Differential Global Positioning System

[Expedition Nutter]

For those who enjoy GPS, you might like to know that DGPS is a system to add to regular GPS which accurizes your position. When satellite signals get distorted because of sun flares, ionic atmpspheric conditions etc, you will suffer a great error in your normal GPS operation.

WAAS is new, it is touted by many GPS companies to be the latest in error correction since sliced bread. However, WAAS operates as well from Satellites. These WAAS satellites are in orbit around the equator, and were designed for AIRCRAFT use, not for us, who are on the ground.

The call for DGPS.
What is DGPS, and how does it work?
DGPS is the Differential Global Positioning System, operated by the US Coast Guard. However, there has been a program whereby a National DGPS system has been put into place. This national DGPS system is under threat of being decomissioned. DGPS works with regular GPS receivers in this way: Your GPS in your Land Cruiser / Land Rover receives satellite signals with a certain degree of accuracy. However in inclement weather, or under certain ionic atmospheric conditions, the satellite signal will degrade tremendously, causing you to possibly become lost (remember, WAAS signals are also satellite driven). When you couple a regular GPS with a DGPS Beacon Receiver on your Land Cruiser / Land Rover, your position will be corrected. Why...? Differential GPS signals come from the Earth. There are hundreds of DGPS transmission stations all over the United States, which constantly transmit to your DGPS enabled receiver. The GPS receiver takes the incorrect signals from the satellite, and the signals from the DGPS transmitter and after some calculations by the GPS, it arrives at the correct location- where you really are in other words.

The National DGPS website:

U.S. Coast Guard Navigation Center

National DGPS Steering Council:

Nationwide DGPS - USCG Navigation Center
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[XtremeMarine]

Waas is new? Dude, where have you been hiding? I've had WAAS technology in my Garmin's since at least 2005. And my yacht's had a DGPS since the beginning of 2006. Ihave been installing WAAS equipped Garmin's on my customer's boats since 2002. Good informative links, but the info represented is a little outdated.

[Expedition Nutter]

WAAS is newer than DGPS I should say. I consider any technology out within the last 5 years as new.

[XtremeMarine]

DGPS has been out longer in military applications. And for commercial as well. But at least in the marine market, WAAS came out for public consumption first. We had DGPS back when I was still a coastie, so I know it's been around. No bitchin' on this end, I just thought the way it was stated was a littl misleading. All good!