[aprssig] odd siting in these here parts

Keith VE7GDH ve7gdh at rac.ca
Sun Sep 14 10:54:10 CDT 2014


MJ KE6SLS wrote...

> I can't image why, but aprs.fi shows my car going 600MPH
> through town. Is it a joke?

No. The site aprs.fi is just going by the data received.
Hessu - please read to the end.

While you might occasionally go quantum from time to time,
or your flux capacitor needs adjusting (I have some for sale
pon eBay if you can't get it back in adjustment) there are
other possible explanations.

2014-09-07 14:50:38 PDT:
KE6SLS-9>T0TWUU,WIDE1-1,WIDE2-1,qAR,KE6SLS
:`4&tl!l>/`"3l}146.700MHz T103 -060 Electric cowboy-Waahoo_"

and then after another 14 beacons (that made it to an
iGate) comes this one which looks familiar...

2014-09-07 15:44:04 PDT:
KE6SLS-9>T0TWUU,KE6HEC-3*,WIDE1*,KE6NVU*,WIDE2*,qAR,W6DWY
:`4&tl!l>/ [Rate limited (< 5 sec)]

While it is possible that your GPS is putting out bogus
data sometimes, or if it's possible, your FTM-350 has been
told to use data from the GPS when it doesn't have a valid
fix (no idea of the FTM-350 is capable of that), in this
particular instance, you are dealing with a delayed packet.

The two beacons that I pasted above are (ALMOST) one and
the same beacon. The second one didn't include the frequency
and the comment... 146.700MHz T103 -060 Electric cowboy-Waahoo_"
The first one was heard direct and gated by KE6SLS. The
delayed on was digipeated by KE6HEC-3 and KE6NVU and finally
gated by W6DWY. Either of the digis or the iGate could have
introduced the delay. You could study the raw data for a while
and eventually which was responsible. The two beacons aren't
identical, because the delayed one didn't include the comment,
but the likelihood of two beacons 55 minutes apart having
identical positions is somewhat low.

MJ - while you might be an electric cowboy in the habit of
saying "wahooooo" all of the time, sending it with (almost)
every single beacon makes your beacons much longer. This
reduces time slots available for others, and lessens the
chance of your own beacons from being decoded. Perhaps you
could tell the FTM-350 to just send it every 10 beacons
or whatever.

Digging further, I was gong too say that it appears that you
are using the same callsign-SSID for an "XASTIR-Raspberry Pi Igate"
and that the solution is to use a different SSID for each station,
but see below!

http://aprs.fi/?c=raw&call=KE6SLS-9&limit=100&view=decoded

2014-09-06 11:11:45 PDT:
KE6SLS-9>T0TXRU,WIDE1-1,WIDE2-1,qAR,KE6SLS
:`4a,lR<0x1c>>/`"4'}147.000MHz T103 +060 Electric cowboy-Waahoo_"
    type: location
    format: mice
    srccallsign: KE6SLS-9
    dstcallsign: T0TXRU
    latitude: 40.80416666666667 °
    longitude: -124.1526666666667 °
    course: 0 °
    speed: 9.26 km/h
    altitude: 16 m
    symboltable: /
    symbolcode: >
    mbits: 101
    posresolution: 18.52 m
    posambiguity: 0
    comment: `147.000MHz T103 +060 Electric cowboy-Waahoo_"

The comment in the following one appears to be truncated. I
don't know if aprs.fi truncated it, or if it happened before
it made it to the APRS-IS.

2014-09-06 11:11:47 PDT:
KE6SLS-9>T0TXRW,KE6HEC-3*,WIDE1*,KE6NVU*,WIDE2*,qAR,W6DWY
:`4a.l]w>/`"4&}147.000MHz T103 +060 Electric cowboy-
[Rate limited (< 5 sec)]
    type: location
    format: mice
    srccallsign: KE6SLS-9
    dstcallsign: T0TXRW
    latitude: 40.8045 °
    longitude: -124.153 °
    course: 191 °
    speed: 11.112 km/h
    altitude: 15 m
    symboltable: /
    symbolcode: >
    mbits: 101
    posresolution: 18.52 m
    posambiguity: 0
    comment: `147.000MHz T103 +060 Electric cowboy-

2014-09-06 11:13:36 PDT:
KE6SLS-9>T0TXRW,WIDE1-1,WIDE2-1,qAR,KE6SLS
:`4a,lJk>/`"4/}147.000MHz T103 +060 Electric cowboy-Waahoo_"
    type: location
    format: mice
    srccallsign: KE6SLS-9
    dstcallsign: T0TXRW
    latitude: 40.8045 °
    longitude: -124.1526666666667 °
    course: 279 °
    speed: 7.407999999999999 km/h
    altitude: 24 m
    symboltable: /
    symbolcode: >
    mbits: 101
    posresolution: 18.52 m
    posambiguity: 0
    comment: `147.000MHz T103 +060 Electric cowboy-Waahoo_"

later...

2014-09-06 11:20:15 PDT:
KE6SLS-9>T0TWWY,WIDE1-1,WIDE2-1,qAR,KE6SLS
:`4&Nl|g>/`"3{}147.000MHz T103 +060 Electric cowboy-Waahoo_"
    type: location
    format: mice
    srccallsign: KE6SLS-9
    dstcallsign: T0TWWY
    latitude: 40.7965 °
    longitude: -124.175 °
    course: 275 °
    speed: 16.668 km/h
    altitude: 9 m
    symboltable: /
    symbolcode: >
    mbits: 101
    posresolution: 18.52 m
    posambiguity: 0
    comment: `147.000MHz T103 +060 Electric cowboy-Waahoo_"

Then comes the beacon comment that makes it look like you are
running an XASIR Raspberry Pi IGate.

2014-09-06 11:20:39 PDT:
KE6SLS-9>T0TXRW,KE6SLS,KE6NVU,WIDE2*,qAR,W6DWY
:`4a.l]w>/`"4&}147.<0x03><0xf0>=4203.13N/12417.74WxXASTIR-Raspberry Pi 
Igate | Brookings, OR [Duplicate position packet]
    type: location
    format: mice
    srccallsign: KE6SLS-9
    dstcallsign: T0TXRW
    latitude: 40.8045 °
    longitude: -124.153 °
    course: 191 °
    speed: 11.112 km/h
    altitude: 15 m
    symboltable: /
    symbolcode: >
    mbits: 101
    posresolution: 18.52 m
    posambiguity: 0
    comment: `147.<0xf0>=4203.13N/12417.74WxXASTIR-Raspberry Pi Igate | 
Brookings, OR

I was going to ask if you were running an XASTIR Raspberry Pi IGate,
or is that coming from somewhere else, but I see that it's the latter.

http://aprs.fi/?c=raw&call=W6DWY&limit=5

2014-09-13 04:56:00 PDT:
W6DWY>APX200,TCPIP*,qAC,THIRD
:=4203.13N/12417.74WxXASTIR-Raspberry Pi Igate | Brookings, OR

While it is entirely possible that you are at times seeing the effects
of delayed packets (caused by a digi or IGate) you are also seeing
the results of an IGate altering your beacons, merging your own
beacon with something generated by the Raspberry Pi IGate.

Hessu - are you watching this? Could this be happening at aprs.fi,
or is it happening back at the R Pi IGate? I suspect the latter,
but perhaps you could come up with an answer.

-- 
73 Keith VE7GDH
UI-View32
www.ui-view.net



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