Beginners iPad for GPS Questions (with apologies)

[Dave Gittins]

I maybe have misheard or half heard or got confused or misread too many things and I have tried to search for the answer before asking dumb questions but not definitively and unambiguously found what I want so please bear with me. I’ll start with a few simple questions.

The time seems to have come to buy an iPad (latest 128 gB + Retina Display + 3/4G version). Precipitated by my Sony Reader having expired, my wife wanting something to show her photos on when visiting the family and the fact that we need a good motoring GPS, which will also cover Europe as we kept getting lost around Faro over Easter. In addition my aeronautical GPSs (Pilot III and Garmin 296) are getting geriatric.

1. If I use an iPad for say Skydemon in the aeroplane (DA-40), I cannot use the 3G. I understand the inbuilt GPS needs to be assisted by 3G so as I can't use 3G in an aeroplane and don't have any urge to use it abroad coz of cost, do I need an external GPS (like a Bad Elf) ?
2. I always thought the maps “moved” by constantly downloading from the ether. Without Wi-Fi or 3G how does that work ? (my Android phone uses fortunes of mobile broadband if I use it for GPS/maps/internet when overseas and out of Wi-Fi range).
3. What’s the best way to get 3G ? Have looked on various providers sites (Vod, O2, 3G) who all seem to do a fixed monthly £15.00 (which presumably runs out at the most critical time) or PAYG, which I hate.

Dave

[RTN11]

Get a samsung galaxy note, far better and cheaper too.

The inbuilt GPS works really well in the aircraft on the move, and you can download maps so they move in flight, and on the road for whatever purpose, for almost any country in Europe.

I have the CAA charts on mine, and it works fine in flight, you can also use Sky Demon on android now, and it's working really well just as the i version does.

[Dave Gittins]

So that is a Galaxy Note 10.1" (slightly larger than the iPads 9.7") at 64 Gb. About £150 cheaper it seems

At work we have HTC Desire phones which are dreadful and terribly slow, very expensive and consuptive of Gb of mobile broadband compared to 'er indoors's iPhone. That has seriously coloured all our judgements against Android powered technology.

"Flying" also tested an ASUS Google Nexus and concluded that whilst it had a lot of bang per buck ($299), it weren't no iPad. Nor they concluded was an iPad mini.

[ben177]

You are correct, the iPad's built in GPS doesn't function without an internet connection, so you will need a GPS antenna. Beware, the iPad uses a different GPS protocol so you need a compatible antenna. The ubiquitous NMEA bluetooth receivers from e-bay at £25 or so won't work. Harry M used to stock compatible GNS GPS receivers for around the £60 mark. Sky Demon's charts sit in the iPad's memory so do not need an internet connection. The internet connection is only used to download the weather and the notams. Strangely however, my wifi only iPad updated the notams whilst in flight earlier this week. I must have flown over a wifi hotspot! db

[Tupperware Pilot]

You are correct, the iPad's built in GPS doesn't function without an internet connection, so you will need a GPS antenna
simpley not true.....I have a ipad2 3g and have used it with out a simcard or internet conection and the GPS has worked fine. Have used it to run memory map. which is stored on the ipad works as a moving map just fine....

[Kejim]

The iPad GPS works fine with no Internet connection, but the map needs to be downloaded to the iPad and stored locally first.

[RTN11]

o that is a Galaxy Note 10.1" (slightly larger than the iPads 9.7") at 64 Gb. About £150 cheaper it seems

Yep, that's the one, I find it great, fast and has never let me down.

Certainly far better than the HTC desire, android has come a long way since then, and the latest version tends to make a lot of i users jealous, as it really is beautiful to use and the widgets are really nice on the home screen.

[ben177]

Poorly worded on my part, the wifi only version won't work without an internet connection. db

[BackPacker]

You are correct, the iPad's built in GPS doesn't function without an internet connection, so you will need a GPS antenna.

That's a bit confusing.

Let's look at the hardware first. The iPad has a combo chip/antenna that does, well, basically everything that has to do with wireless communications. Bluetooth, Wifi, GPS, 3/4G, you name it. If you put the iPad in "airplane" mode this chip/antenna is completely disabled and no radio signal will get in or out whatsoever. That's what commercial airliners want you to do if you are a passenger on their aircraft.

