[postgis-devel] [PostGIS] #1052: Tiger Geocoder 2010 Geocode() "squishing" toward end of block

PostGIS trac at osgeo.org
Thu Oct 13 10:12:13 PDT 2011

#1052: Tiger Geocoder 2010 Geocode() "squishing" toward end of block
  Reporter:  mikepease       |       Owner:  robe         
      Type:  enhancement     |      Status:  reopened     
  Priority:  medium          |   Milestone:  PostGIS 2.0.0
 Component:  tiger geocoder  |     Version:  trunk        
Resolution:                  |    Keywords:               

Comment(by mikepease):


 I found tlid = 43639801
 and gid = 330411 and gid = 368926
 in the tiger.mn_addr table.

 I changed the "tohn" fields to be 3252 and 3253 for the max address on
 that block..

 Then I tried:

 select st_x(geomout), st_y(geomout), *
 from geocode('3253 32nd Ave S   Minneapolis     MN      55406')

 That moved the latitude south as expected to the end of the block where it
 To be precise, it moved it slightly too far south, I think for two

 1) The geometry for that street line segment actually goes a little
 farther south than the more precise MN-DOT street file I have and farther
 south than Google's street data too.  The difference here is maybe about 5
 to 10 meters.

 2) Also, I think maybe your interpolation might put the point at the very
 edge of the block rather than have a bit of a "margin" from the end.  I
 would think the top and bottom edges should be offset 10-20 meters from
 the end of the line segment because a house wouldn't likely be on the very
 edge of the segment.  I think the end of the segment is at the center line
 of the cross street, so you'd need to compensate a margin to get the point
 off of the street and centered a bit on that last parcel on the street.

 Anyway, that's seems to be the more minor issue here.  The big issue
 appears to be that the Tiger data commonly has the incorrect "tohn" (max
 address number) for its address tables.

 That could be an icky problem.
 What are your thoughts?

Ticket URL: <https://trac.osgeo.org/postgis/ticket/1052#comment:16>
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