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ZL3AI > APRDIG 13.05.04 09:44l 180 Lines 6894 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Apr 25, 1/1
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
TAPR APRS Special Interest Group Digest for Sunday, April 25, 2004.
1. APRS/CE
2. Re: Compromise proposal (was: Re: The APRS-WG andspec improvements.)
3. Island Expedition
4. Re: Compromise proposal (was: Re: The APRS-WG andspec improvements.)
5. Re: Island Expedition
6. Re: Compromise proposal (was: Re: The APRS-WG and spec improvements
7. Re: Compromise proposal (was: Re: The APRS-WG and spec improvements
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Subject: APRS/CE
From: Jacob Tennant <jacobtennant@yahoo.com>
Date: Sun, 25 Apr 2004 02:28:15 -0700 (PDT)
X-Message-Number: 1
Would anyone using this program email me as I have some questions about it.
Jacob Tennant-K8JWT
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Subject: Re: Compromise proposal (was: Re: The APRS-WG andspec improvements.)
From: Henk de Groot <henk.de.groot@hetnet.nl>
Date: Sun, 25 Apr 2004 17:48:44 +0200
X-Message-Number: 2
At 13:40 24-4-2004 -0700, Spider wrote:
>I am missing something. Why limit the compressed format to WGS84? What
>does that accomplish versus any other datum?
It provides a stable well definded on-air format without additional dirty
hacks that have to be parsed. Besides that it is already described in the
specification today.
With Bob's addition your receiver is required to parse the comment for the
datum addition. I just made an attempt to save at least one position format
from polution by this hack. It doesn't make sense, compressing a packet to
save space and then add a full 5 byte hack just like that to convey
information that should not be needed in the first place and is eating up
valuable comment space that could be used for less redundant information.
Besides that, the one letter datum specifier is not specified anywhere.
This just opens a new can of worms and I don't see it will be stable in the
near future at all. Its much more easier for any implementation to filter
out the base-91 posits and know they are at least in a globaly accepted
well specified datum without looking further.
But like I already said in a private message to another ham, APRS is
already beefed up with all kinds of dirty hacks, Bob's latest will add to
this pile. Since its already beond repair I guess resistance is futile.
Kind regards,
Henk.
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Subject: Island Expedition
From: "Robert Bruninga" <bruninga@usna.edu>
Date: Sun, 25 Apr 2004 12:44:32 -0400
X-Message-Number: 3
Orlando SUn Article about a contract out for 18 people to go work on Fort
Jefferson an isolated fort/island in the Caribbean.
The fort is 23 acres on a Key 68 miles west of Key West. National Park
Service wants to restore it. But what caught my eye was... "a completely
isolated place, cell phones don't even work there"...
Duh... But no more isolated than any HAM'S basement. I just thought
someone might wanna play radio, though I am sure they have LOTS of other
work in mind... Its in the Dry Tortugas National Park, I think...
No more details. But if they have workparties going out there for
restoration, then there will be regular boat transpotation available. For
what its worth... Bob
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Subject: Re: Compromise proposal (was: Re: The APRS-WG andspec improvements.)
From: "Scott Miller" <scott@3xf.com>
Date: Sun, 25 Apr 2004 10:31:02 -0700
X-Message-Number: 4
>It provides a stable well definded on-air format without additional dirty
>hacks that have to be parsed. Besides that it is already described in the
>specification today.
I fully agree with this proposition. It's already in the spec, it does the
job, and even the Kenwoods support it to some degree.
If we're going to add any extra value, make it a single character to define
ambiguity as something like 2^n centimeters.
Scott
N1VG
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Subject: Re: Island Expedition
From: Steve Dimse <k4hg@tapr.org>
Date: Sun, 25 Apr 2004 17:24:38 -0400
X-Message-Number: 5
On 4/25/04 at 12:44 PM Robert Bruninga <bruninga@usna.edu> sent:
>The fort is 23 acres on a Key 68 miles west of Key West.
Which means for me it is almost exactly the same distance as Havana...
>National Park Service wants to restore it. But what caught
>my eye was... "a completely isolated place, cell phones
>don't even work there"...
You can get there from Key West either by a fast catamaran (one trip daily)
or seaplane (three trips daily), and of course by private boat. The Dry
Tortugas have their own IOTA number, separate from the rest of the Keys,
which makes it a frequent local DXpedition spot. The National Park service
has a small campground there which recently reopened after a couple years
closure due to sewer problems.
I've been out operating IOTA there twice, generates quite a pile-up (even
the home station does pretty well on that count). Always wanted to do a
field day out there, but never could get it organized.
Anyway, it is a very cool place, highly recommended for anyone visiting Key
West as a way to get away from the abomination Duval Street has become.
Steve K4HG
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Subject: Re: Compromise proposal (was: Re: The APRS-WG and spec improvements
From: "KC2MMi" <kc2mmi@verizon.net>
Date: Sun, 25 Apr 2004 19:08:27 -0400
X-Message-Number: 6
< and still require WGS84>
Henk, perhaps it is my lack of experience, but I've never heard of anyone
or thing "requiring" one particular datum. I'm used to seeing things where
a datum is supposed to be identified or selected--but never "required".
Except for local users and local groups, where a "group" requires all work
to be done in one datum within itself.
There are many parts of the world where various other datums are still
being used, simply because the cost of reissuning new cartography for a new
datum is too high.
And, WGS84 itself will no doubt be replaced at some point.<G>
I think specifying the datum in use would be the more reliable way to go.
If a position comes in without a datum specified...that also raises the red
flag saying that the sender is a novice, and the data itself is to be
suspect.
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Subject: Re: Compromise proposal (was: Re: The APRS-WG and spec improvements
From: Wes Johnston <wes@johnston.net>
Date: Sun, 25 Apr 2004 20:31:32 -0400
X-Message-Number: 7
I think what we need is instead of using 5 bytes to spell out WGS84 or
NAD27, we need to list all of them in a table and number them. One byte
gives us 256 datums. Surely there aren't that many... but hey, if there
are, add another byte for 65536 datums.
Wes
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END OF DIGEST
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