Abstract: A ladar system with phase correction. The novel ladar system includes optics for receiving a first signal that is a reflected version of a transmitted laser signal, an optical delay line for providing a second signal that is a delayed version of the transmitted laser signal, and a mechanism for mixing the first signal with the second signal. The second signal is delayed by a time TD that reduces a relative time difference between the first and second signals such that phase errors caused by laser transmitter instabilities and nonlinear modulation are less than a predetermined level.

Abstract: A readout system for receiving return signals originating from one or more energy pulses fired toward a scene. The system includes a first mechanism for detecting energy received from the scene and providing a first signal in response thereto. A second mechanism times a rising edge and a falling edge of a pulse contained in the first signal and provides a second signal in response thereto. In a specific embodiment, a third mechanism determines characteristics of the pulse based on the second signal, which include characteristics, such as pulse width, pulse intensity, and/or pulse centroid, sufficient to generate an image of the scene.

Abstract: A synthetic aperture ladar system using a mode locked laser transmitter. The inventive system (12) includes a mode locked laser transmitter (22); a receiver (40) adapted to detect signals transmitted by said laser (22) and reflected by an object (32) and a signal processor (50) for analyzing the signals. The laser (22) is particularly novel as a synthetic aperture ladar transmitter inasmuch as it includes a mode locking mechanism (180). The mode locking mechanism (180) causes the laser to output energy at all modes within the gain profile in phase with one another. The result is a series of coherent pulses which may be used for synthetic aperture ladar applications. In a particular embodiment, the present teachings are implemented in a multifunctional laser which, in its operational mode, outputs a mode locked beam for synthetic aperture ladar.

Abstract: A laser rangefinding system (12) that utilizes multiple pulse, multiple return, modal range processing for clutter rejection. A laser source (16) emits a series of laser beam pulses (42), and each reflected return from objects (46) in a scene for each of the pulses is recorded. Each return signal above a predetermined threshold is added as a count to a count table within a selected bin representing the range of the return signal. After all of the analog return signals are recorded, the range bin with the most counts is selected as the range of a target.