10,000 km road trip proves Galileo satnav works, says ESA Europe's alternative to the USA's global positioning system (GPS) may only have four satellites in orbit, but European Space Agency (ESA) officials are confident that constellation delivers a valid service. ESA boffins revealed this week that since March 2013 test vehicles around the world have run tests to determine the …
Would I be cheeky to mention this brand spanking new system would be as good as the current NavStar (with WAAS corrections) that we've had officially for some five years now (about 10 years if you count testing), but more expensive (due to royalties that were said to be inflicted onto each device)?
@John
I think that the real issue here is about ownership..... The good ol US of A can switch of / disturb NavStar GPS for others at the flick of a switch, whereas they don't have their finger on a Galileo button.
I also believe that it will have very accurate positioning, 1m for the general public, but that the precision service, I will guesstimate/speculate on 10cm, will only be made available to the Govt and/or Military.
Apart from the small issue of ownership, there's dual frequency operation, guaranteed service availability, quality and integrity making it suitable for safety-critical applications such as primary civil air navigation, emergency signal location and response, and a constellation design making it superior to GPS at high latitudes (and a lot of us in the EU live further north than anywhere in the contiguous US!). So not just a me-too GPS alternative.
> dual frequency operation, guaranteed service availability, quality and integrity making it suitable for safety-critical applications such as primary civil air navigation, emergency signal location and response, and a constellation design making it superior to GPS at high latitudes
All of that is available without Galileo, including the higher apparent elevation near the poles courtesy of GLONASS. Currently available DGNSS weren't designed with all this from the ground up, but it's a testimony to their architecture how we could build up on the initial products.
This is not to say that Galileo and other players do not have a place. On the contrary, the more the merrier. Common professional grade receivers have been multi-constellation (GPS+GLONASS) for over a decade and newer ones already incorporate support for Galileo at the hardware level (signals are largely compatible anyway).
Please gentlemen, if your comment is going to be along the lines of "A" is better than "B", please save it for your mates down the pub. It contributes nothing useful.
@ Khaptain
I would add to that, that if we don't build anything in Europe we will loose our technical ability. And I hope they will not think there is any reason to give the public less accurate results as I cannot find any logical reason for that. And to John Tserkezis I would like to point out that a house is "new" only when it's finished.
Mmmmm.... EggNog :P
So, North America and Europe then.
My ropey old Garmin claims a 2m pin radius with WAAS / EGNOS synced plus 10+ satellites in view, but I believe that this figure is the 68% SD/ND figure. If you want the 95% figure it pushes the uncertainty circle out to a 6m radius assuming a normal distribution, so Galileo is in the same parking space as GPS + WAAS with only 4 satellites operating. Tidy job, I say.
This post has been deleted by its author
You need a minimum of 4 SVs in sight to get a fix, and you'll get a pretty crappy one - as the numbers show. Since the SVs are orbiting, there will only very seldom be 4 in sight, so actual positions will be very sporadic.
At this stage they are not going to be expecting either good positions or a 24/7 service. What they are looking for are performance measures that allow them to calculate how the system should perform with a full constellation (or at least a few more).
What the numbers do back up, is that the system should perform well once the full constellation, or a healthy % thereof, are up there.
Of course one cool thing with more satellites up there is that, with the correct receiver technology, you can compile both Galileo and GPS sources in the same fix.
"Of course one cool thing with more satellites up there is that, with the correct receiver technology, you can compile both Galileo and GPS sources in the same fix."
and Glonass too - it's in a lot of devices because the russians apply import duty to any satnav device which doesn't implement it.
"That my GPS signal will have to be broadcast to different satellites, for them to bounce to each other? Will I have to replace my squariel with a round dish then?"
No, the only drawback is that the ESA system only works during the day, as the signals are reflected off the Sun. (posted on friend's account by Stephen Fry)
<< "Err, it's nothing to do with bouncing signals off the Sun"
< You're new round here, aren't you?
No, and it's bad form to suggest sarcastically that the poster is 'new round here' - in any case, the working of this system has absolutely nothing to do with bouncing signals off the Sun, which would be an idiotic idea anyway.
The working method employed by the system, also in use by other such services, provides not only accurate navigation information but also accurate time information and these two services, completely independent of each other, rely upon one common factor - a known orbital distance. This is based on the orbit of the Moon, which is (a) very well defined and (b) not subject to the major disturbing effects that random sunspots and solar storms cause. Provided at least one of these types of satellites can 'view' the Moon, it 'echoes' a signal from it to measure it.
