Knowing the variables Th1, Rho1, Th2, Rho2, and Phi2, it is possible to rectify the two images (without introducing any distortion) and simulate a virtual stereo rig in a standard setting and with a large baseline.
This problem is similar to the external calibration for stereo [Konolige, 97].
Having a measure of the quality of the disparity image produced by stereo, it is possible to perform a search over the above parameters to evaluate the camera motion. One possible measure is the smoothness of the disparity image.