1. #1
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    Default PASS Devices + GPS = ??

    Hi, All;

    I've seen the ads for Grace Industries' PASS III device that allows an IC to transmit an evacuate order to a user's PASS device. linky

    I've been wondering about this: Why aren't PASS devices equippted with GPS beacons that would tell an IC exactly where his men are in relation to his station. My thinking is this: [list=1][*]Firefighters activate their PASS Devices[*]IC activates a unit that will show the locations of all FFs with PASS devices turned on[*]Safety Officer or designee could create waypoints at various points of the structure (eg. 4 corners of the house and front door)The unit can assume altitude differences of 5 feet or more = 1 floor[*]Unit will then show where firefighters are at all times[*]During a RIT/FAST team situation, the IC can direct the team to the victim much faster.[/list=1]

    Maybe I'm missing something, but this seems to be an ideal use of GPS in emergency services. Are there limitations to the GPS or PASS technology that would prevent this?

    EDIT: whoops. fixed some spelling errors. I kin reed and rite alwrite!

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    The accuracy of the gps is limited by how many sattelites it picks up. Inside a building I rarely get signal at all. Outside the accuracy is usually within 10-30 feet. 10 isn't bad, but 30 feet is way too far to be off an exit point.

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    Having played around a good bith with GPS linked to radio with ham rdaio, I can tell you there will be some definate limitaions.

    1: Accuracy. Most GPS recivers, especially the smaller ones that you would need to integrate with a pass, have an error rate that ranges from 15-100 feet depending on the unit. Given that most of us work in situations where the biulding is under 50 feet wide or deep, your error rate is going to kill a lot of effectiveness.

    2: When do you need a PASS device? Inside the structure. GPS signals are very weak, and have a hard time penetrating structures. The recivers that do manage to sometimes work indoors do so because they have larger antennas, and even that is no guaruntee of sucess. Even a thick tree canopy can block GPS signals. Since teh PASS device is usually on the waist it gets even worse reception as the body blocks signals also.


    Now such a device has definate possibilities in wildland use, and I am working on adapting the ham radio system ( Do a search for APRS for info) for use on search and rescue for us.

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    We use a Motorolla porable radio with built in accountability that use triangulation to locate downed firefighters. No need for GPS with it. In addition, command can see what channel each radio is on. When you turn the radio on and off the portables tellyou what channel you are on audibly. Command can individually page each company, group call evacuation etc.

    Plus command can tell if you radio is on and knows by the firefighters name whoo is holding what radio and what company he responded on. At any time we know how many guys and rigs are on scene.

    It is very easy to do functional accountability.

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    Originally posted by magnolia
    We use a Motorolla porable radio with built in accountability that use triangulation to locate downed firefighters. No need for GPS with it.
    Every one is right about the limitations of GPS, plus it is still a proprietary system that could be shut down, corrupted, or fail due to sabotage, accident, etc.

    I think the radio based technology magnolia spoke of is where you are going to see this aspect of PASS come from. It would not be that difficult to equip each engine with a transmitter/receiver that either triangulates with the aid of radios, other engines, or tripod mounted recievers that could be placed on the other side of the building. This would give you accurate 3-D locating limited only by the strength of your transmitters.

    For the system to really be front-line and fool-proof, we would have to ensure it is can be operated entirely from the scene, including by generator if necessary. With truck mounted repeaters and similiar technology becoming commonplace, I think we will see this technology become the norm in the next decade or so.
    Never argue with an Idiot. They drag you down to their level, and then beat you with experience!

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    Lightbulb

    I agree with previous accounts of GPS reliability inside structures. There is considerable difficulty in obtaining satelite signals under those conditions.

    Another problem, perhaps you haven't considered. In a multi-story building, it would be extremely difficult to determine which floor the firefighter is on...even if a signal could be established. While many GPS units determine elevation on a very limited, somewhat unreliable basis....calculating the exact distance up (or down) from the command post, would be, well....your best guess.

    Wildland applications, Search and Rescue, mapping...the sky's the limit.

