Interactive computer methods for generating mineral-resource maps
Inasmuch as maps are a basic tool of geologists, the U.S. Geological Survey's CRIB (Computerized Resources Information Bank) was constructed so that the data it contains can be used to generate mineral-resource maps. However, by the standard methods used-batch processing and off-line plotting-the production of a finished map commonly takes 2-3 weeks.
To produce computer-generated maps more rapidly, cheaply, and easily, and also to provide an effective demonstration tool, we have devised two related methods for plotting maps as alternatives to conventional batch methods. These methods are: 1. Quick-Plot, an interactive program whose output appears on a CRT (cathode-ray-tube) device, and 2. The Interactive CAM (Cartographic Automatic Mapping system), which combines batch and interactive runs. The output of the Interactive CAM system is final compilation (not camera-ready) paper copy. Both methods are designed to use data from the CRIB file in conjunction with a map-plotting program.
Quick-Plot retrieves a user-selected subset of data from the CRIB file, immediately produces an image of the desired area on a CRT device, and plots data points according to a limited set of user-selected symbols. This method is useful for immediate evaluation of the map and for demonstrating how trial maps can be made quickly.
The Interactive CAM system links the output of an interactive CRIB retrieval to a modified version of the CAM program, which runs in the batch mode and stores plotting instructions on a disk, rather than on a tape. The disk can be accessed by a CRT, and, thus, the user can view and evaluate the map output on a CRT immediately after a batch run, without waiting 1-3 days for an off-line plot. The user can, therefore, do most of the layout and design work in a relatively short time by use of the CRT, before generating a plot tape and having the map plotted on an off-line plotter.
|Interactive computer methods for generating mineral-resource maps
|James Alfred Calkins, A.S. Crosby, T.E. Huffman, A. L. Clark, G.T. Mason, R.J. Bascle
|USGS Numbered Series
|USGS Publications Warehouse