Since this disables the GPS reception too, that's not what you will want to do in a light aircraft, where you want to use the iPad for navigation. So instead you go into the Settings menu and turn off all the radio services individually, except the GPS. (Or, you do as most of us do, and simply don't bother turning anything off.) This means the GPS can now be used by applications. And, like others said, there is NO dependency whatsoever of the GPS part of the chip on any other part of the chip (Wifi, Bluetooth, 3G, ...), with the exception of something called "Assisted GPS".

"Assisted GPS" means that the iPad looks at the 3G towers that are visible, uses these to do a rough triangulation, and then feeds this rough position to the GPS. This means that the GPS is faster in acquiring its (accurate) position. However, assisted GPS is NOT a requirement for the GPS to function. When 3G services are turned off (like they are in my iPad - I only have a prepaid 3G data plan since I rarely use the 3G services) or when a 3G network is not available, it will just take longer for the GPS to get a lock. But once it's got the lock there is zero difference between normal GPS and assisted GPS.

There is one other thing to know about the built-in GPS though. Depending on the aircraft and the exact position where the iPad is mounted/kept, the on-board GPS may not receive a sufficiently strong signal to maintain the lock. In that case you can buy an external GPS (like the Bad Elf Pro and the Garmin Glo), who communicate with the iPad using Bluetooth. This is also the solution if you get the non-3/4G iPad: These iPads do not have a GPS, but they do support Bluetooth, so you can connect them to the Bad Elf Pro or Garmin Glo. (Bad Elf also does a GPS thingy that slides directly into the Apple connector, and thus doesn't need a Bluetooth connection or its own battery or other power source.)

Oh, and these external GPSs don't do Assisted GPS so if they've been turned off a long time they might need a significant amount of time to get a lock. (Absolute worst case, I think, is up to 15 minutes. But that's the scenario where you did not turn on the GPS for many months, and moved to the other end of the world since. They will usually acquire their lock in significantly less than five minutes.)

But honestly, whether you need an external GPS is something you need to try out in your specific aircraft first. I have never had a problem in the aircraft I fly (DR400 and R2160 mostly, with an all-perspex bubble canopy), while others have reported significant problems even if the iPad is kept on the coaming at all times. Only if you get the non-3G iPad can you be sure you need an external GPS.

Next, software. The iPad built-in maps functions all require an active internet connection of some sort (3G or Wifi) since they download satellite and map data "on the fly". In contrast, applications such as SkyDemon, PocketFMS, Air Nav Pro and even TomTom download the maps that you think you need in advance, and do not need to download anything "on the fly". Obviously within the app you need to specify the areas where you're going to fly, and for which the maps and airspace data should be kept up to date. The more areas you activate, the more data needs to be downloaded and stored on the iPad. And in case of some products, the more money you need to pay.

If you do have an internet connection while flying, somehow, then at least SkyDemon is able to download things like weather "on the fly", which may be useful on long flights. I don't know if other products can do this too.

As for your last question, how best to get 3G, well, it really depends on what you want/need. Wifi is pretty much available everywhere. Certainly at home, work and most airfields although you might need to ask around a bit for the password. I personally find I rarely need a 3G connection. So my plan of choice has been a prepaid plan (from Vodafone in my case). It's free until I use it, and then it's relatively expensive, especially when "roaming" in a foreign country. It's possible to buy various day or week bundles, both foreign and domestic, if you suspect you're going to send/receive a lot of data, and that makes things cheaper. But fortunately the amount of data that SkyDemon needs to download weather and notams, and to upload a flight plan is not all that much. To keep the prepaid card active I think I need to load it up with 10 euros each year, and that seems to be about the amount of data I use up anyway, annually.

But of course if you suspect you're going to be a heavy 3G user, then a subscription of some sort, which includes a certain number of GBs each month, will almost definitely be cheaper than a prepaid data plan.

