Personal Locator Device

Posted by: crazyone

Personal Locator Device - 11/08/08 07:07 AM

I been wondering about these devices,Since the other night my Fire Dept and about 4 other dept about 100 people,were alerted to a distress signal in a deep hollow. As we were setting up the command past and such we were told the coords moved to another location and so on for over 21 hours.

we finally figured out the distress signal was coming from a retail outfit ,which of course the earlier shift said all units was not set up and found out later one unit did go off.

I was wondering how the accuracy of these units are in a more remote area. It was funny that all the coords we was getting from a govt sources and setting them in the gps units were way off and the coords kepted moving.

I am no way knocking these devices,but I think there should be a quicker way of getting a faster fix and accurate fix on these units, If it was a true emergency,things might of not gone well. I also don't know if its the equipment we had to track the signal had problems,or the lack of training,or if the satilites were malfunctioning.

I was seriousily thinking about one of these devices,but after the other night,I am kinda of hesitant.
Posted by: Rick_D

Re: Personal Locator Device - 11/08/08 10:34 AM

It sounds like the accuracy will be improving with the retirement of some of the older frequencies:

http://www.noaanews.noaa.gov/stories2008/20081031_sarsat.html

The accuracy, of course, depends a lot on where the thing is triggered, with a canyon probably being the worst possible scenario. I would definitely get one with the added GPS function. I understand that EPIRBs cause far more false alarms than PLBs, since they are designed to self-trigger. I'm interested in a PLB since I solo a good deal, but am waiting for a nice four-ouncer!
Posted by: jasonlivy

Re: Personal Locator Device - 11/09/08 07:03 PM

Quote:
I been wondering about these devices,Since the other night my Fire Dept and about 4 other dept about 100 people,were alerted to a distress signal in a deep hollow. As we were setting up the command past and such we were told the coords moved to another location and so on for over 21 hours.

we finally figured out the distress signal was coming from a retail outfit ,which of course the earlier shift said all units was not set up and found out later one unit did go off.

I was wondering how the accuracy of these units are in a more remote area. It was funny that all the coords we was getting from a govt sources and setting them in the gps units were way off and the coords kepted moving.

I am no way knocking these devices,but I think there should be a quicker way of getting a faster fix and accurate fix on these units, If it was a true emergency,things might of not gone well. I also don't know if its the equipment we had to track the signal had problems,or the lack of training,or if the satilites were malfunctioning.

I was seriousily thinking about one of these devices,but after the other night,I am kinda of hesitant.
The Corspas Sarsat Satellite System using the LEOSTAR satellites are accurate to a two mile radius in about an hour. Then a 121.5 Mhz signal is given off to help the SAR team find the victim quickly. If it has a GPS built into it, it should be 5 minutes within a 100 mile radius, that is if it can obtain a GPS signal.

The ACR PLB is designed to work on either, except for the Terrafix I which only uses the Cospas Sarsat Satellites for location. All of their units gives off 5W of power compared to 0.6W being received by a GPS and/or other units (ie. SPOT) that use GPS entirely for receiving and transmitting. Depending on the interference of the building it was in (metal roof, other barriers that would interfere with the signal), this may have been the problem. In this situation a GPS wouldn't even pick up one satellite.

This leads me to my question: What exactly was the make of the unit? Was it an ACR PLB or something else?
Posted by: dla

Re: Personal Locator Device - 11/10/08 10:38 AM

With SPOT, there is a call-back verification process. The emergency center starts calling the emergency contact numbers to avoid false alarms. After they try the emergency contact numbers then they call out the calvary. Don't they do something similar with the PLBs?
Posted by: midnightsun03

Re: Personal Locator Device - 11/10/08 10:46 AM

I know that in Alaska, when a hand-held EPIRB goes off, the Rescue Coordination Center starts calling the emergency contacts registered with the device. I have no idea whether they do the same for a PLB.

MNS
Posted by: Tango61

Re: Personal Locator Device - 11/10/08 08:30 PM


I would prefer they call the cavalry. <img src="/forums/images/graemlins/smile.gif" alt="" />
Posted by: jasonlivy

Re: Personal Locator Device - 11/11/08 10:55 AM

Quote:
With SPOT, there is a call-back verification process. The emergency center starts calling the emergency contact numbers to avoid false alarms. After they try the emergency contact numbers then they call out the calvary. Don't they do something similar with the PLBs?
This is also the process used in verifying if a PLB rescue is warranted. Obviously, if the beacon hasn't been registered (no emergency contact numbers are listed) the SAR team is then sent out. This is why it's so critical that each PLB be registered and why its the law.

One difference may be that both the emergency contact numbers AND the SAR team are immediately notified. Thus if it is a real rescue situation, the SAR teams are in a position to get out as soon as possible. Only after it has been determined that the stituation is a viable rescue senario is the SAR team given the go ahead to leave. This all happens in a matter of about 15 minutes or so after the initial signal is received.
Posted by: crazyone

Re: Personal Locator Device - 11/11/08 03:37 PM

I have to admit I was not sure what type of unit or if it was a pld or etc. I have gotten my info from the command post and we was being sent out with the coords to a particular area and we searched in the area of the coords until a new set of coords was recieved.

I do have to agree that it was the interfernece of the building material since the store is ontop of a hill and void of trees. I still going to check more on this and hopefully can work something out with the emergency mangement to be better prepared.