MOVING TARGET INDICATOR WITH NO BLIND SPEEDS

Abstract

A moving target indicating system wherein a pulse source which generates radiofrequency drive pulses at a predetermined pulse repetition frequency is connected to the inputs of a pair of channels. The first channel includes a phase-dispersive filter having a first phase-slope dispersion characteristic, while the second channel has a phase-dispersive filter having a phase-slope dispersion characteristic which is the negative of that of the first filter. A pulse group comprising the output of the first and the second channels is transmitted periodically as each drive pulse is applied. The pulse repetition frequency is sufficiently low that when transmitted, echos of only one pulse of each group are received at a time. Due to the "matched" or "conjugate" phase-dispersive characteristics of the filters in the respective channels, the first channel operates in reception upon the reflected pulse originally generated in the second channel and compresses it thus resynthesizing or reconstituting a short duration pulse like the original, while the second channel operates in reception upon the reflected pulse generated in the first channel, compressing it to reconstitute a short duration pulse like the original. A canceler is switched between the outputs of the first and second channels to receive the two resulting reconstituted pulses of each group. In the usual application, fixed target information is cancelled out and moving target information is derived for application to a display device.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1BERNARD L. LEWIS