Polarization4: Division of Aperture

Each of the four cameras in the system is "perfectly co-bored" because the cameras are literally all at the exact same location. This can be observed by looking at the "attachment" for each camera. This means that the pixels from each camera will be perfectly registered without any additional work.

In a real world system, each camera will be displaced from the others by some distance. As a result, each pixel does not see the same location on the ground and some amount of registration must be employed before attempting to exploit the polarization measurements acquired. To modify this simulation to include these spatial and/or angular offsets, simply edit the attachement for each camera.

If you look at the pi.platform file, you will see that each camera has a single channel that employs the same spectral response. However, in the "Options" for the channel you will see that each has a linear polarizer defined at one of the four different angles.

For the scene, the "chunky bar" scene is used. This scene contains a set of four trapazoidal pilars (pyramids with the tops cut off). Each of the four pyramids has a different metal material on it creating four surfaces that polarize the reflected light a different amount.

This simulation uses the Simple atmosphere model, so the skylight and path radiance is not polarized. This was chosen done to simplify the requirements for this demonstration, which was mainly focused on how to create the four camera polarization setup. An improved simulation would employ a polarized atmosphere using MODTRAN4-P and the Classic or Threshold atmosphere model.

The platform looks in on the scene from a 45 degree off vertical position.