Laser polarimetric imaging has great potential application to classify targets which could not be realized by intensity
imaging. A polarimetric imaging system is built to acquire two kinds of images, intensity and polarization degree coded
images, simultaneously. By fusing the intensity and polarization degree images with pseudo-color encoding technique,
we have achieved the classification of different kinds of targets with similar characteristics. Preliminary results show that
higher contrast and better resolution images classified with polarimetric technique could be obtained after speckle
reduction. Coherent speckle noise can be reduced with lowpass filter by treating it as high frequency noise. And lowpass
filter outperforms the normally used median filter in speckle reduction.
Laser polarimetric remote sensing has great potential in target detection, recognition and classification. Here, we propose
a modified laser polarimetric active imaging system. Principles and advantages of polarimetric detection are discussed.
Illuminating with a semiconductor laser, receiving by a Cassegrain telescope, splitting by a polarization beam splitter
(PBS), two images are created on two CCDs simultaneously. Two images of orthogonal polarization states can be
obtained once by using this system and then intensity and polarization degree can be calculated. Dual images coded with
intensity and polarization degree of testing target are obtained and analyzed. Preliminary experiments are conducted, and
the result shows the feasibility of the new method. Image coded with polarization degree can distinguish target, which
cannot be realized in intensity image when the targets have similar reflectivity. Intensity image and polarization degree
image can be fused together through HSI (Hue, Saturation and Intensity) pseudocolor coding. In the fusion image,
different depolarization targets display in different colors, hence the purpose of classifying targets with same material
can be achieved. Compared with traditional approaches which needing 16 images or 2 images, the new method has
extremely improved the measurement efficiency and provides a new way for real-time polarimetric imaging.