[PROJ] Matrix Library in proj?

[Karoline Arnfinnsdatter Skår]

Hi,

The Norwegian Mapping Authority is working on getting our old reference frame, NGO1948, implemented In proj.
The transformation we want to implement is the transformation from/to EUREF89 - NGO1948
We already have a solution that works, but we have been advised to discuss the use of other libraries to solve our problem.
Some background information:

When the Norwegian Mapping Authority introduced the new geodetic datum EUREF89, it was necessary to find a proper transformation technique between the deprecated geodetic datum NGO1948 to the EUREF89. NGO1948 was significant deformed, hereby it was computed and realized in different areas of the country. A consequence of this is huge planar gaps in some counties and municipalities. The gaps are upon 2-3 meters on borders. Description and evaluation of the method are further documented in the articles see [OMathisen2002] and [OMathisen2003]. The processing is done in three steps:
1. Selection of point pairs
2. Deterministic step: 2D Helmert transformation
3. Statistic step: Smoothing Least Squared Collocation

In the solution we have now we have used an open source state of the art matrix library (EIGEN3) to compute the Helmert parameters with LSC. This process will demand inverting and other matrix operations on large matrices (40x40).
The size of the matrices are also dynamic.

At this point there is no matrix library in proj that work with large matrices. Does anyone have a suggestion on how we can solve this? Can we install external packages or do we have to write our own matrix library, so that the library is a part of the source code?

Best Regards

Karoline A. Skaar
Norwegian Mapping Authority
Tlf./mob.: 32 11 82 16/907 40 302
E-post: karoline.skar at kartverket.no<mailto:karoline.skar at kartverket.no>

www.kartverket.no<http://www.kartverket.no/>

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