Exploiting AFSCN Ranging Data for Catalog Maintenance

The Air Force Satellite Control Network (AFSCN) is composed of eight worldwide fixed remote tracking stations (Space Ground Link Stations, SGLS) hosting 15 antennas, plus two mission control nodes, one at Onizuka AFB, CA and the other at Schriever AFB, CO. One of the AFSCN message formats provides AFSCN metric data (range, range-rate, azimuth, and elevation). Currently the AFSCN metric data are not used by the Space Control Center for catalog maintenance. AFSCN satellite data are received at a central processing facility and immediately diverted to the particular Space Operation Squadron (SOPS) in charge of the satellite. Element sets are produced by the SOPS, but the resulting element sets are not in a format usable by Space Command, and no procedure is in place to transfer them to Cheyenne Mountain. There are several advantages to incorporating the AFSCN data into the Space Control Center (SCC) catalog. The AFSCN range measurement is accurate to the 1-meter level, if the site locations are precisely determined and if atmospheric corrections and carefully calibrated transponder and site biases are applied. This paper describes the Lincoln Laboratory effort to make the AFSCN ranging data available to the SCC for use in both catalog maintenance and, since the data is of such high quality, for use in the separate special perturbations catalog at the Mountain. The specific plan for obtaining the AFSCN data, calibrating it in near real-time, reformatting the observations for submission to Space Command, and transmitting the data to Cheyenne Mountain will be described in detail.