On the Simulation and Mitigation of Anisoplanatic Optical Turbulence for Long Range ImagingProceedings of SPIE 10204, Long-Range Imaging II
Document TypeConference Paper
AbstractWe describe a numerical wave propagation method for simulating long range imaging of an extended scene under anisoplanatic conditions. Our approach computes an array of point spread functions (PSFs) for a 2D grid on the object plane. The PSFs are then used in a spatially varying weighted sum operation, with an ideal image, to produce a simulated image with realistic optical turbulence degradation. To validate the simulation we compare simulated outputs with the theoretical anisoplanatic tilt correlation and differential tilt variance. This is in addition to comparing the long- and short-exposure PSFs, and isoplanatic angle. Our validation analysis shows an excellent match between the simulation statistics and the theoretical predictions. The simulation tool is also used here to quantitatively evaluate a recently proposed block- matching and Wiener filtering (BMWF) method for turbulence mitigation. In this method block-matching registration algorithm is used to provide geometric correction for each of the individual input frames. The registered frames are then averaged and processed with a Wiener filter for restoration. A novel aspect of the proposed BMWF method is that the PSF model used for restoration takes into account the level of geometric correction achieved during image registration. This way, the Wiener filter is able fully exploit the reduced blurring achieved by registration. The BMWF method is relatively simple computationally, and yet, has excellent performance in comparison to state-of-the-art benchmark methods.
Document VersionPublished Version
CopyrightCopyright © 2017, Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, or modification of the contents of the publication are prohibited.
- atmospheric turbulence,
- optical wave propagation,
- turbulence mitigation
Sponsoring AgencyAir Force Research Laboratory
Citation InformationRussell C. Hardie and Daniel A. LeMaster. "On the Simulation and Mitigation of Anisoplanatic Optical Turbulence for Long Range Imaging" Proceedings of SPIE 10204, Long-Range Imaging II (2017)
Available at: http://works.bepress.com/russell_hardie/65/