08-16-2017, 08:56 PM
LADAR SENSOR TECHNOLOGY
Abstract
Situation awareness and accurate target identification are critical requirements for successful battlefield management. Ground vehicles can be detected, tracked, and imaged by using airborne or space borne microwave radar. Obscurants, however, such as camouflage net and tree canopy foliage can degrade the performance of these radars. Foliage can be penetrated with long wavelength microwave radar, but generally at the expense of imaging resolution. The DARPA Jigsaw program includes the development of high resolution three dimensional (3D) imaging laser radar (ladar) sensor technology and systems that can be used in airborne platforms to image and identify military ground vehicles hiding under camouflage or foliage. Lincoln Laboratory has developed a rugged and compact 3D imaging ladar system that successfully demonstrates this application. The sensor system, including a microchip laser and novel focal plane arrays, has been integrated into a UH1 helicopter. The sensor operates day or night and produces high resolution 3D spatial images by using short laser pulses and a focal plane array of 32 32 Geiger mode avalanche photodiode (APD) detectors with independent digital time of flight counting circuits at each pixel. With appropriate optics, the 32 32 array of digital time values represents a 3D spatial image frame of the scene. Successive image frames from the multi kilohertz pulse repetition rate laser pulses are accumulated into range histograms to provide 3D volume and intensity information. Other applications for this 3D imaging direct detection ladar technology include robotic vision, navigation of autonomous vehicles, manufacturing quality control, industrial security, and topography