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ZL3AI > APRDIG 09.12.03 10:28l 251 Lines 9174 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Dec 04, 4/7
Path: DB0FHN<DB0RGB<OK0PPL<DB0RES<ON0AR<7M3TJZ<IK6PYS<ON0BEL<ZL2BAU<ZL2BAU<
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Sent: 031209/0721Z @:ZL3VML.#80.NZL.OC #:14233 [Chch-NZ] FBB7.00i $:2449-ZL3AI
From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: APRS WX Protocol Questions
From: Bob Bruninga <bruninga@usna.edu>
Date: Thu, 4 Dec 2003 14:54:25 -0500 (EST)
X-Message-Number: 20
On Thu, 4 Dec 2003, James Jefferson wrote:
>>APRSdos properly computes a running wind speed average...
>
>What does a wind speed average tell anybody? I'm not aware of any
>application that would be concerned with wind speed average
As the original poster pointed out, properly reported "wind speed" is
supposed to be a sustained "average over a 2 minute period". So That is
what I mean by "average" and that is what APRSdos computes and transmits
from an attached WX station...
Some other client programs may not be doing this and thus, giving
missleading instantaneous values just as received from the WX instrument...
Bob
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Subject: Re: National Parks Digi Coverage (Rev 3)
From: WA8LMF2@aol.com
Date: Thu, 4 Dec 2003 15:12:53 EST
X-Message-Number: 21
In a message dated 12/4/2003 11:56:51 AM Pacific Standard Time,
bruninga@usna.edu writes:
>Yosemite 3,400,000 22 ?
Situation here is WORSE than no digi...
There is a defective digi covering this park. It beacons but won't repeat.
Apparently the receiver is broken since it transmits beacons at regular
intervals but won't respond to any one else's transmissions!
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Subject: Re: NMEA at >100,000 feet
From: "Rochte, Robert" <rrochte@gpacademy.org>
Date: Thu, 4 Dec 2003 15:11:44 -0500
X-Message-Number: 22
>Between 35,000 ft and 60,000 ft. the air temp gets very cold down to
>-70 F, BUT the solar insolation gets up to 1,000 w / m^2. Above
>60,000 ft the air temp actually gets warmer. Since the air is
>getting thin, convective cooling goes away.
Another case in point - my solar Montgolfieres. Internal balloon temps at
float (50-60k ft, -65F ambient) typically stay around +55F.
If you can keep the balloon (and 3500 cubic feet of air) warm using only
solar heating in such conditions, then surely you can also keep the payload
toasty with little effort!
73,
Robert
KC8UCH
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Subject: Re: National Parks Digi Coverage (Rev 3)
From: "Sean \\The RIMBoy\\" <sean@rimboy.com>
Date: Thu, 4 Dec 2003 09:51:43 -0600 (CST)
X-Message-Number: 23
On Thu, 4 Dec 2003, Bob Bruninga wrote:
>are traveling and making sure they are covered. With 32 HAMs a day
>visiting the Grand Canyon, we need a digi there... and other places:
(Note, it would help to have a field entitled "state". While I'm familiar
with a number of NP's, I would assume that there might be a few state
parks (ie, Glen Canyon, Mesa Verde?) so it would help to know exactly
where they're at. Why, well some of us may have contacts in those states
that could make that happen.
>TOURIST AREA VISITRS/YR HAMS/DAY APRS REPORTED BY
>----------------- ---------- -------- ---- --------------
>Blue Ridge Pkwy 19,153,000 130 yes
This is one where it'd help to break it down by state (ie, NC has coverage
in these areas, all of NC is covered, coverage is needed in these areas).
>Great Smokies 14,486,000 95 yes spotty
I would assume there is some overlap here with the Blue Ridge Pkwy.
>Mamouth Cave 1,749,000 12 ?
(Mammoth Cave?) I'm going to say yes. I've bcc'd Fred KF4QZN to see if he
knows more info on this. I would think that one way or another there's
some coverage:
http://www.findu.com/cgi-bin/find.cgi?call=KF4QZN*
Last I checked there was coverage in the Cave City area, which is a couple
miles away.
>Natchez Trace Pky 5,737,000 38 some?
Some is probably right. For TN I think there is some coverage provided by
N4CRT-1, W4GGM-1, NT4L-3, and I thought at one point KA4BNI had a digi
South of I40 that was east of Jackson. Probably a good excuse to make a
trip and see what's covered. Unfortunately they're talking crazy weather
here this weekend. IIRC, things get quiet around Hohenwald which is not
too far from the Trace. I'm not sure if that's been resolved with N4CRT-1
or not. Likewise, there was some discussion of putting up a digi in /
near Shiloh TN IIRC. I've bcc'd the person that would know best and may
have some ideas on what coverage is like in those parts of TN.
