Polarization diversity active imaging

Abstract

We present the concept of a Polarization Diversity Active Imager operating at ? = 810 rim. Each pixel of the image is encoded by the polarization degree Pd (0% < Pd < 100%) given by its Mueller Matrix. The measurement of the Mueller matrices is obtained using the Dual Rotation Retarder Technique (DRRT). A theoretical analysis and an experimental validation of this technique are presented. The device is operating in a monostatic configuration, using a semiconductor laser (X = 810 tim) to illuminate the target and a telescope to create the image on a CCD matrix. The experiment is controlled by a computer that drives the rotation of the retarders, the digitalization and the encoding of the image. The measured intensily and polarization images are compared and the information contained in the polarization degree are analyzed. Dual images (intensity-polarization) of different targets are presented, showing the experimental validation of the technique. The application of this active imager to the detection and the decamouflage of target buried in the background (same albedo but different polarization degree) is proposed.

Polarization information processing and software system design for simultaneously imaging polarimetry

“…So we can get four different polarization images of the same scene on two detectors at the same time 3 . …”

“…It increases the amount of information of the detected scene. Various technological approaches of imaging polarimeters have been studied [1][2][3][4][5][6][7][8] . We have designed a simultaneous imaging polarimetry with double separate Wollaston Prism(SIP-DSWP) 9-10 , which is a combination of division-of-amplitude and division-of-aperture.…”

Potential application of visible passive imaging polarimetry in the discrimination of real targets and decoys

“…The most general and widely used formulism of imaging polarimetry is the SVI (5)(6)(7)(8)(9)(10)(11)(12) . In the SVI representation the polarization properties of the electromagnetic radiation can be completely described by the Stokes vector imagery S I that consists of four images known as the Stokes images:…”

“…S 1 , S 2 , and S 3 , images, respectively describes linear polarization, orientation, and circular polarization content of light in the scene. SVI can be determined using a time-sequential intensity measurement approach (5)(6)(7)(8) as in the following arrangement: Other useful images may be obtained using a combination of SVI elements: the degree of linear polarization DLP is a measure of the amount of linear polarization defined as:…”

Compact and robust linear Stokes polarization camera

“…It has been showed that DOLP imaging is a powerful tool to detect man made objects [8][9][10][11] . Manmade objects are usually associated with a higher DOLP than natural objects.…”