Abstract: A method for determining an angle of incidence of periodic optical signals is provided. The method includes detecting whether the periodic optical signals are present; generating a pulsed output when the periodic optical signals are present, the pulsed output corresponding to peaks in the periodic optical signals; predicting a timing of the periodic optical signals from the pulsed output; controlling a gated detector array to take a first reading and a second reading of the periodic optical signals based upon the timing, the first reading being out of phase with the timing and the second reading being in phase with the timing; and generating the angle of incidence by filtering the first reading from the second reading.

Abstract: A combat maneuver training system includes a shooter platform (1) and a target platform (2). A first step is performed at the shooter platform, and operates a rangefinder (18) to determine a laser range of a shooter platform weapon (1A). At the target platform, the operation of the rangefinder is detected, and a controller (10) of the target platform transmits a current location (e.g. from GPS) of the target platform. At the shooter platform, when the target platform is in range, the controller (10) calculates an impact point of a simulated ordinance on the target platform and an impact time, and then transmits this and other information to the target platform. Meanwhile, an operator of the target platform, detecting the rangefinding operation, begins to maneuver the target platform to evade the simulated ordinance.

Abstract: An energy beam threat discrimination system (110) adapted for use with laser beam energy (134). The system (110) includes an first detector (114) for detecting a first laser signal. A second detector (112) detects a coherent laser signal. A timer circuit (124, 126) establishes a time interval between the detection of the first laser signal and the detection of the coherent laser signal and provides an output (130) in response thereto. A control circuit (128, 130) determines, based on the output (130), if the first laser signal and/or the second laser signal is threatening. In a specific embodiment, the first detector (114) provides an event detection flag (118) as an output in response to the detection of a first laser signal. The first detector (114) includes a high sensitivity laser light detector (142), a pre-amplifier (144), and an analog threshold circuit (146). The coherent detector (112) provides a coherent detection flag (116) as an output in response to the detection of the coherent laser signal.

Abstract: This invention relates to unequal path interferometers which are adapted, among other possible uses, for use in detecting coherent radiation as from a laser in a packet of radiation including incoherent background radiation, which includes an unequal optical path length interferometer of the type in which portions of the radiation impinging on the interferometric component are caused to be recombined after travelling two different optical paths; the optical paths differing in length by an amount substantially greater than the coherence length of the non-coherent radiation but substantially less than the coherence length of the coherent radiation; the unequal optical path length interferometric component including a crystalline cell having anisotropic properties; circuitry for applying an ultrasonic sound wave to the crystalline cell to vary the effective index of refraction of the crystalline cell in a preselected systematic manner; a detector for detecting the intensity of the recombined portions and produci