Abstract: A system, device, apparatus and method for receiving a laser signal such as within a LADAR receiver.

Abstract: A system, device, apparatus and method for receiving a laser signal such as within a LADAR receiver.

Abstract: Ladar systems and methods are provided. One embodiment is a ladar system comprising: a chirp generator for generating a chirped waveform; a laser for transmitting a light signal toward a target, the light signal being modulated by the chirped waveform; and a photon-counting sensor for receiving a temporally-modulated photon stream corresponding to the modulated light signal being reflected from the target and toward the ladar system, the photon-counting sensor gated relative to the chirped waveform.

Abstract: An imaging method and apparatus using an unmodulated pulsed laser with a chirp modulated receiver is provided for producing 3D plus intensity imagery of targets in heavily cluttered locations The apparatus includes a laser for emitting a laser beam and synchronizing a receiver to receive a reflected laser signal and transform the reflected laser signal into a displayable image that includes intensity information.

Abstract: An imaging method and apparatus using an unmodulated pulsed laser with a chirp modulated receiver is provided for producing 3D plus intensity imagery of targets in heavily cluttered locations The apparatus includes a laser for emitting a laser beam and synchronizing a receiver to receive a reflected laser signal and transform the reflected laser signal into a displayable image that includes intensity information.

Abstract: Ladar systems and methods are provided. One embodiment is a ladar system comprising: a chirp generator for generating a chirped waveform; a laser for transmitting a light signal toward a target, the light signal being modulated by the chirped waveform; and a photon-counting sensor for receiving a temporally-modulated photon stream corresponding to the modulated light signal being reflected from the target and toward the ladar system, the photon-counting sensor gated relative to the chirped waveform.

Abstract: A system and method for performing high-resolution imagery of a target are provided. One embodiment is a method of performing high-resolution imagery of a target comprising: generating a chirped waveform that modulates a light signal transmitted toward a target for performing active LADAR of the target; generating a low-frequency local oscillator waveform for performing active imaging; and simultaneously performing passive imaging and active LADAR.

Abstract: A high range resolution ladar includes a chirp generator for producing a chirp signal waveform that is used by a laser diode to propagate a divergent laser light waveform. The reflected light signals from the target are directed to a self mixing detector that is coupled to the chirp generator where the responsivity of the detector varies in accordance with the chirp waveform for converting reflected light signals from the target to electrical signals and for mixing the converted electrical signal with the chirp waveform to produce an output electrical signal whose frequency is proportional to the range to the target. The self-mixing detector includes at least one detector having a semiconductor substrate and first and second electrodes deposited on the substrate and spaced from each other, wherein the first set of electrodes is connected to the chirp generator and the second set of electrodes is connected to a memory for storing a plurality of frames of image data.

Abstract: A method and apparatus of a plurality of detecting elements for detecting and producing an image of an object includes a signal generator for generating a waveform signal, a laser for producing a light signal modulated by the waveform signal, and a mixing and detecting device coupled to and driven by the signal generator for converting reflected light signals received from the target into electrical signals and for mixing the converted electrical signals with the waveform signal to produce an output electrical signal. A read-out is connected to the mixing and detecting device for removing the output electrical signals from the mixing and detecting, and a signal processor is connected to the read-out for processing the output electrical signals from the read-out to detect and produce and image of the object.

Abstract: A high range resolution ladar includes a chirp generator for producing a chirp signal waveform that is used by a laser diode to propagate a divergent laser light waveform. The reflected light signals from the target are directed to a self mixing detector that is coupled to the chirp generator where the responsivity of the detector varies in accordance with the chirp waveform for converting reflected light signals from the target to electrical signals and for mixing the converted electrical signal with the chirp waveform to produce an output electrical signal whose frequency is proportional to the range to the target. The self-mixing detector includes at least one detector having a semiconductor substrate and first and second electrodes deposited on the substrate and spaced from each other, wherein the first set of electrodes is connected to the chirp generator and the second set of electrodes is connected to a memory for storing a plurality of frames of image data.

Abstract: A method and apparatus of a plurality of detecting elements for detecting and producing an image of an object includes a signal generator for generating a waveform signal, a laser for producing a light signal modulated by the waveform signal, and a mixing and detecting device coupled to and driven by the signal generator for converting reflected light signals received from the target into electrical signals and for mixing the converted electrical signals with the waveform signal to produce an output electrical signal. A read-out is connected to the mixing and detecting device for removing the output electrical signals from the mixing and detecting, and a signal processor is connected to the read-out for processing the output electrical signals from the read-out to detect and produce and image of the object.

Abstract: In a high range resolution ladar, a chirp signal waveform is propagated as a divergent laser light waveform and the target reflected return is collected and converted to a current proportional to power. An undelayed chirp signal is added in a mixer to the return current and then low pass filtered to recover a mixed intermediate frequency (IF) signal having a frequency proportional to the target range. Periodically, the light circuit is interrupted and the chirp signal is processed through the mixer and low pass filter without a target return current and this output, the mixer self-clutter, is stored. This stored self-clutter signal is subsequently subtracted from the mixed IF signal on a chirp by chirp basis to cancel the self-clutter produced by the mixer. The subtracted signal is then frequency analyzed to determine target range.

Abstract: A method and apparatus of imaging moving targets with an aircraft mounted complex radar system has a plurality of independent, but synchronized synthetic aperture radars (SARs) positioned on the aircraft at equal separation distance .DELTA.x along the flight velocity vector V.sub.p of the aircraft. Frequency modulated (or otherwise coded) pulses are transmitted therefrom with an interpulse period T.sub.p, where 1/T.sub.p is an integral multiple of V.sub.p /.DELTA.x. The pulse repetition frequency, platform velocity, and spacing between adjacent SARs are all chosen to create the effect of a stationary radar momentarily fixed in space. A two dimensional complex IF (intermediate frequency) output signal is recovered by the first SAR on the aircraft. This signal is identical to that recovered by a conventional SAR. The two dimensions are fast time and downtract position. If only one point target is present, the IF output signal is the point target's phase history.