rescue 21

V

vic33004

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does anyone know why the protocals for mayday responders seemingly has not changed with the deployment of the rescue 21 system. i hear calls to/from the coast gaurd station requesting location info. if the 21 system is up and running and a GPS position is aquired by the system, why aren't the USCG stations asking to confirm the position data they already have?

in our area it is often difficult to hear the coast gaurd transmissions, very weak audio, but the signal is strong enough to step on all other broadcasts. i had hoped the issue with poor audio quality/volume would also have gone away with the deployement of the new system and that is not the case, at least here in and around the Miami Fort Luaderdale stations.
 
"i hear calls to/from the coast guard station requesting location info. if the 21 system is up and running and a GPS position is acquired by the system, why aren't the USCG stations asking to confirm the position data they already have? "

If the caller has no DSC, then they need to ask for location info. btw: your post is confusing. To me, at least.
 
Bill, i've not yet heard a single USCG transmition to any station that seeks to confirm the GPS coordinates, i can't believe that not one of the vessels hailing USCG is using a functioning DSC VHF.

sorry for the confusion on the 2nd item, i've updated it, hope it makes more sense now. very often when a location is required i've heard the backwards and forwards as the USCG station tries to get an accurate and complete GPS position from the hailing station. sometimes i can hear both stations but they clearly can't hear each other.
 
Doesn't require DSC to fix a position - although it can fix a position by a properly functioning and transmitting DSC if said DSC signal reaches the RFF (the Remote Fixed Facility - which is just a term for a really tall antenna). MOST calls that the RFF receives on the 'voice' radio on 16 will also be received by the RDF radio, but that will only give a line of position. It would need to be received on two separate RFF's for a fix, and received well enough that two reliable lines of bearing intersect. Even then, there is still an area of uncertainty associated with any radio direction finding fix - like any technology, it has it's upper limits. A DGPS fix is still more accurate, and instead of giving you a position in the middle of an (albeit usually small) elliptical area of uncertainty, it gives you a VERY accurate, precise position. It also confirms the accuracy of either system. Think of it like running the boat - would you just drive the chartplotter, or would you use the chartplotter AND look at where you're going, and where you are, and match that to where you should be?

I'm surprised to hear that the audio quality doesn't sound better with the Rescue 21 system - seems to me, the quality is drastically better. And even failing that, the rest of the technology in the system is downright impressive - the positioning and direction finding, the DSC capabilities, the digital recording and playback, the audio enhancement tools - it really is an awesome tool (or suite of tools). The radios also have some SERIOUS reach.
 
As to the audio quality, I suspect that it is related to having a "desk mike" rather than a "handheld mike". If the mouth is too far away from the mike the signal strength will remain high, but the audio volume will be low ( and sound like a speakerphone ). It happens sometimes around here. So I write this one off to "user error" rather than equipment failure. After all, you caught the signal ( hardware ). The coatie on radio watch is likely looking at something on the desk or elsewhere in the room, or perhaps, simply sitting back rather than up close to the mike. Without experience in using microphones or training in using them, it is easy to have such a mistake.
 
Any decent mike should not require the user to be overly close to that Mike, depending upon what you call close. A distance of 15" to 18" should be very adequate. If the user has to be closer than that then a better mike should be procured.

I get so tired of seeing/hearing these entertainers who think that they have to swallow the mike to be heard. Actually when they do that they are distorting the sound.

G
 
G, the point is that there is a correct distance from the mike, and the allowable range is fairly small. And they are "not in range" or they are "not speaking into the mike". I really doubt the issue is with hardware.
 
Ok, we can push the audio quality issue to the side for the moment and called it poor training for the operators. we don't have to waste time telling the 911 operartor where we are. whats up with the USCG?
 
quote:
Originally posted by vic33004

Ok, we can push the audio quality issue to the side for the moment and called it poor training for the operators. we don't have to waste time telling the 911 operartor where we are. whats up with the USCG?

Click to expand...


Channel 16 is not E-911. There is no permanent address linked to your radio like there is with your landline telephone. And if there was - how often would you be calling from that exact address? Further, a Motor Lifeboat would most likely run aground trying to respond to the front door of your house.
 
quote:
Originally posted by November Charlie
Further, a Motor Lifeboat would most likely run aground trying to respond to the front door of your house.

Click to expand...

Damn it Mike, while I needed the laugh now I have a coffee mess to clean up!
 
911 operators sit at the desk with a telephone headset on. USCG watchstanders do not because they are usually multi-tasking in the comm center while on watch.
 
actually Mike, with the DSC system it is almost exactly like having an address attached to your radio and yes they do know excatly where you are, that was the whole purpose of the rescue 21 system. the trianglation RDF function of it is not as accurate as the DSC, but its not that far off to warrent disregarding it either. regardless it just seems pretty silly to ignore the capabilities of the system which drove its implimentaion and significant cost to us. this may not be as much of an issue in a remote area with light traffic on 16, but in a busy area with lots of traffic on a weekend it sure can be.

in fact if you look at some of the statments issued by the USCG subsequent to the rollout of the system, they are touting having saved time/money on haux calls that eminated from land. this is clearly a benifit of the system and validation that it does work.

Pual, i've never been in a radio room at a USCG station, does the radio operator typically have equipment in the radio room akin to a headset so that he/she can hear the incoming transmissions?
 
The ONLY people I can clearly understand on the radio first time, every time, are Sea Tow operators.

Just finished Kayaking on the Bay with my wife, both of us with our marine radios turned on, and much of the time we were laughing at the incomprehensible radio transmissions. SOME regular transmitters, like to speak so fast the entire message is virtually useless. Simple training on how to use a mike, would do wonders for the marine community.
 
In my 4 years of boating in Little Egg and heard numerous emergencies and seen deaths I have only heard 3 DCS calls only one had any information on it. Just pushing the button doesn't do much if the NMEA data, GPS or boats MMSI is not programmed into the radio or the radio is not properly interfaced to the chart plotter or GPS. All you get is an alarm your radio goes to channel 16 and your screen says no data. I have seen many more working AIS A & B transponders on a daily basis. However AIS is not DSC. A well equiped AIS properly interfaced can call another AIS equiped vessel through the integrated DSC function on the radio.
Bill
 
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