[postgis-users] What SRID is the USGS 24k Quad Grid?

[Paragon Corporation]

 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 at refractions.net] 
Sent: Monday, October 30, 2006 11:14 AM
To: lr at 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 at fuhr.org]
> Sent: Sunday, October 29, 2006 10:14 PM
> To: lr at 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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