Telemetry modulation and coping
Abstract
Digital telemetry has supplanted analog telemetry for deep space communications. With digital telemetry, the telecommunications systems design engineer may use error correcting codes. This allows increased error protection at the cost of increased bandwidth. All science telemetry returned from the Voyager and Galileo spacecraft are protected by error correcting codes. Both the modulation and coding of digital telemetry for the deep space channel are considered. The descriptions include relative performance of some competing schemes. However, the treatment given here is, of necessity, cursory. A small class of modulation schemes has proven to be best for the deep space channel. The digital telemetry is either phase-shift-keyed onto a squarewave subcarrier and then phase modulated onto the carrier or the digital telemetry is directly phase modulated onto the carrier.
- Publication:
-
The Deep Space Network: A Radio Commun. Instr. for Deep Space Exploration
- Pub Date:
- July 1983
- Bibcode:
- 1983dsnr.nasa.....K
- Keywords:
-
- Algorithms;
- Coding;
- Deep Space Network;
- Pulse Frequency Modulation Telemetry;
- Digital Data;
- Error Correcting Codes;
- Mathematical Models;
- Phase Shift Keying;
- Signal To Noise Ratios;
- Traveling Wave Tubes;
- Space Communications, Spacecraft Communications, Command and Tracking