Using a GPS on an airplane?
 

I use to bring a handheld device with me to record my flights. The problem is that reception gets worse and worse as I move away from the window. Anyone here have an idea on how to strap the handheld device to the window so that it can have the best possible reception?

It seems like my GPS device doesn't work on B787s. I suspect it has to do with the windows as I don't have any issues on other airplanes including the Airbus A350. Anything that I can do to address this issue on the Dreamliner?

Thanks!

How about a suction cup mount to the window?

Didn't crossed my mind. Will suction cups work on an airplane window?

GPS on an airplane is going to be very marginal at best because the amount of sky you can see from your seat is quite limited and GPS requires something approximating line of sight to 4 satellites or it just thumbs it's nose at you.

In addition to the idea of suction cupping it to the window you also might fare better with an overwing seat--that big sheet of metal out there will bounce the signal to some degree and thus let you see a lot more sky. This degrades the fix but not enough to be meaningful in this situation.

(The GPSes on the airplane itself use an external antenna, they aren't stuck trying to look out through a window.)

Besides a suction cup, is there anything else that I can use to hang the GPS near the window?

I found that GPS works quite well all over Europe no matter where I'm sitting, but these are probably smaller aircraft. First of all I set the phone in airplane mode, of course.

I usually find holding my phone to the window is enough for google maps to show me my location.

If you want to record: why not use flight radar to just download the flight data afterwards? That will save you the trouble.

I have had some success by trapping the unit with the window shade against the lower sill. Of course it all depends on the design.

That won't work for OP though as 787 does not have window shade right? (never been on one). Suction cup is probably the easiest but I think if a flight attendant sees it, he/she might ask you to take it down as it could become dangerous in a turbulence (flying object launch toward your head similar to mounting on a windshield of cars).

Ok, let's get the B787 out of the way first... Your GPS isn't likely to work attached to the windows as the "shades" are electric. There is an electrical current that runs through a gel in the window (how much current determines how dark the shades go). That'll interfere with most "radio-type" electronics...

Now, for a worse signal the further inside you get in the plane, consider all the wiring that is involved... IFE mostly, but wiring to control the other various systems in the plane like communications, engine and wing controls... then there's the fusoelage of the plane itself. you're sitting inside what is effectively a type of faraday cage. If you get signal while sitting in the central aisle, you're lucky. Unfortunately there isn't much you can do. There's not much you can do except to try to get a seat by a window. As for hanging it off a window, I'd check to see if there is a suction cup mount for your GPS device. If it's a smartphone, there are many you can find on Amazon. They might not work in heavy turbulence (they're not meant to stand up against that) and you may annoy the cabin crew (I've seen them ask "vloggers" to unmount them) but for the most part, they do work.

As a previous poster has said, maybe something like flightradar24 might be a better way to record your path.

You got a background in engineering?

Actually three for 2D coordinates (triangulation), 4 to add 3D (which yields altitude). Nowadays more handheld GPSs and Smartphone support many of the other positioning systems too (GLONASS, Galileo, Beidou, etc.) With well over 100 positioning satellites now, it's virtually impossible to not be able to see at least a half dozen or so of these at any time at say FL350 (from the non-electrified window anyway).

From the 787 pilots I have discussed this with, they don't know of a good workaround for GPS in the back of the bus for the reasons noted by our friend StuckInYYZ . I've heard a variety of stories from mounting the external GPS to the furthest back window on the captains side, to an interesting tape effort to the escape hatch are successful; but alas I'm not sure those will help those of us in the cheap seats too much.

I'd find a friend with a suction cup mounted GPS to try in a 787 before you spend money on one. Hopefully 2021 will yield some long-haul flights for me again; if so I'll try it with my Stratus & Foreflight. I don't normally carry that for commercial flights, but I'm all for experimenting. #science

A longtime Flyertalker was kind enough to PM me about old (now closed) threads on this subject, which may be of passing interest. Due to the age of the other threads and changes in technology over the last dozen years, it wouldn't make much sense to combine them, but readers may find some postings of interest:

https://www.flyertalk.com/forum/trav...ight=GPS+plane

https://www.flyertalk.com/forum/trav...ight=GPS+plane

https://www.flyertalk.com/forum/trav...ight=GPS+plane

https://www.flyertalk.com/forum/trav...ight=GPS+plane

Thanks for the links. Interesting read to remember the cell phone restrictions pre inflight wifi/entertainment.

Nope. Faraday cages and how they work became relevant for a few projects I was involved in (both for and against) in the past. Similar issues although different application.

The 787 though is different. Was interested in the tech for the shades when they announced it way back when. It has been around for a while, just never saw it applied on an airplane before. While it's a cool technology, not a big fan of how it's applied in this case. It's a compromise for a couple of scenarios. But it also introduces behaviours that aren't great either. But that's true of all technology and features.

