COAT Measurements and Analysis
Abstract
Coherent optical adaptive techniques (COAT) have been studied by experiment, by analysis, and by computer simulation. The experiments have utilized a 21-channel, visible-wavelength, multidither COAT system, while the computer simulations have dealt with both multidither (outgoing-wave) and phase- conjugate (return-wave) systems. Thermal blooming and turbulence distortions and complex-target effects (speckle-modulations) have been studied. This report summarizes the status of the 21-channel DARPA/RADC, visible-wavelength, multidither COAT experimental model and associated hardware and its use in the experimental measurements on this contract. Experimental observations with the 21-channel COAT system show that blooming distortions occurring in the first 30% of the focused propagation path can be compensated, leading to roughly a factor of 1.5 increase in peak focused-beam irradiance. Computer simulation of phase-conjugate (return-wave) COAT systems has shown almost no blooming compensation. Experimental measurements of COAT operation with equal transmitter and receiver apertures and semidiffuse, extended-glint scotchlight surfaces have failed to produce any degradation in the system convergence level, even though significant spurious modulations within the dither band were observed in the COAT receiver.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1976
- Accession Number
- ADA023479
Entities
People
- A. Kokorowski
- Chia-Yi Yeh
- James E. Pearson
- M. E. Pedinoff
- W. P. Brown Jr.
Organizations
- HRL Laboratories