1991 Volume 1991 Issue 67 Pages 55-68
This report describes the configuration and performance of the airborne equipment developed for navigation experiment using Engineering Test Satellite-V(ETS-V). A pair of airborne equipment have been developed and installed on a Beechcraft B99 of the ENRI and a Boeing 747 cargo aircraft of Japan Air Lines. Each of them consists of L-band antennas, a transmitter/receiver, MODEM's and a data processor, etc. It has capabilities to conduct voice/data communications and to return ranging signals in response to interogations from the ground earth station.
Three circular patch antennas (peak gain: 7dBi) are mounted on the B747. One of them is selected with switches to cover the satellite direction on the NOPAC route. The B99 has a 4-element conformal array (peak gain: 10dBi) on each side and a circular patch antenna (peak gain: 7dBi) in the nose radome. One of these antennas giving the most appropriate coverage is selected with switches according to the satellite direction. This configuration gives almost entire coverage over the upper hemisphere of the aircraft except for the backward direction.
The MODEM's of BPSK, A-QPSK and PM, and a SS modulator are installed on board the aircraft for data communications. For digital voice communication, an LPC voice codec is used with the BPSK MODEM. An NBFM MODEM is used for comparison with the digital voice communication.
Both airborne equipment have been tested and confirmed to meet the requirement for electrical performances under environmental conditions specified in RTCA's DO-160A.
