[aprssig] OBJ engine on APRS-IS (lat/long format)

Bob Bruninga bruninga at usna.edu
Fri Feb 24 12:14:14 EST 2012


> The problem I have with the co-ordinates is that hessu's 
> library only supports decimal degrees for lat/long. 
> So everything has to be in that format.

We must be very clear to distinguish how things are coded and handled
internally from what is the APRS human interface.  It may be easier for
programmers to deal in decimal degrees, but everything presented to the user
should be in the APRS standard of DDMM.mm and DDDMM.mm. (or DD MM.mmN etc)
We must remember it is the end user we are serving, not programmers.

> Since the Item-As-Message is a standard APRS Item packet 
> in the message text, the coordinates will be APRS-standard, 
> albeit scrunched together on today's radios.

Yes, the scrunch was intentional since the APRS standard fields are DDMM.mm
and DDDMM.mm.  The spec was intended to cleary make that HUMAN interface to
avoid the tower-of-babble we hear when voice users try to describe a
LAT/LONG.

I hope the "Item-As-Message" is just a typo and not an attempt to introduce
yet another protocol, since the APRS documented name for this is
"Item-in-Message". 

Bob, WB4APR 





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