Citation
Abstract
This article studies the fading channel between a grounded asset on the South Pole of the Moon and a DSN station utilizing a 34-meter antenna. Due to geometrical constraints in the Earth-Moon system, missions operating in the lunar South Pole will need to communicate with Earth by pointing their antennas at a maximum elevation angle of 10 degrees. This fact, combined with low gain antennas typically found on-board rovers and landers, will cause signal reflections with the Moon surface and create fading effects that are uncharacteristic of space applications. On the other hand, the receiving stations on Earth will utilize highly directional antennas, an uncommon situation in most systems suffering from fading effects (e.g.,, mobile communications). Unfortunately, a complete characterization of the fading channel is not possible since no measurements of the scattering function and/or power delay profile at the South Pole of the Moon are currently available. Therefore, we study the channel properties from an analytic point-of-view assuming that it can be modeled as wide sense stationary process with uncorrelated scattering function. In particular, we derive expressions for the Doppler power profile, channel coherence time and average fade duration as a function of the receiving antenna directivity. Results indicate that, for missions transmitting at tens or hundreds of kilobits per second, the stochastic channel between the South Pole of the Moon and Earth exhibits slow fading. Furthermore, the time selectivity of the channel is directly related to the receiving antenna directivity and operating frequency.
Keywords
Details
- Volume
- 42-216
- Published
- February 15, 2019
- Pages
- 1–30
- File Size
- 1.6 MB