Satellite telemetry Tracking and Control Subsystems Col Johne keesee October 29. 2003 Massachusetts Institute of Technology
Satellite Telemetry, Tracking and Control Subsystems Col John E. Keesee October 29, 2003 Massachusetts Institute of Technology 1
Overview The telemetry, tracking and control subsystem provides vital communication to and from the spacecraft Tt&c is the only way to observe and to control the spacecrafts functions and condition from the ground October 29. 2003 Massachusetts Institute of Technology
Overview • The telemetry, tracking and control subsystem provides vital communication to and from the spacecraft • TT&C is the only way to observe and to control the spacecraft’s functions and condition from the ground October 29, 2003 Massachusetts Institute of Technology 2
Outline tt&c functions and trades Command System functions Encoding/ Decoding Messages Interfaces Telemetry systems Sensors and transducers ADC Formats Concerns/Design principles October 29. 2003 Massachusetts Institute of Technology
Outline • TT&C functions and trades • Command System functions – Encoding/Decoding – Messages – Interfaces • Telemetry systems – Sensors and transducers – ADC – Formats – Concerns/Design principles October 29, 2003 Massachusetts Institute of Technology 3
tt&c functions Carrier tracking Command reception and detection Telemetry modulation and transmission Ranging Subsystem operations October 29. 2003 Massachusetts Institute of Technology
TT&C Functions • Carrier tracking • Command reception and detection • Telemetry modulation and transmission • Ranging • Subsystem operations October 29, 2003 Massachusetts Institute of Technology 4
Carrier Tracking Two-way coherent communication Transmitter phase-locks to the received fre equency Transmitted frequency is a specific ratio of the uplink frequency Easy to find and measure the frequency received on the ground Doppler shift provides range rate October 29. 2003 Massachusetts Institute of Technology
Carrier Tracking • Two-way coherent communication – Transmitter phase-locks to the received frequency – Transmitted frequency is a specific ratio of the uplink frequency • Easy to find and measure the frequency received on the ground • Doppler shift provides range rate October 29, 2003 Massachusetts Institute of Technology 5