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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Where exactly did you get this <st1:State
w:st="on"><st1:place w:st="on">California</st1:place></st1:State> data set, and
what projection/datum documentation came with it? Various distributors of
TIGER data, especially state governments, have massaged the data to various
state plane projections. Any information you have about the source would be
helpful; in addition, how is the input projection being described to ogr2ogr?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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</span></font></span></span></font><![endif]><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>Ed<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Ed McNierney<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>TopoZone.com<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
gdal-dev-bounces@xserve.flids.com [mailto:gdal-dev-bounces@xserve.flids.com] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Martin, Daniel A<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, February 02, 2005
5:09 PM<br>
<b><span style='font-weight:bold'>To:</span></b> gdal-dev@remotesensing.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [Gdal-dev] Problems with
ogr2ogr and TIGER line data - Californiais a bit off</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I've been using ogr2ogr for some time (Windows binary from
OpenEV_FW) to convert the entire TIGER line data from the census into workable <st1:Street
w:st="on"><st1:address w:st="on">Map<st1:PersonName w:st="on">Info</st1:PersonName>
TAB street</st1:address></st1:Street> layers. Something we
recently noticed is that our resulting streets in <st1:State w:st="on"><st1:place
w:st="on">California</st1:place></st1:State> are off by a about 1/10th of a
mile. Nothing terrible, but enough to make them unusable for our
purposes. I went to check my old files to see if the problem is new, but
I found it in the files I was creating about two years ago. I've done
very little work in <st1:State w:st="on"><st1:place w:st="on">California</st1:place></st1:State>,
so I've never noticed it before.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I started to think this was a projection issue. So, I
started checking other states throughout the country. I've not checked
them all, but all the other states I have checked are absolutely dead on.
This includes states from all corners (<st1:City w:st="on">Washington</st1:City>,
<st1:State w:st="on">New York</st1:State>, <st1:State w:st="on">Florida</st1:State>)
and in the middle of the country (<st1:State w:st="on">Missouri</st1:State>, <st1:State
w:st="on"><st1:place w:st="on">Illinois</st1:place></st1:State>). But <st1:State
w:st="on"><st1:place w:st="on">California</st1:place></st1:State> appears to be
the only one that is incorrect. This also appears to affect all of <st1:State
w:st="on"><st1:place w:st="on">California</st1:place></st1:State>, and isn't
isolated to one small part.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>As a control, I've used several of our internal data layers
that I'm quite confident in, and the Microsoft Terraserver WMS layer.
Terraserver makes it really easy to see when streets are off.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Another oddity is that this effect is lessened if the layer
is loaded into MapServer (versus Map<st1:PersonName w:st="on">Info</st1:PersonName>),
I'm guessing since MapServer uses OGR. The data is still out of place in
MapServer, but not quite as much. We've tested the data in multiple
versions of Map<st1:PersonName w:st="on">Info</st1:PersonName> just to be sure
that wasn't part of the problem.</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Any ideas on why this would happen? I'm using the
basic command line options for ogr2ogr.</span></font><o:p></o:p></p>
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