Abstract: A method and apparatus for synchronized clocking between a radar receiver and a radar transmitter includes sharing a reference signal between the transmitter and receiver, dividing the common reference into a transmit clock signal in the transmitter and a receive clock signal in the receiver. The receive clock signal and the transmit clock signal are synchronized using a trigger pulse. The synchronization is performed to achieve a 180 degree phase shift between the transmit and receive clocks. Radar pulse transmissions occur on an edge of the transmit clock coinciding with the trigger pulse. A signal recorder is activated on the edge of the receive clock each time the trigger pulse is received. The signal recorder is deactivated after a fixed interval based upon the receiver clock signal.

Abstract: A method for removing clutter related frequency components from power spectrums generated from weather radar return signals to provide improved windshear detection capability. Weather radar return signals are synchronously detected and digitized to provide i and q time domain sample sequences. The i and q time domain sample sequences are passed through a window function and then transformed to frequency domain sequences by a Fast Fourier Transform. A power spectrum is generated from the frequency domain sequences. The spectrum is subjected to a Spectral Gaussian Envelope Discrimination (SGED) process in which the spectral envelope is scanned to identify any lobe therein having a slope greater than a predetermined minimum. A first pseudo-Gaussian sigma, calculated from the width and maximum amplitude of any such lobe, is compared with a second pseudo-Gaussian sigma, calculated from known conditions.

Abstract: A radar utilizes an antenna stabilization error correction system to automatically estimate and correct attitude sensor errors in pitch, roll and elevation. The radar system includes an antenna, an antenna positioner, a transmitter receiver, a signal processor, an antenna controller and stabilization processor and the antenna stabilization error correction system. As part of the normal signal processor sub function, ground clutter signals are extracted from the received signals. These signals are the primary input to the antenna stabilization error correction system. Other inputs are received from the signal processor, antenna controller and stabilization processor and an external aircraft radio altimeter. The antenna stabilization error correction system processes the signals and estimates pitch, roll and elevation errors which are passed back to the antenna controller and stabilization processor.