Differences between Aquatic and Terrestrial GPS Systems

Many people have Global Positioning System (GPS) in their cars and trucks. The most common GPS uses radio signals from faraway satellites to locate positions. The Department of Defense first developed it to help government ships and watercraft better navigate waters. So, naturally, GPS is now used on commercial watercraft and on pleasure boats.

Typical Uses of Aquatic GPS

Aquatic GPS devices support valuable features designed especially for navigators. They ensure pleasure and safety. Marine devices have a navigate-to-point feature, which shows the course the user will follow. They also have a MOB or man overboard feature that lets the user immediately mark where someone fell overboard.

Aquatic GPS may have charts that can let users see visual outlines of sea life and obstacles below the surface of the water and, therefore, what dangers may be below. Aquatic GPS devices store maps of the surface of the water. The navigator can see all these visual representations by looking at the screen of the device.

Aquatic GPS helps users “see” their way to the waypoint (their destination) even when visibility is poor. GPS also gives the depth of the water and tells the distance, speed and time of arrival. Once the waypoint is put into the device, the user can save it for future reference. Sophisticated features that some aquatic GPS has include predictions of the tides and giving the time of sunrise and sunset. Others pinpoint the location of fish for navigators who are fishermen.

Aquatic GPS Not Just for Navigators

But aquatic GPS is not just for navigators. If is also for marine researchers who use it to chart what’s below oceans, lakes and rivers. Some clean-water experts, for example, take water samples and use GPS to pinpoint exactly where those samples came from. Others combine aquatic GPS with superior illumination and high-quality cameras to find, film, photograph submerged life such as worms, sponges, animals and fish. Others use it to find shipwrecks.

Terrestrial GPS, a New Technology

GPS is with us to stay. Therefore, technologists in the field are always looking to improve on it. Terrestrial GPS is a new system that pinpoints locations more precisely than conventional GPS. Its developers say that it can accurately spot a location to within seven inches. The reason is that since its signal towers are on the ground, the signals do not have to travel as far as do signals from satellites thousands of miles above the earth. Signals that do not have to travel long distances are stronger and, therefore, more accurate in determining location. The towers for terrestrial GPS can be placed indoors or outdoors. However, people using terrestrial GPS receivers need to be near a GPS “hotspot.”