Sean...
--
The punk rock will get you if the government don't get you first.
--Old 97's
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
KG4NRC http://www.rimboy.com Your source for the crap you know you need.
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Subject: Re: NMEA at >100,000 feet
From: "Scott Miller" <scott@opentrac.org>
Date: Thu, 4 Dec 2003 13:10:33 -0800
X-Message-Number: 24
A few people have pointed this out, and I understand... I've had to explain
it to a few people talking about the 'cold of space'. I'm actually just
trying to be cautious because, at least for this launch, the enclosure
isn't my responsibility and I can't be sure it'll maintain its intended
temperature. So I'm just trying to plan for the worst. Besides, it gives
me a chance to play with dry ice and stuff. =] Finding it around here can
be tough, except for around Halloween, but I think Praxair carries it now,
and I'm already set up to handle liquid nitrogen if it comes down to that.
Now, what I'd like to see is some sort of variable-albedo surface.. maybe
something like this? http://www.eink.com/ If you're getting too cold,
just change to black for awhile. Too hot, change to white.
Scott
----- Original Message -----
From: "Bob Bruninga" <bruninga@usna.edu>
To: "Scott Miller" <scott@opentrac.org>
Cc: "TAPR APRS Special Interest Group" <aprssig@lists.tapr.org>
Sent: Thursday, December 04, 2003 11:04 AM
Subject: Re: [aprssig] NMEA at >100,000 feet
>Remember, the sun is shining up there above the clouds and things only get
>cold if you put them in White Styrofoam to try to "insulate them". Then
>they get as cold as the air temp (which is very cold, but also ver thin).
>But if they are black and in the sun, then they stay warm.
>
>But then they are harder to see and dont have the safety of FOAM when it
>lands on someone. We solved the problem by placing our 8 AA cells in a
>clear plastic coke bottle and painted the cells black and the sun kept
>them warm. In fact, the temperature only went up not down as it got above
>the clouds...
>
>So things dont have to be cold unless you design it that way..
>
>Bob
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Subject: NMEA at >100,000 feet
From: "brunson1" <brunson1@gte.net>
Date: Thu, 4 Dec 2003 13:33:37 -0800
X-Message-Number: 25
Scott-
Here is the highest point on Andy's first flight in 2001:
T116-11>APRS:$GPGGA,151908,4521.2688,N,12347.8956,W,6,10,1.0,31371.0,M,-21.2
,M,,*7F
T116-11>APRS:$GPRMC,151940,A,4521.2410,N,12348.1117,W,014.1,254.5,090801,018
..2,E*6A
T116-11>APRS:$GPGGA,151941,4521.2400,N,12348.1170,W,1,10,1.4,31618.5,M,-21.2
,M,,*76
T116-11>APRS:$GPRMC,152014,A,4521.1859,N,12348.3041,W,013.8,234.8,090801,018
..2,E*66
(31618.5 meters = 103,733.59 ft)
By the way, dry ice can be found at Baskin Robins & some grocery stores.
Craig
N7TSZ
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Subject: Re: NMEA at >100,000 feet
From: Gonzales Andy <agonzales@arc.nasa.gov>
Date: Thu, 4 Dec 2003 13:39:35 -0800
X-Message-Number: 26
>A few people have pointed this out, and I understand... I've had to explain
>it to a few people talking about the 'cold of space'. I'm actually just
In earth orbit, objects in the sun can be at +250 F, while objects in
the shade can be at -250 F. In deeper space, say on the surface of
Mars you'd be lucky if the temperature at the equator on a hot
summer's day got up to +70 F.
--
Andy Gonzales
KG6RWO
NASA / Ames Research Center
Moffett Field, CA 94035-1000
Bldg. N-244, Rm. 240
MS 244-19
agonzales@arc.nasa.gov
650-604-0309
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Subject: Re: NMEA at >100,000 feet
From: "Scott Miller" <scott@opentrac.org>
Date: Thu, 4 Dec 2003 13:46:02 -0800
X-Message-Number: 27
Ok, here's another question... the NMEA format would seem to imply that it's
possible to use feet rather than meters - at least, one would assume that's
why the 'M' is there. Now, DOES anyone actually use feet in NMEA? Do I
even need to parse that field and convert, or can I assume that it will
always be meters? Maybe I don't need to worry about the extra digit at
all....
>By the way, dry ice can be found at Baskin Robins & some grocery stores.
Baskin Robins, eh? I'll have to ask next time I'm there. They sell it in
quantities larger than a scoop, I hope? =] I've only seen it in grocery
stores in very rural areas where you'd need it for transport on the way
home. I'm pretty sure Praxair had a 'dry ice now available' sign up last
time I went by, though.
Scott
N1VG
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