A partial calibration technique for a 128 × 128 pin diode 3D flash LIDAR camera is presented. This paper presents dark non-uniformity correction (NUC) of a 3D flash LIDAR camera using dark frame subtraction. Dark frames are taken near threshold for intensity return to generate simultaneous trigger on a flash LIDAR camera, with trigger ramp set to zero for both range and intensity returns. Frames are cropped to a region of interest (ROI) and concatenated ideal dark intensity and dark range return into dark frames, processed into calibration files with nearest neighbor correction in dark intensity frames to correct out slowly varying, high intensity temporal noise when operating near threshold. Results and validation of applied NUC on 3D flash LIDAR camera are presented. We characterize a 3D flash LIDAR camera with PIN diode architecture including range walk, gain characterization in both intensity and range domains. Characterization of 3D flash LIDAR imager was performed using a fiber laser operating at 1550 nm, 20 μJ energy per pulse, TTL triggering, a pulse generator to generate time delay necessary for triggering the laser from the camera ARM signal, and an attenuator for fine control of the output signal. Time delay is relative to the range domain, whereas output signal is relative to the intensity domain.
Laser radar for entry, descent, and landing (EDL) applications as well as the space docking problem could benefit from a low size, weight, and power (SWaP) beam control system. Moreover, an inertia free approach employing non-mechanical beam control is also attractive for laser radar that is intended to be employed aboard space platforms. We are investigating a non-mechanical beam steering (NMBS) sub-system based on liquid crystal polarization grating (LCPG) technology with emphasis placed on improved throughput and significant weight reduction by combining components and drastically reducing substrate thicknesses. In addition to the advantages of non-mechanical, gimbal free beam control, and greatly improved SWaP, our approach also enables wide area scanning using a scalable architecture. An extraterrestrial application entails additional environmental constraints, consequently an environmental test plan tailored to an EDL mission will also be discussed. In addition, we will present advances in continuous fine steering technology which would complement the coarse steering LCPG technology. A low-SWaP, non-mechanical beam control system could be used in many laser radar remote sensing applications including meteorological studies and agricultural or environmental surveys in addition to the entry, descent, and landing application.