GPS - operation

KO4IPV

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Can anyone tell me exactly how the GPS works when using a mobile ham radio ? The complete working of the feature itself.
 

AK9R

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APRS allows you to beacon your position so that others can see where you are. A GPS receiver provides your position so it can be included in the beacon.

Yaesu System Fusion and D-STAR also have the capability to include your position in the data stream when you transmit. Again, a GPS receiver is necessary to provide your position.
 

KO4IPV

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For an example.. Go to Google Maps APRS -- Zoom in on your location. You'll see all the APRS uses around you.
Great info Thankyou , so when purchasing a mobile transceiver, a mobile radio that has the feature that is GPS is also capable of APRS ? True or false ?
 

paulears

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I'm really confused with that Google Maps screen - in my area it is showing some of the local shipping with their AIS transponders - but not ALL of them, as in my own, for example, is missing from the map, but clearly visible on every ship finder AIS I've used before. How do these ships get incorporated into APRS - because they certainly have no ham radios on board. I've clicked on one of the boats, and I'm listed as being 250m from it - but I'm invisible. The local repeater is there, and also a diving boat in the middle of the houses!
 

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paulears

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Neat! That would also explain why they may not receive my transmissions - I have a testing/demo licence and the antennas are deliberately low down, and shielded deliberately from the south, through to the north, on the westward side. If whoever is feeding in is on that side off me it explains why I'm missing. For info - MTB102 is a WW2 torpedo boat, moored near to my office.
 

AK9R

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Great info Thankyou , so when purchasing a mobile transceiver, a mobile radio that has the feature that is GPS is also capable of APRS ? True or false ?
Not always true. APRS-capable radios will say so in the feature list.
 

paulears

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Definitely not in many cases - I have two GPS equipped radios that do absolutely nothing with the data. The firmware includes features that suggest they probably have similar/identical GPS implementation, but although the specs infer that the GPS location is broadcast there seems no mode that includes any data transmission I can find, so these radios simply display their current location. I suspect GPS implementation is now a chipset feature for radios using the latest generic chips - but there is no actual purpose.
 

k6cpo

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APRS allows you to beacon your position so that others can see where you are. A GPS receiver provides your position so it can be included in the beacon.

Yaesu System Fusion and D-STAR also have the capability to include your position in the data stream when you transmit. Again, a GPS receiver is necessary to provide your position.
Yaesu System Fusion radios (at least the higher end ones) have a built-in GPS and APRS modem. Any VHF radio can be made to beacon on APRS with an external GPS receiver and a APRS controller.
 
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