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C.J. Robinove

Publications and source records attributed to C.J. Robinove.

9 recordsLinked to original sources
USGS1986

Spatial diversity index mapping of classes in grid cell maps.

The landscape diversity index indicates the number of classes of land that are in proximity to each point in a digital grid cell map. The index is D=100(i-1)/(n-1), where i = the number of landscape classes within a selected distance of each grid cell and n = the total number of mapped classes. The use of the index is illustrated by calculating the diversity index at each grid cell for each of five mapped classes and displaying the resulting diversity index map that portrays the complexity of the scene. The method is applicable to land-use planning, site selection, or description of landscape complexity.-Author

Photogrammetric Engineering and Remote Sensing↗
USGS1983

Application of digital mapping technology to the display of hydrologic information; a proof-of-concept test in the Fox-Wolf River Basin, Wisconsin

The Fox-Wolf River basin in east-central Wisconsin was selected to test concepts for a water-resources information system using digital mapping technology. This basin of 16,800 sq km is typical of many areas in the country. Fifty digital data sets were included in the Fox-Wolf information system. Many data sets were digitized from 1:500,000 scale maps and overlays. Some thematic data were acquired from WATSTORE and other digital data files. All data were geometrically transformed into a Lambert Conformal Conic map projection and converted to a raster format with a 1-km resolution. The result of this preliminary processing was a group of spatially registered, digital data sets in map form. Parameter evaluation, areal stratification, data merging, and data integration were used to achieve the processing objectives and to obtain analysis results for the Fox-Wolf basin. Parameter evaluation includes the visual interpretation of single data sets and digital processing to obtain new derived data sets. In the areal stratification stage, masks were used to extract from one data set all features that are within a selected area on another data set. Most processing results were obtained by data merging. Merging is the combination of two or more data sets into a composite product, in which the contribution of each original data set is apparent and can be extracted from the composite. One processing result was also obtained by data integration. Integration is the combination of two or more data sets into a single new product, from which the original data cannot be separated or calculated. (USGS)

Water-Resources Investigations Report↗
USGS1982

Space platform albedo measurements as indicators of change in arid lands

The change in albedo of arid lands is an indicator of changes in their condition and quality, including density of vegetative cover, erosion, deposition, surficial soil moisture, and man-made change. In general, darkening of an arid land surface indicates an increase in land quality while brightening indicates a decrease in quality, primarily owing to changes in vegetation. Landsat multiband images taken on different dates can be converted to black-and-white albedo images. Subtraction of one image from another, pixel by pixel, results in an albedo change map that can be density sliced to show areas that have brightened or darkened by selected percentages. These maps are then checked in the field to determine the reasons for the changes and to evaluate the changes in land condition and quality. The albedo change mapping technique has been successfully used in the arid lands of western Utah and northern Arizona and has recently been used for detection of coal strip mining activities in northern Alabama. ?? 1983.

Advances in Space Research↗
USGS1982

Landsat monitoring of desert vegetation growth, 1972-1979 using a plant-shadowing model

Landsat digital data spanning the period 1972-1979 were analyzed to monitor the status of vegetation within and outside an exclosure in the northern Sinai (precipitation 100-150 mm/year). This 6??6 km exclosure was fenced off in the summer of 1974 and subsequently has been free from the anthropogenic pressures (overgrazing, cultivation in small fields, and harvesting of dry plants as firewood) that continued outside the exclosure. The recovery of the ecosystem within the exclosure is monitored applying a previously tested model. The model quantitatively describes the reduction in the reflectivity to zenith due to shadowing effects by mostly vertical plants. The darkening (reduction in the reflectivity) in the exclosure was compared to the status before the fencing-off and to the essentially unchanging bare sands outside the exclosure. The vegetation protrusion parameter s (sum of the products of plant height times diameter for a unit area of the surface), calculated from Landsat digital data for the exclosure, increased from essentially zero in 1972 and 1973 to about 0.18 in 1975 and changed only within narrow limits from 1975 to 1979. The s value of 0.18 indicates that if the clumps of the plants protruding from the surface in the exclosure were laid horizontally on the soil, they would cover 18 percent of the area. This parameter provides a quantitative measure of the condition of the ecosystem, but the relation to the total green and/or brown biomass remains to be determined. ?? 1983.

Advances in Space Research↗
USGS1982

Computation with physical values from Landsat digital data

Landsat digital images are commonly analyzed by using the digital numbers for each pixel recorded on a computer-compatible magnetic tape. Although this procedure may be satisfactory when only a single, internally consistent image is used, the procedure may produce incorrect results if more than one image is used for analysis as in mosaics or temporal overlays. The digital numbers for each pixel should be converted to their dimensioned equivalents such as radiance, as measured at the satellite, in milliwatts per square centimetre per steradian, or reflectance.-from Author

Photogrammetric Engineering and Remote Sensing↗