Abstract
Flash LiDAR instruments offer many advantages over scanning LiDAR instruments for rendezvous and landing applications in a space and extra-terrestrial context by the absence of moving parts. This abstract deals with the development of an image sensor for the above-described applications. The 1280(H)x1024(V) pixel image sensor is designed to provide 500fps in full frame readout mode, and 2000fps at smaller ROI, e.g., 500(H)x500(V). Consequently, the update rate for the 3D point cloud will be in the order of 5 – 20 Hz. Presently, the circuit is already validated to a frame rate of [400 – 450] Hz; after further ADC (operation) optimization, the full frame rate is in reach. The pixel pitch of the image sensor is 14µm, and can operate in 3 different modes: • RM1: fast time gating with RST, readout without CDS • RM2: slower timing gating due to limited S&H settling time, CDS readout • RM3: fast time gating with photodiode sensitivity modulation, CDS readout. The Control diodes for the RM3 mode are reducing slightly the responsivity of the other modes, but this does not affect the targeted distance accuracy for the RM1 and RM2 modes. The selectivity between “on” and “off” state in RM3 mode is limited, but sufficient to allow multiple NDR accumulation of samples at large distances. The readout noise is expected to be < 8 e-rms for RM2 & RM3, and < 50e-rms for RM1. All functional tests on chip level are successfully completed; the package for the final application is designed and the radiation tests to check the space environment resistance are planned.