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[aprssig] Packet errors

Steve Dimse steve at dimse.com
Sat Dec 23 00:23:14 UTC 2006


On Dec 22, 2006, at 6:21 PM, Bogdan, Rick wrote:

> Can anyone tell me what's wrong with this packet?
>
> ka1udx>APRS,TCPXX*,qAX,T2WXCWOP:@222322z1234.56N/ 
> 01234.56W_045/001g006t042a1wka1udx>APRS,TCPXX*,qAX,T2WXCWOP:@222322z12 
> 34.56N/01234.56W_045/001g006t042a1w
>
> It shows up at FindU.com as a bad packet.
>
Presuming that you simply hit the paste button twice, explaining the  
double packet (it does not show double on the findU error page or the  
raw data page) it is a weird side effect of using a made up lat/lon.  
Many trackers and programs send zeros as a lat/lon when none is  
entered. I could test for this with a compound boolean like

(($lat == 0) && ($lon == 0))

instead I just use

($lat+$lon == 0)

Since western hemisphere lats are represented as negative, the sum of  
the lat and lon you are sending add up to zero.

I didn't intend for this test to look for people that enter the same  
made up number for lat and lon, but it does, and it caught you! You  
should not be sending bad positions, it makes maps in all the clients  
look screwy, and messes up things like my near page.

Enter your correct latitude and longitude and it will work fine!

Steve K4HG




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