| |
ZL3AI > APRDIG 04.02.04 14:05l 251 Lines 9617 Bytes #999 (0) @ WW
BID : 2776-ZL3AI
Read: GUEST
Subj: TAPR Digest, Feb 02, 3/4
Path: DB0FHN<DB0THA<DB0ERF<DB0FBB<DB0GOS<ON0AR<ON0AR<VK3TE<ZL2BAU<ZL2BAU<
ZL3VML
Sent: 040204/1133Z @:ZL3VML.#80.NZL.OC #:18325 [Chch-NZ] FBB7.00i $:2776-ZL3AI
From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: Xastir and Toporama Maps
From: Adi Linden <adil@adis.on.ca>
Date: Mon, 2 Feb 2004 14:19:57 -0600 (CST)
X-Message-Number: 15
Toporama is a source for free maps from the Government of Canada. They are
at <http://toporama.cits.rncan.gc.ca/toporama_en.html>.
Adi
----------------------------------------------------------------------
Subject: Re: GPS Signal re-radiation
From: "Richard Amirault" <ramirault@erols.com>
Date: Mon, 2 Feb 2004 15:59:06 -0500
X-Message-Number: 16
Wouldn't this give *every* GPS unit inside all the same co-ords ... the
co-ords of the rooftop antenna??
----------------------------------------------------------------------
Subject: Private Voice Alert.
From: Bob Bruninga <bruninga@usna.edu>
Date: Mon, 2 Feb 2004 16:19:45 -0500 (EST)
X-Message-Number: 17
If you have a fixed station and want to have an ALWAYS-ON monitoring
channel for VOICE calls, just use your APRS station with a PL other than
100. I'll call this PRIVATE voice alert.
My kids (both licenesd) were locked out of the building and were unable to
raise me, because I had no monitor on in the office (though I do have APRS
running all the time). Duh... I should turn the volume up and set CTCSS!
THen they can raise me on 144.39 if needed using my unique PL.
PLEASE never operate fixed station on PL100 voice alert! It drives mobile
voice alert stations crazy. But until now, I had not realized that I
could have the same advantage in my office while not bothering others by
simply choosing my own "unique" CTCSS on 144.39. Then you can put that in
your POSITION text so that others needing to raise you can see what it is.
My STATUS text might say. "At work. PL107"
or something like that...
de WB4APR@amsat.org, Bob
----------------------------------------------------------------------
Subject: Re: GPS Signal re-radiation
From: "Sadowski, Allan" <allan.sadowski@ncshp.org>
Date: Mon, 2 Feb 2004 16:32:07 -0500
X-Message-Number: 18
Like I said in my original posting...
"I do not care that the summing node (antenna) on the roof does not
accurately reflect the position inside the building"
I just need the signals in a lab.... to test some gear... I'm not trying
to find my position in the building...
The good news is that through the SIG... I've found a commercial product
that does this... is cheap... and in fact was made for in vehicle use...
so that you could mount the GPS anywhere in the vehicle... but there is
an external antenna that is outside... and a feed line... and powered
internal re-radiating antenna... so in fact multiple GPS's can get
signals inside the vehicle/trailer/boat/room...
ALOHA
AH6LS
-----Original Message-----
Richard Amirault
Wouldn't this give *every* GPS unit inside all the same co-ords ... the
co-ords of the rooftop antenna??
----------------------------------------------------------------------
Subject: Re: GPS Signal re-radiation
From: "Mike Yetsko" <myetsko@insydesw.com>
Date: Mon, 2 Feb 2004 16:29:31 -0500
X-Message-Number: 19
I wonder, not that it really matters... But wouldn't that mean that no
matter where you were in the coverage of the 're-radiator', the GPS
would report the position of the first receiving antenna?
Well... Maybe not! I guess it would mean that the path was to the
receiving antenna, PLUS a common offset. The common offset would
be the key, and would affect each of the positions differently.
Might be kind of weird!
----------------------------------------------------------------------
Subject: Re: GPS Signal re-radiation
From: "Stephen H. Smith" <WA8LMF2@aol.com>
Date: Tue, 3 Feb 2004 13:50:52 -0800
X-Message-Number: 20
Richard Amirault wrote on 2/2/2004, 12:59 PM:
>Wouldn't this give *every* GPS unit inside all the same co-ords ... the
>co-ords of the rooftop antenna??
Yes. But the original inquiry was just to get GPS signals inside the
building for testing GPS devices, not actual position determination.
Furthermore, the re-radiation coverage radius would be smaller than the
average resolution of civilian GPS devices so the error would be
insignificant if the outside antenna is mounted directly above the
center of the test lab.
