Abstract: A synthetic aperture radar (SAR) which operates at UHF frequencies and which includes a two element antenna. The SAR generates a null in the backlobe of the antenna pattern at the location of a target which is steered rather than trying to obtain directivity in the mainlobe. Both analog and digital implementations are provided. In the analog approach, required phase shifts are performed at a frequency higher than the RF output frequency and the receive and transmit nulls are steered separately to increase the width of the null so as to allow for wider SAR swaths. The digital implementation involves steering the null only on receive and multiplying fast time samples by a complex phase correction similar to that used in the analog approach to form the beam. The phase correction is also performed prior to range resolution which employs "stretch" processing, so as to achieve high range resolution.

Abstract: The present invention is a radar system that detects turbulence by breaking a range cell return down into spectral segments using an FFT processor. The standard deviation of the spectrum is determined and the system compares that standard deviation to a reference threshold of a non-turbulent return if the signal is above noise. If the threshold is exceeded, the range cell is marked for turbulence display. Once the turbulence display is completed it is overlayed on the weather display. To improve matching of the feature size to the variance calculation the invention performs both range and azimuth post detection integration subsequent to the FFT but before variance calculation.

Abstract: A system for real beam radar ground mapping using a monopulse antennae to determine off-boresight angle of target returns. Off-boresight angle is converted to azimuth bins. After processing, return energy for each contiguous azimuth bin of an illuminated area is dumped during a respective "look" of the antenna.