[aprssig] Extending javAPRSSrvr's dupeTime
Pierre Thibaudeau
ve2prt at sympatico.ca
Mon Sep 22 21:36:53 EDT 2008
Today, 17:26 -0700, Keith VE7GDH wrote:
> Pierre VE2PRT wrote...
>
> > The target I was following was a balloon and it appeared to be
> > bouncing up and down. (See the altitude value.)
>
> My question would be why on earth was the balloon using a path of
> WIDE1-1,WIDE2-2? That's a three hop path that would have triggered every
> WIDEn-N digi including the "WIDE1-1 only" digis out to the horizon.
> Their path is part of the problem. If digis are causing the delays, much
> of the problem can be eliminated by not going through so many digis. The
> more digis it goes through, the more chance of it going through one that
> can cause a delay. However, from an altitude of less than 3000 feet at
> least in the samples you provided, maybe the impact wouldn't be huge.
Thank you for your observations. I will follow up locally.
However, these balloons climb to 75000+ft so they are heard by quite a
number of digi's anyway. Even if they are not digipeated on RF, they
are going to be sent over the Internet many times.
>
> # 1221916877 sam sep 20 09:21:17 EDT 2008
> VE2WMG-10>APOT03,VE2RAW-3,WIDE1*,WIDE2-2,qAR,VE2PCQ-3
> :/201321z4519.15N/07322.31WO006/020/A=000949
> 10.1V 19C HDOP01.1 SATS07
>
> # 1221916921 sam sep 20 09:22:01 EDT 2008
> VE2WMG-10>APOT03,VE2RAW-3,WIDE1*,WIDE2-2,qAo,VE2HOM
> :/201321z4519.33N/07322.16WO060/017/A=001382
> 10.1V 19C HDOP01.0 SATS08
>
> Both of the above went through VE2RAW-3. Therefore, VE2PCQ-3 and VE2HOM
> should have heard the beacon at exactly the same time. It appears there
> was a delay of abut 44 seconds.
>
> # 1221916927 sam sep 20 09:22:07 EDT 2008
> VE2WMG-10>APOT03,VE2RAW-3,WIDE1*,WIDE2-2,qAo,VE2FET-1
> :/201321z4519.15N/07322.31WO006/020/A=000949 10.1V 19C HDOP01.1 SATS07
>
> Above, it was gated again another 6 seconds after VE2HOM gated it.
> VE2FET-1 should have heard it via VE2RAW-3 at exactly the same time as
> VE2CPA-3 and VE2HOM.
Packets #1 and #2 above are different (see the coordinates and altitude).
The target has traveled horizontally and climbed some 433ft.
Packet #3 is a repetition of packet #1, received 50 seconds after the
original #1.
Overall, if we take out all packets that have transited through VE2FET-1,
all is fine.
'73 - Pierre
__
Pierre Thibaudeau
VA2RKA/VE2RIO/VE2RVR/VE2RQF/VE2RTO/VE2LKL sysadmin
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