Tilted surfaces in short-wave infrared imagery: Speckle simulation and a simple contrast model


An effective simulation of speckle with tilted surfaces illuminated by short-coherence-length lasers is presented. Two new tools for assessing speckle and/or its contrast under these conditions are developed and validated. The first is a simulation of the time-domain tilted-surface effects that provides speckle imagery. The second is a simple intuitive model for contrast derived from speckle reduction due to averaging. Field results of speckle imagery for a laser-illuminated target and a short-wave infrared imager validate the simulation. Simulated speckle is compared visually with the actual speckle. Also, contrasts of the speckle generated by simulation and actually imaged in the field are compared for one tilt angle. Existing analytical models of the contrast also validate the simulated speckle contrast. Contrast-versus-angle characteristics of simulated speckle are compared with the general analytical contrast model for speckle from tilted surfaces. © 2007 Society of Photo-Optical Instrumentation Engineers.

Publication Title

Optical Engineering