Some people might think that can't work because sometimes the Moon isn't in the sky, but the satellites use a special, powerful laser on a motor-driven beam to send infra-red light around in the sky until the Moon is found, again not relying on sunlight in any way.
The services have a great up-time, the only time it cannot be provided is during a lunar eclipse (since the Moon is actually offline at such a time) or during February 29th in a Leap Year (since that is an unpredictable day during an abnormal year).
I do wish some people would treat serious scientific discussion more respectfully.
Think of it not as a replacement, but a redundant backup and complement to existing systems.
You can use GPS *AND* Galileo. This will provide more accurate data, an immunity to a single "GPS blocker" (for those idiots who are getting arrested after they interfere with airport landing GPS because they want to bunk off of work), quicker lock-on times (fastest-satellite-first), etc. And the more sats you put up - of any system - the better generally supported devices will get.
There's also a ton more commercial service in Galileo that people are crying out for, which is the real reason it exists, but even the basic consumer with an iPhone 6 or Galaxy S6 should be benefiting from the arrangement.
And, yes, it stops the US - in theory - holding the world to ransom if it wanted to. When people whine about ICANN, the NSA, etc., just apply the same logic to the GPS constellation and see where it leads. And that's without even assuming that the US could - one day in the future - see some of the new European states as "hostile".
Just give me an Android phone, or even a Bluetooth serial GPS device, that speaks NMEA sentences and can get fixes from GPS, GLONASS, Galileo or as many similar services as possible and I'll be a happy man.
Hell, I'd have it if it saved me a second on first lock, or it gave me a second longer in between high-rise buildings, and locked down my accuracy by a meter or so and the devices were not much more expensive than existing GPS-only devices. Those alone would aid my sat-nav apps in making sure I'm on the right road at the right time as much as possible, enough to justify an upgrade or additional purchase.
And I just put a GPS tracker on my car. I'd happily pay twice the price for it to use every satellite imaginable and/or every cellular network possible in order to make sure that if some git steals it that I stand a slightly better chance at noticing / recovering it.
Not ready for prime time. Turn on GPS and the high capacity Li-Ion battery goes flat in about two hours (YMMV). Amusingly, a dedicated handheld GPS works on two low capacity AA cells for many, many hours; thus proving that the people that design smartphones have made a FAIL. They need to fix that.
"thus proving that the people that design smartphones have made a FAIL."
Umm, that's like comparing battery life on a watch to that on your phone because it also displays the time. There are a lot of power requirement differences between a dedicated GPS device and a smartphone. For example, in addition to the GPS receiver, a smartphone:
- has a much higher DPI screen than a dedicated device, most dedicated devices will have a DPI < 100, some smartphones are exceeding 400 DPI, so that's 300 extra pixels to light for each inch, the screen being the biggest battery sucker of all on a smartphone
- has an always on data connection
- generally pulls mapping data from online sources, this is effectively the same as making a phone call while the data is transferring as far as battery usage is concerned
- is potentially scanning up to 3 frequencies (2, 3 and 4G networks) for a better cell network to switch to
- it may have WiFi and bluetooth on too where WiFi is scanning for open networks
- is powering a much more powerful hardware spec (quad core CPUs etc.)
If you have just the GPS receiver active on a phone with mapping data stored locally, no SIM card, WiFi off etc. I would take an educated* guess that you'd get a good 6-12 hours of use from it.
*I've written GPS polling applications for Android, that polls and uploads a location every 5 minutes and doing this barely scratches the battery life, maybe reduces it by 5-10% over a day. It is the screen and mobile data connections that suck battery.
"If you have just the GPS receiver active on a phone with mapping data stored locally, no SIM card, WiFi off etc. I would take an educated* guess that you'd get a good 6-12 hours of use from it."
Not really.
I read your post just before a one hour drive, and with a one month old, fully charged SGS3, set all networks off, including voice, mobile data, wifi and bluetooth. Only app running was Navmii, using local maps, with positioning on.
After one hour's driving I'm left with 75% charge. So I might expect at best four hours. I don't believe the SD card takes any worthwhile power, and the phone got reasonably warm (although less so than with all networks enabled and on-line mapping).
My guess is that the positioning and voice synthesis is computationally intensive, and a dedicated GPS has better hardware for this that uses less power.
I suspect you're right that there's benefit to turning off the networks - I reckon that the implied four hours is significantly better than the perhaps two to two and half hours I'd get using Google Maps and online modes, but you're over optimistic about the benefits.
