Base files will be kept on-line for a minimum of 90 days and archived on magnetic tape for a minimum of one year. To avoid costly and inconvenient data re-sampling, please do not delay downloading files. Equipment malfunction and measurement problems can be detected earlier and corrected more easily when field measurements are differentially corrected in a timely manner. In addition, retrieval of older data files from magnetic tape may take some time and cause additional delays. This time is offset from local time in Columbia, Missouri by 5 to 6 hours.
Size depends upon the number of visible satellites at the time of data collection.
The compressed data files are expanded after downloading by simply running the executable files from a DOS prompt. The SYNC2RAW utility is available from the under the utilities file directory. The BBS has no directory or file listing for the GPS data files. The user simply responds to the download file prompt by supplying the names of the files needed using the appropriate naming convention. Access to the Columbia Environmental ResearchResearch Center BBS is freely provided to all users within the U.S. Geological Survey and to all cooperating agencies and partners.