Simviation Forums

Europe has just begun the long process of sending the Galileo system into orbit (30 satllites all in all)
While it may take several years before the aviation industry can have practical use of it, I still think it can mean a small revolution.

It will be more accurate than GPS, which means that in theory it will render the ILS obsolete. We're talking accuracy of <1m.
and because of the accuracy, even more aircrafts can take the skies (if the authorities allows)  8)

More aircraft to the skies...

There is one thing in having more cars to the road, but when each flying car carries hundreds of passengers...  hmmm

Mind you I'd much prefer that than the idea of a plane carrying 700 people in as proposed in the New Airbus A380. Imagine what lengths a terrorist would go to wipe out 700 people and a multi-million

The americans are annoyed, again taking away their "freedom"  ::)

I was under the impression that due to atmospherics it was impossible to get any sort of GPS system accurate to any less than about five metres. How do they intend to guarentee accuracy to less than 1?

By having a constellation of 30 sattelites I imagine that they plan on keeping them in low-earth orbit, instead of geostationary. That could be a factor, though I'm not sure.

I was under the impression that due to atmospherics it was impossible to get any sort of GPS system accurate to any less than about five metres. How do they intend to guarentee accuracy to less than 1?

Ground correction stations... same thing some car nav units use. Only works when in range of them, when not in range you have the sattelites only.

Best chance of trying out the accuracy was in 1991, when the US army had a shortage of their custom-built units and were forced to increase the precision of the free-use signal for a few weeks

Is the civilian signal still "de-accurized" ?   I had an older Magellan, hand-held GPS that I tested at known waypoints along  the Northfolk & Southern Railroad mainline. After sitting still for three minutes it was always well within 3-meter accuracy (except for elevation).  I've heard that newer units using WAAS (that must be the ground correction stations) are well under 1-meter accuracy (even better with an external antenna). These are relatively inexpensive, hand-held units. I'm sure the $5,000 Garmin in the plane I rent is at least as accurate. I mean.. GPS approaches are considered precision.. right ?

I've heard that carefully set up surveying units can be accurate to sub-centimeter.

Anyway.. If civilian aviation units are accurate enough to guide a vehicle moving at 100+mph "precisely" to a runway (and have been used for years now).. I can't imagine how much more accuracy you'd need ?

[quote]Is the civilian signal still "de-accurized" ?

I don't pretend to understand why Galileo would be any great improvement over what we have now. However, I think anything making navigation more accurate & therefore safer can only be applauded & welcomed.

because of the accuracy, even more aircrafts can take the skies (if the authorities allows)

I think this is debatable in the current climate & I'm not sure it's relevant. A move towards reducing the number of aircraft movements is far more likely. IMHO

Glonass has just been resurrected from the ashes. Works almost the same as GPS but has unique sattelite IDs that are sent together with the location.

Gallileo is different again because it's a two-way system

I don't pretend to understand why Galileo would be any great improvement over what we have now. However, I think anything making navigation more accurate & therefore safer can only be applauded & welcomed.

I think this is debatable in the current climate & I'm not sure it's relevant. A move towards reducing the number of aircraft movements is far more likely. IMHO

The aviation industry anticipates an increase in air traffic of around 20% in the next 10 years. And if authorities are trying to reduce that number, I have a hard time seeing how that adds up.

And we can fit more aircrafts in the sky  :)
Just some months ago, the Eurocat2000E was introduced in Sweden. It replaced the old ATCAS from the late 70's, so ATC is now able to handle more traffic, with the same safety standards as before.
Eurocat is already in service in Hungary, Ireland, Denmark and Finland.

I'm pretty positive of this, but like you said, it's debatable.  

The aviation industry anticipates an increase in air traffic of around 20% in the next 10 years. And if authorities are trying to reduce that number, I have a hard time seeing how that adds up.

One way would be to operate larger capacity aircraft like the A380. I don't know if this is the answer & only time will tell. Meanwhile, I don't see how any navigation aid can alter the fact that international airports in the UK are operating at their full capacity now & could not handle more traffic even if they wanted to or the locals allowed it. One answer to that is more airports or extensions to existing ones. There is strong opposition to both of these solutions even though they're supported by the government. Basically, people want to fly when it suits them but very few of them are prepared to live anywhere near a busy commercial airport. Knowing what it was like living on the approach to Heathrow back in the 1960s I can't say I blame them.