Radar signal analyzing system

Claim 2

In a moving target detection apparatus, a system for analyzing a sequence of signals whose amplitude envelope varies with the doppler information derived from a moving target, said system comprising: means to store said sequence of signals, means to repeatedly read out said stored signals during a plurality of equal duration readout intervals, means to produce a succession of analyzing signals each having a duration equal to one of said readout intervals, means to stepwise vary the frequencies of said succession of analyzing signals, means to continuously vary the freqUencies of said succession of analyzing signals, means to mix said repeatedly readout signals with said succession of frequency signals; and filter means to receive the output from said mixer means and to pass a signal whenever the instantaneous frequency of the readout signals differs from the instantaneous frequency of the analyzing signals by a frequency which is passed by said filter.

Claim 3

The system of claim 1 wherein the means to continuously vary the frequencies of the analyzing signals comprises means to repeatedly sweep these frequencies at constant rates which vary from one readout interval to the next.

Claim 4

The system of claim 2 including means to synchronize the sweeps of the analyzing frequencies so that the beginning of each sweep coincides with readout of the oldest signal in said storing means.

Claim 5

The system of claim 1 including means to modulate the amplitude of said readout signals before said signals are mixed with said analyzing signals.

Claim 6

The system of claim 1 wherein the stored signals are read out at a rate higher then the rate at which they are stored.

Claim 7

The system of claim 1 wherein the means to produce analyzing signals comprises a variable frequency oscillator whose frequency varies in response to two voltage inputs.

Claim 8

In a moving target detection apparatus, a system for simultaneously analyzing a plurality of sequences of signals whose amplitude envelopes vary with the doppler information derived from moving targets at an equal plurality of range intervals, said system comprising: a plurality of storage means for separately storing said pluralities of sequences of signals, means for repetitively reading out said stored signals into a plurality of analyzing channels with each channel corresponding to a particular one of said plurality of range intervals. a variable frequency oscillator for generating a sequence of frequencies, a plurality of mixer means, one for each said analyzing channels, for simultaneously receiving the signals readout from said storage means, a plurality of filters, one for each said analyzing channels, for passing a predetermined range of frequencies, said pluralities of filters receiving the outputs of said plurality of mixer means for passing difference frequencies from said mixers whenever these difference frequencies fall within said predetermined range of frequencies.

Claim 9

In a moving target detection apparatus, a system for simultaneously analyzing a plurality of sequences of signals whose amplitude envelopes vary with the doppler information derived from moving targets at an equal plurality of range intervals, said system comprising: a plurality of storage means for separately storing said pluralities of sequences of signals, means for repetitively reading out said stored signals into a plurality of analyzing channels with each channel corresponding to a particular one of said plurality of range intervals. a variable frequency oscillator for generating a sequence of frequencies, a plurality of mixer means, one for each said analyzing channels, for simultaneously receiving the signals readout from said storage means, a plurality of filters, one for each said analyzing channels, for passing a predetermined range of frequencies, said pluralities of filters receiving the outputs of said plurality of mixer means for passing difference frequencies from said mixers whenever these difference frequencies fall within said predetermined range of frequencies.

Claim 10

The system of claim 7 wherein the frequency of the variable frequency oscillator is held constant during certain complete readouts of said stored signals and varies continuously during other complete readouts of said stored signals.

Claim 11

The system of claim 7 including two sources of variable input voltage connected to said variable frequency oscillator to vary the frequency thereof.

Claim 12

The system of claim 9 wherein the first of said two sources of variable input voltage is a staircase generator.

Claim 13

The system of claim 10 wherein the second of said two sources of variable input voltage is a sawtooth generator.