A Modernization Deployment Strategy to Meet Military and Civil Needs

Clifford W. Kelley, Douglas Martoccia, Rex Pendley

Abstract:	Because of the uncertainty of the current launch strategy and slow military user equipment replacement, the current replenishment approach does not support the timely insertion of new missions and civil capabilities into the GPS constellation. This threatens the future of GPS as the world’s standard navigation and timing service. To address this problem, a study of deployment strategies to meet urgent military and civil needs was conducted. The most promising candidate option involves launching the remaining Block IIR satellites now in storage and Block IIF satellites on a fixed schedule. This may push the number of satellites on orbit to over 40 at the peak. Since this exceeds the number of PRN codes in the GPS ICD, a method using antipodal satellites with the same PRN number was developed and tested against eight receivers in the lab to assure receiver backward compatibility. The largest system impact arises from providing additional channels to the Control Segment to monitor the additional navigation signals. Additionally, the Master Control Station will be required to process significantly more L-band data, so the services and mission servers are expected to need an upgrade. Overall, we determined that a launch on schedule approach saves launch costs by launching at a fixed rate and effective methods exist to meet the need for improved civil and military capability much sooner that the current Government plan.
Published in:	Proceedings of the 12th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1999) September 14 - 17, 1999 Nashville, TN
Pages:	1343 - 1352
Cite this article:	Kelley, Clifford W., Martoccia, Douglas, Pendley, Rex, "A Modernization Deployment Strategy to Meet Military and Civil Needs," Proceedings of the 12th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1999), Nashville, TN, September 1999, pp. 1343-1352.
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