John Maris is a professional navigator and surveyor, offshore and coastal within the Oil and Gas exploration industry. With the increasing use of SatNav among the general user popu...view moreJohn Maris is a professional navigator and surveyor, offshore and coastal within the Oil and Gas exploration industry. With the increasing use of SatNav among the general user population, in vehicles, mobile phones and other applications, he is attempting to increase the awareness of users of how GPS, navigation and mapping combine to give us these systems. It is a fascinating and fantastic technology but not without its problems. A higher understanding of how it works will enable you to get the best out of your system, avoiding confusion and being misled.view less