THE ADVANTAGES OF APPLYING GPS FREQUENCY TRANSLATORS TO RANGE TRACKING

Abstract

When applying the Global Positioning System (GPS) to Time, Space, and Position Information (TSPI), the use of GPS frequency translators should be considered. The primary space positioning problem in the test and evaluation applications is trajectory reconstruction. Although this can be accomplished by flying a GPS receiver on the test vehicle and telemetering its position to the ground, there are significant advantages to translating the “L” band GPS signals to “S” band, and transmitting the broad band signal to the ground for processing. A translator-based system offers several advantages. Physical advantages include smaller size, lower weight, and lower cost. Technical advantages include: 1) ground station data aiding that provides a 6 dB advantage, 2) elimination of system bias errors, 3) computation complexity at the ground station vs. the vehicle under test, and 4) the ability to reconstruct a test scenario enabling flexibility in data analysis techniques.