A Replenishment Phase Study for the NAVSTAR Global Positioning System.
Abstract
A Q-GERT simulation model was designed to estimate the replenishment phase for the Global Positioning System using the original block buy of 28 satellites. Block I satellites were not considered in the study. The model determines the best fixed launch schedule without replenishment to find out when the initial constellation falls below 18 satellites. Additionally, the model was modified to determine the best fixed launch schedule that would maintain the constellation at 21 functional satellites 99% of the time. Sensitivity analysis was performed on the parameters of satellite design life and reliability through final orbit insertion. Satellite availability curves were used to show the number of operational satellites over time. Point availability curves were used to display the fraction of 21 satellites available each month of operation. A satellite attrition analysis was performed by selecting up to three satellites for deletion and evaluating coverage over the major land areas. Originator supplied keywords include: Global positioning system; GPS replenishment; and Navigation satellite.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1984
- Accession Number
- ADA152030
Entities
People
- D. J. Aderhold
Organizations
- Air Force Institute of Technology