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At least 433 records · Page 24

Application of ERTS-1 imagery to detecting and mapping modern erosion features, and to monitoring erosional changes, in southern Arizona

The author has identified the following significant results. The red MSS band 5 gives the sharpest definition of modern arroyos. On the best images, modern arroy0s can be distinguished as narrow as 150 to 200 feet in reaches where their contrast with adjacent areas is only moderate, and as narrow as 60 to 75 feet where their contrast is high. Both the red and infrared bands show differences is soils and vegetation. In the late fall and winter imagery, band 7 generally is the most useful for mapping the areas of the more erodible soils. A map at 1:1,000,000 scale has been prepared that shows all the arroyos within the 17,000 square mile study area that have been identified from ERTS-1 images. Also, from U-2 color infrared airphotos, a 1:125,000 scale map has been made of a 50 mile reach along San Simon Wash, in southeastern Arizona. This map shows not only the arroyo channels and narrow flood plains that have developed since 1890, but also areas within a few miles of the wash that are severely guilled, severely sheet-eroded, and moderately sheet-eroded. Two important effects of the third largest recorded flood of the upper Gila River also have been determined from the ERTS-1 images. The inundated area is best displayed on band 7, and the areas of severe sand/gravel erosion/deposition show best on band 5.

Morrison, R. B.↗

Mapping Atlantic coastal marshlands, Maryland, Georgia, using ERTS-1 imagery

Eastern coastal marshes are the most extensive and productive in the United States. A relatively low cost, moderately accurate method is needed to map these areas for management and protection. Groundbased and low-altitude aircraft methods for mapping are time-consuming and quite expensive. The launch of NASA's Earth Resources Technology Satellite has provided an opportunity to test the feasibility of mapping wetlands using small scale imagery. The test sites selected were in Chesapeake Bay, Maryland, and Ossabaw Island, Georgia. Results of the investigation indicate that the following may be ascertained from ERTS imagery, enlarged to 1:250,000: (1) upper wetland boundary; (2) drainage pattern in the wetland; (3) plant communities; (4) ditching activities associated with agriculture; and (5) lagooning for water-side home development. Conclusions are that ERTS will be an excellent tool for many types of coastal wetland mapping.

Anderson, R. R.↗

Identification and mapping of coal refuse banks and other targets in the anthracite region

ERTS-1 MSS data covering parts of Pennsylvania's southern and eastern middle anthracite coal fields were studied to determine how well accumulations of coal refuse could be identified and mapped by computer analysis and processing. Spectral signatures of coal refuse targets were similar to water, but had higher reflectances in all channels. Relative reflectances were in the order 4 5 or = 6 7. Although no underflight photography was at hand to judge mapping success, correlation was made, with 1:24,000 scale U.S.G.S. maps dated 1947 and 1948. Coal refuse targets correlated well with existing maps.

Borden, F. Y.↗

Coastal and submarine features on MSS imagery of Southeastern Massachusetts: Comparison with conventional maps

Three ERTS-1, MSS images of southeastern Massachusetts, including Cape Cod Bay, Cape Cod, and Nantucket Sound, show a variety of dynamic geologic and hydrologic phenomena. Coastal features imaged include the coastline at different time in the tidal cycle, harbors, lakes and ponds, marshes (wetlands), and beach and dune areas; submarine features include tidal flats, shoals, dredged and natural channels, and bars. Comparison with conventional maps at 1:1,000,000 and 1:250,000 scales show many inaccuracies between the ERTS imagery and the two map scales. The ERTS-1 imagery can be used to increase the accuracy of these maps, portray additional environmental information, and provide the capability for frequent updating of maps at such scales. ERTS-1 imagery provides a very cost effective method for provision of certain types of environmental data for Cape Cod and environs.

Williams, R. S., Jr.↗

Evaluate the application of ERTS-A data for detecting and mapping snow cover

The author has identified the following significant results. It is concluded from data analysis that the amount of information in ERTS-1 imagery with practical application to snow mapping is substantial. For the Arizona and California test sites, it appears that the extent of the mountain snowpacks can be mapped from ERTS-1 data in more detail than is depicted in aerial survey snow charts. In the Salt-Verde watershed, the agreement between the percentage of the area snow covered as measured from the ERTS-1 data and from aerial survey charts is generally well within 10%. In nearly all of the areas in which greater discrepancies occur, the differences can be explained by changes in snow cover during the interval between the two observations. In the southern Sierra Nevada, the agreement between ERTS-1 data and aerial survey charts is of the order of 5% in all cases, except for the Kaweah Basin on one date. In addition to comparative analysis with aerial snow charts, the ERTS-1 data have also been compared with high altitude aircraft photography. The ERAP data have provided an excellent source of correlative information. The results of the comparative analysis indicate that although small details in the snow line that cannot be detected in the ERTS-1 data can be mapped from higher resolution aircraft data, the boundaries of snow cover can be mapped just as accurately from ERTS-1 data.

