A general signal-level simulator for aperture synthesis radiometers

Aperture synthesis technique is a feasible means to provide high spatial resolution at low frequencies. But due to the impacts of system errors, time varying scenes, and different inversion algorithms, analytic studies of system performances are difficult or impossible, and the need of numerical simulation appears. In this paper, a signal-level simulator is presented. It covers brightness temperature generator, the process of antenna array collecting thermal radiation and transforming thermal radiation signal to RF signal, amplifying and filtering of receivers, complex cross-correlation, and inversion. Simulations are conducted, and the results demonstrate the validity of the simulator. The simulator provides a means to assess measurement accuracy and sensitivity, as well as to evaluate the calibration approach, investigate the inversion robustness in front of errors and so on.