3 satellites will give you a 2D fix if you can supply the third coordinate--in the early days they sometimes did this to make marine units cheaper. A ship is always close enough to sea level that you can assume the elevation to be the height of the antenna.

And seeing all the satellites requires you have a GPS that can use all the networks.

How do you get the streaming map data though, unless you were getting a fast data connection through plane Wifi or you got good mobile signal, meaning you turned on the cellular radio?


I used to use GPS receivers with bluetooth connections with my DSLR to geotag so it would take a long time for these receiver to find satellites but eventually they would and I was able to geotag some photos taken on the train. I could also see the elevation changes as the plane took off or landed.

But I just mostly held it up (it's tiny) against the window. Some planes like some 747 configuration has a flat surface near the window, like for the little storage compartments below the windows on the upper deck. But I wouldn't leave it there long because turbulence could cause it to slide around and away from me.

A lot of the times, I kept it in a jacket pocket nearest the window and that was enough to get signals, which is perfect because the receiver has blinking LEDs which would draw attention.

Cell phones have GPS chipsets. Being near the window, the cell phone should pickup GPS signals. I map a remote property without cell or WiFi using a backcountry app.

So an app. which preloads the maps so that you don't need a data connection?

I think I once tried using a Garmin on a plane too. Can't recall what happened but probably worked okay.

Won't work on a B787.

I have ridden 787 a few times but I prefer the routes and the layouts of the 777 more, at least on UA.

iPhones since I believe the 4S have not needed a data or wifi connection for the GPS to work. A connection is needed for the online versions of Google maps. I have used offline maps without a cell connection on both Android and iOS devices. The Android backcountry map app is one reason I keep my old Samsung which has no cell service.

There's another option: Flightaware.com. Let the plane's ultra-expensive GPS+transponder do the heavy lifting.
[MENTION=692075]TGarza[/MENTION]: I can confirm that iPhones and iPads with cell modems DO NOT need internet or even an active SIM card for the GPS to work. Many (most?) airlines and many private pilots use iPads as electronic flight bags. Ideally, the iPad connects to the plane's ADS-B receiver via WiFi to get the GPS data, BUT if that fails the software will use the iPad's built-in GPS receiver.

My hard core Garmin never had any problems connection from the test table.

What do you mean by that?

I have legacy Garmin GPSMAP 276c and 476c and current 276cx. They have never had a problem finding at least a dozen satellites just sitting on the tray table by the window.

Even on a B787?

I don't recall whether I've had them on a 787. I'm generally not a fan of that aircraft since I like the shades open during the day and my main carriers don't use them on the routes I fly most often.

Me neither. I'm not a fan of the B787. I much prefer the A350.

Apparently there's a way to add a carabiner to a Garmin GPS device. I wonder if there's a way to hang it somewhere close to the window whether flying Y or J?

I can confirm this. I routinely use GPS apps while hiking in areas with no cell service. I have also once tried a phone with no SIM installed and using a radio relay--the GPS part of it worked, under the conditions the radio range turned out to be too short to be of much use for what I was after. (It provided a text version of a walkie talkie, but used your phone as the interface.)

In my experience GPS locks on planes can be hard especially if your phone's aGPS data hasn't been refreshed recently. IF you just got a clear ground lock before take-off, you should be able to establish a lock mid-air reasonably easily. If that doesn't happen, hold it to the window for a good 5-10 minutes. On B737s and A320s I've had no issues.

On 787s... that's a totally different story. Cell signals struggle with 787s whether I'm in Japan, China or the US. I haven't tried GPS independently because by the time I think about it I remember how I should refresh my aGPS by opening GPS Status but by then I lack network connectivity. But then again I mostly fly on J for 787 routes so usually I'll just enjoy my PDB or just start playing some music to cure my boredom rather than worry about GPS.

Fairly certain no phone actually needs a cellular network to lock. The GPS has always been independent of network, but the assisted portion may help download GPS data for a faster lock. The problem with many older phones, especially back when Google Maps didn't have an offline option was they just wouldn't load the map, but a standalone GPS app like Android phones have had would be able to confirm you have a GPS lock and display coordinates.

A typical GPS receiver, either in a phone or a stand alone unit will get a lock more quickly if you have not moved appreciably since your last fix. This is due to a roadmap of the satellites called an "Ephemeris" being constantly downloaded from the system. Among other things it contains info for the satellites that should be available and their approximate positions. When you change locations before a power up, the old map is no longer accurate, and the device must start from scratch, so to speak. Add to this the fewer sats visible through your window and the difficulty is compounded. My iPhones keep GPS active in Airplane Mode, so I would recommend obtaining a fix before taking off and try and keep a fix the whole trip if it might be desired.