The USB uplink handles voice, telecommand (low bandwidth), and ranging signals. The downlink handles voice, telemetry (lots, including astronaut biometrics) and either ranging or video. The ranging code system is quite interesting and is relevant to an understanding of GPS. It relies on the Chinese Number Theorem, which is also widely used in cryptography. Also discussions about the ARIA aircraft, which filled in the big gaps between ground stations for orbital and descent communications, and their direction finding and signal acquisition antennae.
No Comments Yet