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ZL3AI > APRDIG 19.02.04 14:14l 295 Lines 11443 Bytes #999 (0) @ WW
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: David VanHorn <dvanhorn@cedar.net>
Date: Tue, 17 Feb 2004 11:41:40 -0500
X-Message-Number: 24
At 08:21 AM 2/17/2004 -0800, Scott Miller wrote:
>I assume direct is preferred for the rest of the flight?
>
>Anyone got an idea for a simple, reliable algorithm a tracker could use to
>decide when to switch from direct to wide mode? I suppose the easy way to
>do it would be to add an altitude parameter to the configuration... anything
>above that altitude would skip the path completely. Too bad the GPS can't
>provide height-above-ground...
When speed = 0?
Altitude is a guess, what if it lands on a hill?
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Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Tue, 17 Feb 2004 11:38:27 -0500
X-Message-Number: 25
>Anyone got an idea for a simple, reliable algorithm a tracker could use to
>decide when to switch from direct to wide mode?
>I suppose the easy way to do it would be to add an altitude parameter to
>the configuration... anything above that altitude >would skip the path
>completely. Too bad the GPS can't provide height-above-ground...
Ever thought about when the speed = 0 m/s for x sec then unproto =
RELAY,WIDE
It is my assumption that as long as the balloon is in the air it is moving.
When it hits the ground, trees, or (god forbid) telephone pole, it will no
longer be in motion... That is something a GPS can get from its'
information and you won't have to worry about HAAT.
My assumption might be incorrect, though... Can anyone tell me why this
wouldn't work?
Eric KF4OTN
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Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Tue, 17 Feb 2004 11:40:46 -0500
X-Message-Number: 26
>Someone mentioned WIDE maybe not being good enough for recovery... how
>about setting a path of RELAY, WIDE2-2 and a max altitude of 10,000 feet?
>It'd also be nice to have a faster beacon rate on the way down to get a
>better projection of the >landing site. You'd want to cut it back again
>after landing to conserve batteries, though.
You wouldn't need the packets going out as frequently once the balloon has
stopped... Maybe a good, corner-pegging, speed-controlled algorithm would
work for this?
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Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: Robbie WA9INF <mwrobertson@comcast.net>
Date: Tue, 17 Feb 2004 10:49:15 -0600
X-Message-Number: 27
I agree.. However, before I could respond to myself, :-), Scott came up
with my solution.. So I agree with Him as well.. An altitude sensor
controlled path mechanism needs to be thought out, and if not, isolate
TVs, wives, and lets enjoy a couple balloon tracks a year??
Or, how about making the balloonists use a different frequency
altogether? <G> REALLY GUYS, just kidding here.....
Robbie
Robert Bruninga wrote:
>>>>Robbie WA9INF <mwrobertson@comcast.net> 2/17/04 10:59:45 AM >>>
>
>>Need to think about it a little... Generally the balloon is
>>gonna fall in no-mans land... How can anyone assure
>>that it will land close enough too a "WIDE" so that it
>>will be heard?
>
>REPLY: Yes, clearly the BEST solution for finding the
>downed balloon is to use RELAY. BUT....
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Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: "Scott Miller" <scott@opentrac.org>
Date: Tue, 17 Feb 2004 08:52:36 -0800
X-Message-Number: 28
>Ever thought about when the speed = 0 m/s for x sec then unproto =
>RELAY,WIDE
>
>It is my assumption that as long as the balloon is in the air it is moving.
>When it hits the ground, trees, or (god forbid) telephone pole, it will no
>longer be in motion... That is something a GPS can get from its'
>information and you won't have to worry about HAAT.
>
>My assumption might be incorrect, though... Can anyone tell me why this
>wouldn't work?
Swinging from a tree, maybe?
Actually the biggest problem from my perspective is the lack of RAM in the
tracker. Counters for things like 'number of seconds since last movement'
all come out of a total of 192 bytes of RAM, and things are getting pretty
tight. Something stateless would be better. The altitude check only
requires a couple bytes of FLASH config space to store the altitude setting.
Scott
N1VG
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Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Tue, 17 Feb 2004 12:11:33 -0500
X-Message-Number: 29
Yeah, but swinging from a tree isn't going to throw a speed vector that
much. Maybe when the speed is less than 5 mi/hr or something like that. My
whole point is that altitude won't work because it doesn't factor in HAAT.
If it is at 12,000 ft but is actually in a small valley between peaks then
the signal might be blocked but the GPS says that it is too high. But I'd
be willing to bet that 9 times out of 10 when the GPS says the velocity is <
5(?) mi/hr then it is on the ground or close to it.
Does anyone have any graphs on Altitude and Velocity v. time??? That would
be an interesting cross of data...
-----Original Message-----
From: Scott Miller [mailto:scott@opentrac.org]
Sent: Tuesday, February 17, 2004 11:53
To: TAPR APRS Special Interest Group
Subject: [aprssig] Re: APRS enabled balloon on 144.39 over Colorado
>Ever thought about when the speed = 0 m/s for x sec then unproto =
>RELAY,WIDE
>
>It is my assumption that as long as the balloon is in the air it is
moving.