I have faced this same issue (of getting GPS signals inside buildings)
when testing new GPS hardware with APRS programs. For example, to see
what GPS sentences the particular device outputs, how much software
smoothing and averaging is done inside the device (i.e. how much
"wobble" and "jitter" is reported by a given device when it is
stationary), is the D7, KPC3+, etc. properly configured for GPS
feedthrough, etc.
A very useful freebie tool for these purposes is Visual GPS available at:
http://www.visualgps.net
This FREEWARE program will monitor the output of GPS devices and
construct graphs of position variation over time.
Another use of re-radiators is to allow the use of hand-held GPS, PDA
GPS devices or position-enabled cell phones inside a car or van without
having to physically connect them to an antenna mounted on the roof.
Position error here is obviously non-existent (unless you are worried
about the difference in position between the front and rear of a bus or
ultra-stretch limo!)
Now if you REALLY need to know your position indoors, I saw an article
about a year ago about a company developing pseudo-lites
(pseudo-satellites - micropower GPS-simulator transmitters that would be
positioned INSIDE warehouses, aircraft hangers, sprawling factory
floors, underground command centers, etc.) that would make a GPS work
normally in these places.
Stephen H. Smith wa8lmf (at) aol.com
Home Page: http://wa8lmf.com
Ham Radio/Mobile SSTV page: http://members.aol.com/wa8lmf/ham
APRS Stuff
http://members.aol.com/wa8lmf/aprs
----------------------------------------------------------------------
Subject: Re: digi_ned.ini
From: Henk de Groot <henk.de.groot@hetnet.nl>
Date: Mon, 02 Feb 2004 22:35:50 +0100
X-Message-Number: 21
Hello Adi,
At 21:26 30-1-2004 -0600, Adi Linden wrote:
>The default digi_ned.ini supplied with the digi_ned sources, is it
>suitable for a generic digipeater that has 2 ports, one RF and the other
>to an igate? Just wondering which lines I should be changing.
Most rules define the port number as "all", the only specific rules are to
allow one more hop to port 2. The idea was that port 1 is on 2 meters and
port 2 on 70cm. Since there are not so many digi on 70 cm the idea was to
allow transmission on 70cm of packets that are normally not digipeated
anymore. On 2 meters a station may also hear other nearby digis but on 20
it doesn't.
>I am hoping not to have to understand every detail of the config right now
>but to get it up and running quickly and tweak later.
The easiest way is to either kick out the specific rules or to have a
digi_ned.ini generated for you. The latter is done by the configuration
program of digi_ned floppy. This is a single floppy that first time you
start it launches a configuration program and after answering the questions
generates a working system. I would say that is a painless quick and easy
start.
You can find the floppy image on <http://www.homepages.hetnet.nl/~pe1dnn>.
After unzipping you get an executable, if you run that it will ask for a
1.44 MB floppy and makes writes an image on that. Now you have a floppy you
can boot, the whole system is contained on this floppy, it doesn't use the
harddisk.
Good luck, kind regrads,
Henk.
----------------------------------------------------------------------
Subject: PocketAPRS icons
From: Henk de Groot <henk.de.groot@hetnet.nl>
Date: Mon, 02 Feb 2004 22:51:43 +0100
X-Message-Number: 22
Hello all,
A long time ago I patched the icons of PocketAPRS to ones I like better.
One of my grieves was that I could not clearly see overlays. Also some
other icons I did not understand.
Anyway, I kept it as private patch... up to now! I put the update on my
website, including the wheelchair icon. I can only replace icons that are
already there, not create new ones so I can't cover all of Bob's new icons.
Anyway, just see for youself if you like it, otherwise you can always
reload the original. For this patch you need a clean version of
pocketAPRS.prc version 1.94; this is not included!
Anyway good luck with it. Oh yeah, the address:
<http://www.homepages.hetnet.nl/~pe1dnn/#PAPRS_Icon>
Kind regards,
Henk.
P.S. the link to the maps for Africa were lost in an earlier update, this
is restored now too.
----------------------------------------------------------------------
Subject: Re: GPS Signal re-radiation
From: "Mike Yetsko" <myetsko@insydesw.com>
Date: Mon, 2 Feb 2004 17:10:29 -0500
X-Message-Number: 23
>Richard Amirault wrote on 2/2/2004, 12:59 PM:
>
>>Wouldn't this give *every* GPS unit inside all the same co-ords ... the
>>co-ords of the rooftop antenna??
>
>Yes. But the original inquiry was just to get GPS signals inside the
>building for testing GPS devices, not actual position determination.
I thought about this after my original post, and no, it wouldn't. It would
give a location that was wrong, but not the receiving antenna. It would
give a location that was based on the 'timing' to the original received
antenna plus a 'constant' for all channels received which was the delay
from the receiving antenna to the actual GPS. Electronic repeating
circuitry might make this error fantastically large, depending...
----------------------------------------------------------------------
Read previous mail | Read next mail
| |
