LoginRegister Search
Subject: APRS: Keeping the Caravan Together

You are not authorized to post a reply.   
AuthorMessages
Craig Miller
Title Sponsor


02/26/2008 11:41 PM Alert 

When in a caravan it is a challenge to keep track of the vehicles behind you.  When in the forest a single turn and you lose sight of the vehicle behind you.  In the desert you want to stretch out to avoid the dust.  Add to that challenge the simultaneous need to navigate, keep track of the schedule, provide trail information to those behind you, and concentrate on the road and someone always Keeping track of the vehicles in your group, while navigating the trail, and someone always seems to get separated.  APRS is a simple and elegant solution to this problem.

Automated Position Tracking System (APRS) station allows you to see on your GPS or computer based map the location of other APRS beacons.  A beacon is an APRS station that only broadcasts its location.  Byonics has release a new fully integrated beacon that you can place on the vehicles in your expedition group.  You will then be able to see the location of each vehicle.

The solution requirest that you buy the tracker, an antenna and GPS and that the pieces get soldered together (sigh) but it looks very straight forward to compile. If you were to buy a GPS, I'd suggest getting one that has the SIRF Star III chipset. It is sensitive enough to be able to stay locked on to the satellite signals even under tree canopy.
http://www.byonics.com/microtrak/mt8000.php

Tracker (w/ 8w amp): $150

 

http://www.byonics.com/microtrak/mt_antenna.php

 

http://www.byonics.com/tinytrak/gps.php

 

The GPS can be found cheaper elsewhere, but this allows you to single source it.

GPS (Byonics GPS2): $69

Antenna: $9


My Overland Adventure Blog
Tim Woodson



03/18/2008 2:35 AM Alert 
Don't have that problem in Nevada! You could see the dust cloud from Space and each other up to 10 miles apart.
Just kidding, We just use CB's and GPS, But for when I am out alone I just got a SPOT Satellite Messenger.

Jeep Grand Cherokee
The Offroad Cadillac
Gabe Greene



04/21/2008 10:13 PM Alert 
For your spot, do you have it set up for tracking on Google map online?
Craig Miller
Title Sponsor


04/21/2008 10:26 PM Alert 
Gabe,

Tim isn't a regular here so I'm not sure if he'll reply. I have a SPOT as well, but I don't use the tracking feature for a few reasons:

- I don't want to waste the batteries. For me, the SPOT is for communicating at specific intervals and I want to know that the batteries are good in an emergency. For example, when my wife goes to Nepal next fall she will only have one set of batteries and most likely not be able to find Lithium batteries when she is in town. In this case, it makes more sense to just leave it off and save it for checking in with an "I'm OK" each night and for true emergencies.
- There website doesn't offer any means of setting up a "guest account" where people can see where you are, but be restricted from modifying your account settings.
- It only beacons every 5 minutes, so it doesn't make a very good track capture utility. I'd much rather track my trip with my GPS and e-mail the track to my friends when the trip is over.


My Overland Adventure Blog
Davis M



04/21/2008 10:49 PM Alert 
Craig, I'm sure you've checked this, but I thought I remembered seeing Nepal at the very fringe of Spot coverage. Perhaps GlobalStar reception has improved since I last looked. dm
Craig Miller
Title Sponsor


04/21/2008 11:47 PM Alert 
I hadn't actually checked. Thanks for the tip. I'll take a look before she winds up carrying a paperweight 1/2 of the way around the world.

Craig

My Overland Adventure Blog
Eric V



04/23/2008 6:52 PM Alert 
I have a tiny trak sitting in my tool box drawer. I bought it about a year ago and couldn't figure out which part I needed to unsolder on the radio to make it work. So there it sits. If you want to do APRS the Kenwood 700 or now the new 710 are the radios to have. I think the TH7A handheld also has the APRS built into it too.

If you are all running HAM radios in your party I'm having a hard time understanding why you would need the APRS, you should just be able to periodically check up on each other or call each other if someone has a problem. Even on simplex on 5 watts I'm able to talk about 70 miles away. Granted I'm in the high desert without any huge obstructions but I can't imagine getting so far apart to not be able to chat verbally.

SPOT is really cool. You can set it up to email yourself and then set up an automatic forward to a website. My friend did this on his recent adventure www.cruiserexpeditions.com He didn't always update the message but the coordinates were updated so we could see him making progress. Check his blog for the SPOT posts.


Eric V.
99 UZJ 100 Land Cruiser Barnacle Edition Under Construction and a few other Cruiser projects
David Buchanan



04/23/2008 7:29 PM Alert 
[Hijack on] Eric you don't happen to have any spare CB radios laying around do you? Shawna is looking to drop one in her trail rig once we get the LWB all sorted out. [Hijack off]

1973 Series III
1995 RRC LWB
2000 Discovery II
2000 P38
Craig Miller
Title Sponsor


04/23/2008 7:45 PM Alert 
Eric,

Talking doesn't tell you where someone is. You can call to someone and they can report that they are "rolling", but they might be rolling in the wrong direction. It is also easier if the trip leader can just glance down at a screen and quickly see that everyone is still on track and moving, precluding the need to call at all. Is it mandatory? No, but neither is a HAM radio, GPS, or 1/2 of the other gear we bring along. Is it convenient? Yes.

The Kenwoods work well if you want to run APRS through a simple GPS, but if you want to hook it up through a computer and do more than simple APRS they don't work well. The TNCs in them are poor and don't work well when hooked up to external devices. They are fantastic radios for people just looking to do simple APRS with a good GPS like a Garmin 276 or 60CSx.

My Overland Adventure Blog
Eric V



04/24/2008 5:09 AM Alert 
Craig,

I have a feeling our experiences are much different with wheeling with groups. Therefore our needs might be different. I'm still interested in the APRS but I'm sort of alone out here in the desert and I don't have anyone to show me how it exactly works. I'm one of those R&D guys when it comes to electronics. Research and Duplicate.

Eric V.
99 UZJ 100 Land Cruiser Barnacle Edition Under Construction and a few other Cruiser projects
Craig Miller
Title Sponsor


04/24/2008 7:24 AM Alert 
Yes, the desert is different than the woods. In the woods, you can be 1/8 of a mile apart and still not be able to see each other so it is difficult to tell how spread apart you are.

Other than tracking vehicles, the other application of APRS is to share information. E.g. I can add a campsite waypoint to my screen and it automatically shows up on your screen. Sharing lat/lon vi voice works, but APRS works a little easier. I'm a mapping geek though, so I probably get more excited about the mapping technologies than most.

Craig

My Overland Adventure Blog
Eric V



04/26/2008 2:49 AM Alert 
Craig,

Could you post a photo of your setup in action?

Eric V.
99 UZJ 100 Land Cruiser Barnacle Edition Under Construction and a few other Cruiser projects
Craig Miller
Title Sponsor


04/26/2008 1:25 PM Alert 
I only have voice setup right now. I am re-doing the computer side of my truck and adding APRS support to Overland Navigator. My setup will be based around a removable tablet UMPC (EO Tuftab) and a Elcom Bluetooth tracker/tnc w/ an embedded GPS. I'll definately post photos when it is finished.

Craig

My Overland Adventure Blog
You are not authorized to post a reply.
Forums > Skills & Gear > Communications > APRS: Keeping the Caravan Together



ActiveForums 3.6
Copyright (C) 2010 Northwest Overland Society, LLC   Terms Of Use  Privacy Statement