[aprssig] conveying map view
archer at eskimo.com
Wed Sep 22 14:15:51 CDT 2004
On Tue, 21 Sep 2004, Bill Herrmann wrote:
> At 05:10 PM 9/21/2004 -0700, Curt Mills wrote:
> >I'm starting to like the idea of posting an object of a certain
> >format, rather than a message. If it had a standard format, clients
> Curt's onto something here. APRS clients already support it and...
Let's keep things straight here: It was A.J. Farmer's idea, and a
> (from the APRS spec - in the object/item section)
> The position may be in lat/long or compressed lat/long format, and the
> report may also contain Extended Data.
> Guess what we already have in the extended data definitions... Range!
> (from the APRS spec)
> The 7-byte RNGrrrr Data Extension allows users to transmit a precalculated
> omni-directional radio range, where rrrr is the range in miles (with
> leading zeros). For example, RNG0050 indicates a radio range of 50 miles.
> Sounds to me like it is an already defined frame that can contain both
> center and range information. Not only that, but objects, by definition,
> are supposed to include the senders callsign. (I should note that either
> objects or items would appear to work.)
> The only compromise involved is to change the range meeting from RF range
> to range of map view. I think most of us would agree that that is a
> reasonable change.
So we just need to key off something special in the packet, whether
it be an "eyeball" symbol with an included range field, or what.
This is starting to sound very cool. Good find!
Curt, WE7U http://www.eskimo.com/~archer
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