Elevation issue with .asc files

Question

Hello, first time positing so I hope this is the correct place.

I have received multiple .asc files (Lidar Data) that I would like to create a surface from in Civil3D Autocad. However, when I load in the file it looks like the height values are in millimetres. Do .asc files from ArcGIS always have heights in millimetres or can they be exported with heights in metres?

Thanks in advance.

danretired · Answer

hmmmm the short answer woud be

raster * 1.0

or in your case multiply  by 0.001

to convert millimeters into meters

KevinDodd · Answer

Hello Dan, thank you for the reply.

I received the data from a client who was given it by a third party so I am not sure how it was exported.

Do you know of an easy way to covert the files to a floating point raster?

KevinDodd · Answer

Hello Dan,

Thank you for the reply. Unfortunately I don't know how the files were generated. I received the files from a client who purchased the data set from a third party.

What you have said about reducing the file size is interesting. The file sizes are around 25MB and cover an area of 1km².

Do you know of a straight forward way to covert the file to a floating point raster?

Thanks again for the reply.