SIGNAL-TO-NOISE DETECTOR FOR NON-STABILIZED DOPPLER RADAR

摘要

An improved signal-to-noise detector is provided for inclusion in the frequency trackers used in Doppler aircraft radar systems. The signal-to-noise detector of the invention samples noise over the entire pass band of the frequency tracker input except for a range of frequencies above and below the tracking frequency of the local oscillator. In this way, should the system attempt to lock onto a side lobe or image return, rather than the true Doppler return, the Doppler return would cause the noise level to rise, so that the system could not lock onto the spurious return, and in this way erroneous tracking is prevented.