Method of Telemetry, Tracking and Control Monopulse System Simulation and Evaluation in Jamming

To evaluate the performance of spacecraft angle measurement in jamming, a method of TT&C (Telemetry, Tracking, and Control) monopulse system analysis is proposed in the condition that antenna keeps tracking the target. First, a geometric model of large aperture parabolic antenna is established, and the antenna patterns of sum, azimuth difference and elevation difference channel are derived through EM computation. Next, the positions and the simultaneous visibility of spacecraft and jammer are derived with orbit computation software. Then, formulae to calculate the positions of jammer in the antenna pattern, i.e. the angle of nutation and procession, are derived and used. Once again, according to the positions of spacecraft and jammer that relative to the ground station, the expressions to estimate the power of signal, internal noise, jamming are suggested, which are used to calculate the SNR and correlation coefficient. At last, the performance of the TT&C monopulse system of fix target and single observation is discussed. And the validity and feasibility of the method are verified with BD-2A as the target and X37-B as the Jammer. The proposed method realizes a kind of full path simulation which contains antenna pattern and its sidelobe, motion of target spacecraft and jammer, internal noise of receiver. It is more practical in engineering analysis.