Has anyone played around with connecting a DGPS receiver such as the Trimble "Beacon on a Belt" with recreational grade GPS?
I've read that all Garmins accept corrections from a DGPS receiver.
Figured someone might be crazy enough to try and get it to work.
Could be useful in a robotic total station situation.
I wonder if the coast guard beacon correction results in noticeably better accuracy than the WAAS system?
Since no one else has replied I will contribute my minimal knowledge. The coast guard signals get you down to maybe the 2 meter level at best. They are basically obsoleted by WAAS. I am not sure if the CG stations have much of a future.
I had several older Garmins GPS-48 and GPS-60CS and acquired a Garmin differential receiver off of ebay and experimented for a while. You can probably still get DGPS corrections off the internet too. But to what end. Not survey quality and not clearly any improvement over WAAS.
while I have not used Coast Guard corrections for a long time (I bought a beacon back in the late 90's for a particular project), I recall that it was under 1 m with respect to NAD83. WAAS gives corrections with respect to ITRF (WGS84), so right off the bat there is a 1 to 2 m bias. Of course, you could setup a data collector to apply the transformation, but not sure if the consistency is there. Other correction services exist (for a fee) that get you down to decimeter level.
I was curious, because the USCG DGPS, when used in conjunction with the Trimble Pro XR's and GeoExplorer series is generally accurate to <3' (usually as good as 1.5' when mission planning is employed and there is a clear view of the sky).
The GeoExplorer uses a patch antenna, probably similar to the Garmin units.
I never knew the Garmin units supported DGPS corrections. I suspect it must have to do with marine applications ( fish finders and such).
Knowing your position to within 3' could be useful in a search routine for a robot.
I realize newer expensive instruments offer this as an option. I was thinking along the lines of an experiment.
WAAS is great if your located in the plains of the Midwest or flying a plane. Not so good if your on the West coast with mountains.
" You can probably still get DGPS corrections off the internet too."
I wonder why there is not an app for that yet? Seems like the perfect app for an iPhone.