Last, as an "in between" solution: If you already have a smartphone with a data plan, then you can see if you can turn on "tethering". This means the smartphone starts acting as a Wifi access point, router and masquerading device. Essentially this means that the iPad sends out a Wifi packet, which is picked up by your smartphone and forwarded to the internet via the 3G connection. And vice versa of course. This means your 3G data plan of the smartphone is used, and the iPad doesn't need its own data plan.

"Tethering" is sometimes enabled by default by your provider (typically if it's included in your data plan), or you may need to install an additional app. Which, in turn, might require "jailbreaking" of your smartphone.

[airpolice]

This question comes up all the time and seems to bring out the fanatics on both sides.

My experience is that the Memory Map software using the CAA charts is great on the New iPad (there is no iPad 3, there was iPad, iPad 2 and then the New iPad) and with an external Bluetooth GPS receiver, it is fantastic.


I use a GNS5870 MFI receiver, £80 from any good supplier. This lives in my shirt pocket, with the iPad on the passenger seat. When I look at traces done using this, compared with the iPad using inbuilt "gps" to record positions, the differences are enough to make it well worthwhile.

Sample rates are massively better and you have more accurate traces as a result.

I "heard from a bloke in the pub" that during periods of GPS jamming, the iPad & iPhone still know where they are, and the external "proper" GPS devices are screwed. That suggests to me that the iPad's native "assisted gps" is actually just Cellular mast triangulation.

[lederhosen]

I have a bad elf pro. It interfaces with Air Nav and provides a good moving map display on my rather ancient ipad. The logging function is interesting to review previous flights using the bad elf app. However does anyone know a good app which shows altitude and speed as well as position from the log?

[BackPacker]

However does anyone know a good app which shows altitude and speed as well as position from the log?

Where is the log kept?

I have found that the iPad in general is a bit of a one-way street ending in a cul-de-sac: You can get (data) in, but you can't get (the data) out. This is because all the apps live in their own "sandbox" which is inaccessible to other apps. If the app doesn't supply a method to get the data out, then the only way of getting the data out is to jailbreak your iPad.

So if the log is kept in Air Nav Pro, and that app doesn't give you the altitude data you want, and also doesn't allow you to export the log, then you're pretty much stuck.

On the other hand, if the log is kept in the Bad Elf itself, and you can access the data over USB in some sort of standard format, then there are tons of sites where you can convert this to other formats (even XLS if necessary), and eventually import it in any navigation app. Google Earth or Google Maps might be an option, and if you want to look at each and every track point in detail, then OziExplorer would be my recommendation.

[dublinpilot]

Next, software. The iPad built-in maps functions all require an active internet connection of some sort (3G or Wifi) since they download satellite and map data "on the fly". In contrast, applications such as SkyDemon, PocketFMS, Air Nav Pro and even TomTom download the maps that you think you need in advance, and do not need to download anything "on the fly". Obviously within the app you need to specify the areas where you're going to fly, and for which the maps and airspace data should be kept up to date. The more areas you activate, the more data needs to be downloaded and stored on the iPad. And in case of some products, the more money you need to pay.

If you do have an internet connection while flying, somehow, then at least SkyDemon is able to download things like weather "on the fly", which may be useful on long flights. I don't know if other products can do this too.

FYI PocketFMS and EasyVFR by PocketFMS (€69 on Android or iOS) can download weather and advanced weather (72 hour, hour by hour forecasts from Top Meteo...no additional cost) on the fly, along with EuroControl NOTAMs.

As others have said there are two types there are two types of iPad; wifi and 3G. Only the 3G has built in GPS and it is NOT dependent on phone receiption. If a phone receiption is available it can speed up the time to first fix, but it is not required. The wifi version does not have GPS, but it can get a reasonable fix from phone masts while on the ground. It won't be able to in the air, becuase it doesn't have a GPS.

You also mention about about driving maps. As others have said these can be different. Apple's built in maps and Googles free maps both use 3G receiption to pull down map tiles as needed, so if you don't have a 3G connection then you won't have any maps. Of course when you are away on holidays you are roaming and this is when 3G tends to be expensive!

As BackPacker says, teathering to your smartphone is the way to go when at home. When away I'm afraid the answer is probably different for each country and probably involves getting a local sim.

