Utilizing computer vision techniques on sonar images to estimate velocity of an Autonomous Underwater Vehicle

The REMUS autonomous underwater vehicle uses a high defination forward looking sonar for obstacle avoidance. I am attempting to use vision and optical flow techniques to estimate the velocity of the vehicle in the forward and lateral directions between sequential sonar images, like the one pictured below.

Utilizing computer vision techniques on sonar images to estimate velocity of an Autonomous Underwater Vehicle

Thesis Research: The REMUS autonomous underwater vehicle uses a high defination forward looking sonar for obstacle avoidance. I am attempting to use computer vision and optical flow techniques to estimate the velocity of the vehicle in the forward and lateral directions between sequential sonar images, like the one pictured below.