Datum
Moving coordinates between datums, frames, and epochs.
These tools move coordinates between datums, frames, and epochs: NAD 83, the ITRF, WGS 84, NAD 27 and other old datums, and legacy datums worldwide. Surveyors and GIS analysts use them when GNSS data meets older control or a map on a different datum. For modern GNSS positions in the US, start with the NAD 83 transformation. The common pitfall is treating NAD 83(2011) and WGS 84 as the same, which puts a meter or more of error in the data.
I want to move coordinates between NAD 83, ITRF, and WGS 84
- Transform between NAD 83 and ITRF or WGS 84
Transforms a position between NAD 83 (2011, PA11, or MA11) and ITRF2020, ITRF2014, ITRF2008, ITRF2005, ITRF2000, or WGS 84 at one epoch, with the NGS HTDP parameters, and shows the meter-level difference between them.
- Transform between ITRF and WGS 84 realizations
Transforms a position between International Terrestrial Reference Frame realizations (ITRF2020 back to ITRF88) and the WGS 84 realizations aligned with them, at the coordinates' epoch, with the IERS parameters.
I want to bring an old US datum to NAD 83
- Old US datums to NAD 83 (NADCON5)
Converts a latitude and longitude from a region's old datum to NAD 83 with the NGS NADCON5 grids, or back: NAD 27 in the conterminous US and Alaska, Old Hawaiian, Puerto Rico 1940, St. Paul 1952, American Samoa 1962, and Guam 1963.
I want to convert a legacy datum to or from WGS 84
- Legacy datum to or from WGS 84
Converts a latitude and longitude between a legacy datum (ED50, NAD27, OSGB36, Tokyo, AGD66, Pulkovo 1942, SAD69, or Arc 1960) and WGS 84 with the published EPSG transformation, and states its accuracy, which is meters, not centimeters.
I want to apply a Helmert transformation I have the parameters for
- Helmert transformation (7 or 14 parameters)
Applies a 7-parameter Helmert transformation, or a 14-parameter time-dependent one with rates, to ECEF coordinates, in the position-vector or coordinate-frame convention you name, forward or exactly reversed.
I want to move a position to another epoch
- Move a position between epochs (ITRF2020 plate motion)
Propagates an ITRF2020 position from one epoch to another with the rigid-plate velocity of its tectonic plate, or with a site velocity you give, and flags zones where plates deform and rigid motion does not apply.
Guides that use these tools
- GNSS control to OPUS to state plane: An OPUS position in ITRF2020 to NAD83(2011), then state plane coordinates, the orthometric height, and the combined factor for ground distances.