What does the "D" on the signal strength bar for a given GPS satellite represent?

Hello. I can't find this in the manual. On the satellite status page GPS satellites have a "D" usually, but not always, show up on the signal strength bar for the satellites. Galileo satellites don't seem to show this. Let me know. Cheers!

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allory over 4 years ago +1 verified

In the really old days of GPS the positional errors were often in the 10s of meters. A system known as differential GPS was developed which used corrections from a known location to correct some of the…

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+1 allory over 4 years ago

In the really old days of GPS the positional errors were often in the 10s of meters. A system known as differential GPS was developed which used corrections from a known location to correct some of the error. Originally this was only available in limited locations near a ground station and with special receivers. Eventually the corrections were available from a few additional satellites and on most GPS receivers.

Still referred to as Differential GPS, the satellites for which corrected information was available had a small 'D' showing on the signal strength bar.

The writeup at the following link gives a much better description: http://www.gpsinformation.org/dale/dgps.htm

0 9erFife over 4 years ago in reply to allory

Excellent. Thanks so much for your help! It appears that the "D" symbols only show up when I have WAAS toggled on, which makes a lot of sense. Cheers.

0 allory over 4 years ago in reply to 9erFife

Right. My brain was not coming up with WAAS (Wide Area Augmentation System), that’s when the correction is satellite based.

0 atlas_cached over 4 years ago

You will find many things that are not in the Garmin manual at GPSrChive.

0 9erFife over 4 years ago in reply to atlas_cached

Awesome. Thanks.

Edit: Woa, that site is amazing, haha.