Evaluating and Correcting 3D FFASH LiDAR Imagers

Date of Award


Degree Name

Ph.D. in Electro-Optics and Photonics


Department of Electro-Optics and Photonics


Paul F. McManamon


This research presents methods and results of characterizing and correcting PIN photodiode 3D flash LiDAR cameras, with the goal of significantly simplifying and improving the calibration system design. 3D flash LiDAR detectors use time to digital conversion (TDC) circuits to estimate the time of flight of a pulse when a detection threshold is met. As the underlying time to digital conversion (TDC) circuits require more space and power, these circuits will cause, in high bus loading events, electronic crosstalk. These events are more likely to occur in situations where many detectors simultaneously trigger, something that can occur when viewing a flat object head-on with uniform illumination, thus limiting these sensors to image a full frame due to this simultaneous ranging crosstalk noise (SRCN). Solutions were devised including using a windowed region of interest to mitigate additional noise by preventing triggering on all of the focal plane array (FPA) except the windowed region, and methods using a checkerboard pattern for imaging the full frame, including using a physical target downrange and a spatial light modulator.


Optics, 3D flash LiDAR, LiDAR, range walk, spatial light modulator, optical systems, imager characterization, non-uniformity correction, photo-response non-uniformity, NUC, high frame rate, laser radar, ladar, crosstalk, electronic crosstalk

Rights Statement

Copyright © 2021, author