[FWTools] Off Topic Projection Issue State Plain

Jamie Adams jaadfoo at gmail.com
Fri Feb 20 17:42:49 EST 2009


I can't answer which states use ft vs m, but I can tell you there are EPSG
stateplane definitions that use feet.  Look in the gdal or proj folder under
share - in either there is a similarly named file esri_extra.wkt, or
esri.extra.  These have the alternate stateplane defs.

-Jamie

On Fri, Feb 20, 2009 at 1:36 PM, Travis Kirstine
<traviskirstine at gmail.com>wrote:

> I am looking for some insight to the state plane coordinate system nad
> 83.  According to the National Geodetic Survey the published unit is
> the meter.  However individual states can legislate to have survey
> foot as the unit.
>
> From ESRI Docs
> http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=State_Plane_Coordinate_System
>
> "The standard unit of measure for SPCS 27 is the U.S. Survey foot. For
> SPCS 83, the most common unit of measure is the meter. Those states
> that support both feet and meters have legislated which feet-to-meters
> conversion they use. The difference between the two is only two parts
> in one million, but that can become noticeable when datasets are
> stored in double precision. The U.S. Survey foot equals 1,200/3,937 m,
> or 0.3048006096 m."
>
> I have looked through the  epsg / stateplane.csv files and notice that
> all the units are in meters for coordinate systems using Nad83. I am
> trying to determine if any states are officially using us survey feet
> as the unit for the SPCS 83 projection.  Any insight would be much
> appreciated.
>
>
>
> --
> Travis K.
>
> Toronto, Canada
> ------------------------------------------------------------
> "She knows there's no success like failure
> And that failure's no success at all."
> -Bob Dylan-
> ------------------------------------------------------------
> _______________________________________________
> FWTools mailing list
> FWTools at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/fwtools
> http://fwtools.maptools.org/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.maptools.org/pipermail/fwtools/attachments/20090220/6afcbd44/attachment.htm 


More information about the FWTools mailing list