topic Re: ASC raster in wrong place, but the spatial reference is correct. in ArcGIS Pro Questions

ASC raster in wrong place, but the spatial reference is correct.

dagiannitto — Wed, 19 May 2021 20:36:13 GMT

Hi, I have a weird problem with some lidar data i downloaded. I added it to my map as a .asc raster file, but it has appeared in Africa when it should be in Scotland. The spatial reference is correct, so i don't know why it is in the wrong place?

Thanks.

Re: ASC raster in wrong place, but the spatial reference is correct.

JayantaPoddar — Wed, 19 May 2021 23:00:44 GMT

What is the spatial reference used? What is the extent of the layer (check Layer Properties > Source)? Share its screenshot, if possible.

I believe the raster could have been wrongly defined a Projected Coordinate System whereas the values are referring to that of a Geographic Coordinate System (Decimal Degrees).

Could you check if using Define Projection to the Raster dataset (Coordinate System: GCS_WGS_1984) resolves the issue.

Re: ASC raster in wrong place, but the spatial reference is correct.

dagiannitto — Thu, 20 May 2021 07:45:48 GMT

Hi Jayanta, I have already ensured that the projected coordinates system is WGS 1984, and the UTM zone is also correct. I will be able to send a screenshot shortly

Re: ASC raster in wrong place, but the spatial reference is correct.

dagiannitto — Thu, 20 May 2021 09:04:58 GMT

Re: ASC raster in wrong place, but the spatial reference is correct.

JayantaPoddar — Thu, 20 May 2021 10:19:58 GMT

~~That extent tells me that the data is not georeferenced~~. ~~Lidar could be just the raw data, with no spatial reference. Please check if the Lidar data is overlaying properly on map?~~

Could you tell me from where you downloaded the data? If it's open for public, please share the URL.

Edit: My mistake. I assumed the comma to be a period in the XY extent values.

Re: ASC raster in wrong place, but the spatial reference is correct.

dagiannitto — Thu, 20 May 2021 09:45:47 GMT

Ah ok. I downloaded the data from Edina Digimap Lidar Data Download (edina.ac.uk) I don't believe it is open for the public as you need an account to access the data.

Re: ASC raster in wrong place, but the spatial reference is correct.

JayantaPoddar — Thu, 20 May 2021 10:17:18 GMT

Thank you for the additional info.

The correct coordinate system could be British_National_Grid.

Could you use Define Projection, for defining British_National_Grid as the coordinate system?

Re: ASC raster in wrong place, but the spatial reference is correct.

dagiannitto — Thu, 20 May 2021 11:10:01 GMT

I am trying to now, do you know if it would be projected or geographic coordinate system?

Re: ASC raster in wrong place, but the spatial reference is correct.

dagiannitto — Thu, 20 May 2021 11:12:22 GMT

Actually i have got it, and it is all sorted now. thank you so much!

Re: ASC raster in wrong place, but the spatial reference is correct.

scarson_sbbg — Wed, 12 Jan 2022 22:25:11 GMT

@dagiannitto What did you do to fix your issue?