[Xastir] CAD object transmissions?

[Craig Anderson]

I'm approaching this from the perspective of the
balloon recovery effort I helped with last weekend.
What I did was virtually the same as all Civil Air
Patrol searches and probably a good portion of
"normal" S&R operations.  An airplane and a
number of ground search teams where you can't
physically get together and compare maps.

I would need these to go over the APRS channel
(or should I say frequency).  That APRS channel
could be co-resident with a TCP/IP over AX.25 KISS
channel that I suppose could really be carrying the
CAD objects.  But I suppose that shoe-horning this
into the existing APRS standard as much as possible
would be the simplest approach, even if Xastir was
the only application that really understood the extra
bits in the packets.  The APRS Multiline protocol looks
like a great place to start and add a few extra bits.

Functionally, I would like to have everyone be able
to see the same picture and, in effect, treat the Xastir
map as a shared blackboard.  A CAD object with a
small text string attached, even if that text string is only
accessible by bringing up the "Station Info" on the object.
This should include Xastir being able to "digipeat" those
objects, even if other normal APRS digipeaters may
not be able to retransmit them.

We plan on running most of our frequencies other
than 144.39 to reduce the clutter of all the other
stations and avoid the overwhelming congestion
of way too many digipeaters in some areas.  So
we don't plan on depending on a lot of pre-existing
digipeaters.  And I'd rather not depend on an SQL
database.

The ability to send out a "cancel" packet to remove
a CAD object would be good.  Or maybe that should
be an "update" packet, where one of the updates is
"remove", then everyone can update an object.
Suppose we add a "}U" or "}C" to the end of the APRS
Multiline protocol packet to do the update or cancel.
I, myself, am not concerned about interoperability
with other programs since I can specify everyone
run Xastir and the value added is worth the effort.

I'm imagining a HAZMAT incident in a town and the
EOC starts marking off road closures, command posts,
decon areas, shelters, and down-wind evacuation areas.
Everyone can see the whole picture, just like a status
board.  And others can add new problems to the board.

Am I going too far with this?

Count me in as a beta-tester, along with my RACES group.

Craig


On May 16, 2007, at 2:08 PM, Curt, WE7U wrote:

> On Wed, 16 May 2007, Craig Anderson wrote:
>
>> That would be hugely useful to me.
>>
>> The ability to create a coordinated, distributed,
>> common operating picture for a search & rescue
>> effort.  Like NetMeeting for S&R.
>>
>> Could I talk someone into that?  :-)
>
> Question:  Would multiple clients talking to a central SQL database
> (thereby getting the same information and generating similar views)
> suit your purpose, or do you have a need to transmit the info across
> APRS channels?  Both?
>
> --
> Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
> "Lotto:    A tax on people who are bad at math." -- unknown
> "Windows:  Microsoft's tax on computer illiterates." -- WE7U
> "The world DOES revolve around me:  I picked the coordinate system!"