[BackPacker]

The wifi version does not have GPS, but it can get a reasonable fix from phone masts while on the ground.

Is this true? I've never had my hands on a Wifi-only iPad, but I have always understood that the Wifi-only iPad, only did Wifi and Bluetooth. No GPS, no 3G or any other type of cellular protocol. So presumably it can't receive the signals of any phone mast, and has no way of knowing where it is based on that data. With the possible exception of using a database of Wifi Access Points and their location.

It does seem to have a digital compass though, for what it's worth.

Apple - iPad - View all the technical specifications. (http://www.apple.com/ipad/specs/)

[englishal]

My EE 4G phone package for about £35 per month includes discounted roaming data for as little as 50p...£2.50 gives 100MB in all of Europe, USA, etc. Ideal for a day trip or extended trip abroad. Tether the iPad and download Notams, file flight plans etc...

PS I have a non 3G iPad and 3G iPad. Both work great in the cockpit but I pair the non 3G to external BT GPS. The 3G one I don't bother and never had a GPS signal issue.

[lederhosen]

The log is in Bad Elf and the track can be exported to google maps for example where the track info is excellent. However I am interested in also seeing speed and altitude. GPS tracks looked promising but seems to struggle with the data from a long flight.

[172driver]

I've recently gone through this, so here goes recent practical experience:

First of all, a WiFi only iPad does NOT have a GPS receiver built in. The reason apparently is that the two connectivity modules (3/4G & GPS) sit on the same chip.

You will therefore not be able to use any of the various programs with a WiFi-only iPad out of the box.

HOWEVER, there is a little thinky called Bad Elf GPS that plugs into the iPad's port. And this works a treat! Cost is about USD 100.

I have been using ForeFlight (in the US) with this combo and it works perfectly, never lost signal. There are, however, two caveats:
- ForeFlight is an 'always on' App and together with the little GPS is very power hungry. I never ran out of juice, but would guess the iPad battery would be dead after about 4 hours (longest flight I did with it was about 3 hours). If you have a car charger for the iPad the Bad Elf has a charge-through port that let's you keep the iPad charging while you fly.
- watch where you put the iPad - if left in the sun it easily overheats. I had to let mine cool down during one flight after I left it sitting in the sun for about 15 minutes.

I find the ForeFlight / iPad combo an amazing tool, highly recommend it!

One correction: you can allow the iPad to power down while it is running ForeFlight, by allowing 'sleep' in the settings menu (Settings > Apps > ForeFlight). I never did this, as I was worried about getting a lock on the satellites while in flight.

[dublinpilot]

The wifi version does not have GPS, but it can get a reasonable fix from phone masts while on the ground.

Is this true? I've never had my hands on a Wifi-only iPad, but I have always understood that the Wifi-only iPad, only did Wifi and Bluetooth. No GPS, no 3G or any other type of cellular protocol. So presumably it can't receive the signals of any phone mast, and has no way of knowing where it is based on that data. With the possible exception of using a database of Wifi Access Points and their location.

Sorry BP, you're dead right. A brain fart from me.

Of course the wifi only version has no location information at all.

[echobeach]

Last year bought 3rd gen ipad uk 3G and wifi. Sky demon on ipad.

Flew VFR to Mallorca.

Was not sure about all the GPS issues you raised but. ....

Didn't lose signal once.
Best touring device I have ever had
Once a day on ground wifi and notams and weather all downloaded, more often when wifi available.

My view as humble vfr tourer is that this is the most useful device I have come across.
Notams, weather plogs airfield plates all on ipad.

Faultless gps navigation.

Little else to say. Best tour yet.

[Dave Gittins]

Thanks for all the help and advice, especially those who have taken the time and trouble to write me lengthy dissertations on the subject. ... it looks like the best thing is the 128 gB + Retina Display + 3/4G version. Plus a subscription to Skydemon.

As I now understand it a "Bad Elf" or similar is only needed on a non 3G / GPS iPad.

I'll look into a 3G/4G supplier in due course once it's running on WiFi.

Any comments on use of 3G for an iPad and which suppliers to use ?

