ch_swisstopo_README.txt 1.47 KB
Newer Older
xuebingbing's avatar
xuebingbing committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
# ch_swisstopo_README.txt

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.

* ch_swisstopo_CHENyx06a.tif
* ch_swisstopo_CHENyx06_ETRS.tif