In order to understand the phenomenology of optimum data acquisition and analysis and to
develop an understanding of capabilities, field measurements of multiband, polarimetric data can
substantially assist in developing a methodology to collect and to exploit feature signatures.
In 1999, Duggin showed that images obtained with an 8-bit camera used as a polarimeter could
yield additional information to that contained in a radiometric (S0) image. It should be noted that
Walraven and Curran had performed some very fine experiments almost two decades earlier,
using photographic film, and North performed careful polarimetric measurements of the
skydome using a four-lens polarimetric film camera and convex mirror in 1997. There have been
a number of papers dealing with polarimetric field measurements since that time. Recently,
commercial color cameras have become available that have 12-bit depth per channel. Here, we
perform radiometric and chromatic calibrations and examine the possible use of a Nikon D200
10.2 mega pixel, 3 channel, 12-bit per channel camera fitted with a zoom lens as a potential field
imaging polarimeter. We show that there are still difficulties in using off-the-shelf technology for
field applications, but list some reasons why we need to address these challenges, in order to
understand the phenomenology of data collection and analysis metrics for multiple data streams.
Development of reliable imaging polarimeters and the models that predict their performance is dependent on the ability to assess their accuracy. Field tests frequently result in contradictory data and laboratory measurements are often not representative of materials in the field. To address these concerns, we have built a device with which the calibration of imaging polarimeters (both stationary and moving) can be verified and the polarimetric properties of materials in the field can be measured with accuracy. The device is a handheld, non-imaging polarimeter that is capable of highly calibrated phenomenology measurements in both the lab and field. Multiple optical heads enable monitoring of samples from a variety of angles in order to characterize polarimetric signatures as a function of source, sample, and sensor geometry. The device may also be used in unattended diurnal monitoring of polarimetric signatures of the sky,
backgrounds, and targets of interest, providing a correlation between observed polarization phenomenology and weather conditions. The handheld device and the associated data acquisition system is small and portable enough that it can be taken to the field readily and is simple enough that calibration and system performance is predictable and verifiable. In this paper, we describe the design and performance of the non-imaging handheld polarimeter, performance specifications, and measurement results to date.
The automated, or semi-automated analysis of scene elements in a clutter background is more complex in polarimetric imaging than in conventional imaging. This is largely due to the fact that misregistration of the orthogonal images used to calculate the Stokes parameter images introduces an artificial clutter. Further, there is little reported information on polarimetric image clutter. We present representative findings from an analysis of polarimetric image data, obtained over various backgrounds with various geometries, and examine the manner in which systematic and random variations impact feature discriminations.