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I have two files:

  1. A point shapefile containing latitudes and longitudes of points.
  2. A .kml file that I am converting to a line shapefile.

Objective: To find the minimum perpendicular distance of the points from the lines. Suppose we have four points p1, p2, p3, p4 and two lines l1, l2. For point p1, I have to find the distance of the closest line. Same for other points.

I joined the line shapefile on point shapefile. As a result, I get an extra field in the point shapefile. The extra field denotes the required minimum distance. The problem is that I do not know the unit of this distance. I am using NAD 1983 geographical coordinate system (GCS) whose angular unit is degrees.

I tried changing the GCS of both point and line shapefiles to a projection coordinate system with distance units as meters. However, this displaces the points far away from the lines (virtually not displaced at all) in ArcMap. Consequently I get the distances in thousands of miles, which is erroneous.

Please suggest a way out.

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    Changing the projection of the data frame is one of the best answers, so you probably want to rewrite the question to address how your attempt failed, so your procedure can be corrected. – Vince May 10 '15 at 20:52
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    I would suggest that the point shape file doesn't have a spatial reference defined or that a transformation is required between what it is and what you want it to be, the KML should be WGS84/Geographic which is manditory from the KML spec.. what projected CRS are you using? Does it suit your data? How are you applying the projected coordinate system? You will get "correct" angles in geographic but your distances will be in DD, the angles will change slightly in projected coordinates... perhaps create a field and copy your angles before they're overwritten (if that's important). – Michael Stimson May 10 '15 at 22:53
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I realized my mistake and figured the way out.

Mistake: My point data was in a csv file. Since I wanted my distance to be in meters, while converting csv to shp, I was straightaway choosing a projected coordinate system (PCS). Probably, the ArcMap was not able to define a spatial reference and hence was locating the points far away from where they actually were.

Solution: I first converted the csv to shp using WGS84. And then converted it to a PCS. I also converted the line shapefile which was in WGS84 to the same PCS. Then I joined the line shapefile on the point shapefile. This gave me the required distance.

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