RADIOMETRIC VALIDATION OF MOREHEAD STATE UNIVERSITY GROUND STATION

The 21-m antenna ground station at the Morehead State University has undergone an upgrade over the past several years to make it ready to support upcoming lunar (and beyond) missions. Among the first missions to be supported are the Artemis 1 Cubesats including Lunar IceCube, Lunar H-map, NEAScout, and CuSP, as well as the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) mission. The ground station is now furnished with new X-band transmission and reception capabilities , with the same signal processing for telemetry, tracking and command functions as those in the NASA Deep Space Network (DSN). Architecturally, the Morehead station appears just like any other DSN antenna, albeit with a different aperture size, transmitting power and receiving noise temperature. The Morehead station is considered as a DSN affiliated station. It can be scheduled to support DSN missions via a common DSN scheduling interface. As part of the effort to certify the system readiness to support Artemis 1 Cubesat mission operations, we tried to demonstrate the system performance with spacecraft that are currently in flight, to the extent possible. Validation of telemetry processing was relatively easy to accomplish by shadow tracking spacecraft scheduled for DSN tracking. These shadow passes were conducted on a non-interference basis to avoid impact to the missions. Performance metrics such as received carrier signal to noise ratio (SNR) was used to characterize the system G/T (Gain over Noise Temperature) of the Morehead antenna. Due to the difference in performance, e.g., smaller aperture and higher noise temperature, a limited number of passes have sufficient link margin for successful telemetry symbol synchronization and decoding at the Morehead station. In those cases, the received symbol SNR was also used for performance characterization, as a supplement to the carrier SNR.