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.

Abstract: A method and apparatus for determining the strength and proximity of a pulsed-laser radar signal is provided. A photodetector detects signals and provides the signals to a decision network. The decision network evaluates the signals and generates an output pulse when a detected signal is a valid signal according to predetermined criteria implemented in the decision network. A processor is coupled to the decision network for counting output pulses. A threat indicator is driven by the processor in proportion to the output pulse count.

Abstract: A photodetector receives an optical signal and converts it an electrical signal. A pulse stretcher converts the electrical signal into a first signal which is characterized by having an increased pulse width relative to the electrical signal. A noise averager converts the electrical signal into a second signal which is representative of the average noise component of the electrical signal. A threshold reference is generated as a linear function of the potential difference between the first signal and the second signal. A first comparator compares the magnitude of the first signal and the threshold reference signal and generates a first logic output which is true if the magnitude of the first signal is greater than the magnitude of the threshold reference signal.

Abstract: Sense voltages representative of transmitter power and the temperature of the transmitter output stage are summed and fed to the input of a high gain amplifier. The output of the amplifier provides bias to the transmitter driver stage and, thus, controls the total transmitter developed power. The resulting overall feedback system provides precise transmitter power control and output stage thermal protection.