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| author | Even Rouault <even.rouault@spatialys.com> | 2019-12-16 20:27:09 +0100 |
|---|---|---|
| committer | Even Rouault <even.rouault@spatialys.com> | 2019-12-16 20:27:09 +0100 |
| commit | 204ed7ff3ee4462bf4c0ffa327683bcaabe13eff (patch) | |
| tree | 06bfee8273236655eb65373e966c38dcfd6d1bbe /ch_swisstopo | |
| parent | 9550eef8af6001ebdce4fe1a1f58a981bba45444 (diff) | |
| download | PROJ-data-204ed7ff3ee4462bf4c0ffa327683bcaabe13eff.tar.gz PROJ-data-204ed7ff3ee4462bf4c0ffa327683bcaabe13eff.zip | |
Add README files
Diffstat (limited to 'ch_swisstopo')
| l--------- | ch_swisstopo/.github/README.md | 1 | ||||
| -rw-r--r-- | ch_swisstopo/README.ch_swisstopo | 25 |
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diff --git a/ch_swisstopo/.github/README.md b/ch_swisstopo/.github/README.md new file mode 120000 index 0000000..c650f31 --- /dev/null +++ b/ch_swisstopo/.github/README.md @@ -0,0 +1 @@ +../README.ch_swisstopo
\ No newline at end of file diff --git a/ch_swisstopo/README.ch_swisstopo b/ch_swisstopo/README.ch_swisstopo new file mode 100644 index 0000000..d229ace --- /dev/null +++ b/ch_swisstopo/README.ch_swisstopo @@ -0,0 +1,25 @@ +# README.ch_swisstopo + +The files in this section result from the conversion of datasets originating +from [Swisstopo](ttps://www.swisstopo.admin.ch) + +## Included grids + +### Switzerland: LV03 (system CH1903) -> LV95 (system CH1903+) + +*Source*: [swisstopo](https://www.swisstopo.admin.ch/en/knowledge-facts/surveying-geodesy/reference-frames/transformations-position.html) +*Format*: GeoTIFF converted from NTv2.0 (.gsb) +*License*: [Creative Commons CC0 1.0 Universal](https://creativecommons.org/publicdomain/zero/1.0/legalcode) +*Credit*: (c) 2007 swisstopo + +Recommended to transform from Swiss reference frame LV03 (system CH1903, EPSG:21781) to Swiss reference frame LV95 (system CH1903+, EPSG:2056). +LV95 is aligned to ETRF93, but shifted by several 100 meters. +CH1903+ is the official reference system for federal surveying and for all national geobasis data regulated by federal law since 2017. +CHENyx06a.gsb gives corrections (distorsions between LV03 and LV95) in CH1903, CHENyx06_ETRS.gsb gives the corrections in ETRS. +Several transformation services are available on https://www.swisstopo.admin.ch/en/maps-data-online/calculation-services.html +(web forms and REST web geoservices) to support the exact transformation procedure between CH1903 and CH1903+ +using the REFRAME algorithm (finite element transformation). +The difference between the grid and finite element transformation is on a level of below several millimeters. + +* CHENyx06a.tif +* CHENyx06_ETRS.tif |