topic Re: ARCMAP - TRANSFORMATION in Data Management Questions

ARCMAP - TRANSFORMATION

ChuckTurlington — Fri, 02 Jun 2017 12:27:37 GMT

Hello,

I am using ArcMap 10.4.1.

I want to manually calculate the transformation (WKID 1515) using the values from the Transformation Tables. I am familiar with matrices and can easily apply the 3 or 7 parameter method. I believe what ESRI is describing as the "Position Vector" method would use the matrices formulation. However, the WKID 1515 is only given as a "Coordinate Frame" method. Can I assume the dx, dy, dz...values tabulated for the Coordinate Frame method could also be used in the matrices formulation to solve the transformation ? If not, does ESRI have the tabulated parameters for the other methods ?

Re: ARCMAP - TRANSFORMATION

VinceAngelo — Fri, 02 Jun 2017 14:20:17 GMT

Please stop using ALL CAPS in your question titles. If you think it's a way to attract interest, I can assure you that it's in fact driving away potential viewers.

- V

Re: ARCMAP - TRANSFORMATION

MelitaKennedy — Wed, 14 Jun 2017 22:20:16 GMT

Coordinate Frame and Position Vector are both 3D Helmert transformations in XYZ / ECEF space. The difference is the formulation of the rotation matrix. Basically, change the signs of the rotations and you can use the other method. I finally memorized that fact that the lower left element of the position vector's rotation matrix is negative.

If you haven't, you should take a look at the IOGP (EPSG) Guidance Note 7-2 on this page: Guidance notes

Melita