Barnes, J. C.↗

Preliminary albedo map of the south polar region

A preliminary albedo map of the Martian south polar region in stereographic projection was prepared mainly from mission test video system (MTVS) prints before rectified and gridded prints were received, but some adjustments were made to conform with a semi-controlled photomosaic. Wherever possible, use also was made of crater coordinates. Two versions of the map are presented: one with a coordinate grid overlay and one without it. The precision of the coordinates is generally within 1 deg in latitude and the corresponding are in longitude. The maps show both the albedo markings and, with subdued contrast, the craters and topographic features that are necessary to locate the former. The map covers the range of latitudes from - 65 deg to the south pole.

Devaucouleurs, G.↗

Radiation balance mapping with multispectral scanner data.

Energy budget and radiation balance relationships have been measured from the ground by investigators in several disciplines. Airborne and spaceborne multispectral sensors provide a new measurement capability for large-area synoptic mapping of these quantities. Procedures for estimating and mapping total exitance and radiation balance from multispectral scanner data are discussed, and example maps for an agricultural application are presented. This information extraction technique is an extension of the usual recognition mapping performed with multispectral scanner data, and represents a first step in the quantitative interpretation and assessment of surface conditions with remote sensor data.

Malila, W. A.↗

Orbital mapping of the lunar magnetic field.

Examination of the lunar magnetic field as deduced from the orbital magnetometer data, with major emphasis on the general mapping of the lunar field over the orbit track of the Apollo 15 subsatellite. A detailed analysis of the data from a series of overflights of the Van de Graaff region at two different altitudes is also presented. This latter set of data makes it possible to determine the scale size of the region and the contrast between the remanent magnetization associated with the magnetic feature and its surroundings. The low altitude data from the Apollo 16 subsatellite, just prior to its impact into the lunar surface, are then examined. Data obtained while the moon was in the solar wind are used to construct a map which shows the lunar limb regions associated with the detection of limb compressions. This map is used to make qualitative inferences concerning the lunar remanent field in regions not covered by the contour maps.

Sharp, L. R.↗

Principles and techniques of polarimetric mapping.

This paper introduces the concept and potential value of polarimetric maps and the techniques for generating these maps in operational remote sensing. The application-oriented polarimetric signature analyses in the literature are compiled, and several optical models are illustrated to bring out requirements of a sensor system for polarimetric mapping. By use of the concepts of Stokes parameters the descriptive specification of one sensor system is refined. The descriptive specification for a multichannel digital photometric-polarimetric mapper is based upon our experience with the present single channel device which includes the generation of polarimetric maps and pictures. High photometric accuracy and stability coupled with fast, accurate digital output has enabled us to overcome the handicap of taking sequential data from the same terrain.

Halajian, J.↗

Mapping of the major structures of the African rift system

The author has identified the following significant results. The new fault map of the main Ethiopian rift, based on aerial photo compilations, generally agrees well with the maps produced from ERTS-1 imagery. Characteristically, the ERTS-1 imagery shows some of the major faults to be more extensive than realized from ground studies, though due to the angle of sun illumination some east-facing fault scarps are not easily discernible on the imagery. The Corbetti caldera, shows up surprisingly poor on the imagery, and is shown to be an adjunct to an older, larger caldera now occupied by Lakes Awassa and Shallo. The lithological boundaries mapped by De Paola in the rift are difficult to discern on the ERTS-1 imagery. On the Somalian plateau, east of the rift, a denuded caldera has been identified as the source of much of the lavas of the Batu Mountains. Further south, ERTS-1 imagery amplifies the structural and lithological mapping of the Precambrian rocks of the Shakisso-Arero area, and of the Kenya-Ethiopia border region. For the first time with some certainty, it is now possible to say that on the evidence of the ERTS-1 imagery, the Western Rift does not continue northeast beyond the Sudan-Uganda border, and is thus not to be sought in western Ethiopia.

Mohr, P. A.↗

Mapping coastal vegetation, land use and environmental impact from ERTS-1

The author has identified the following significant results. Vegetation map overlays at a scale of 1:24,000 compiled by multispectral analysis from NASA aircraft imagery for all of Delaware's wetlands are being used as ground truth for ERTS-1 mapping and by state agencies for wetlands management. Six major vegetation species were discriminated and mapped, including percentages of minor species. Analogue enhancements of wetlands vegetation and dredge-fill operations have been produced using General Electric's GEMS data processing and ERTS-1 false color composites. Digital, thematic land use, and vegetation mapping of entire Delaware Bay area is in progress using Bendix Corporation's Earth Resources Data System and ERTS-1 digital tapes. Statistical evaluation of target-group selection reliability has been completed. Three papers have been published on ERTS-1 coastal vegetation and land use. Local and state officials are participating in the ERTS-1 program as co-investigators.

