Advanced techniques for target discrimination using laser speckle
Abstract
A new high-resolution imaging technique known as wavelength decorrelation is demonstrated in the laboratory for measuring target shape and estimating surface-scattering properties. In these demonstrations, the target is flood illuminated with a frequency-scanning Ti:sapphire ring laser. As the laser frequency changes, the speckle pattern in the backscattered light appears to boil; the time-varying intensity at a point in this pattern carries information about the target's range-resolved laser radar cross section U(z). A range resolution of better than 1 mm is demonstrated. A theoretical analysis of wavelength decorrelation is also presented, including the mathematical framework for predicting wavelength-decorrelation signatures. An additional technique known as speckle tracking is described for measuring a target's angular dynamics.
- Publication:
-
Lincoln Laboratory Journal
- Pub Date:
- 1992
- Bibcode:
- 1992LLabJ...5..367S
- Keywords:
-
- Frequency Scanning;
- Imaging Techniques;
- Radar Cross Sections;
- Ring Lasers;
- Solid State Lasers;
- Speckle Patterns;
- Target Acquisition;
- Optical Radar;
- Sapphire;
- Titanium;
- Lasers and Masers