Test circuit for a pulsed-laser detector
First Claim
1. A pulsed-laser radar detection apparatus, comprising:
- a photodetector;
a decision network coupled to the photodetector, said decision network generating an output pulse when a signal detected by the photodetector is a valid pulsed-laser signal according to predefined criteria which are implemented in the decision network;
counting means for counting output pulses;
modulator means for generating a number N of simulated valid pulsed-laser signals, said modulator means being positioned in a field of view of the photodetector;
switching means connected in series with the modulator means for engaging the modulator means; and
means for comparing the number of output pulses counted by the counting means to the number N of pulses generated by the modulator means to determine whether the decision network is functioning properly.
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Abstract
A pulsed-laser radar detection apparatus includes a decision network coupled to a photodetector. The decision network generates an output pulse when a signal detected by the photodetector is a valid signal according to predefined criteria which are implemented in the decision network. An indicator provides an audible or visual indication that a valid signal has been detected. According to the present invention, a Q-switched modulator is provided in the field of view of the photodetector to generate a simulated valid signal. A test switch is connected in series with the modulator such that closing the test switch causes a simulated valid signal to be generated by the modulator.
43 Citations
5 Claims
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1. A pulsed-laser radar detection apparatus, comprising:
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a photodetector; a decision network coupled to the photodetector, said decision network generating an output pulse when a signal detected by the photodetector is a valid pulsed-laser signal according to predefined criteria which are implemented in the decision network; counting means for counting output pulses; modulator means for generating a number N of simulated valid pulsed-laser signals, said modulator means being positioned in a field of view of the photodetector; switching means connected in series with the modulator means for engaging the modulator means; and means for comparing the number of output pulses counted by the counting means to the number N of pulses generated by the modulator means to determine whether the decision network is functioning properly. - View Dependent Claims (2, 3)
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4. A pulsed-laser radar detection apparatus, comprising:
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a photodetector; a decision network coupled to the photodetector, said decision network generating an output pulse when a signal detected by the photodetector is a valid pulsed-laser signal according to predefined criteria which are implemented in the decision network; a microprocessor coupled to the decision network, said microprocessor including means for counting output pulses, means for generating a pulse train having a number N pulses, and means for comparing the number of output pulses counted by the counting means to the number of pulses N generated by the pulse train generating means to determine whether the decision network is functioning properly; switching means connected in series with the microprocessor for enabling the pulse train generating means; a field effect transistor having a gate, a source, and a drain, wherein the gate is connected to the pulse train generating means of the microprocessor and the source is connected to ground; a light emitting diode positioned in the field of view of the photodetector and having an anode and a cathode, wherein the anode is connected to the drain, said light emitting diode generating simulated valid pulsed-laser signals in response to said pulse train generating means; a capacitor having one terminal connected to the cathode and another terminal connected to ground; a power supply; and a resistor having one terminal connected to the cathode and another terminal connected to the power supply. - View Dependent Claims (5)
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Specification