I get super small cell size when I'm importing sonar data

10-08-2020 03:57 AM
New Contributor

I've got some sonar data of a river that I'm importing into ArcMAP. The sonar data comes from a humminbird sonar device that is loaded into ReefMaster software and then converted into shapefile-, CSV-, or ASC-format.

The problem is, when I'm importing the sonar data from ReefMaster into ArcMAP, the depth is the same as it should, it varies between 0-5 meters. But the cellsize becomes super small, about 10^-5. So later when I'm creating a cross section of the river, the length and width of the river is super small but the depth is correct. 

I've tried to change the cellsize, but I just get error messages. The same goes for changing the z-factor, it just makes the depth very small, and doesn't change the xy coordinates. A strange thing is that when I'm using the measure tool on the map, I get the correct width of the river. But the cross section seems to use the cell size rather than the length and width that the measuring tool uses. 

I'm using the coordinate system: GCS_WGS_1984.

What I'm trying to do is to process the sonar data in ArcMAP and the import it into Hec-Ras in order to do some fluid simulations. Exactly as this person is doing: Generating River Geometry data to HEC_RAS by ArcGIS from DEM - YouTube . 

I've attached a picture of the cross section. It is 0.002 meter wide but it should be about 90 meters wide. 

I'm really new to ArcMAP and this project is for my master thesis, so all help is appreciated. 


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