Interferometric Vision-Based Navigation Sensor for Autonomous Proximity Operation

The Vision Based Navigation (VisNav) developed at Texas A&M is an opto-electronic sensor that employs specific structured light sources to provide a cost-effective and robust six degree-of-freedom (DOF) relative position and attitude determination. Interferometric Vision-Based Navigation Sensor called “iVisNav” is newly proposed with additional features. This paper presents a new algorithm that involves procurement of rate information, a characteristic of relative motion between two vehicles, by simultaneous usage of beacons (infrared light sources) and a single camera. The algorithm utilizes an interpretation of the geometry of structured beacons, and the phase shift of modulated infrared beam along each travel path. The time derivative of phase shift provides a measure of radial velocity between a beacon and the projection. Evaluation of phase shift measurements with a linear least squares model results in a robust estimation of the relative rate information. A sensor prototype is currently being developed and the preliminary results are discussed in this paper. Moreover, the sensor source integration with a laser Doppler Lidar is being studied, which when incorporated provides a high accuracy rate estimation of an aerospace vehicle.