[GRASS-user] Determining Datum From Projection Coordinates [SOLVED]

[Rich Shepard]

On Thu, 3 Mar 2011, Tom Russo wrote:

> This is true of State Plane Coordinate Systems in NAD27, but not UTM.

Tom,

   That looks famililar.

> FWIW, it looks like since your lat/lons are specified at such low
> precision, the NAD27/NAD83 datum shift might be irrelevant.

   I decided to use the lat/lon because no datum is applicable until it's
projected.

> Of course, the *best* way to determine the datum would be to query the
> agency that produced the data...

   Er, ... I don't think they'd know. Considering the state of the flat file
(an Access table), and the lack of completeness of some attributes (such as
depth to bedrock), I'll go with what I have. And, these data originated with
the folks who dug the wells so ...

Thanks,

Rich