Precise Navigation for High Resolution Geophysics in Hudson Bay

Historically, the vast majority of high resolution geophysics surveys carried out in Canada and in most parts of the world have used various types of radio navigation aids, often in combination with satellite systems, to provide accurate position control for the seismic vessel and its associated sensors. Hudson Bay poses a unique problem in that it is one of the great oceans of the world but does not have any permanent navaids providing navigation control for the passage of ships. The difficult and relatively restricted access to the shoreline would make the establishment of a temporary radio navigation system not only logistically difficult but cost prohibitive. This paper briefly presents the theory of operation for each of the systems used, provides an operational summary of the data collection methods, describes the post processing of the integrated data set and addresses the accuracy considerations of the system as used in Hudson Bay.