Buige, A. | Search NASA

NASA NTRS1978

FAA global positioning system program

An overview of the FAA global positioning system (GPS) program is presented. The program's emphasis is on the potential applications of the system to civil aviation. The program is examined in relation to investigations of low cost equipment technology and potential improvements and/or modifications to the system. GPS program concerns such as the signal to noise ratio of the satellites, the system performance, and the cost/performance considerations are discussed. Requirements for an ideal receiver to be implemented into the GPS are summarized.

Buige, A.↗

NASA NTRS1973

ATS-F Comsat Millimeter Wave Propagation Experiment

The ATS-F Comsat Millimeter Wave Propagation Experiment has been designed to gather statistical data on the attenuation caused by rain at millimeter wave frequencies. These data will be used to determine system design parameters for future communications satellite systems operating at frequencies above 10 GHz. The experiment has 39 ground terminals transmitting at 13.2 or 17.8 GHz to a transponder on board the ATS-F satellite. The transponder retransmits these signals at 4 GHz to a central earth terminal which records their amplitudes once each second. The data will be analyzed to provide probabilities of attenuation as functions of parameters such as rainfall, location, and time. These probabilities can then be used to determine the required power margins of millimeter wave communications systems. Techniques of overcoming severe attenuation such as site diversity and the use of a spot beam to increase the power level at selected locations will also be evaluated.

Westerlund, L. H.↗

NASA NTRS1965

Telemetry test system

Telemetry system for rapid checkout for space tracking and data acquisition network

TRACKING↗