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ZL3AI > APRDIG 31.10.03 14:50l 253 Lines 9205 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Oct 29, 2/3
Path: DB0FHN<DB0FOR<DB0MRW<OK0PKL<OK0PPL<DB0RES<ON0BEL<SP7MGD<ZL2TZE<ZL3VML
Sent: 031031/1237Z @:ZL3VML.#80.NZL.OC #:11691 [Chch-NZ] FBB7.00i $:2247-ZL3AI
From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: APRS via AO-40 Satellite
From: "Germino" <mgermino@sbcglobal.net>
Date: Wed, 29 Oct 2003 17:03:02 -0800
X-Message-Number: 11
Will the Earth Station use USB?
Mike
AD6AA
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Subject: Re: APRS via AO-40 Satellite
From: Bob Bruninga <bruninga@usna.edu>
Date: Wed, 29 Oct 2003 20:27:53 -0500 (EST)
X-Message-Number: 12
On Wed, 29 Oct 2003, Germino wrote:
>Will the Earth Station use USB?
Whatever it takes to put the signals where we want them in the downlink...
BOb
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Subject: Where to find APRS icons
From: "Sean \\The RIMBoy\\" <sean@rimboy.com>
Date: Wed, 29 Oct 2003 16:52:29 -0600 (CST)
X-Message-Number: 13
Aside from Bob's site, does anyone have a good resource for where to
download APRS icons? ie, all of the icon's in a 16x16 GIF format like
what is used on findu would be ideal. It's part of retooling the
nashvilleaprs.net website for those that might care.
TIA,
Sean...
--
Believing I had supernatural powers, I slammed into a brick wall.
--Paul Simon
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
KG4NRC http://www.rimboy.com Your source for the crap you know you need.
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Subject: Re: APRS via AO-40 Satellite
From: Wes Johnston <wes@johnston.net>
Date: Wed, 29 Oct 2003 21:14:38 -0500
X-Message-Number: 14
Bob,
I was just looking at
http://web.usna.navy.mil/~bruninga/ao40ant/ao40crankW.jpg , and wanted to
know if you ever heard of a very useful product called Duct Tape? lol....
Wes
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Subject: APRS Packet Errors
From: Steve Dimse <k4hg@tapr.org>
Date: Wed, 29 Oct 2003 21:17:10 -0500
X-Message-Number: 15
Deep Breath.
I'm not trying to be a packet cop, nor am I demanding people correct any
errors, nor (especially) do I want to interpret for people what is wrong
with their packets, but I think the following information may be useful to
the APRS community. Please, let's not have a flame war over this...
I've been watching the log of my parser for almost 4 years now (geez, is
findU really that old???), it contains messages when the parser detects a
packet error. I have fretted for a long time about whether to release the
information. I went ahead and created a page to display it, and after due
consideration (and seeing the same callsigns appearing day after day,
perhaps meaning that people aren't aware of their errors), I decided to go
ahead.
http://www.findu.com/cgi-bin/errors.cgi
default is 6 hours, you can change it with the last parameter, e.g. for 24
hours:
http://www.findu.com/cgi-bin/errors.cgi?last=24
The page does not display callsigns with a single error, as there are many
of these caused by things like mangled packets and unitialized GPSs, my
target is persistant errors.
I've written software for too long to ever claim anything I've written
since "Hello World!" is bug-free, and after all, these error messages were
included specifically so I could hunt for bugs in my code. That said, I am
concerned that I will suddenly get a mailbox full of messages complaining
that my parser is busted. Please treat this as a chance to learn more about
the protocol.
My parser is rather strict, packets that appear fine in some programs will
not parse in mine, a side effect of the Perl language and regular
expressions...for example, somewhat simplified code for parsing a
lat/lon/icon set is:
m/(\d\d\d\d\.\d\d)([NS])(.)(\d\d\d\d\d\.\d\d)([EW])(.)/
after this executes, $1 is lat, $2 is N or S, $3 is symbol table/overlay,
$4 is lon, $5 is E or W, and $6 is the symbol. If each and every condition
set for in the above regular expression is not matched, then the packet is
rejected. This means, for example, using n instead of N for north will
reject the packet...as it should IMHO, because the spec clearly states it
is N. Other code may implement the parsing differently. For example, in
javAPRS, I simply tested for 'S' in the NS position, and negated the
latitude if present, which means an 'n' would parse correctly (though an
's' would not). I suspect others take similar shortcuts in their parsers,
being rigorous in a language without regex's can be painful, and writing an
APRS parser is already plenty painful!
