| |
ZL3AI > APRDIG 29.02.04 12:31l 209 Lines 7098 Bytes #999 (0) @ WW
BID : 2927-ZL3AI
Read: GUEST
Subj: TAPR Digest, Feb 27, 1/1
Path: DB0FHN<DB0THA<DB0ERF<DB0FBB<DB0GOS<DB0EEO<DB0RES<ON0AR<ZL2BAU<ZL2BAU<
ZL3VML
Sent: 040229/1009Z @:ZL3VML.#80.NZL.OC #:20075 [Chch-NZ] FBB7.00i $:2927-ZL3AI
From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
TAPR APRS Special Interest Group Digest for Friday, February 27, 2004.
1. Map Manager APRSdos map progress
2. Re: Inexpensive GPS Receiver
3. Re: Inexpensive GPS Receiv
4. Re: Inexpensive GPS Receiv
5. Re: Inexpensive GPS Receivers
6. The "Best" map
7. Linux C task...
----------------------------------------------------------------------
Subject: Map Manager APRSdos map progress
From: Steve Dimse <k4hg@tapr.org>
Date: Fri, 27 Feb 2004 06:54:50 -0500
X-Message-Number: 1
Just to show where APRS MM is headed, I written some code to import the
1007 APRSdos map library found on tapr.org. You can search it by call or
lat/lon, and it will return the maps covering a given point:
http://mm.aprs.net/cover.cgi?call=k4hg-8
This uses the center and range parameters in the map, and is not perfect,
especially with wider area maps (South America and East Pacific maps are
listed for me. Significantly though, if a detail map appears in the list,
it is usually a close fit.
The cover.cgi now links to a new dmap cgi, which uses the dosgeo cgi
instead of dosmap.cgi to render the maps, making it portable to other
rendering cgis.
So using this page will give you faster access to all 1007 maps than you
could ever have had before, allowing you to pick and download one
quickly...
Now imagine the database also contains all the PocketAPRS and WinAPRS
maps...
Once I have this running better, I'll move on to the librarian functions,
allowing the parameters in the database to be tweaked for best results, and
develop some automatic geo generating files to pick the best map.
Steve K4HG
----------------------------------------------------------------------
Subject: Re: Inexpensive GPS Receiver
From: Derek Koonce <redderek@jps.net>
Date: Fri, 27 Feb 2004 09:05:27 -0800 (GMT-08:00)
X-Message-Number: 2
Cables can also be made. Look for Purple Connector for the round Garmin
connectors. I have the drawings for making and eTrex connector out of an
old credit card and centronics connector pins.
Derek.
KE6JTP.
-----Original Message-----
From: Chris Rose <kb8uih@sbcglobal.net>
Cables available from www.bluehillsinnovations.com for GPS units.
Chris
KB8UIH
----------------------------------------------------------------------
Subject: Re: Inexpensive GPS Receiv
From: rwf <rwf@bsrg.org>
Date: Fri, 27 Feb 2004 11:59:37 -0500
X-Message-Number: 3
Curt, WE7U" <archer@eskimo.com wrote:
>Delorme earthmate.
Not unless you add an (extra cost) converter box
Not too inexpensive then
>Rand McNally unit.
>
>Deluo units, serial or USB.
USB not compatible with D700 serial input
----------------------------------------------------------------------
Subject: Re: Inexpensive GPS Receiv
From: Robbie WA9INF <mwrobertson@comcast.net>
Date: Fri, 27 Feb 2004 14:41:19 -0600
X-Message-Number: 4
Do I understand correctly, seems I read the "New" EarthMate has NMEA
output?
Robbie
----------------------------------------------------------------------
Subject: Re: Inexpensive GPS Receivers
From: "Stephen H. Smith" <WA8LMF2@aol.com>
Date: Fri, 27 Feb 2004 13:05:51 -0800
X-Message-Number: 5
Robbie WA9INF wrote on 2/27/2004, 12:41 PM:
>Do I understand correctly, seems I read the "New" EarthMate has NMEA
>output?
YES! It's standard NMEA alright but is USB interfaced in the standard
unit. You have to buy a separate (optional) serial interface cable to
use it in the standard serial mode with a D700, TinyTrak, or other
NON-PC device.
Or buy the optional battery power box. The Earthmate II docks into the
battery box which in turn provides a serial interfacce. [ The basic
Earthmate unit itself has no battery compartment, since the default USB
cable powers the unit from the PC USB port it is plugged into. ]
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: The "Best" map
From: Steve Dimse <k4hg@tapr.org>
Date: Fri, 27 Feb 2004 20:52:26 -0500
X-Message-Number: 6
I've been thinking about what constitutes the "best" map for a given
request. Let me present my thinking, I'm very interest in hearing different
viewpoints, please make constructive comments!
Initially, I thought the best map would be the one with the most detail
covering a given area, which is the way cover.cgi sorts. However after
loading the APRSdos map library and playing a bit, I can see that is not
the case much of the time. The problem I think is the center/range numbers
inside the dos maps, which aren't always a close representation of the true
coverage of the map. It might be possible to play with these to get the
right numbers, but that is a lot of manual work, does not scale well for
worldwide implementation.
It is a particular problem when there are a lot of nearby maps with similar
detail levels, for example:
http://mm.aprs.net/cover.cgi?call=w3ado
That led me to try the the distance from the map center to the requested
point, but again I wwasn't satisfied with the choice when I looked at it
across a sample of APRS positions. A little more thought, and I hit on the
idea of multiplying the detail number by the distance. So far I think this
is a reasonably good choice, hitting the map I'd pick most of the time.
I've modified the cover.cgi page to show these quantities, and while the
list is still sorted by detail, the algorithm I'm favoring would pick the
map with the lowest number in the quality column (often not first in the
list). Take a look and see what you think.
If you want to try a wide variety of areas, I added a wildcard feature,
which will return the list for the last position received by findU, hitting
refresh will give you a new list.
http://mm.aprs.net/cover.cgi?call=*
If you find any particular problems, and particularly if you see a better
algorithm, please let me know.
Steve K4HG
----------------------------------------------------------------------
Subject: Linux C task...
From: Steve Dimse <k4hg@tapr.org>
Date: Fri, 27 Feb 2004 21:30:17 -0500
X-Message-Number: 7
There is a pretty quick task someone with a little knowledge of C and Unix
could perform were they interested in helping the APRS Map Manager project.
I have uploaded the first release of pocketmap.pl to the sourceforge
project.
https://sourceforge.net/projects/aprsmapserv/
This is an application where Perl is really not the best choice, C would be
far more efficient, and since a large map takes a couple seconds of CPU
under Perl, the efficiency will become important. I'm hoping someone could
convert it to C for me and create the makefile I'd need to compile and link
it to gdlib under Linux, allowing me to finish work on the infrastructure.
I'll do this if I have to, but I've not used C and Linux, learning the
make/compile/link commands would take time I could use in better ways right
now.
Thanks,
Steve K4HG
---
END OF DIGEST
Read previous mail | Read next mail
| |