>When it hits the ground, trees, or (god forbid) telephone pole, it
>will no longer be in motion... That is something a GPS can get from
>its' information and you won't have to worry about HAAT.
>
>My assumption might be incorrect, though... Can anyone tell me why
>this wouldn't work?
Swinging from a tree, maybe?
Actually the biggest problem from my perspective is the lack of RAM in the
tracker. Counters for things like 'number of seconds since last movement'
all come out of a total of 192 bytes of RAM, and things are getting pretty
tight. Something stateless would be better. The altitude check only
requires a couple bytes of FLASH config space to store the altitude setting.
Scott
N1VG
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Subject: Icon for *unmanned* balloon
From: "Rochte, Robert" <rrochte@gpacademy.org>
Date: Tue, 17 Feb 2004 12:23:15 -0500
X-Message-Number: 30
Am I using the right icon for an unmanned balloon? I seem to get a few APRS
messages sent to the balloon's ID on each flight asking questions like, "how
cold is it up there?"...
Perhaps I'm somehow making it look like a manned balloon?? Or is there only
one icon anyway?
Thanks.
73,
Robert
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Subject: TCP/IP operation - NOT
From: Glenn Wiebe <gswiebe@mb.sympatico.ca>
Date: Tue, 17 Feb 2004 11:29:00 -0600
X-Message-Number: 31
Hi all:
I've been using WinAprs (registered, now 2.7.2) for many years and the
only ports as listed under Settings>TCP/IP Connections I've ever been
able to open are: 1) Secondary APRS Net Server 2) second.aprs.net 10151
APRServe - backup: (I suspect they are the same) 3) 204.118.115.12 23
west usa:. The first two rapidly fill the screen with world wide
stations and the last one does nothing. All the rest - and there are
dozens including a local feed that others can open - come up with: TCP
Open Failed. Yes I am on line. Any suggestions?
73 de Glenn...VE4GN
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Subject: RE: Icon for *unmanned* balloon
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Tue, 17 Feb 2004 12:31:49 -0500
X-Message-Number: 32
I think there is only one SYMBOL for a balloon. (A little green one on my
screen!!!)
73s,
Eric KF4OTN
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Subject: A bad path on a BALLOON?!?
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Tue, 17 Feb 2004 13:07:28 -0500
X-Message-Number: 33
KG4KBW-1>APRS,KF4OWQ-2*,WIDE5-5,qAS,KG4LKY:@171305z3706.61N/08404.40WO354/00
0/Mic-E/M2/In Service>
Gosh I really HOPE this is not a balloon as it is showing up with this
path!!! This shouldn't even be on a terrestrial station!!!
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Subject: Re: APRS enabled balloon on 144.39 over Colorado
From: "J. Lance Cotton" <joe@lightningflash.net>
Date: Tue, 17 Feb 2004 12:14:40 -0600
X-Message-Number: 34
Christensen, Eric wrote:
>Yeah, but swinging from a tree isn't going to throw a speed vector that
>much. Maybe when the speed is less than 5 mi/hr or something like that. My
>whole point is that altitude won't work because it doesn't factor in HAAT.
>If it is at 12,000 ft but is actually in a small valley between peaks then
>the signal might be blocked but the GPS says that it is too high. But I'd
>be willing to bet that 9 times out of 10 when the GPS says the velocity is <
>5(?) mi/hr then it is on the ground or close to it.
Regardless of the calculation method for "still flying" versus "landed":
If a TinyTrak III or SOTT or OpenTracker or any other similar device is used
for balloon tracking, then you have some interesting options.
With the TT3, you can go get one of the $1, 8-pin PICmicro chips with a
built-in 4MHz oscillator and write a simple little program that snoops the
GPS serial data and grabs the altitude and speed data (or whatever...) from
the NMEA string. When the data meets the criteria for "up high, in the sky",
the PIC can toggle the TT3's "alternate config profile" line, which can have
a separate path. Then when the balloon comes to rest, the chip can switch
the TT3 back to a "find me" mode.
If you use the SOTT (Son of TinyTrak), you can, of course, write this code
into the tracker PIC itself, with no extra external devices.
And with the OpenTracker, you can write your own firmware as well, plus you
gain all of the telemetry options that you lose when using a TinyTrak rather
than a full TNC.
With these options available, it's a wonder that folks still use a GPS tied
to a TNC, with it accompanying long transmit string (and therefore shorter
battery life). Even the standard APRS-spec format for
position/course/speed/altitude data is more compact than raw NMEA and when
you get into the APRS Compressed packet format and MIC-E encoding methods,
you gain even shorter transmit times (and higher likelihood of packet
receipt success).
The OpenTrac spec even allows one to make available the fullest position
resolution provided by your GPS, which goes beyond the APRS position spec.
Not that 10 meters is going to make that much difference...
And with the open-source trackers, you can even make a modified SmartBeacon
algorithm tuned just for balloon tracking, if the standard SmartBeaconing
doesn't cut it for you.
73 de KJ5O
--
J. Lance Cotton, KJ5O
http://map.findu.com/kj5o-14
joe@lightningflash.net
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