Author Topic: Galileo Navigation System  (Read 951 times)

Galileo Navigation System
« on: December 13, 2017, 03:31:01 pm »
Does anyone who knows about these sort of things have any thoughts on how effective the new European  Space Galileo Nav System that was launched today will be?

Kim

  • Timelord
Re: Galileo Navigation System
« Reply #1 on: December 13, 2017, 03:46:58 pm »
I expect it'll be quite effective if Trump or the future leaders of the Republic of Gilead decide to turn off GPS.
To ride the Windcheetah, first, you must embrace the cantilever...

quixoticgeek

  • Mostly Harmless
Re: Galileo Navigation System
« Reply #2 on: December 13, 2017, 03:48:56 pm »
Short answer: very.

Longer answer: They launched 4 satellites bringing the total in orbit to 22, they will need 4 more satellites to complete the constellation. (useless trivia, the launch was the 82nd consecutive successful launch for Ariane 5).

In terms of the geek in the street, if you have a device which works with Galileo, then it will give you better accuracy (approximately CEP of 1m). As for devices, well the Wahoo Elemnt Bolt I just bought has Galileo support built in already, and given that most devices just use an off the shelf chipset from the likes of broadcomm et al, I would expect this to be the norm for many devices. If the EU really wanted to get wide spread adoption, they could do what Russia did. Russia imposed a $25 import duty on all GPS devices that did not support GLONASS (The russian version of GPS). Now everything from your iphone to an eTrex supports Glonass.

So go check what your device supports, look forward to the launch of the final 4 needed for a full constellation (Q3 2018 current schedule). There will be further launches of another 8 satellites, which I think will be in orbit spares, they are scheduled for 2020, 2021 and 2022+.

Bring on EU's own accurate Global Positioning System!

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

fuaran

  • rothair gasta
Re: Galileo Navigation System
« Reply #3 on: December 13, 2017, 05:40:50 pm »
It also makes sense to use multiple systems at once. ie GPS, Glonass and Galileo gives you over 80 satellites in orbit (plus a few extra for WAAS, EGNOS, etc).
So at any point on earth, you probably have 12 satellites above you. Even in a urban canyon, your device could get a signal from about 6 of them, which is enough for a fairly accurate position.

Re: Galileo Navigation System
« Reply #4 on: December 13, 2017, 06:13:13 pm »
It also makes sense to use multiple systems at once. ie GPS, Glonass and Galileo gives you over 80 satellites in orbit (plus a few extra for WAAS, EGNOS, etc).
So at any point on earth, you probably have 12 satellites above you. Even in a urban canyon, your device could get a signal from about 6 of them, which is enough for a fairly accurate position.

Silly question, but can GPS's use the three systems in combination?  In other words, if the six satellites a device could see were two each from GPS, Glonass and Galileo, would it be able to use them to calculate a plot?

quixoticgeek

  • Mostly Harmless
Re: Galileo Navigation System
« Reply #5 on: December 13, 2017, 06:17:02 pm »
Silly question, but can GPS's use the three systems in combination?  In other words, if the six satellites a device could see were two each from GPS, Glonass and Galileo, would it be able to use them to calculate a plot?

Possibly, would depend on how they are implemented.

One thing to be aware of with having multiple systems is that you can end up just more confused. If I have 2 altimeters and one says I'm at 3000m and one says I'm at 4000m, what am I at? If you have 3, and one says 3000, one says 3005 and one says 4000, you're probably at 3000. If you have 3 gps systems, each with a slightly different level of accuracy, you could be told you are at one of 3 positions. Where are you? Given that they all use the same rough model of the oblete spheriod, but it's only a guide.

So be careful of thinking more systems == more accuate...

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: Galileo Navigation System
« Reply #6 on: December 13, 2017, 06:54:43 pm »
I'm not convinced my Etrex 30 (sees GLONASS as well as GPS) actually makes any use of the extra sats.  Sure, it sees the extra sats and displays their position onna pretty screen, but the self-assessed 'accuracy' figure doesn't change when you turn GLONASS off and on.
"This is a complex subject, with a need for more than one highlighter pen."

Kim

  • Timelord
Re: Galileo Navigation System
« Reply #7 on: December 13, 2017, 06:56:49 pm »
I find the eTrex 30 performs better than the Vista HCx in urban canyon environments, but I haven't been scientific about it, and it may just be that the receiver is more sensitive.
To ride the Windcheetah, first, you must embrace the cantilever...