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    hmmm after hours of the discovery channel i would have to argue a tad about gps not working in buildings.. i may just be totally arrogant feel free to point that out but u.s. military has some sweeet %#&* ya know??? i think with everything we have today they could still incorporate more technology into it to atleast get you within hey 5 feet.. we all know it can be done i mean we have cameras as small as a pinhead! with what happened at the training in florida could that mans life have been saved if they found him the first time around??? possibly.... all im saying is if they were pushed enough to do it we would have it... (i had to stir up the fire a little)

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    Having played with military and civilian GPS a great deal, I can assure you its leaves much to be desired inside buildings, or for that matter under a thick tree canopy.

    The transmitters on the sattelites are fairly weak, and the signal not very strong at all once it reaches earth, and in most cases not nearly strong enough to be picked up without a good clear view of the sky.

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    Lightbulb

    i see where your coming from but dont you think they could mount a hig power transmitter up to an engine to cover a smaller maybe 1x1x1 mile area?????? that as well would work with great signal even thru concrete walls as long as it is close it will be fine... infact all they need is a mini cell phone tower and that can do the same thing... this day in age almost anything can be done just how much is the gov going to cover.. we all know if there was some huge story where a massive disaster could have been prevented by this measure and people to to become irate the fed gov would DIVE right in and say "look what we have found" like nothing ever happened. again this is just a point i dont mean to sound snappy .

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    ilwannabe21

    With all due respect, I suggest you do some homework regarding HOW GPS works. The downlink signal from at least 3, preferably 4 satelites needs to be acquired by the GPS receiver on the ground...not the other way around. The device, whether handheld or mobile mounted, is only a receiver of these weak signals from the satelite. You need to have a somewhat unobstructed view of the sky...in order to RECEIVE the signals from the satelite.

    The GPS device does not transmit. It receives signals from satelites, makes a computation..and prompts your location on the display.

    From Garmin.com

    "Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map."
    Proudly serving as the IACOJ Minister of Information & Propoganda!
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    It all boils down to value for your money. Most departments would rather have microphones built into their SCBA masks, or even better hose to fight fires. Folks with a great deal of experience with the best technology available have stated that it not very accurate, not to mention reliable. I would also be leery of getting nuked by radio waves of large transmitters attached to trucks.

    Itís important to keep thinking outside of the box however, and just because cold water is being dumped on it now doesnít mean that itís not important to think about things like this.

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    ikjnow exactly how it work it triangulates on a postion. what im saying is it does not have to be gps there are other ways of tracking thing.. it can be based off of infa-red signals if need be the point i was trying to make it the hold position tracking can be done but it wont happen because people are cheap everything is about money. flat out thats it.. why would someone need gps in a fire.. the fire isnt global.. they have local area positioning sensors that can get you withing 3-5 feet of a person they just dont cover a large area which means ineffective.... all i would look for if i were in charge and 4 of my 5 men came out.. is he on the nw ne or sw or se corner.. ok rescue team i know hes in the sw corner do your job..... righti does not have to be deadly accurate it would need to get the job done. thanks for listening

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    Deadly accurate????? More like deadly inacurate.
    I walked into the Gulf of Mexico holding a hand held
    brand new 2003 newest model GPS .when I was chest deep
    it told me I was 6' ABOVE sea level. No trees no roof
    not even any clouds. It Knew where it was but not how high.
    I would not want to tell my RIT that 2 men are GAURANTEED
    on the 2nd floor let them die trying to find the brothers
    and end up pulling dead firemen from the 3rd floor and dead
    RIT firemen from the 2nd floor

    sorry guys rant mode off

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    the only gps the is super accurate is military the have i believe 8 satilies they can pinpoint you within i believe 1-3 feet if not closer. civilians cannot buy that stuff but when you take something and make it more mobile on a smaller scale it is easier.. again nothing is berfect look at thermal imagers everyone has complaints on them.. then cant hardly see thru water but they are used to help.. in situations involving buildings and fire you cant predic everything but i would rather have something giving a close idea of where i am then nothing at all.. that is all i would want.. nothing is perfect even machines make errors nothing to then but pray..

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    I have a really bad keyboard btw parden all of the errors

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    It's known as three-dimensional trilateration...and is somewhat different than triangulation.

    But you knew that...right?
    Proudly serving as the IACOJ Minister of Information & Propoganda!
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