Klemas, V.↗

ERTS-1: Automated land-use mapping in lake watersheds

The author has identified the following significant results. ERTS-1 computer compatible tapes were used as a basis to generate land use maps in lake watersheds in southeastern Michigan. These maps, generated on a repetitive basis, provide information essential to governmental agencies concerned with planning and control of lake eutrophication. The ERTS mapping products included geometrically current land use map overlays at 1:250,000 and 1:48,000 scale and area measurement printouts. The printouts provide, within the watershed boundaries and by land use category, a quantitative measure of the amount of land, in square kilometers and acres. This quantitative measure of land use in watersheds is essential to the development and application of deterministic models, which compute nutrient flows into lakes and establish lake eutrophication rates.

Chase, P. E.↗

Vegetation mapping from ERTS imagery of the Okavango Delta

The Okavango is Botswana's major water resource. The present study has been specifically directed at mapping vegetation types within the delta and generally concerned with finding what information of value to plant and animal ecologists could be extracted from the imagery. To date it has been found that. (1) It is possible to map broad vegetation types from the imagery. (2) Imagery of the delta records the state of the system in a manner which will facilitate long-term studies of plant succession. (3) Phenological events can be detected. (4) The imagery can be used to detect and map wild fires. This will be useful in determining the role of fire in the ecology of the region. Using the imagery it is thus possible to map existing vegetation and monitor both short and long-term changes.

Willamson, D. T.↗

Relationship of roof falls in underground coal mines to fractures mapped on ERTS-1 imagery

ERTS imagery is of unique value for mapping of certain fractures that are not identifiable on aircraft imagery. Because color infrared and ERTS imagery complement each other both sources of data were used to map fractures in western Indiana and eastern Illinois. In the Kings Station Mine, Gibson County, Indiana, most roof falls reported had occurred in areas where mapped fractures were closely spaced and intersecting. Using this information as a basis for extrapolation, roof fall hazard maps were prepared for other mine sites. Various coal resources programs related to energy and environment also were conducted.

Wier, C. E.↗

An evaluation of the utility of ERTS-1 data for mapping and developing natural resources of Iran

The author has identified the following significant results. Results are reported in structural mapping leading to tectonic interpretation; in surficial deposits mapping; in analysis of salt diapirism in southwest Iran; in updating and correcting existing hydrological maps; in monitoring fluctuations of water in some intermittent lakes; in the delineation of wetland areas and the study of fluvial suspended load of the head of the Persian Gulf in relation to the fishing industry; in exercises in soil mapping; in range and agricultural surveys and inventory using multistage sampling methods, and in the computer analysis of ERTS-1 digital tapes for urban land use. The completion of a 1:1,000,000 false color photomosaic of Iran is also discussed.

Ebtehadj, K.↗

A system to geometrically rectify and map airborne scanner imagery and to estimate ground area

A system of computer programs were developed which performs geometric rectification and line-by-line mapping of airborne multispectral scanner data to ground coordinates and estimates ground area. The system requires aircraft attitude and positional information furnished by ancillary aircraft equipment, as well as ground control points. The geometric correction and mapping procedure locates the scan lines, or the pixels on each line, in terms of map grid coordinates. The area estimation procedure gives ground area for each pixel or for a predesignated parcel specified in map grid coordinates. The results of exercising the system with simulated data showed the uncorrected video and corrected imagery and produced area estimates accurate to better than 99.7%.

Spencer, M. M.↗

A high-resolution map of the galactic-center region

A 2-cm wavelength map of the region in the vicinity of the galactic center is presented that represents an improvement in resolution by a factor of 2.7 over Hollinger's (1965) map and an improvement in sensitivity and coverage over the Downes, Maxwell, and Meeks (1965) map. The improved map reveals the great complexity of this region and the existence of a large number of densely clustered discrete sources and many new hitherto unresolved features.

Kapitzky, J. E.↗

Cartographic research in EREP program for small scale mapping

The author has identified the following significant results. Skylab photography is suitable for producing planimetric maps with graphical representation of landform at scales up to 1:100,000. It cannot supply all the detail necessary for maps at this scale, but it may be used to produce a sound framework which can be completed by detail from other sources. Its principal cartographic use is for original mapping of undeveloped areas of the world, but it would also be useful for the revision of existing maps and for monitoring extensive urban changes.

Mott, P. G.↗