Abstract: A method and system for phased array radar antenna calibration to be made in flight employs a synthesized initial transmission signal having a notch in the main direction of beam. This has the effect of returning reflected receiver signals that are main lobe clutter free, but contain clutter returned solely from the sidelobe radiation. The received clutter data is processed to yield a set of coefficients that, when combined with subsequent radar signal return resulting from a signal having a main lobe, provides a return signal that is free from aircraft induced distortions and misalignments that can result in sidelobe induced false alarms. All data processing is conducted in the time domain rather than the frequency domain, thus, avoiding Doppler frequency foldover problems due to ambiguities from signals received at multiple aspect angles.

Abstract: An arrangement for detecting quadrature phase errors introduced by a synchronous demodulator between the two quadrature channels, in-phase (I) and quadrature-phase (Q), of a synchronous demodulator, and for correcting for such detected quadrature phase errors without the need for high data sampling rates. During an initial test period, a periodic symmetrical test signal of known frequency is introduced into the synchronous demodulator. During the test period, the output of the synchronous demodulator is integrated over an integer multiple of periods to detect the quadrature phase error introduced by the synchronous demodulator, and an error signal is generated representative of the detected quadrature phase error. During a following period of operation of the synchronous demodulator, the in-phase (I) and quadrature-phase (Q) signals produced by the synchronous demodulator are applied to a quadrature phase error correction network, along with the generated quadrature phase error signal.

Abstract: An apparatus for combining signals from a plurality of radar installations is described. A methodology for combining signals from a pluraltiy of radar installations/sensors has been developed. This methodology provides enhanced target detection performance by properly fusing together the commensurate range-Doppler filter bins of each sensor. In this methodology, the processing of each of the individual radars in the Doppler frequency domain is provided such that a common velocity domain is obtained from each of the radars. Using a zero fill discrete Fourier transform, the velocity domain obtained from each radar is further normalized to have a common bin size. Additionally, for the higher frequency radars, the normalized velocity bins are unfolded so that each radar signal produces the same number of velocity bins in its respective velocity domain.