Do you sometimes wonder how your Garmin Marine GPS system works?
Garmin Marine GPS Systems are a Global Positioning System (GPS) designed specifically for the marine industry. This includes items such as marine databases, marine units, and functions useful to marine users, for example, a Garmin Boat GPS will contain items useful for navigating on a boat, ports, navigation aids on the ocean, and may include fish finders, or weather radar.
GPS was originally developed by the US Department of Defence, consisting of several orbiting satellites and the ground-based equipment for determining position. The first satellite was released in 1978, and GPS was released for public use in the 1980s. By 1994 there was a full complement of 24 satellites that should cover all locations on the globe always. For some time, the US GNSS (Global Navigation Satellite System) was the only available system. The GPS system is now available from several different countries. Current Garmin models usually work with the original US GPS satellites and with the Russian GLONASS system, while some track the Chinese BeiDou system. Garmin GPS technology is constantly following the advancing technology of the satellite systems, Garmin estimate that common coverage should soon be averaging around 20 satellites at any one time.
A GPS satellite sends a signal with its precise location and time. The GPS receiver calculates its position by triangulation based on the time it takes to receive the signal from the satellite. The more satellites, the better for accuracy, however a minimum of three are required for 2D and 4 for 3D positions. With current GPS satellites available in most positions there can be up to 8 satellites available. The receiver and satellite signals are radio signals, so they require something close to line-of-sight. The signal capability will depend on your clear view of the sky, antenna strength, and satellite positions relative to your location.
Garmin Marine GPS Specifics
The main difference between a Garmin boat GPS and an automotive, aeronautical, or outdoor GPS is that it is built for applications that a boat owner wants. The available antenna quality is better than average off water applications, improving signal capability, and the equipment itself is more accurate with more complex programming.
Garmin Marine GPS provide software that can be connected to radar equipment for weather and depth finding or fish finding information.
Garmin Marine GPS Accuracy
Marine industries, especially commercial boating, require more accuracy and features than your average fair-weather sailor, or GPS applications not purpose-built for marine applications.
Garmin GPS technology is very accurate these days. However, it is possible to improve basic accuracy for Garmin Marine GPS with WAAS and DGPS functions, to under 3m.
WAAS (Wide Area Augmentation System) is a standalone function available with some Garmin Marine GPS which improves signal quality by providing corrections to the atmosphere.
DGPS (Differential GPS) is another function available in Garmin Marine GPS which can be specifically useful to Marine GPS. Differential GPS corrects the GPS signal by adding the data from a ground station. The US Coastguard provides a series of towers that provide the DGPS correction signal to Marine GPS users.
The latest Garmin Marine GPS include signal error checking, where any erroneous signals are automatically discarded.