Precision DSN radiometer systems: impact on microwave calibrations

摘要: The NASA Deep Space Network (DSN) has a long history of providing large parabolic dish antennas with precision surfaces, low-loss feeds, and ultra-low noise amplifiers for deep-space telecommunications. To realize the benefits high sensitivity, it is important that receiving systems are accurately calibrated monitored to maintain peak performance. A method described measure system performance calibrate using procedures, software, commercial instruments easy implement efficient use. utility measurement procedures receiver calibration technique were demonstrated by performing tests at Ka-band (32 33.68 GHz) frequencies Goldstone on 34-m beam-waveguide antenna. Observations multiple radio sources used dependence antenna gain temperature source elevation derive parameters. experimental results illustrate some ways nonlinearity can negatively impact simple radiometer analysis provide quantitative information enables engineer adjust linearize system. When not practical, experimenter or operator apply connection coefficients measured values thereby compensate nonlinearity. >