Publications

Software tools have been developed at the U.S. Geological Survey's EROS Data Center to extract topographic structure and to delineate watersheds and overland flow paths from digital elevation models. The tools are specialpurpose FORTRAN programs interfaced with general-purpose raster and vector spatial analysis and relational data base management packages. The first phase of analysis is...

This month we demonstrate an example of the use of thermal infrared imagery to produce a relatively sharp surrogate shaded-relief image. The image shows one aspect of the drama and usefulness of calibrated thermal imagery that (because of compatible projection and pixel size) can be easily combined with other spectral bands of a satellite image. Such data can be enhanced in yet another...

In late May 1986, the advancing Hubbard Glacier blocked the entrance to Russell Fiord near Yakutat, Alaska, creating a large ice-dammed lake. Runoff from the surrounding glaciated mountains raised the level of the lake to about 25 m above sea level by 8 October, when the ice dam failed. Remote sensing offers one method to monitor this large tidal glacier system, particularly the glacier...

No abstract available.

Gridded surface data sets are often incorporated into digital data bases, but extracting information from the data sets requires specialized raster processing techniques different from those historically used on remotely sensed and thematic data. Frequently, the information desired of a gridded surface is directly related to the topologic peaks and pits of the surface. A method for...

Vector-based geographic information systems usually require annotation, such as a polygon number or attribute data, in a suitable location within a polygon. Traditional methods usually compute the polygon centroid, test the centroid for inclusion or exclusion, and select some alternative point when the centroid falls outside the polygon. Two problems are associated with this approach: (1...

Title III of the Alaska National Interest Lands Conservation Act (ANILCA, 1980) established the Yukon Flats National Wildlife Refuge (YFNWR). Section 304 of the Act requires the Secretary of Interior to "prepare, and from time to time revise, a comprehensive conservation plan" for the refuge. Before developing a plan for the refuge, the Secretary shall "identify and describe--a) the...

No abstract available.

No abstract available.

In cooperation with the International Landsat community, and through the Landsat Technical Working Group (LTWG), NOAA is assembling information about the status of the Worldwide Landsat Archive. During LTWG 9, member nations agreed to participate in a survey of International Landsat data holding and of their archive experiences with Landsat data. The goal of the effort was two-fold; one...

Data collection and preliminary analyses have begun for a study that will evaluate the usefulness of satellite data for assessment of land surface features and climatic variables. The objective of the study is to determine what relationships exist between routinely available ground-based climatic and land surface information and satellite-obtained land surface information. The overall...

In 1985, the U.S. Geological Survey initiated a research program to produce 1:250,000-scale land cover maps of Alaska using digital Landsat multispectral scanner data and ancillary data and to evaluate the potential of establishing a statewide land cover mapping program using this approach. The geometrically corrected and resampled Landsat pixel data are registered to a Universal...