[aprssig] Object Tip o' the Day

John Gorkos jgorkos at gmail.com
Fri Jun 10 16:19:05 EDT 2011

If you're one of the remarkably helpful people injecting Objects into the APRS 
network, PLEASE follow the spec.

Just as an example, here's an anonymized beacon that's being injected into the 

NXXXX-10>BEACON,qAR,W8DF-5:;147.00+*111111z4212.85N/08536.57WrKARC RPTR PL94.8

The object name is "147.00+".  However, according to the Spec, Chapter 11 for 
"Object Report Format -- with Lat/Long position", the Object name is a 
mandatory 9 characters long.  So, on both my parsers and the Perl parsers, 
this beacon blows up, nothing makes it to the maps, and puzzled looks abound.
I'm not sure what the firmware parsers do (Argent, Kenwood, Yaesu, etc) with a 
non-spec-following packet.

Just wanted to pass this along.  I've sent three helpful emails to beacon-
broadcasters today because I believe beacons are the Right Thing, but they 
need to be done the Right Way.

Also, while I'm on my soapbox.. 
WTH is wrong with people and coordinates and APRS?  Really, is it that hard?
Let's play "Find what's wrong with these positions":

Nice try, but you can't have a "Minutes" value in your Latitude over 60.

This is bafflingly wrong.  43.233N 77.1W isn't the right format.
Both of these first two came from "wview" software, it seems.   Perhaps the 
author could do some verification?

Not only do you not know where you are, you tell the world in the wrong 
format.  It doesn't matter if you're parked on the Prime Meridian, you have to 
give me an E or a W to fit the spec.

!4520.34N/1620.20E#9A7S-10 APRS4R IGATE
Fail on Longitude.  Need 5 digits before the decimal.  At least we know this 
guy is East of the prime meridian.

!2111,72N/101136.09W#PHG47506/ http://craeg.remtronic.com
Comma, period, they're all pretty much the same, right?  Not too sure about 
the 6 digits in the Longitude, either.  Perhaps there's some wraparound effect.

;146.920- *111111Z4328.18N/0854.76WrT094 R20m Fremont Rptr
This one gets the "SO CLOSE" award.  He actually space-padded the object name 
(see top of message, before I started ranting), then managed to dork up the 
Longitude with 4 instead of 5 digits left of the decimal.

!494713N/00917.48E#APRSsop DH4FAJ 
If my wife missed periods the way hams do, I'd need three jobs to pay for all 
my kids.

Short, sweet, and almost missing the point.  The "/" is the SYMBOL TABLE, the 
missing character at the end of the message would tell me what symbol to 

=5120.94N/0.01W/www.nehr.org.uk {UIV32}
Another guy withing spitting distance of the Prime Meridian, and unwilling to 
spend the zeros to tell the rest of us about it.

!5000.01/01208.22E# (APRS DIGI Marktredwitz) 1
We could ASSUME North here on the latitude, but the spec doesn't allow for 

; 146.760-a*000000z3802.17NS08424.17W#PHGphgd/R,SSn,Wn BARS Digi in Lexington, 
Another object that was SO CLOSE.  Corrrectly padded to 9 characters, then the 
"S" in place of the symbol table.  Note:  this COULD be correct.  Someone tell 
me if it is.  Is this the correct format for an overlay icon?

All of these packets came across APRS-IS in the space of about 30 seconds.  
take a gander here:
at the "Number of packets received from APRS-IS per second" graph.  See that 
red fuzz at the bottom?  That's ignorance and laziness manifesting itself in 
our network.  This is the place to be involved.  This is where people like the 
ones on this list can stand up and say "Stop polluting our ether with bad 
packets."  Software developers - put simple checks in place to keep your users 
from spewing garbage into the spectrum.  Use APRS.FI and look at the stations 
in your neighborhood in RAW PACKET mode.  If you see red, do a little 

John Gorkos

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