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Full-Text Articles in Physics
Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb
Phase Gradient Algorithm Method For 3-D Holographic Ladar Imaging, Jason W. Stafford, Bradley D. Duncan, David J. Rabb
Electro-Optics and Photonics Faculty Publications
3-D holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3-D holographic ladar data for phase corrections across multiple temporal frequency samples. Substantial improvement of range compression is demonstrated with a laboratory experiment where our modified PGA technique is applied. Additionally, the PGA estimator is demonstrated to be …
Upgrade To The Pierre Auger Cosmic Ray Observatory's Lidar System, Emily B. Petermann
Upgrade To The Pierre Auger Cosmic Ray Observatory's Lidar System, Emily B. Petermann
Department of Physics and Astronomy: Dissertations, Theses, and Student Research
The Pierre Auger Cosmic Ray Observatory currently operates four elastic lidar systems in order to characterize the atmospheric aerosol content above the observatory. The atmospheric information gained by the lidar system is then used in the calibration of the observatory’s four fluorescence detectors. Currently the four lidars in operation are unable to accurately determine the aerosol content below a distance of 1 km. A project is currently underway to upgrade the current lidar system by adding an additional detector to each of the existing lidar systems. The considered designs for this upgrade and the initial results from the upgrade prototype …
Heterodyne Ladar System Efficiency Enhancement Using Single-Mode Optical Fiber Mixers, Donald K. Jacob, Martin B. Mark, Bradley D. Duncan
Heterodyne Ladar System Efficiency Enhancement Using Single-Mode Optical Fiber Mixers, Donald K. Jacob, Martin B. Mark, Bradley D. Duncan
Electro-Optics and Photonics Faculty Publications
A theoretical performance analysis of a heterodyne ladar system incorporating a single-mode fiber receiver has been performed. For our purposes, the performance parameters of interest are the coupling and mixing efficiency of the ladar receiver, as they relate to the overall system carrier-to-noise ratio. For a receiver incorporating a single-mode fiber mixer, the received and local-oscillator fields are matched both spatially and temporally at the detector, yielding 100% mixing efficiency. We have therefore focused our efforts on determining an expression for the efficiency with which a diffuse return from a purely speckle target can be coupled into the receiving leg …