An acquaintance of mine described an aircraft locating system that sounded promising. As I understand it, a device on the plane periodically transmits GPS coordinates on ham radio frequencies, for which there are many repeaters that can presumably be reached by a flying aircraft. The gps coordinates are automatically entered into a database with a unique identifier. The database can be accessed on the internet, thereby allowing anyone to check the last known location of a plane providing they know the identifier.
Anybody heard of this - do I have the story right? Is there a web site reference? Is this system up and running? Is the database close to real-time?Effectiveness?
erich
It and variations thereof are used by ham radio ops, commercial operations, police/fire/rescue, hikers, etc. For amateur radio, involves transmitting GPS position to ground based repeater linked to internet, etc. Usually used with ground vehicles, personnel, as I'm not not aware of any method to auto switch repeaters as you fly in/out range. Would work fine without switch probably within 75-200 miles of a given repeater, subject to xmtr power and receive performance at each station.
I have been using APRS for weather spotting for some time. It works real well for that. Vehicles show up on the maps the National Weather Service uses so they don't have to constantly ask where everyone is.
There are big drawbacks to this system for aircraft like it has a lot of pieces and two more antennas and the system has a very low capacity because of low data rates and limited numbers of digipeaters. Also you don't know what the coverage area is.
I hadn't thought about it, until it was pointed out to me tonight, but the system Doug Reeves has been evaluating
http://www.itzcomm.com/SPOT/SatelliteTrackers.html has most of the benefits without most of the drawbacks of APRS, for someone wanting that sort of thing.
For a government notification of serious trouble the PLB would still seem to be the way to go. You own it and the service is free, but it won't tell anyone where you are unless you make the major decision to activate it.
If you want someone to be able to tell where you are and how goes the trip, the Spot sounds great. It is all in one small, inexpensive package and the subscription is reasonable. It sounds like the coverage is everywhere in the US and quite of bit of other territory. Just throw it up on the glareshield.
Doug's experience suggests battery life, while transmitting, may be pretty limited. I would be interested in hearing more about that.
For me the PLB still seems like all I need, but if I was married or something like that, I'm pretty sure I would also get the SPOT.