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List:       postgis-users
Subject:    RE: [postgis-users] What SRID is the USGS 24k Quad Grid?
From:       "Paragon Corporation" <lr () paragoncorporation ! com>
Date:       2006-10-31 11:48:00
Message-ID: 00ea01c6fce2$6a88da80$2e9b2e40 () n
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 Thanks Paul and Mike,

The closest match to this in the table appears to be 2163.  I think Mike Fuhr was \
right about the 4167, and then I projected that to 32661, but depending on which \
software I used to display 32661 it either looked straight-up or was rotated 90 \
degrees.  Projecting to 2163 gave more appealing results.  I guess 32661 is missing a \
parameter that different software are guessing at.

Anyrate - I have another problem.  The quad24 is nice but a little too granular and \
the quad100 is not granular enough.  I'm guessing  I need to simplify the geometry.  \
Would I use the simplify function for that?  I recall when I did that, I got some \
bizarre holes, but that could be because I wasn't sure what to put in for tolerance.

Thanks,
Regina

-----Original Message-----
From: Paul Ramsey [mailto:pramsey@refractions.net] 
Sent: Monday, October 30, 2006 11:14 AM
To: lr@paragoncorporation.com; PostGIS Users Discussion
Subject: Re: [postgis-users] What SRID is the USGS 24k Quad Grid?

I've seen that grid once apon a time... is it this?

PROJCS["USA Lambert",GEOGCS["GCS_USA_Sphere",DATUM
["USA_Sphere",SPHEROID["SPHERE",6370977.0,0]],PRIMEM["Greenwich",
0],UNIT["Degree",0.017453292519943295]],PROJECTION
["Lambert_Azimuthal_Equal_Area"],PARAMETER["False_Easting",
0],PARAMETER["False_Northing",0],PARAMETER
["Central_Meridian",-100],PARAMETER["Latitude_Of_Origin",45],UNIT
["Meter",1]]


On 30-Oct-06, at 12:34 AM, Paragon Corporation wrote:

> 
> No that didn't work. The actual data is not in degrees.  I think its 
> in meters of some sort, but not sure which one.  My fear is that its 
> more than one SRID like it's a set of UTM ones and so I would have to 
> change my SRID for each slice as the UTM zone changes.
> 
> Thanks,
> Regina
> 
> -----Original Message-----
> From: Michael Fuhr [mailto:mike@fuhr.org]
> Sent: Sunday, October 29, 2006 10:14 PM
> To: lr@paragoncorporation.com; PostGIS Users Discussion
> Subject: Re: [postgis-users] What SRID is the USGS 24k Quad Grid?
> 
> On Sun, Oct 29, 2006 at 09:34:58PM -0500, Paragon Corporation wrote:
> > I wanted to use the USGS 24K Quad Grid for some statistical analysis.
> > Unfortunately I don't know what the spatial reference system is that 
> > is used.
> > 
> > The file is located here
> > 
> > http://data.geocomm.com/catalog
> > 
> > and is the USGS 24Quad Grid file.
> 
> I didn't see any metadata so I'd guess 4267 (longlat NAD27) or maybe
> 4269 (longlat NAD83).
> 
> --
> Michael Fuhr
> 
> 
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> postgis-users mailing list
> postgis-users@postgis.refractions.net
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