topic Generate Near Table in Geoprocessing Questions

Generate Near Table

ScottBlankenbeckler — Thu, 27 Oct 2011 15:43:50 GMT

I am trying to use the generate near table to get distances from a point to all surrounding polygons, but have a couple questions.

Input Feature and Near Features (Coord system) - GCS_WGS_1984

1. How do I get the output NEAR_DIST to display meters
2. If 1 is not possible without re-projecting data how do I convert NEAR_DIST to meters
3. What is the unit of measure for the output?
Changing the output coordinate system does not change the values of NEAR_DIST.

example:
NEAR_DIST 0.071014 (? units)

Re: Generate Near Table

DanLee — Thu, 27 Oct 2011 17:21:18 GMT

The proper way to do spatial analysis, especially with measurements involved, is to project your data FIRST. A distance in decimal degrees (NEAR_DIST 0.071014 as you mentioned) doesn't make sense because the ground distance it covers varies with locations on earth.

You need to use the Project tool to project your data; then run the Near tool again - the NEAR_DIST values will then be in the projected feature units.

Re: Generate Near Table

ScottBlankenbeckler — Thu, 27 Oct 2011 17:31:03 GMT

The problem is thus...

I need to get the X/Y of the initial point but it needs to be in DD. This value is passed back to a map service. But I also need to calculate the distance from the above point to surrounding polygons but need to give that data in meters or feet.

Since all of this will be done for a web application time is critical. The fewer geoprocesses I need to employ the better.

Re: Generate Near Table

ScottBlankenbeckler — Thu, 27 Oct 2011 17:44:13 GMT

Figured it out.

Just needed to set the output coord system for the geocode to a projected coord system and it still gave me x/y in lat/long but allowed to do near table in meters.