I have a dedicated GPS that shows me a map. When I turn it on, and tell it to keep the map on the screen the whole time, the batteries only last 30 minutes. My smartphone does much better than that (and does other things too).
Now, if you are talking about a GPS that just displays Lat/Long as 7-segment digits on a monochrome LCD display, then you may be right, but if that is all your GPS does, then it is a design FAIL. Climbing over the local moutains I need something more than Lat/Long - and paper maps don't survive the weather (particularly driven rain/snow) up there.
My handheld GPS device uses 2 AA cells (rechargable or standard) and lasts over 24 hours. I do long cycle rides and rely on the GPS to get me around - typically 10 or 12 hours. I did the 1000 mile Lands to John O'Groats ride and only used 6 AA cells in total with continuous map location tracking.
OTOH, my smartphone lasts a limited number of hours on a charge and is not sufficiently rugged to use in inclement weather, vibration etc. so it's kept well protected from the elements.
Both have their uses, but if I wanted to have a reliable location for all conditions, it's the dedicated device that wins hands down.
It'll be interesting to see if this low level of battery usage remains when tracking several GPS systems.
"Show me a 20 year old protocol that isn't."
MIDI.
But that's really the exception to the rule.
I'd rather have NMEA as then it DOESN'T MATTER to the majority of programs that use it (including things like gpsd which even Android etc. smartphones use internally). They don't need to "know" about Galileo. They just need a standard, old-fashioned NMEA sentence, same as they always used.
The cost for backward compatibility is clunky protocols, basically. But there's nothing particularly "wrong" with asking for backward compatibility with NMEA sentences from new location devices. So long as we don't hit an unsurpassable "limit" on the accuracy we can convey (alright, we might have to stick in a new sentence or two, in a way that old GPS-only software will just ignore, but still be able to read "normal" NMEA accuracy), there's nothing wrong with saving having to rewrite dozens of pieces of perfectly working software.
You underestimate NMEA0183. It's ubiquitous, simple to implement, easy to parse, is not necessarily limited to 4800bps (some devices can be switched to 38400, easily giving you 10hz position updates), requires a minimum of one data line (plus ground) to connect and although originally a closed standard has been reverse engineered so everyone can play with it. Some of the sentences are a bit clunky, but so what? Show me a 20 year old protocol that isn't.
The replacement (at least for marine use) is NMEA2000, which is a binary protocol based on CANbus, requires particularly expensive cabling and equipment to use and the purchase of the specification to implement. Google CANbus-usb converters, there aren't many.
As for battery life magically draining when your GPS is on, typical power draw for a GPS receiver is 20mA. Oh noes, GPS is eating my batteriez!!!1!!!!
> Some of the sentences are a bit clunky
*Some*?
For example,
http://esr.ibiblio.org/?p=801
"Why GPSes suck, and what to do about it" from 2009
> Show me a 20 year old protocol that isn't.
Some protocols are really neat, do the job well, provide all the information you need in an unambiguous fashion - those deserve to have a 20-year life. Some - not so much.
I'm going to ignore the points about the simple serial versus CANbus transport, if only because so much GPS data - wrapped in NMEA sentences - is transported across Bluetooth, WiFi, ethernet, files on SD cards etc that the majority of people confronted with it care about the data formatting and can just ignore the transport layers.
> NMEA0183. It's ubiquitous,
Yep.
> simple to implement,
Badly, yes (much of the blame lies with the protocol itself).
> easy to parse,
Up to a point.
> although originally a closed standard has been reverse engineered
Correct. We have esr to thank for that.
> NMEA2000, which is a binary protocol based on CANbus, requires particularly expensive cabling and equipment to use
Huh?
> and the purchase of the specification to implement.
Been largely reverse-engineered too.
There are some serious limitations with NMEA that make it a rather inadvisable choice for precise positioning and timing applications. A lot of the time, unfortunately, we are forced to use it due to external constraints, but that does not make it good. Btw, I'm not advocating NMEA 2000 either, I don't have enough experience with it.
"Back in 2002 EU officials stated that the EU would switch off Galileo to aid US security."
It was and is widely believed that the alternative was that the USA would shoot the birds out of orbit.
It'd be interesting to see what would happe if they pulled the same posturing with Glonass or the Chinese systems (Yes, there's a chinese satnav constellation, just not a very big one)
Yes even trains use it.
And basically they don't want something like that with an off switch in the hands of a govt on another continent.
And come to think of it neither would I.
A similar view held by China and Russia.
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