Citation
Abstract
The amount of data that can be sent on telemetry links for tracking spacecraft depends upon the signal-to-noise power ratio. Both spacecraft and ground system can be sized to determine and optimize the amount of received signal power. The noise power depends on a variety of contributors, but for most NASA deep-space interplanetary missions, the receiver noise temperature is usually ~20 K or higher depending upon elevation angle. Given that near-Earth missions such as those to the Moon depend more and more on larger-diameter antennas such as those of the NASA Deep Space Network (DSN), the added hotbody noise of the lunar disk can be significant, resulting in overall system noise temperatures of ~200 K or higher. This significant increase can severely affect data rates and its variation as a ground antenna tracks a lunar orbiter needs to be characterized.
Details
- Volume
- 42-200
- Published
- February 15, 2015
- Pages
- 1–17
- File Size
- 999.6 KB