So, if you see something on the page that you think is legal, please be
absolutely certain before complaining to me about a bug in my program. I
have included the link to the APRS spec on the page, please get the spec
and go byte by byte looking for the problem, don't just look at it with
another program. Like all the APRS authors, I've had to do manual
decomposition hundreds of times, so I just want to spread the fun around!
Enjoy!
Steve K4HG
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Subject: Re: Where to find APRS icons
From: Steve Dimse <k4hg@tapr.org>
Date: Wed, 29 Oct 2003 21:19:36 -0500
X-Message-Number: 16
On 10/29/03 at 4:52 PM Sean \The RIMBoy\ <sean@rimboy.com> sent:
>Aside from Bob's site, does anyone have a good resource for where to
>download APRS icons? ie, all of the icon's in a 16x16 GIF format like
>what is used on findu would be ideal. It's part of retooling the
>nashvilleaprs.net website for those that might care.
Well, the findU icons (courtesy of Brent) are simply images that can be
requested from the server by a URL, a look at the source code of a page that
displays them will give you the URLs, and they follow a simple pattern...
Steve K4HG
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Subject: Re: Where to find APRS icons
From: "Sean \\The RIMBoy\\" <sean@rimboy.com>
Date: Wed, 29 Oct 2003 17:15:52 -0600 (CST)
X-Message-Number: 17
On Wed, 29 Oct 2003, Steve Dimse wrote:
>
>Well, the findU icons (courtesy of Brent) are simply images that can be
>requested from the server by a URL, a look at the source code of a page that
>displays them will give you the URLs, and they follow a simple pattern...
Yeah, I thought about that... thought I might see if there was a better
place to get it before I script something up. Guess I'll be writing that
script now ;)
Sean...
--
Believing I had supernatural powers, I slammed into a brick wall.
--Paul Simon
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
KG4NRC http://www.rimboy.com Your source for the crap you know you need.
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Subject: Re: Where to find APRS icons
From: James Jefferson <jj@aprsworld.net>
Date: Wed, 29 Oct 2003 20:48:31 -0600
X-Message-Number: 18
http://www.jarviscomputer.com/jim/aprs-symbols/
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Subject: IC-746 on APRS/VHF Packet
From: "Matthew Stennett" <wa4tkg@iwon.com>
Date: Wed, 29 Oct 2003 21:56:56 -0500 (EST)
X-Message-Number: 19
Hello:
I am wondering HOW to wire up my IC-746 for operating packet on VHF.
Anyone who has this done through the REAR PANEL accessory connector, let me
know.
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Subject: Re: APRS Packet Errors
From: Steve Dimse <k4hg@tapr.org>
Date: Wed, 29 Oct 2003 22:12:49 -0500
X-Message-Number: 20
On 10/29/03 at 9:17 PM Steve Dimse <k4hg@tapr.org> sent:
>I'm not trying to be a packet cop, nor am I demanding people correct any
>errors, nor (especially) do I want to interpret for people what is wrong with
>their packets,
I wasn't disappointed. It was less than a half hour after the message
appeared before someone sent me a grossly malformed packet asking me to
explain what was wrong.
Would anyone volunteer to interpret any errors people are too lazy to
interpret for themselves?
Steve K4HG
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Subject: RE: MODIS and APRS
From: "Mark Conner" <n9xtn@cox.net>
Date: Wed, 29 Oct 2003 21:20:04 -0600
X-Message-Number: 21
I've not heard of anyone doing "amateur" reception of MODIS. I think
you're looking at 5 figures in a price tag for a ground station. Try a
Google search for "MODIS direct broadcast ground station".
This site has readout of practically all MODIS data being recorded, with a
delay of around 2-4 hours: http://rapidfire.sci.gsfc.nasa.gov/realtime/
This site is more related to fires, and uses direct broadcast received at
Salt Lake City (plenty of coverage for SoCal). This also has a delay of
around two hours after overflight: http://activefiremaps.fs.fed.us/
Two satellites have MODIS on board, Terra which passes over around 1030
local, and Aqua which is at 1330 local.
For less money (and less capability), you can use NOAA HRPT broadcasts and
look at the Channel 3 data (3.7 micron). Fires show up quite well, but it
takes a larger fire to show up in the NOAA data. You can see examples at
http://www.osei.noaa.gov/Events/Fires/ . HRPT ground stations are more
reasonably priced.
73 de Mark N9XTN
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