Underwater optical measurement of position and orientation using a prepared, passive target

Abstract

In order to provide an accurate and efficient method of docking, station keeping, and navigation for the JASON remotely operated vehicle, an optical tracking method is investigated. The method needs to be accurate enough for underwater control and fast enough to enable timely control. The method presented solves the camera location problem in a closed form and is accurate for accurate measurements of image plane coordinates. Target design criteria are discussed and a prepared, passive target is selected. Testing and error analysis reveal that the approach gives good results for camera lenses with focal lengths greater than 4.8mm. The effects of underwater use are discussed and a non-numerical method of compensating for the underwater effects is presented. The compensation method shifts the image plane coordinates toward the image plane center and gives results that are within acceptable error margins.