10.4 Design of Telemetry/Telecommand and Telecommunication Technology
345
well as the proper margin. At the same time, the channel budget table could make
designers understand the subsystem and provide theoretical data for the adjustment
of specifications and the selection of some hardware.
10.4.3 Telemetry/Telecommand and Telecommunication
of Lunar Lander to Ground
The telemetry/telecommand and telecommunication architecture for deep
space probe generally included unified carrier and suppressed carrier. The
unified carrier architecture was applied in telemetry/telecommand and the
suppressed carrier modulation was generally applied in telecommunication. The
telemetry/telecommand and telecommunication subsystem of spacecraft was
composed of telemetry/telecommand instruments and telecommunication instruments. According to requirements of different missions such as telecommunication
on lunar surface of the Chang’E-3 lunar lander, the relay telecommunication instruments for telecommunication between the lunar lander and the lunar rover were
onboard.
1. Telemetry/Telecommand Instrument
The telemetry/telecommand instruments generally included receiving antenna,
telemetry/telecommand transponder, power amplifier and transmitting antenna.
1) Antenna
The antenna was an important component of spacecraft telemetry/telecommand and
telecommunication subsystem, and its task was to form a stable and reliable radio
frequency transmission channel with the ground antenna to meet predetermined
requirements. The function of spacecraft antenna was to convert the guided wave into
the space wave and transmit the downlink radio frequency signal to ground station,
or to receive the uplink radio frequency signal transmitted from ground station to the
spacecraft and convert the space wave into the guided wave as required [2]. Generally, the telemetry/telecommand antennas should be full space coverage antennas
for lunar soft-landing missions. The configuration of telemetry/telecommand and
telecommunication antennas of the Chang’E-3 lunar lander was shown in Fig. 10.2.
The telemetry/telecommand antennas of the Chang’E-3 lunar lander included Sband antenna A/B, X-band transmitting antenna A/B and X-band receiving antenna
A/B, where the S-band antenna A/B were transmission and reception common
antennas.
Generally, two half space (or quasi half space) covered telemetry/telecommand
antennas were applied for Earth orbit spacecraft. Two antennas were installed
symmetrically on the surface of spacecraft to achieve quasi full space coverage.
The pattern of the antenna array is shown in Fig. 10.3.
According to the analysis results of spacecraft attitude and the relative position
to Earth in the mission process, two X-band telemetry/telecommand antennas were
345
well as the proper margin. At the same time, the channel budget table could make
designers understand the subsystem and provide theoretical data for the adjustment
of specifications and the selection of some hardware.
10.4.3 Telemetry/Telecommand and Telecommunication
of Lunar Lander to Ground
The telemetry/telecommand and telecommunication architecture for deep
space probe generally included unified carrier and suppressed carrier. The
unified carrier architecture was applied in telemetry/telecommand and the
suppressed carrier modulation was generally applied in telecommunication. The
telemetry/telecommand and telecommunication subsystem of spacecraft was
composed of telemetry/telecommand instruments and telecommunication instruments. According to requirements of different missions such as telecommunication
on lunar surface of the Chang’E-3 lunar lander, the relay telecommunication instruments for telecommunication between the lunar lander and the lunar rover were
onboard.
1. Telemetry/Telecommand Instrument
The telemetry/telecommand instruments generally included receiving antenna,
telemetry/telecommand transponder, power amplifier and transmitting antenna.
1) Antenna
The antenna was an important component of spacecraft telemetry/telecommand and
telecommunication subsystem, and its task was to form a stable and reliable radio
frequency transmission channel with the ground antenna to meet predetermined
requirements. The function of spacecraft antenna was to convert the guided wave into
the space wave and transmit the downlink radio frequency signal to ground station,
or to receive the uplink radio frequency signal transmitted from ground station to the
spacecraft and convert the space wave into the guided wave as required [2]. Generally, the telemetry/telecommand antennas should be full space coverage antennas
for lunar soft-landing missions. The configuration of telemetry/telecommand and
telecommunication antennas of the Chang’E-3 lunar lander was shown in Fig. 10.2.
The telemetry/telecommand antennas of the Chang’E-3 lunar lander included Sband antenna A/B, X-band transmitting antenna A/B and X-band receiving antenna
A/B, where the S-band antenna A/B were transmission and reception common
antennas.
Generally, two half space (or quasi half space) covered telemetry/telecommand
antennas were applied for Earth orbit spacecraft. Two antennas were installed
symmetrically on the surface of spacecraft to achieve quasi full space coverage.
The pattern of the antenna array is shown in Fig. 10.3.
According to the analysis results of spacecraft attitude and the relative position
to Earth in the mission process, two X-band telemetry/telecommand antennas were