MODULATION CONSIDERATIONS FOR THE TRANSMISSION OF REAL-TIME SPACE TELEVISION
Abstract
Modulation considerations for the design of a real-time space/earth television link were treated. To illustrate two extremes of transmission possibility, the baseband signal was assumed: (1) digitally encoded and modulated on a carrier as binary PCM/PM; and (2) analogue modulated as wideband FM. Standards of quality established for the design of each system were then used to estimate receiver power requirements. The performance and complexity of these two approaches were then reviewed with parameters typical of a moon mission. In comparing the digital to the analogue approach, it was found that the analogue system was superior in all respects, e. g., simplicity, reliability, and spacecraft power. Identical comparisons as the foregoing were necessary to establish the modulation techniques for Telstar and Relay, the world's first wideband communication satellites. It is not surprising, therefore, that these satellites utilize analogue wideband FM with frequency-following receivers.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1963
- Accession Number
- AD0406315
Entities
People
- Jean A. Develet Jr.
Organizations
- The Aerospace Corporation