Why isn't GPS more accessible and simple.

[Bazel]

I've been doing some internet searching and am amazed to find how inaccessible GPS radio transmissions are to Ham radio. I know that the Federal GMRS rules allow a GPS location signal to be communicated between radios but try and find out what frequency is used. The Garmin RIno will share GPS locations with other Rino users and won't tell you the frequency. The signal is also weak and almost useless because it won't go through a repeater and unless you're on top of a hill you could nearly shout as far as the radio will send the signal.

Then you have VHF Marine radios that will share GPSs locations and even send an emergency location to the Coast guard by pushing a button. Another unpublished frequency. There is also ARLES ( not sure if I got the acronym right) but this requires a couple hundred bucks of gizmos and as far as I can tell doesn't do GPS location sharing between radios unless you have an internet connection and device.

So tell me why can't the FCC set a frequency aside for genera use. There is no reason that you shouldn't be able to hook a handheld or any GPS for that matter to your radio and do some location sharing with other radios. I can do that on my marine radio. Are they afraid they will put the over complicated systems out business? Or is it because as in all things they get lobbied by the self interested moneyed businesses?

 

[ScanWI]

GPS is used very widely in Ham Radio, Mainly on 144.39. The FCC has set aside our bands and we can do with them what we please. The Ham Community is more or less self governed inside of our bands. It can be difficult to set up but GPS sharing is very common, the main problem is finding a GPS with the correct outputs to interface with the radio.


Automatic Packet Reporting System - Wikipedia, the free encyclopedia

 

[mmckenna]

Marine VHF uses the AIS for position sharing.
U.S. VHF Channels

AIS 1 is 161.975MHz
AIS 2 is 162.025MHz
I don't know the exact protocol they use off the top of my head, but it's not a secret.

A number of new amateur radios are coming with this capability, specifically Kenwood and Yaesu are currently selling radios that will do this, both hand held and mobiles. Those use the APRS protocol. To confuse things the D-Star radios use a separate format that is not directly compatible with APRS>

It's been a while since I've read the FCC waiver that Garmin got to run GPS data on the Rino GMRS/FRS radios, but if I recall correctly, the original ones only used FRS channels as data wasn't allowed on GMRS. It used the same channel that you were talking on so real time position data would be available to the other person. They then filed a waiver request to open it up on the GMRS channels, same set up, used the same frequency you were doing your voice TX on. I think they -may- have filed to allow it on the 467MHz GMRS channels, and that could have allowed it to pass through repeaters, but you do need to remember that the GMRS repeaters are privately owned, and there is no requirement that they be opened to the public or pass any signals that the owner doesn't want.

I run a trunked radio system, and we can do GPS position data through our system. I have two ways of doing it. On the trunked system, the radios transmit their location over the control channel. for conventional use they use the same channel as the voice, or we can set them up to send position data on a separate channel. P25 and DMR/MotoTrbo and NXDN all have the capability to do this.

Any analog FM radio system can be made to do this also, there are various ways of doing it, but it's not rocket science. As the poster above me said, the hard part can be finding a GPS that will directly interface to your radio. Back when I was running APRS, I had to fabricate an interface that would power the GPS receiver, and send serial data to the radio, not difficult, but not an off the shelf thing. There are off the shelf systems that are plug and play for some amateur radios, specifically the Kenwood TM-D710. For commercial radios it used to be difficult to find thing, now most manufacturers make radios with built in GPS, or you can find after market GPS enabled speaker microphones that plug right in to hand held radios.

 

[WA0CBW]

All of the frequencies you are looking for are published on the FCC web site as well as many other sources including this site.
BB

 

[zz0468]

I've been doing some internet searching and am amazed to find how inaccessible GPS radio transmissions are to Ham radio.

Isn't that what APRS is doing???

 

[robertmac]

I'm confuzzled

Not sure if the OP was talking about Ham, Garmin, Marine, or general mobile/land radio. As has been pointed out, Ham is really active on APRS, GPS location/messages/email, etc.. All the big 3 radio companies have GPS radios. Then there are other companies selling TNCs. So I'm not really certain of the question in this thread.

 

[cavmedic]

Garmin Rino's , when enabled will send the data burst on what ever channel you are operating on at the time of the transmission.

 

[Bazel]

Useful GPS

Garmin has the type of GPS location info I am talking about, but Garmin's GPS locator, which is between two mobile radios and will track continously, is very weak (1/2 watt) and I'm guessing is a little bit better than using a loudspeaker or yelling. THe only useful way of using it would be searching for your buddy and being able to see his signal if you happen to walk close to him, climb a hill or get a lucky skip signal.

What I don't see is GPS capability that you can add to a mobile radio so it can see another mobile radio. Sure you could use a cell phone in conjunction with the radio and do it but then if you both had cells that worked in that area, what's the point.

In my case my brother has had a heart attack followed by a stroke but has mostly recovered, but he still has some mild memory issues and one eye that doesn't track. When he takes off on a hunt, even in familiar area he tends to get off track because of his bad eye and has a hard time with complex instructions and devices like GPS radios (garmin rino) but can manage them if he practices alot.

So what I would like to see is a decent GMRS radio with GPS tracking capability or a way to build it or add it on for inter mobile radio tracking. I believe the issue here is the idea of a continuous tone broadcasting over a frequency, but since there are frequencies set aside, why can't I pick them up in my radio and get a location directly.

 

[LtDoc]

It sounds like you are looking for a 'dedicated' system, which I'm sure it can be done though. I very much doubt if will be done on amateur radio, look for a dedicated and priovate type service instead. And since I didn't see it mentioned, is your brother a ham? If not, then that's just one more complication.
- 'Doc

 

[hill]

The VHF Marine Band Digital Selective Calling (DSC) used with GPS is not an unpublished frequency, since, i uses Marine Band Channel 70 (156.525 Mhz).

Please see the below links for DSC information.

Digital Selective Calling - Wikipedia, the free encyclopedia

USCG: Rescue 21

Digital Selective Calling Radios - Nautical Know How

 

[mmckenna]

Here is a better solution for what you are trying to do:

Garmin | Astro®

Basically it's a GPS tracking of a Rino but it uses the VHF MURS frequencies. Switching to VHF alone will help with signal propagation. They claim it will do 9 miles, line of site, but I can't find any mention of the actual power output of the unit.

It's a lot more money, and you'll have to figure out a way to get your brother to wear it. Looks like you could take it off the collar and put it in a pack for him.

 

[KB7MIB]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

If it's on the MURS channels, it should be 2 watts.

 

[AgentCOPP1]

This is another question that I'm going to add to this thread. Does anyone know what frequency the GPS satellites transmit on? I thought it would be a cool little experiment to point an antenna up there and see if I can hear the satellites.

 

[nd5y]

Does anyone know what frequency the GPS satellites transmit on?

Global Positioning System - Wikipedia, the free encyclopedia

 

[LtDoc]

Maybe another misconception, or I'm just reading the question 'wrong'. The GPS signal isn't retransmitted to another radio, only the information contained in that GPS 'signal'. Big difference there! That information is extracted and translated into some 'standard' form and then sent to another radio to be extracted again and displayed. The actual frequency of use by that GPS receiver doesn't really matter, only the information contained in that signal received on that frequency.
The position information can be gotten from several sources, not strictly/directly from a GPS receiver. One of those sources is the internet site for 'aprs.fi' for position reporting with ham radio. That position information must first be sent to that site of course. That 'position' can be found/computed in several ways too, it doesn't absolutely have to be from the GPS system. (If the reporting site doesn't move, there's no need for a GPS to figure it's position for every transmission, so no GPS needed.)
- 'Doc