Multiple target indicator and discriminator

Claim 2

In a radar of the sequential lobe type wherein a radar signal is transmitted and received by antenna means, and the received radar signal is a composite signal containing a phase modulated signal component caused by multiple targets occurring within one radar beamwidth, a multiple target indicator comprising, detection means connected to said composite signal for producing an output signal derived from said phase modulated signal component, and indicating means connected to receive said detecting means output signal and producing a signal indicative of the presence of muultiple targets.

Claim 3

The apparatus of claim 1 wherein said sequential lobe radar includes means for producing a signal representative of a tracking angle error and further including, means connected to receive said detection means output signal for producing a tracking angle error bias signal, multiple signal adding means for producing an output signal representing the sum of said tracking angle error bias signal and said tracking angle error signal, and antenna positioning means responsive to said signal adding means output signal for positioning said antenna means so that said radar tracks only one of said multiple targets.

Claim 4

The apparatus of claim 1 wherein said sequential lobe radar includes means responsive to said composite radar signal and producing therefrom a first output signal representative of traverse tracking angle error and a second output signal representative of elevation tracking angle error, wherein said detection means comprises first synchronous detection means producing a traverse angle error bias output signal and second synchronous detection means producing an elevation angle error bias output signal, and further including, first signal adding means connected to receive and add together said traverse tracking angle error signal and said traverse angle error bias signal for producing an output signal, second signal adding means connected to receive and add together said elevation tracking angle error sIgnal and said traverse angle error bias signal for producing an output signal, and antenna positioning means responsive to the output signals from said first and second signal adding means output signal for positioning said antenna means so that said radar tracks only one of said multiple targets.

Claim 5

The apparatus of claim 3 wherein said means producing a first and second tracking angle error signal includes a Doppler frequency tracker containing a phase detector connected to receive said composite signal and an oscillator responsive to output signals from said phase detector, said oscillator producing output signals which are fed back to said phase detector and said phase detector output signal representing a phase difference between said oscillator output signal and said composite signal and further including, an interconnection between said phase detector output signal and said first and second synchronous detection means for providing an input signal representing said phase modulation component to said first and second synchronous detection means.

Claim 6

In a radar of the sequential lobe type wherein a radar signal is transmitted and received by antenna means, and the received radar signal is a composite signal containing an amplitude modulated signal component cause by multiple targets occurring within one radar beamwidth, a multiple target indicator, comprising first detection means connected to said composite signal for producing an output signal derived from said amplitude modulated signal component, and indicating means connected to receive said first detection means output signal for producing a signal indicative of the presence of multiple targets.

Claim 7

In a radar of the sequential lobe type wherein a radar signal is transmitted and received by antenna means, and the received radar signal is a composite signal containing an amplitude modulated signal component cause by multiple targets occurring within one radar beamwidth, a multiple target indicator, comprising first detection means connected to said composite signal for producing an output signal derived from said amplitude modulated signal component, and indicating means connected to receive said first detection means output signal for producing a signal indicative of the presence of multiple targets.

Claim 8

The apparatus of claim 5 wherein said sequential lobe radar includes means for producing a signal representative of a tracking angle error and further including, means connected to receive said first detection means output signal for producing a tracking angle error bias signal, signal adding means for producing an output signal representing the sum of said tracking angle error bias signal and said tracking angle error signal, and antenna positioning means responsive to said signal adding means output signal for positioning said antenna means so that said radar tracks only one of said multiple targets.

Claim 9

The apparatus of claim 5 wherein said sequential lobe radar includes means responsive to said composite radar signal and producing therefrom a first output signal representative of tracking angle error and a second output signal representative of elevation tracking angle error, wherein said first detection means comprises, paraphase amplifier means connected to receive said composite signal producing first and second output signals, said first and second signals being in an anti-phase relationship, first synchronous detection means connected to receive said first and second paraphase amplifier output signals producing a traverse angle error bias signal, and second synchronous detection means connected to receive said first and second paraphase amplifier output signals producing an elevation angle error bias signal, and further including, first signal adding means connected to receive and add said traverse tracking angle error signal and said traverse tracking angle bias signal for producing an output signal, second signal adding means connected to receive and add said elevation tracking angle error signal and said elevation tracking angle bias signal for producing an output signal, and antenna positioning means responsive to the output signals from said first and second signal adding means output signal for positioning said antenna means so that said radar tracks only one of said multiple targets.

Claim 10

The apparatus of claim 7 wherein said means producing first and second tracking angle error signals includes an envelope detector and further including, an interconnection between said envelope detector and said paraphase amplifieR for providing said amplitude modulated signal component to said paraphase amplifier.

Claim 11

The apparatus of claim 5 wherein said composite radar signal also contains a phase modulated signal component caused by multiple targets occurring within one radar beamwidth and further including, second detection means connected to said composite signal for producing an output signal when the presence of said phase modulated signal component is detected in said composite signal, and indicating means connected to receive said second detection means output signal for producing a signal indicative of the presence of multiple targets.

Claim 12

The apparatus of claim 9, wherein said sequential lobe radar includes means responsive to said composite signal for producing therefrom a signal representative of a tracking angle error and further including, means connected to receive the output signal from said first detection means for producing a tracking angle error bias signal derived from said amplitude modulated signal component, means connected to receive the output signal from said second detection means for producing a tracking angle error bias signal derived from said phase modulated signal component, switching means having an input connected to receive said composite signal and having a first output connected to said first detection means and a second output connected to said second detection means for selectively connecting said input to one or the other of said first and second outputs, signal adding means for producing an output signal representing the sum of said tracking angle error bias signal and said switching means output signal, and antenna positioning means responsive to said signal adding means output signal for positioning said antenna means so that said radar tracks only one of said multiple targets.