Police traffic radar for calculating and simultaneously displaying fastest target speed
First Claim
1. A method of measuring the speed of moving targets in police traffic surveillance radar unit having at least two display windows, comprising the steps of:
- (1) transmitting a radar signal toward one or more moving targets;
(2) receiving a spectrum of radar return signals from moving and stationary objects, said stationary objects being defined as those objects which have no relative velocity with respect to said police traffic surveillance radar unit if said radar unit is not moving;
(3) calculating the speed of a moving target which has the strongest radar return signal which is not the radar return signal indicative of the speed that the police traffic surveillance radar unit itself is moving, said strongest radar return signal being found in said spectrum of radar return signals;
(4) calculating the speed of at least one of the fastest moving targets having a radar return signal in said spectrum of radar return signals; and
(5) displaying in a first of said at least two display windows the speed of the moving target having said strongest radar return signal which is not the radar return signal indicative of the speed that the police traffic surveillance radar unit itself is moving, and simultaneously displaying in a second of said at least two display windows the speed of one of the fastest moving targets determined in step (4) above.
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Accused Products
Abstract
A police radar utilizing digital data transmission from the antenna unit to a separately housed counting and display unit. The antenna has a double balanced mixer to suppress even order harmonics. The counting and display unit has a computer programmed to perform digital signal processing on the digital data received from the antenna to improve the quality and accuracy of calculated speeds for patrol speed, strongest target speed and fastest target speed. Fastest target speed can be displayed simultaneously with strongest target speed. Signal processing techniques are used to suppress false signals caused by double and triple bounce, harmonics, intermodulation products, video display terminal interference, etc.
91 Citations
18 Claims
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1. A method of measuring the speed of moving targets in police traffic surveillance radar unit having at least two display windows, comprising the steps of:
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(1) transmitting a radar signal toward one or more moving targets; (2) receiving a spectrum of radar return signals from moving and stationary objects, said stationary objects being defined as those objects which have no relative velocity with respect to said police traffic surveillance radar unit if said radar unit is not moving; (3) calculating the speed of a moving target which has the strongest radar return signal which is not the radar return signal indicative of the speed that the police traffic surveillance radar unit itself is moving, said strongest radar return signal being found in said spectrum of radar return signals; (4) calculating the speed of at least one of the fastest moving targets having a radar return signal in said spectrum of radar return signals; and (5) displaying in a first of said at least two display windows the speed of the moving target having said strongest radar return signal which is not the radar return signal indicative of the speed that the police traffic surveillance radar unit itself is moving, and simultaneously displaying in a second of said at least two display windows the speed of one of the fastest moving targets determined in step (4) above. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An police traffic radar apparatus, comprising:
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first means for transmitting radar energy using an antenna and receiving radar energy reflected as a result of said transmission using the same antenna and for converting said received radar energy into a lower frequency composite signal resulting from all reflected radar energy from stationary and moving targets which reflected said radar energy, said conversion accomplished while substantially eliminating even order harmonics in said composite signal, said composite signal being amplified by an amplifier in said first means having adjustable gain; counting and display means for calculating and displaying at least the speed at which said police traffic radar apparatus is moving and for calculating and displaying the speed of the moving target which has the strongest reflected radar signal that meets predetermined qualifications; second means coupled to said first means for adjusting the gain of said amplifier in accordance with data received from said counting and display means to keep the amplitude of said composite signal within predetermined limits; third means for digitizing said sample data and transmitting said digitized data as a serial data stream to said counting and display means; and fourth means in said counting and display means for calculating and simultaneously displaying with the speed of the moving target which has the strongest reflected radar signal that meets predetermined qualifications the speed of the fastest moving target which is reflecting radar energy so as to create a signal processed by said counting and display means that meets predetermined noise to signal power requirements and passes other predetermined qualification and disqualification tests. - View Dependent Claims (15, 16, 17, 18)
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Specification