ground patterns was investigated. Spatial frequency distribution and orientational information were derived from ERTS-1 imagery of Kansas for each of 80 sample areas, each 37 km in diameter. The application of classification algorithms to this data reveals that a high degree of correlation exists between the physiography of a sample area and its frequency information. Specifically, the band of frequencies between 1.1 and 2.8 cycles/km appear to contain most of the information needed in distinguishing different physiographic regions.

Ulaby, F. T.↗
NASA NTRS1975

Mapping forest vegetation with ERTS-1 MSS data and automatic data processing techniques

This study was undertaken with the intent of elucidating the forest mapping capabilities of ERTS-1 MSS data when analyzed with the aid of LARS' automatic data processing techniques. The site for this investigation was the Great Dismal Swamp, a 210,000 acre wilderness area located on the Middle Atlantic coastal plain. Due to inadequate ground truth information on the distribution of vegetation within the swamp, an unsupervised classification scheme was utilized. Initially pictureprints, resembling low resolution photographs, were generated in each of the four ERTS-1 channels. Data found within rectangular training fields was then clustered into 13 spectral groups and defined statistically. Using a maximum likelihood classification scheme, the unknown data points were subsequently classified into one of the designated training classes. Training field data was classified with a high degree of accuracy (greater than 95 percent), and progress is being made towards identifying the mapped spectral classes.

Messmore, J.↗
NASA NTRS1975

Interdisciplinary applications and interpretations of ERTS data within the Susquehanna River basin

The author has identified the following significant results. The full potential of high quality data is achieved only with the application of efficient and effective interpretation techniques. An excellent operating system for handling, processing, and interpreting ERTS-1 and other MSS data was achieved. Programs for processing digital data are implemented on a large nondedicated general purpose computer. Significant results were attained in mapping land use, agricultural croplands, forest resources, and vegetative cover. Categories of land use classified and mapped depend upon the geographic location, the detail required, and the types of lands use of interest. Physiographic and structural provinces are spectacularly displayed on ERTS-1 MSS image mosaics. Geologic bedrock structures show up well and formation contacts can sometimes be traced for hundreds of kilometers. Large circular structures and regional features, previously obscured by the detail of higher resolution data, can be seen. Environmental monitoring was performed in three areas: coal strip mining, coal refuse problems, and damage to vegetation caused by insects and pollution.

Mcmurtry, G. J.↗
NASA NTRS1975

Cropland acreage estimates from temporal, multispectral ERTS-1 data

Temporal, multispectral Earth Resources Technology Satellite (ERTS-1) images as pertinent to cropland acreage estimates are illustrated and discussed. A cropland classifier is described that evaluates approximately registered, temporal, and multispectral digital ERTS-1 data acquired over a 14 section test site in central Iowa during 1973. Satellite-derived acreage estimates are compared with estimates derived from low-level images. Discrepancies between these estimates are discussed. Satellite coverage critically timed with a crop development calendar is noted to improve classifier effectiveness.

Carlson, R. E.↗
NASA NTRS1975

Resolution enhancement of ERTS imagery

A method is described for combined interpolation and enhancement of ERTS multispectral scanner data sets. Previous research has shown that good enhancement is most easily achieved when there are a large number of data points contained within the radius of gyration of the system point spread function. This requirement can be met using ERTS data by interpolating the data before enhancement. By varying the interpolation scale factor the data set can be empirically matched to a precalculated optimum restoration filter. Once the proper match of data and filter has been found the enhancement can be carried out directly or the enhancement and interpolation operations can be combined into a single filter thereby greatly reducing the processing time. Experimental results of applying this technique are shown along with more conventional methods of image interpolation and enlargement.

Mcgillem, C. D.↗
NASA NTRS1975

Stream pattern analysis using optical processing of ERTS imagery of Kansas

A spatial frequency analysis was carried out to obtain large-scale geologic and other ground pattern spatial frequency and orientational data from an optical data processing system using Earth Resources Technology Satellite-1 (ERTS-1) imagery of Kansas as input. The Diffraction Pattern Sampling Unit (DPSU) of the optical data processing system consists of a photodiode array containing 32 wedge-shaped photodiodes and 32 annular ring diodes. The curve obtained from the intensity distribution of the frequency spectrum yielded by the ring diodes gives the spatial frequency contributions due to ground features on the image. The curve obtained from the wedge-shaped diodes indicates the orientation of features in the sample area. Ten sample sites were used for each of eight geologic-physiographic regions. Comparison of ERTS-1 images with their respective spatial frequency and orientational curves reveals that preferred orientations of drainage produce recognizable peaks.

Mccauley, J.↗
NASA NTRS1975

Mapping forest vegetation with ERTS-1 MSS data and automatic data processing techniques

This study was undertaken with the intent of elucidating the forest mapping capabilities of ERTS-1 MSS data when analyzed with the aid of LARS' automatic data processing techniques. The site for this investigation was the Great Dismal Swamp, a 210,000 acre wilderness area located on the Middle Atlantic coastal plain. Due to inadequate ground truth information on the distribution of vegetation within the swamp, an unsupervised classification scheme was utilized. Initially pictureprints, resembling low resolution photographs, were generated in each of the four ERTS-1 channels. Data found within rectangular training fields was then clustered into 13 spectral groups and defined statistically. Using a maximum likelihood classification scheme, the unknown data points were subsequently classified into one of the designated training classes. Training field data was classified with a high degree of accuracy (greater than 95%), and progress is being made towards identifying the mapped spectral classes.

Messmore, J.↗
NASA NTRS1975

Evaluation of ERTS MSS digital data for monitoring water in the lower Chesapeake Bay area

Water samples collected during the ERTS overpasses of the lower Chesapeake Bay area have been analyzed for chlorophyll, particles, and sediment. Five ERTS images were sufficiently cloud free that a correlation analysis of radiance values from the MSS bands with the water parameters could be performed. A low correlation was established for chlorophyll, except during algal blooms, when band 6 was responsive. There was a fair to good correlation with particles for combinations of band 5, particularly bands (5 minus 6). Sediment correlations were excellent for band 5 or combinations of band 5 with bands 4 and 6. It was evident that such factors as the atmosphere, tide, and different water masses were tending to confuse the data.

Bowker, D. E.↗
NASA NTRS1975

Application of ERTS-1 and multiplexed SLAR imagery for the study of flooded shorelines

The major purpose of this study is to determine the accuracy of visual interpretations of data from two different sensors (ERTS-1; ERIM's multiplexed SLAR) for the study of flooded shorelines. Uncomplicated and primarily visual interpretation techniques are employed. These methods are considered most readily available to officials of local and small regional organizations who may need rapid reconnaissance mapping and information for the organization of disaster relief. Assumptions concerning the timely receipt of such remotely sensed data by those directing the relief have been made. Generally, it is determined that ERTS-1 and SLAR data are complementary, especially with respect to the interpretation of urban or built-up areas which are flooded, and together they can provide the necessary information for guiding relief operations.

Bryan, M. L.↗