APRS in Search and Rescue (SAR)
Applications
This page is somewhat dated, and there have been improvements in APRS technology benefiting the SAR world since I wrote this back in 2000. The Washington SAR 2005 Conference is taking place this very weekend in Leavenworth, WA while I'm updating this page, and Herb/KB7UVC is there and pushing APRS. Here are some more thoughts:
DMapper is a small application that links several popular topographic databases with APRS. Check for more info at http://www.dmapper.com and you'll be impressed with Dave's work. You can track up to eight APRS trackers with DMapper, then have the data manually or automatically transfer to Maptech topomaps or several other topo map databases.
The PocketTracker is a miniature transmitter (not transceiver) and TinyTracker 3 combo built into an Altoids can. It transmits are truly pure digital signal that works great. Combined with a small GPS these units make great miniature trackers.
Garmin produces a wrist GPS called the Forerunner, and with a common sub-mini cable (on both ends) you can connect to a Kenwood TH-D7A for a great SAR tracker.
This brings to mind the story I tell when showing the SAR page in the APRS Powerpoint presentation. The accompanying picture (displayed below) talks of an old GPS World magazine article about equipping a SAR dog with a pouch containing a GPS. The dog is instructed to search the area, hang with the victim for awhile, then return to base camp. The GPS is removed and the data is plotted on the electronic map showing where the dog went, and where it "lingered" which may be the location of the search victim. Search teams are then dispatched to the area. In my slightly changed version, the SAR dog is equipped with the same GPS tied to a new (at the time) Kenwood TH-D7A. You probably know that the TH-D7A is a two-band radio. You put APRS on the top, then a voice frequency on the bottom. Turn the squelch and volume up, then send the dog on its way. You do have to re-train the search dog to STAY when it finds the victim. Back at base camp you watch the progress of the tracker, and hopefully the dog finds the victims and sits down next to him. You notice the dog icon is no longer moving around the map. The victim may be semi-conscious and trapped or incapable of moving, and may be delirious with dehydration, or cold from being in the elements for awhile, but gets a good dose of adrenaline and becomes instantly alert when you pick up the radio, tuned to the same freq in the dog tracker radio, and announce (in a deep voice) "woof woof. My name's Fido, and I'm here to save you. There's water and whiskey in my left pouch, and cookies in the right. I'll take one too. Help yourself while my human friends hump it up here to us." If that doesn't rejuvinate the life cycle, nothing will. The victim should still be nice and alert when the good guys arrive.
Remainder of original text:
Having just returned from the SAR 2000 Washington Conference, held over the May 19th weekend in Packwood, WA, I'm filled with ideas on implementing APRS as an additional communications tool for use in Search and Rescue. Here are some thoughts, and I invite your comments to help develop this information further. I've been invited to present APRS at the SAR 2001 Washington Conference, scheduled for May 19-21 at the Shelton County (WA) Fairgrounds just north of Shelton.
Urban SAR: As is, APRS and SAR should work fairly well in urban SAR applications, where the primary interest is tracking vehicles or other (non-foot) resources. This is primarily true because of the detailed urban maps offered by Chicago Maps Precision Mapping and Delorme Street Atlas. I see the biggest use of APRS in urban SAR is helping identify the locations of known assets where buildings and street signs have been knocked down. Anyone running APRS at the EOC, mobile EOC, or other location could help identify the exact location of tracked assets. Using APRSsa+, damaged areas can be annotated on the APRS maps, and current location of tracked assets will be shown on the maps. As damage reports are filed, those reports can be entered into APRS. It might also be helpful to mark with evacuation routes are opened, and which are closed (thus sharing this information with other APRS users). Keep the details up to date, and you'll have a good situation map, and one that can be printed and distributed. As with routine use of APRS for public service, we're an additional communications tool, and not designed to replace, but rather supplement, voice reporting. Please feel free to submit your ideas and comments on using APRS in an urban SAR applications.
