Missing CRS in WAsP

[Antoine Borraccino]

Hello WAsP team,

I am using Lambert-93 (epsg: 2154) for my wind projects as the most common CRS in France. I cannot find it anywhere in the WAsP CRS list. As a workaround, i've turned to tell WAsP it is ETRS89, although the maps and coordinates I have imported really are in Lambert-93.

Questions:

1. Could this "wrong CRS" given purposedly to WAsP risk to create issues with the flow modelling results?
2. Would it be possible to implement this CRS in releases?
3. Any suggestion? Is it possible to set up a custom CRS? (haven't found that info)

Thanks in advance,
Antoine Borraccino

[Stefan Blagojevic]

Hi Antoine,

If the coordinate system does not match in WAsP, there will be an offset which will impact the results. We recommend to stick to a single CRS and use it throughout the project.
I know that QGIS has Lambert-93, where you could transform the projections.

Best regards,
Stefan

[Stefan Blagojevic]

The actual WAsP model runs purely in a metric system and doesn't care about the geographical location of the sites. It's only relevant in a few places:

1) Preparing KML for Google Earth visualisation

2) Pulling down GWCs automatically from the GWA data set server

3) Warning about location mismatch between OWC and met. station

4) Pulling down barometric reference data automatically for air density calculations.

So, the results will not be much affected by a slight shift in location caused by a wrong coordinate system, but generally the whole program will not behave quite right. That's why we now require a CRS for each vector map.