The microwave imaging radiometer sample and integration time

In a microwave imaging radiometer system the antenna foot-print moves across the scene to be sensed, which corresponds to a convolution of the antenna pattern with the brightness temperature distribution of the scene in mathematical terms. During the imaging procedure, there are several factors which will influence the spatial resolution of the final radiation image: the low pass filtering effect of the antenna pattern, the blurring from the radiometer integrator and the spatial frequency overlap may be caused by sampling. The best resolution could be obtained by compromising between all factors. In general, when a signal with unknown spatial frequency content is to be sampled, a low pass filter must be applied during measurement in order to avoid the overlap of the signal spectrum. From this point of view, the low pass filtering effect of the antenna pattern and the radiometer integrator is beneficial. Additionally the highest spatial frequency that could be restored is the cut-off frequency of the low pass filter.