KML to Layer cannot measure geometry - WGS84 reprojected with accurate units?

[carywg]

My question is in regard to KML to Layer tool. When using this tool to generate GIS layers from KML line features, I am left with a GIS layer in WGS84 coordinate system.

My problem is that I need to measure lengths (using the Calculate Geometry tool) on this newly created layer and in order to do that the layer must be in a Projected Coordinate System and not a Geographic Coordinate System. When I attempt to reproject the created WGS84 layer to the right coordinate system the units are inaccurate and cannot be used for length calculations. I have tried a number of Projected Coordinate Systems that should be accurate for the layer but without achieving accurate units.

I was originally attempting this from CAD (Microstation) based data that I applied the proper coordinate system to within the CAD software, then exported to KML for proper georeferencing. But the KML embeds it with the WGS84 coordinate system. Erasing any chances to properly calculate length within ArcGIS.

I have replicated this effect using a regular stream shapefile from Montana. The layer starts in State Plane, then is exported to KML, then imported back into GIS from KML to the WGS84 coordinate system. As you can see from the attached pictures, the units never return to their original state before these conversions. And ultimately lengths can never be calculated again.

Is there anyway to using this KML function and still be able to reproject the files back to their original Projected Coordinate System in order to measure their lengths and geometry?

Attached are screenshots and map packages of the data. Thanks or any help on this topic!

Cary G.
New York, NY
GIS Consultant

[justgis]

This may be the long way to do this but if you export the layer to a shapefile setting the coordinate system to that of the data frame (the state plane map), and then use the new shapefile, you should be able to bypass this issue. I tested it and it worked for me.

[carywg]

Thanks for the quick reply. Your correct about that. But I am really interested in how to continue from the point once the KML has been imported. If there is anyway to return back to a feasible projection and accurate units. Any idea how to go about that?

Thanks for posting.

Cary G
New York, NY
GIS Consultant

[justgis]

Once you have the shapefile in your state plane map, make 2 new fields, X and Y, and run a calculate geometry on them. i tested it and it worked for me.

[justgis]

OOPs. I should have said make a new length field and run calculate geometry on it.

[carywg]

That doesn't seem to address the topic of the post. I have the KML imported shapefile reprojected back to the original Montana State Plane in the attached screenshot illustrating the incorrect lengths and units. Also attached is a screenshot of the correct units/lengths of the shapefile in the original State Plane Coordinate Sytem before exporting to KML, as you have attempted. This was attached to be used as a reference for the correct original units/lengths.

Your right about the units and length measurements being correct in the original State Plane shapefile before the export to KML but that is not the point of the post. The goal is to see if we can establish proper lengths and units AFTER the KML to Layer process.

Cary G
New York, NY
GIS Consultant

[justgis]

I am able to get correct lengths using the procedure I described.
See attached.