[GRASS5] m.proj Difference?

Jeshua Lacock jeshua at SierraMaps.com
Sat Jun 8 19:56:31 EDT 2002

On Friday, June 7, 2002, at 04:43 AM, Glynn Clements wrote:

>> I entered all of the same projection values as I did before, and when I
>> attempt to convert the same values I converted with Beta 11, I get
>> results in the Y within 0.7 meters, and the X is off by about 510
>> meters. I get similar results with adjacent coordinates being off by a
>> slight amount positively or negatively based on the direction traversed
>> from the first test point.
>> All of the coordinates that I converted with Beta 11 are on the money,
>> and I need to convert some more because of a data loss.
>> It seems like it must be a datum shift or some slight difference in the
>> ellipsoid parameters.
> Unlike earlier versions, the pre4 version of the proj library performs
> datum shifts. Ensure that both locations have the correct datum.

Hi Glynn,

They are both in the NAD 27 datum, spheroid Clark66, 6378206.4, 

Do you know how I can ensure that I am entering the datum parameters 


Jeshua Lacock __________________________
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http://OpenOSX.com           Fax:        760.935.4845

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