ASC File Upload Issue: Missing Spatial Reference


I’m encountering an issue while uploading an ASC file to Cesium Ion. The error message states, “Missing or invalid spatial reference system.” The file contains elevation data but seems to lack the spatial reference information required for georeferencing.

Here is the header of my ASC file:
ncols 1000
nrows 1000
xllcorner 2568000
yllcorner 1206000
cellsize 1
nodata_value -9999
449.77975 449.75098 449.70349 449.65601…

Can anyone provide guidance on how to correctly specify the spatial reference system and units in the ASC file’s header for compatibility with Cesium Ion?

Any help would be greatly appreciated.

Hi, Are you able to provide an asset id for us to investigate further? It would also be helpful if you could provide information about how this file was generated.


Here is the asset id: 2337383 (swissBATHY3D_CHLV95_LN02_2570_1205.asc).

This file comes from the swissBATHY3D which contains bathymetric data in the form of a very accurate digital elevation model that describes the topography of the Swiss lakebeds.