High resolution range tracking circuit

Claim 2

In a high resolution range tracking circuit, the combination comprising: a. a stable oscillator for generating a sine wave output of a predetermined frequency; b. a first binary counter coupled to the output of said stable oscillator for producing a transmitter trigger pulse in response to a predetermined count of said stable oscillator output signal; c. a continuous phase shifter having an input coupled to the output of said stable oscillator and having an output; d. a second binary counter having an input coupled to the output of said continuous phase shifter and having an output; e. a tracking gate generator having an input coupled to the output of said second binary counter for generating a gating signal in response to a predetermined count of said stable oscillator output signal; f. radar receiver means for receiving echo signals from a target of interest; g. a gating circuit coupled to said radar receiver and to said tracking gate generator for allowing target signals from said radar receiver to pass when a gate signal is present from said target gate generator; h. feedback circuit means in circuit with said tracking gate generator, said radar receiver and said continuous phase shifter for maintaining the tracking gate generated by said tracking gate generator in coincidence with a selected target signal.

Claim 3

The range tracking circuit of claim 1 wherein said feedback circuit means includes a discriminator circuit having a first input coupled to said tracking gate generator, a second input coupled to said radar receiver and providing an output voltage proportional to the relative time of arrival of said tracking gate signals and said target signals.

Claim 4

The range tracking circuit of claim 2 wherein said feedback circuit means further includes a memory circuit coupled to and providing a continuous output voltage proportional to the rate of change of range of said tracking discriminator; a variable speed motor coupled to said continuous phase shifter and to the output of said velocity memory circuit for changing the speed of said continuous phase shifter in response to the output of said tracking discriminator.

Claim 5

The range tracking circuit of claim 2 wherein said discriminator circuit includes: a. a first detector channel that provides tracking correction signals when the signal to be tracked is separate and discernible and provides an enabling pulse when the signal to be tracked is not separate and discernible; b. a second detector channel coupled to said first detector channel and being responsive to said enabling pulse to continue to provide tracking correction signals until the signal to be tracked is discernible.

Claim 6

The range tracking circuit of claim 2 wherein said discriminator comprises: a. a first gated detector having a first input coupled to the output of said tracking gate generator, a second input coupled to the output of said radar receiver and having an output; b. a second gated detector having a first input coupled to the output of said tracking gate generator, a second input coupled through a delay circuit to said radar receiver and having an output; c. a first gated amplifier having a first input coupled to the output of said first gated detector, a second input and an output; d. a second gated amplifier having a first input coupled to the output of said second gated detector, a second input and an output; e. a comparator circuit having a first input coupled to the output of said first gated detector, a second input coupled to the output of said second gated detector and output; f. an astable multivibrator having an input coupled to the output of said comparator circuit and having a first output coupled to the second inputs of said first and second gated amplifiers and having a second output; g. a third gated detector having a first input coupled to the output of said radar receiver a second input and an output; h. a fourth gated detector having a first input coupled through a delay circuit to the output of said radar receiver, a second input and an output; i. a third gated amplifier having a first input coupled to the output of said third gated detector, a second input coupled to the second output of said astable multivibrator and an output; j. a fourth gated amplifier having a first input coupled to the output of said fourth gated detector, a second input coupled to the second output of said astable multivibrator, and an output; k. a video to binary converter coupled to said radar receiver and to the second inputs of said third and fourth gated detectors to provide tracking information while said first and second gated amplifiers are gated off and said third and fourth gated amplifiers are gated on.

Claim 7

The range tracking circuit of claim 1 wherein a jitter compensation circuit means is coupled to said first and second binary counters and to said tracking gate generator to provide jitter compensation on a cycle by cycle basis in responsE to the transmitted pulse.

Claim 8

The tracking circuit of claim 6 where said jitter compensation circuit means includes: a. a transmitter tube modulated by a delayed signal from said first binary counter; b. a first sweep generator being turned on by the output of said first binary counter and being turned off by the firing of said transmitter tube; c. boxcar detector means coupled to said first sweep generator for producing an output signal whose peak amplitude is proportional to the intentional delay plus the delay caused by jitter; d. a second sweep generator coupled to the output of said second binary counter for producing a sweep identical to the sweep of said first sweep generator; e. a multiar circuit coupled to said boxcar detector means and said second sweep generator for generating an output trigger pulse when the rise of the sweep voltage from said second sweep generator equals the output signal from said boxcar detector means.

Claim 9

The range tracking circuit of claim 2 wherein said discriminator comprises: a. a plurality of gated detectors; b. a plurality of gated amplifiers; c. each of said gated detectors having an input coupled to said radar receiver; d. analog circuit means including a position memory circuit coupled between said gated detectors and said gated amplifiers for tracking a memorized point within the overall target signal.