Wrong Location

Donald E Robinson

Active Member
I collected data for ±3 hours with both the T2 and LS, and processed the data with great results.

I set-up the base and rover as usual. Everything checked OK. I set mag nails at 3 locations on a country road with tall trees on both east and west sides. I obtained good locks and collected 600 epochs at each point.

All distances and elevations checked using a Total Station.

Upon plotting the points I notice that they were thousands of feet out (northing and easting) I plotted the Long/Lat on google earth and I was in the middle of the North Atlantic!

I checked the LS and the stored coordinates, for the base, were correct.

The only thing I noticed was that there were two North Carolina Coordinate system in the LS. Both were identical except one had the following n the geoid model file: geoid2009u70.bin. The other coordinate system had the correct model file. I am not sure which one I used.

The one which I believe is correct contains geoid12b_conus.db3.

It also contains HTDP WGS84(ITRF2008)to NAD83(2011)/NAVD88/SPCS83 North Carolina Zone, while the other one does not contain the "HTDP". What does this stand for?

I believe this might be the problem. Can someone tell me how to fix this so I get the true coordinates.

Thanks in advance for any help you can give.
 

Shawn Billings

Shawn Billings
5PLS
HTDP Horizontal Time Dependent Transformation. It's a product of NGS for converting from WGS84 to NAD83 and takes into account local area shifts.

I'd need more information to guess at why you are seeing a few thousands of feet off. What did you use to plot the points on Google Earth?
 

Donald E Robinson

Active Member
HTDP Horizontal Time Dependent Transformation. It's a product of NGS for converting from WGS84 to NAD83 and takes into account local area shifts.

I'd need more information to guess at why you are seeing a few thousands of feet off. What did you use to plot the points on Google Earth?

Sorry Shawn.. I found it! My error!
 
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