GPS Network Implementation for Missile Defense Testing

Andrew W. Sutter and James P. Cunningham

Abstract:	The current Department of Defense (DOD) Ballistic Missile Defense (BMD) test flights depend on range radars for real-time tracking. The Global Positioning System (GPS) potentially provides a cost-effective and more accurate source of real-time position data as a backup or replacement to those radars. GPS can potentially deliver positions with sub-meter to meter accuracy in real-time, and decimeter level accuracy post-flight. The Wide Area Differential GPS (WADGPS) corrector based technique being developed under the direction of NSWCDD has been shown to deliver meter level accuracy over vast areas comparable to that needed for BMD testing. Additionally, long-baseline kinematic software has been shown to deliver decimeter accuracy over similar baselines. Use of either of these techniques however, requires the establishment of a network of reference tracking stations. In this preliminary study, various GPS reference station networks were designed and subsequently examined to determine their ability to support BMD test flights. Two primary criteria were considered for this determination. The first criteria addressed to what extent the networks simultaneously tracked all satellites visible to the missile. The second criteria examined the proximity of the stations both to each other and to the missile trajectory. Both simulated and actual data for these test flights are discussed. A National Missile Defense (NMD) flight was launched from Vandenberg Air Force Base towards the Kwajalein Atoll on January 16, 1998. For this flight, a recommended network was constructed that tracked between 17 to 19 of the 21 satellites visible to the missile. Additionally, this network maintained relatively close distances between stations. Both WADGPS and long-baseline kinematic simulated results are presented. Two Theater Ballistic Missile Defense (TBMD) trajectories were also considered. The first of these, an actual TBMD flight, was launched from the Pacific Missile Range Facility (PMRF) on Kauai and impacted in the broad ocean area to the north-west. GPS data was collected from the missile and also from widely distributed reference stations. A second simulated TBMD trajectory was also launched from PMRF and impacted near the Kwajalein Atoll. For both of these trajectories a recommended network was constructed that tracked all satellites visible by the missile. Both actual and simulated long-baseline GPS results are presented.
Published in:	Proceedings of the 57th Annual Meeting of The Institute of Navigation (2001) June 11 - 13, 2001 Albuquerque, NM
Pages:	797 - 808
Cite this article:	Sutter, Andrew W., Cunningham, James P., "GPS Network Implementation for Missile Defense Testing," Proceedings of the 57th Annual Meeting of The Institute of Navigation (2001), Albuquerque, NM, June 2001, pp. 797-808.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In