Wilderness SAR: Updated Aug 2004: Prior to this update, there wasn't much to offer the SAR folks other than Xastir APRS using topo .bmp or .jpg maps, and using them wasn't as easy or seamless as using one of the other APRS applications with Precision Maps, Street Atlas, or MapPoint. IMHO, Well, we're finally seeing some leaps and bounds in integrating APRS with the leading SAR topographic maps in the form of a program called DMAPPER (www.dmapper.com) that processes the APRS AX.25 data and outputs files that are imported in several topographic map programs, including the most prominent used today: MapTech.
From this past weekend's discussions, the SAR folks would like to have man-portable and dog-portable trackers available for their use. One of our issues to resolve and is coming up with trackers, and a sufficient number of them, that are light enough, and sturdy enough, and have enough power to run for 6-8 hours at a time. (It would be perfect if SAR resources would pay for these). We have a ways to go, although the Kenwood TH-D7A and GPS combo is a great starting point. Alternatively, a combination of TigerTracker, TinyTracker, MIM, or PIC chip, along with a GPS engine and radio, something like a Maxxon or Tekk VHF/UHF transmitter, at 5 watts, will work. Whatever the process of activating the tracker, it needs to be kept simple. so that a non-radio operator can at least turn it on. The SIG has already made some good suggestions on antenna solutions and remedies, such as the ground-plane tail wire, to resolve the ground plane issues. I agree that a 5/8 whip is a no go, as is a rubber duck for just the opposite reasons. A small 19" flexible antenna, with a ground plane tail wire, may be a good solution to ensure the comms get through. Canopy block will continue to be an issue for GPS reception, even though SA is officially turned off now. We'll just have to deal with that. Another issues came up regarding reporting of positions onto VHF and the iGates, and in some cases this is not desired. My solution was to switch to another packet frequency, and employ a nearby portable remote digi on the same frequency. There will be a need for some remote WIDE digis, one like Bob King/K7OFT demo'd at the last Summer Gathering.
In the May 2000 issue of GPS World there is a relatively good article on outfitting a search dog with a GPS. It's held on a doggie backpack. The idea is for the dog to go out and search, then return to base camp. The GPS data is downloaded and viewed on a map, seeing where the dog travelled. I didn't figure out how the reporting data was supposed to show where the search victim was located. By simply adding a TH-D7A to this solution, and reporting once per minute, then training the dog to seek, find, and stay, then the folks back at base camp can monitor the APRS screen and wait for the position report to stabilize at one location. Send the search teams to those coordinates, and find the lost/injured person.
As part of the presentations at SAR 2000, I incorporated several graphics from a company called Point Research (http://www.pointresearch.com) is offering an OEM card "Dead Reckoning Module" or DRM, that has a man-portable tracker employing DR, or Dead Reckoning technology. Their unit, which clips onto your belt, employs a magnetic compass, pedometer, and altimeter, and is "programmed" with a known position at base camp. The unit keeps track of it's position as the wearer walks around, and reports its position back via a 900MHz radio transmitter at low power (e.g. unlicensed operation). I tried to get a loaner to check out and demo how the unit operated in mountainous terrain, but was unsuccessful. I also don't know the details of the software application back at base camp. There is no digipeater solution to this, since it's not allowed by the FCC. Another variant of this unit incorporates a GPS, further refining the position data. These are slick little units, and I'm sure will find their ways into may SAR organizations if they can guarantee mountainous terrain position reporting accuracy, and have a good topo map solution on the host software. I did not obtain the price information for this cool stuff. Frankly, I'll bet it's pricey.
I don't believe each and every SAR organization will be able to have all this tracking equipment on hand and ready to use. We'll continue to have those resources as part of our "stuff", and hopefully are willing to lend it out or put it into action if needed. We're the ones who know how to use it, and we should let the SAR management folks know of this capability, and how to contact us. I have several "base" stations ready to deploy, but they can only run APRSdos, so the map detail is not of any use for a SAR application. None of us have time to sit down and draw a map of the terrain features when the search is starting. Those details need to be immediately available, and ready for use.
The Snohomish County Search and Rescue held a mock search in early May. Here is the link to a file created by Curt Mills..... http://www.eskimo.com/~archer/mock-search.txt This is good, important reading.
Dave