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[aprssig] The best resolution of position from APRS

Robert Bruninga bruninga at usna.edu
Tue Jan 3 16:26:41 UTC 2006


>>> scott at opentrac.org 01/03/06 10:36 AM >>>
>> Bob said that no one should use it at all, lest the be 
>> tempted to use it on an Object or Item which wouldn't be 
>> decoded by the  Kenwoods.
>
>That's OK... in a few months, everyone can just 
>buy one of my new trackers.=]  They'll already 
>do compressed items/objects...
> Doesn't bother me at all if Kenwood doesn't want 
>to fix their firmware!

Scott, remember we went through all this when you
first came to APRS and wanted to change everything
with an all new protocol.  It is not Kenwood you would
be screwing up, it is 10,000 existing APRS users of 
kenwood radios.

Compressed objects were obsoleted in APRS1.1.
We know that the 10,000 kenwoods out there do 
not properly display the object name of a compressed
object.  There is nothing going to change that.
And since 85% of all mobile users that RECEIVE APRS
data and display it while mobile use the kenwoods,
it makes no sense to use it.

Having you put into your trackers  the ability to 
generate obsolete and unsupported compressed 
objects is just putting a time-bomb into the APRS
system that will just guarantee that 85% of all mobile 
operators won't see them if an open-tracaker
happens to unknowingly use it.

Please consider working within the limitations of
APRS so that we dont end up with a tower of
babble and undermine the ability of end-users
of APRS to comuncate objects.  No matter what
hardware or software they use.

Last time this came up, we presented a modification
to the EXISTING formats that would be 100%
backwards compatbile to all existing software, 
hardware and firmware, yet would give finer
resolution down to a foot.  ALSO and of equal
importance it included the DATUM as well.  SInce
in my opinion, sending that kind of precision is 
useless if the datum is not included.

See the spec:
http://www.ew.usna.edu/~bruninga/aprs/datum.txt

If users need greater precision, use that option.
not the obsolete compressed object format.

Thanks
Bob







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