Automation of the G/T Characterization Measurements for DSS-17

Gain over System Noise Temperature (G/T) is a metric commonly used in radio frequency (RF) engineering to measure the performance of an antenna against the amount of noise contributing to the receiver's signal caused by its internal hardware. While the gain of an antenna is typically inferred geometrically by comparing signal strength of a given antenna to that of an isotropic antenna, system noise temperature must be found experimentally by calibrating the antenna to a black body radiator (in this case, the moon), and comparing the measured power on the black body to that when the antenna is aimed at cold sky. This comparison is measured several times and followed by a sweep in elevation to generate a tip curve which yields a measurement of atmospheric contribution to the signal. From here, G/T can be calculated. The traditional process of measuring system noise temperature introduces room for user error. Writing software which automates the G/T measurement procedure ensures that more accurate data is obtained and reduces the possibility of user error in the procedure. Using Systems Tool Kit (STK) to model Morehead State University's 21-meter deep space antenna, a privately-owned affiliated node on the Deep Space Network[1], as well as Python programming to generate pointing predicts[2], this automation will command DSS-17 to point on and off the moon without the need for users to input pointing commands during the test. This automation will function for both the X-band and S-band frequency feeds utilized on the antenna.