Laser radar focal plane array for three-dimensional imaging (Update)

Previous efforts to develop 3-D laser radar (ladar) imagers have required multiple laser pulses and complex stable scanning and timing systems in order to generate images. This paper describes an approach that will enable a complete 3-D ladar image (angle-angle-range) to be captured with a single pulse. Using a unique processor chip that is bump bonded directly behind the detector array, the sensor provides separate independent range finder circuitry for each pixel. The time-of-flight for each pixel is recorded on the chip and the values are then read out serially. This approach allows the range resolution to be determined by the laser pulse width and electronics bandwidth and to be independent of image framing rates. This paper will discuss the status of the imager that is being assembled as well as preliminary results form field demonstrations. The specifications of the demonstration unit are for a 32x32 pixel imager with a resolution of .3x.3x.3 meters (1x1x1 feet). The system is expected to operate at approximately video framing rates (30 frames per second) and the resulting image will be displayed in a false color picture on the processor monitor.