Collision avoidance system

Claim 2

In a radar indicator system wherein an echo signal is represented by intensification of a cathode ray beam of said indicator and said system includes system synchronizer means providing synchronizing signals for synchronizing the start of the indicator deflection sweep wave for deflecting said cathode ray beam, means for intensifying said beam comprising: echo signal receiver means having output means, signal generator means having first and second input means and first and second output means, first delay circuit means for coupling said receiver output means to said signal generator input means, second circuit means for cyclically applying to said signal generator second input means synchronizer signals from said system synchronizer means, third circuit means controlled by said receiver output means coupled to said signal generator second input means, means for applying an output of said signal generator first output means for enabling said third circuit means, means for applying an output of said signal generator second output means for causing said third circuit means when enabled to produce a signal, and means for applying an output of said signal generator second output means to intensify said beam of said radar indicator.

Claim 3

Apparatus as described in claim 1 wherein: said signal generator means comprises bistable means, said signal generator first input means comprises SET means for said bistable means, and said signal generator second input means comprises RESET means for said bistable means.

Claim 4

Apparatus as described in claim 2 wherein said third circuit means comprises: converter means for converting the time of occurrence of said echo signal relative to said synchronizing signal into an analog signal, first sweep generator means triggered by the said signal generator second output means for providing an output sweep wave, and comparator means for comparing the amplitudes of said analog signal and said output sweep wave for producing an output signal substantially during equality thereof.

Claim 5

Apparatus as described in claim 3 wherein said converter means comprises: range sweep generator means triggered by said synchronizing signal and providing a range sweep wave, and sample and hold circuit means having first and second input means and output means, said first and second input means of said sample and hold circuit means being respectively supplied with said echo signal and said range sweep wave.

Claim 6

Apparatus as described in claim 2 wherein said echo signal receiver means includes variable amplitude threshold circuit means for selectively passing signals only above a selected amplitude to said first delay means and to said third circuit means.

Claim 7

Apparatus as described in claim 2 wherein said second circuit means includes OR gate means having first and second input means, said first and second OR gate input means being respectively coupled to said system synchronizer and to the output of said third circuit means.

Claim 8

Apparatus as descrIbed in claim 2 wherein said third circuit means includes first AND gate means enabled by the first output means of said signal generator means.

Claim 9

Apparatus as described in claim 2 wherein said means for applying an output of said signal generator second output means to intensify said beam includes second AND gate means having first and second input means and output means coupled to the intensifier grid of said indicator.

Claim 10

Apparatus as described in claim 8 including means for enabling said second AND gate during whole, time-separated paintings of displays on said cathode ray indicator.

Claim 11

Apparatus as described in claim 8 including: azimuth scanning antenna means, deflection means cooperating with said indicator and driven in synchronism with said antenna means, switch means operated in synchronism with said antenna means for storing representations of echo signals received during a first complete painting scan interval of said indicator on said indicator screen, for inhibiting painting during a first subsequent interval substantially equal to said first interval, and for storing on said indicator screen representations of echo signals received during a painting scan interval subsequent to said first subsequent interval and substantially equal to said first interval.

Claim 12

In a radar indicator system wherein an echo signal is represented by intensification of a cathode ray beam of said indicator and said system includes system synchronizer means providing synchronizing signals for synchronizing the start of the indicator deflection sweep wave for radially deflecting said cathode ray beam, means for intensifying said beam comprising: threshold circuit means having output means for selectively passing said echo signals only when greater than a predetermined amplitude, bistable means having SET and RESET input means and first and second output means, delay means coupled between said threshold circuit output means and said SET input means, circuit means for connecting said system synchronizing signals to said RESET input means, AND gate means having first and second input means and output means, circuit means for connecting said threshold circuit output means to said first input means of said AND gate means, circuit means for connecting said first output means of said bistable means to said second input means of said AND gate means, first sweep generator means triggered by said system synchronizing signals and having output means, sample and hold means having first and second input means, circuit means for supplying the output of said AND gate means to said first input means of said sample and hold means, circuit means for supplying the output of said first sweep generator means to said second input means of said sample and hold means, comparator means having first and second input means, circuit means for supplying an output of said sample and hold means to said first input of said comparator means, second sweep generator means responsive to said bistable means second output means, circuit means for supplying an output of said second sweep generator means to said second input of said comparator means, means for providing an output of said comparator means to said RESET input means, and means for connecting said second output of said bistable means to said indicator for intensifying said cathode ray beam.

Claim 13

In a radar indicator system wherein an echo signal is represented by intensification of a cathode ray beam of said indicator and said system includes system synchronizer means providing synchronizing signals for synchronizing the start of the indicator deflection sweep wave for radially deflecting said cathode ray beam, means for intensifying said beam comprising: threshold circuit means having output means for selectively passing said echo signals only when greater than a predetermined amplitude, bistable means having SET and RESET input means and first and second output means, delay means coupled between said threshold circuit output means and said SET input means, circuit means for connecting said system synchronizing signals to said RESET input means, AND gate means having first and second input means and output means, circuit means for connecting said threshold circuit output means to said first input means of said AND gate means, circuit means for connecting said first output means of said bistable means to said second input means of said AND gate means, first sweep generator means triggered by said system synchronizing signals and having output means, sample and hold means having first and second input means, circuit means for supplying the output of said AND gate means to said first input means of said sample and hold means, circuit means for supplying the output of said first sweep generator means to said second input means of said sample and hold means, comparator means having first and second input means, circuit means for supplying an output of said sample and hold means to said first input of said comparator means, second sweep generator means responsive to said bistable means second output means, circuit means for supplying an output of said second sweep generator means to said second input of said comparator means, means for providing an output of said comparator means to said RESET input means, and means for connecting said second output of said bistable means to said indicator for intensifying said cathode ray beam.