[aprssig] UTM grid (was: APRStt for SAR using...) Yes!

Tom Hayward esarfl at gmail.com
Fri May 17 01:52:01 EDT 2013

On Thu, May 16, 2013 at 9:20 PM, Greg Higgins <gs.higgins at sbcglobal.net> wrote:
> Hate to disappoint you Bob, but you have bad information regarding SAR
> groups. As of 2008, DHS / FEMA mandated ALL SAR groups to transition to
> USNG. This had a lot to do with Hurricane Katrina and the large number of
> SAR teams from around the country that responded that were using a
> hodgepodge of different datum's that caused confusion and problems.
> And your statement; " And all SAR folks are required by training to know how
> to read a UTM grid map which they are *required* to use" was true until
> 2008. Now they are required to use USNG. The national USAR groups have
> adopted USNG, it is incorporated in their training and DHS / FEMA have
> courses available for training purposes.
> The USNG Standard:
> http://www.fgdc.gov/standards/projects/FGDC-standards-projects/usng/fgdc_std
> _011_2001_usng.pdf
> There is a lot of information available, Google it.

The proposal Bob posted is 100% in compliance with the USNG spec--no
disappointment or transitioning required. UTM and USNG share the same
grid, and the 6-digit UTM grids he is talking about are identical to
USNG truncated grid coordinates (see page 17 of spec linked above).
For any search less than 10,000 sq km, there is no difference between
6-digit UTM grid and USNG. If the guy transmitting was using UTM and
the receiver thought it was USNG, it wouldn't matter because they both
plot on the same point on the map.

Bob is not a SAR professional, so I think we can excuse him for not
using the modern acronym for a familiar old grid system. Besides,
Bob's point was that APRStt works with any grid system.


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