Planetary Rover Absolute Heading Detection Using a Sun Sensor

A relatively inexpensive Sun sensor for determining the absolute heading of planetary rovers to within ± 3° using a monochrome charge-coupled device (CCD) camera is presented. The Sun sensor was developed for the Field Integrated, Design and Operations (FIDO) rover. This rover is an advance technology rover that is a terrestrial prototype of the rovers that NASA/JPL plans to send to Mars in 2003. The goal of the FIDO team was to develop a Sun sensor that fills the current cost/performance gap, uses the power of sub-pixel interpolation, makes use of current hardware on the rover, and demands very little computational overhead. In addition, a great deal of emphasis was placed on robustness to calibration errors and the flexibility to make a transition to a flight rover with very little modification.