Blind Compensation of Angle Jitter for Satellite-Based Ground-Imaging Ladar: FY17 Line-Supported Integrated Systems Program
Abstract
Space-based ground-imaging ladar has become more feasible with recent technological advances. Compact fiber-optic lasers and single-photon-sensitive Geiger-mode detector arrays push the design towards low pulse energies and high pulse rates. A challenge in implementing such a system is imperfect pointing knowledge caused by angular jitter, exacerbated by long distances between satellite and ground. Without mitigation, angular jitter would cause significant blurring of the 3D data products. Reducing angular jitter to avoid such problems might require extreme mechanical isolation, advanced inertial measurement units (IMUs), star trackers, or auxiliary passive optical sensors. These mitigations can increase cost and size, weight, and power (SWaP) considerably. An alternative approach is demonstrated that uses only the ladar data to mitigate the unknown jitter, similar to blind deconvolution. Expectation Maximization is used to jointly estimate the 2-axis-jitter time series and the 2D ground surface. Reasonable assumptions about the jitter spectrum and the spatial-frequency spectrum of the ground are incorporated as prior distributions in a way consistent with Bayes rule.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 22, 2017
- Accession Number
- AD1086044
Entities
People
- Charles A. Primmerman
- Ethan J. Phelps
Organizations
- MIT Lincoln Laboratory