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I have two shapefiles. One is an original route polyline file and another is an updated polyline file, where the shape is modified to google maps.

How can I compare the updated shapefile with the original and report how much shift or variation is there in the second file, with reference to the original ?

There seems to be a feature compare tool in ArcGIS , but seems that it will not suit the purpose.

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  • better you can use select by location and option is identical option
    – user9213
    Jul 30 '12 at 16:58
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this technique will give an approximate deviation in the shift...

convert the original and modified line data to point features (feature to point in arcgis desktop 10). Then perform "Near" option. This will give the distance between the original and the modified.

From the distance value in the output, you can filter the extreme deviations and then average the values.

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Perhaps you are talking about a "shift" that happens due to different geographic coordinate systems. If thats the case, one method is to find which two GCS are present and find resources that discuss the differences.

If you have two shp files that clearly are consistently off, then one (or both) or the shp files probably have the wrong GCS defined. You could compare the difference in X and Y shift by inspecting the "extent" of each file (in ArcGIS, this is is layer properties, source tab), and do some simple subtraction either using scripting, or just pencil & paper.

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  • No youzer..i am not referring to the shift due to different CRS. Rather I need to report the corrections and shift in meters which happened to the original data, when I preferred to correct it using google maps base layer. Jul 26 '12 at 4:48
  • Youzer, welcome to our site! Even though your reply does not appear to answer the question as clarified, it's still insightful and good advice: thank you for your contribution.
    – whuber
    Jul 26 '12 at 12:33
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    Hi Adarsh, I'm still not certain what you are asking. What base layer did you orginially use to digitize the polyline? Are you talking about a systematic shift, or shifts only to some parts of the polyline?
    – youzer
    Jul 26 '12 at 20:31
  • Youzer, not clear about the source from which base layer (shape file) was created.But when it is checked with google maps, it has lot of shift, so we are correcting it. is it possible to quantise these corrections like Average shift > 1 m , or % of segments with more than 1 m shift with Original shape file = 12,000 etc. Jul 31 '12 at 12:39
  • Adarsh, it sounds like you do have a systematic shift occuring. While you can manually correct it and report that shift in several ways as you mentioned, a more elegant solution might be trying to redefine the GCS of that shp file. I forget how Google Maps/Earth exactly works with GCS/projections of files that come in, but Google certainly has a consistant GCS. You could try redefining your shp file's GCS to Google's and see if that fixes the shift for you. If you are "reporting the shift correction" instead, it is a bit of a hack -- the file is no longer as reliable a source as it could be.
    – youzer
    Jul 31 '12 at 16:41
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If you are interested in change detection then may be this python script will help you in identifying the updated feature between two version of layers.

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  • The link in this answer is broken.
    – PolyGeo
    Aug 23 '15 at 4:15

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