"3" seems cheapest (£15 / month for 10 GB) but I am not sure about the coverage.
Mostly I have used Vodafone (since around 1986) but they are only OK until the slightest hiccup when their customer services and ability to fix anything (at least in my experience) is appalling !!!

[wb9999]

Of course the wifi only version has no location information at all.

dublinpliot, I'm not sure that is correct either. My wifi-only iPad does show my approximate position (not sure what is based on, wifi signals?). The maps app says the accuracy is 20 metres, but my position on the map is spot on. A wifi iPad without an external GPS would be useless in-flight.

[BackPacker]

As I now understand it a "Bad Elf" or similar is only needed on a non 3G / GPS iPad.

Not quite. There have been reports of bad reception with the built-in GPS in certain airframes and mounting positions. In that case a Bad Elf Pro, Garmin Glo or other external GPS is the solution. Also, it seems these external GPSs have a significantly higher refresh rate than the internal GPS. So if you want/need a very detailed track log you may get better results with them.

But initially I would wait and see how the internal GPS works out for you. For most of us it's good enough.

(not sure what is based on, wifi signals?)

Found this on Google:

http://answers.yahoo.com/question/index?qid=20100423183519AAuFT1

Apparently there's a database out there that contains the locations of thousands of public access points, and if any of these are in range, then that location is given. Or triangulation is done if multiple are within range.

If that's not possible, then apparently the location of your public IP address is used. This will usually not be any more accurate than the city you are in.

But as wb9999 said, both methods will not work whatsoever in flight.

[Dave Gittins]

My iPod Touch, which has Wi-Fi but quite definitely no cellular connectivity at all, always knows exactly where it is when connected to Wi-Fi

.. to within the nearest couple of metres.

Most Apps ask to "use your present location" and then do so very accurately. this has so far worked in Dorking, at Gatwick, in Northampton, Manchester, in Santorini, in Faro etc. Something somewhere must know the location of the Wi-Fi router it is connecting via.

Often it is more accurate than my HTC Desire (:ugh:) which has seriously coloured my view of Android devices.

[172driver]

Dave:

Provider: I switched from Vodafone to Three years ago, mainly due to their substantially lower roaming charges at the time. Never had a coverage issue and my bills dropped by 60%.

WiFi-based location services: as I understand it, it is as BackPacker says, IOW your device will get the location info from ANY WiFi it sees, wether you are logged into it or not. Hence the pretty good location info on the ground, especially in cities. Obviously, this is totally useless once in the air.

I don't have personal experience with the native iPad GPS (as mentioned earlier, mine is WiFi-only), but the Bad Elf definitely works. I recently flew a long x-country in the US, where the briefer included a warning about potential GPS outages / jamming during my flight (this was over remote parts of the SW with lots of military zones). I have no idea if there were any, but little thingy never lost the signal. Well worth the $ 100.-

[tmmorris]

Wifi location services works because most iPhone users have gps turned on and whenever the device sees a wifi connection it sends the location of that wifi access point - private or public - to Apple. You can turn this off (or have location services turned off, which is what I mostly do) but most users don't bother.

As a result it's startlingly accurate - on a recent holiday in the US using my wifi only iPad it was never more than 50m out and usually less than 5.

Useless in the air, as stated.

Tim

[India Four Two]

I used SkyDemon on an original iPad with a Garmin Glo (Bluetooth enabled GPS and GLONASS sensor) during some flights in NZ last year. I was very impressed.

The combination worked almost flawlessly, even though the Glo was in the pocket of my shorts. The only time I had a signal dropout was during manoeuvering for some photos of a mountain top. Even then, it was only the altitude that was lost.

However, I found the iPad heavy and unwieldy for cockpit use and I have now replaced it with a Wi-Fi iPad Mini. I think it is the perfect size. I just need to find a good yoke-mount for it.

I agree with tmmorris about the location accuracy of a non-GPS iPad. I'm sitting in my favorite restaurant and my location is reported as less than 10 m away - exactly where the Wi-Fi server is located.

[Whopity]

I've been trialing a Nexus 7 with Memory Map, Skydemon and GPS. Works brilliantly at a reasonable price. I don't even us 1G let alone 3 or 4! The iPad is best for watching TV!