[aprssig] Re: Aerial or Satellite Photos/Map for APRS Use

[Curt, WE7U]

On Mon, 17 Dec 2007 mconner at aer.com wrote:

> Many states have high-resolution photos for agricultural and
> survey purposes, but you may need ArcMap or similar software to
> rigorously rectify them to a lat/lon grid.  You can try Googling
> for "Farm Service Agency" or FSA and something like "orthophoto".
> Nebraska has some 1-meter imagery available for this.

There are open-source ways of doing some (most?) of the
warping/georeferencing as well, but require some knowledge to know
how to use them.  Some who can self-study and is motivated enough
can figure it out.


> You can also try the USDA's website at
> http://datagateway.nrcs.usda.gov/ and see if they produce
> something in a useful format for you.  It appears any of their
> recent ag survey imagery is only available in a MrSID format,
> which will require a GIS client like ArcMap for use.

Or the free viewer to convert it back to the non MrSID
representation of the file first.   They usually make these viewers
available for Windows and Linux.

--
Curt, WE7U: <www.eskimo.com/~archer/>     XASTIR: <www.xastir.org>
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