Spatial -

NOAA Datums Videos 2014

Differential correction with NA2011 and the newest epoch of NAD83

See our and Datums Basics and GPS Tutorials for the long-awaited results of months of rigorous testing and peer review

Trimble Positions software has replaced Trimble GPS Analyst in ArcGIS 10.1

ALASKA GPS and GIS users - check out Joel Cusick's Datum and Projections presentation Feb 2013

ArcGIS 10.1 - New and Cool improvements see Presentation from Melita Kennedy, ESRI : Projections and Datums Dec 2012

Home GPS Tutorials Hoping Trimble will adopt NAD83(2011) or IGS08 standard
Hoping Trimble will adopt NAD83(2011) or IGS08 standard PDF Print E-mail

While it is understood that Trimble supports many users not on the North American continents, it is suggested that Trimble adopt NAD83(2011) , NAD83(PA11) and NAD83(MA11) as the standard in North America, the Pacific and Marianas for the following reasons-


1.   The current “NEW’ coordinates in the CBS is a somewhat of a misnomer.

 A closer look at say  CORS, GARLIC (GARL),  NEVADA (ITRF00 (1997)-Derived from IGS08 (NEW))

reveals that NAD83(2011) epoch 2010 coordinates (on which IGS08 is based) have been transformed by HTDP software and displayed  in the Pathfinder Office base station properties tab in ITRF00 epoch 1997.  Since differentially corrected data takes on the reference frame of the base station data, the GPS data you collect today is being moved back to the same epoch as the base station.  In geologically stable areas, these velocities are minor (1-2 mm/yr) and 15-30 mm shift is not terrible.  In tectonically active areas, after multiply these velocities by 15 YEARS, shifts might exceed Trimble specs for sub-meter accuracy, your own project standards or impact the ability to line up with modern imagery and GIS sets.

     Hawaii ~ 80 mm/yr  

     CA near San Andreas Fault ~ 50 mm/yr 

     South-Central Alaska ~40 mm/yr 

     Pacific  Northwest Coast ~ 15 mm/yr 

2.Trimble product specs

TerraSync is offered at 3 levels : Standard,  Professional and a  Centimeter edition.

It concerns me that Trimble boasts submeter accuracy but that accuracy could easily be blown away by reference frame inconsistencies in the Trimble Community Base Station list within the Pathfinder Office differential correction.  I am not intimately familiar with this software so please correct me if this statement is misguided.

3. North American agencies have adopted this standard


    NGS data sheets offers coordinates both IGS08 and NAD38(2011) reference frames for the current standard – absolute antenna position. 

    This would restore users ability to directly compare base station coordinates in Pathfinder Office with the NGS datasheet.

    Online Position User Service (OPUS)

     As of September 2011,  OPUS currently offers solutions in either IGS08 or NAD38(2011)

     US Coast Guard (USCG)

     USCG beacons and OmniStar in North America broadcast in NAD83(2011)

    Department of the Interior (DOI)

    In the early 2000’s  USGS, BLM and NPS were mandated to move from NAD27 standard to NAD83.