WindyWindyWindy
Active member
Well that's true of everything.However it's only an "aid to navigation" so its also good practice to use it with a degree of caution.
Well that's true of everything.However it's only an "aid to navigation" so its also good practice to use it with a degree of caution.
That is what I thought at first; that there was a chart datum error. However a couple of years later taking a deeper draft vessel in the same channel the GPS plotter had me mid channel so its reasonable to assume the first time was a GPS error.
There is an awful lot of spurious information about GPS in this thread.
Might I suggest anyone who is interested look at the actual data rather than listen to this guff!
Real Gen
More real Gen
Truth about SA
Mate. 35 years in aviation. First 12 were military aviation. Served in all of the 1990s conflicts and in civil aviation since the turn of the century including teaching GPS theory as one of many subjects ,so you don't need to lecture me on GPS.You can read and believe those links if you wish ... generally of course not to be argued with ... BUT having been in two War Zones assisting Fuel Distribution - I can tell you straight - degradation or denial of service is and was a reality .....
The new generation satellites have been delayed in launch ... previous generation satellites running well over time are having 'outages' ....
Do you know how SA works ? It was based on the Ground Tracking Stations checking / updating the sats ... random errors were uploaded to influence the positional data a civilian plotter would calculate. You honestly think that is not possible now ?
Consider the heated debate and final agreement between USA and Europe regarding Satellite Navigation and denial of service. It is no fantasy - it is a reality. The agreement stands today - Europe agreed to degrade and or switch off Galileo in co-ordination with US GPS if requested. Augmentation will be first to go ... then its a downward path ...
It may not be called SA today .... but it has even greater potential today than ever before.
that kind of reminds me of being lost in London city centre with a sat nav that kept loosing its signal because of the high buildings .I'm in Hong Kong right now, and the accuracy of GPS when in the urban canyons of Hong Kong is pretty bad - hundreds of metres from where I actually am! Anywhere where than can be multiple paths caused by reflection or refraction from buildings, cliffs or whatever can degrade the accuracy quite severely.
It's why mobile phones use wifi assistance. The use wifi signal strength for distance triangulation.that kind of reminds me of being lost in London city centre with a sat nav that kept loosing its signal because of the high buildings .
It's becoming more and more difficult to find radios with LW these days, to replace old ones as they become unserviceable.Decent quartz watch does it. Just correct it off the BBC time signal on long wave. There is always Slocum's 'Tin Clock' (and Lunar system)
It's why mobile phones use wifi assistance. The use wifi signal strength for distance triangulation.
If you think that is hard, then you want to try pouring diesel from a 20 litre can into my deck filler in a F5.And if it's fuel distribution in a war zone you want to discuss I can do that too:
Cannot beat an A-Z on your lap, with it open, leaning on the steering wheel, as you drive.that kind of reminds me of being lost in London city centre with a sat nav that kept loosing its signal because of the high buildings .
If you think that is hard, then you want to try pouring diesel from a 20 litre can into my deck filler in a F5 without getting it all over the deck.
By the time it has all gone down your oilies & into your boots you will wish you had not bothered.
Cannot beat an A-Z on your lap, with it open, leaning on the steering wheel, as you drive.
[/QUOTI I got busted by the police years ago doing exactly that driving a 40ton truck down the m40 , pre planning my route oops.
It was 20 years ago. These days it's a hybrid system.You talk about 'gaff' ????
Suggest you read up about AGPS on a Mobile Phone .... its actually the GSM signal - nothing to do with WiFi ....
Oh yes - Fuel Distr .... if it wasn't for people like me working with Strategic Fuel who were based in Bahrain during GW1 - the Coalition Forces would have been seriously short of fuel.
Oh and the picture you showed of Air to Air .... developed from pioneering work by Flight Refueling in UK - who my Father was a member of the team ...
????????
Even that doesn't help much in an area where a small building is more than 10 stories high - the multipaths and reflections basically reck the geometry. It isn't so much the strength of the GPS signal - there's usually plenty, it's the complex environment. And Hong Kong is a place where you get WiFi and cellphone signals even on the underground!It's why mobile phones use wifi assistance. The use wifi signal strength for distance triangulation.
It was 20 years ago. These days it's a hybrid system.