Aspects of acoustic transponder surveys and acoustic navigation

New off-the-shelf hardware has allowed improved techniques for acoustic transponder deployment and surveying, saving time and improving the accuracy of results. In particular, affordable acoustic deck units which allow continuous computer sampling of acoustic ranges while the ship is under way (merged with simultaneous GPS position data), allow application of a variety of survey techniques, to determine the exact transponder positions or separations. Apart from a particular hardware setup used, various possible analysis techniques are summarized and results compared from a number of applications. In addition, the positioning problem using 2 or 3 acoustic transponders is discussed. The solutions are presented together with their respective errors, allowing simple rule-of-thumb estimates for positioning (or velocity) accuracy, as a function of the uncertainty in input parameters (e.g. transponder positions, acoustic travel time, depth measurement)