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Difference accuracy between identify tool and Measure tool. (big Problem)

Question asked by dllamasgmtgis-esridist Employee on Nov 29, 2016
Latest reply on Mar 2, 2017 by abdallah_91@yahoo.com

Hi everybody

 

We are facing a very importan issue in our production site, for any particular geometry in our published parcel map (polygon fc) we see different values for shape area.  Figure 1 shows a value of 2719.06456 in SHAPE.STArea().  This is from the Identify window.

 

 SHAPE.STArea

When using the “Measure a Feature” option in the Measure Tool we see a value of 2435.802941.

 Measure a Feature 

This feature class is generated from a copy of the original parcel map on our production database and as you can see below, it shows an area of approximately 2435.761602 (it also shows a slight difference in the value in the windows but is pretty close).

 feature classgenerated from a copy of the original parcel map on our production database 

The published map is created from a spatial view by joining a copy of the production map with a table from our tax database. 

 

Questions:

  •      Why the slight difference when using the identify tool and the Measure Tool?
  •      More importantly…Why the different values when comparing the production and the published maps?  The Measure Tool looks like is providing the correct value.

This is a big problem for us since we published the area information so our users can analyse assessment values for the properties and compared with the tax system.

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