Method and apparatus for pulsed-laser detection
First Claim
1. A method for determining the strength and proximity of a pulsed-laser radar signal which has been detected by a radar detection apparatus, said radar detection apparatus comprising a photodetector, a decision network coupled to the photodetector, a processor coupled to the decision network, and a threat indicator coupled to the processor, the method comprising:
- evaluating the detected signal with the decision network, said decision network generating an output pulse when the detected signal is a valid signal according to predefined criteria implemented in the decision network;
counting output pulses which occur for consecutive detected signals with the processor;
providing a look-up table in the processor having predetermined values therein;
looking up the count in the look-up table and generating a value which corresponds to the count; and
driving the output level of the threat indicator in proportion to the generated value.
20 Assignments
0 Petitions
Accused Products
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.
72 Citations
10 Claims
-
1. A method for determining the strength and proximity of a pulsed-laser radar signal which has been detected by a radar detection apparatus, said radar detection apparatus comprising a photodetector, a decision network coupled to the photodetector, a processor coupled to the decision network, and a threat indicator coupled to the processor, the method comprising:
-
evaluating the detected signal with the decision network, said decision network generating an output pulse when the detected signal is a valid signal according to predefined criteria implemented in the decision network; counting output pulses which occur for consecutive detected signals with the processor; providing a look-up table in the processor having predetermined values therein; looking up the count in the look-up table and generating a value which corresponds to the count; and driving the output level of the threat indicator in proportion to the generated value. - View Dependent Claims (2)
-
-
3. 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 signal according to predefined criteria which are implemented in the decision network; processing means coupled to the decision network, said processing means including means for counting output pulses which occur for consecutive detected signals, a look-up table having predetermined values therein, and means for looking up the count in the look-up table and generating a value which corresponds to the count; and a relative threat indicator coupled to the processing means, wherein the indicator generates an indication having a characteristic which is proportional to the generated value. - View Dependent Claims (4, 5, 6, 7, 8, 9)
-
-
10. An apparatus for detecting a valid pulsed-laser radar signal and for providing an indication of the relative strength and proximity of the detected signal, comprising:
-
a photodetector for detecting an optical signal and for converting it to an electrical signal; a first amplifier coupled to the photodetector for boosting the electrical signal thereby creating a first signal V1; an RC network coupled to the first amplifier for stretching the pulse width of the first signal V1 thereby creating a second signal V2; a second amplifier coupled to the first amplifier for extracting a DC offset from the first signal V1 thereby creating a third signal V3; a differential amplifier having a positive input coupled to the second signal V2 from the RC network, a negative input coupled to the third signal V3 from the second amplifier, and a threshold output; a first comparator having a first input coupled to the threshold output, a second input coupled to the second signal V2 from the RC network, and a first logic output A; a second comparator having a first input coupled to the threshold output, a second input coupled to the first signal V1 from the first amplifier, and a second logic output B; a microprocessor coupled to the first logic output A from the first comparator and to the second logic output B from the second comparator, said microprocessor being programmed to evaluate the timing of logical values on outputs A and B, wherein the microprocessor further comprises means to count consecutive valid pulsed-laser signals, means to store the count, and means to provide a statistical correlation to signal strength and signal proximity based on the count; and an alert indicator coupled to the microprocessor and having means for providing an alert indication that can vary in degree between a low level and a high level, wherein if output A is true and output B is false then a valid pulsed-laser signal is detected and the alert indicator is driven at a low level, and wherein the alert indicator is driven at a level that is determined by the statistical correlation of the count.
-
Specification