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GPS Users in the United States: Heads Up!
GEOID12 is not yet available for use with GNSS Solutions, or for loading into FAST Survey with the Ashtech Geoids tool, or for use with MobileMapper Field or ProMark Field. The changes from GEOID09 may be very small: here in Salt Lake City UT, there is only a millimeter of difference between G09 and G12.
(You can check this out by computing the GEOID difference online with the [ GEOID12 ] tool and the [ GEOID09 ] tool, then comparing the difference.
IMPORTANT: If you use OPUS, old reference frame solutions (NAD83_CORS96) will only be available for four more days! CORS96 EXPIRES on July 15th!
You can read about NAD83_2011 [ here ]. If you use CORS or OPUS in the United States, you cannot put off dealing with this any longer!
In some areas NAD83_2011 may be a big deal. For many sites the changes are insignificant. For example RBUT, the nearest CORS to my office NAD83_CORS96 Epoch 2002:
latitude = 40 46 51.80741 N
longitude = 111 48 31.49063 W
ellipsoid height = 1668.462 m
latitude = 40 46 51.80799 N
longitude = 111 48 31.49014 W
ellipsoid height = 1668.472 m
Not a big deal, but your mileage may vary.
(Also remember that the new frame is based on absolute antenna calibrations.)
I am preparing a white paper on how to bulk update positions and velocities in GNSS Solutions for NGS CORS sites. I will send out a dedicated note when it is available.
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