GPS fix on cruising Aircraft ?

philip4242 · Regular Visitor Joined: May 26, 2004 Posts: 123

I'll be shortly crossing the Atlantic for the first time with my Micromaxx MDPPC150 with me.

I know I'm not allowed to have it switched on during take-off or landing, but I'd REALLY like to see the big numbers for Velocity and Altitude on it, once we're cruising.

What's the best way to get a GPS fix in these circumstances, given the restricted view of the sky out of the aircraft window, and the high velocity while it's actually trying to get the GPS fix ?

And I WON'T be attempting to put my external antenna outside !
_________________
Getting older and more senile by the minute !

Philip

mikealder · Posted: Fri Mar 31, 2006 11:30 pm Post subject:

You will need a window seat to get this to work in flight, the GPS reciever fitted is not the most sensitive, and the small aircraft window combined with the field of view will further compound the problem, it will give you something else to do during the long haul, that is looking for a GPS signal, it is possible but certain aircraft use coated glass thas attenuates the GPS signal, try the window seat (or stand by an entry door window, inform the cabin staff what you are doing i.e. no Bluetooth or WIFI involved) and give it a try - Mike

Skippy

jrisch · Occasional Visitor Joined: Oct 27, 2005 Posts: 38

Sorry, Skippy, but I think your advice is irresponsible. Just 'cos you haven't crashed a plane yet by ignoring their rules doesn't make it right. Most modern aircraft use a fly-by-wire system which can (but not necessarily will) be upset by your electronic devices.

Regards, John

martike · Regular Visitor Joined: Aug 02, 2005 Posts: 194

But if he's discrete, nobody notices, and he behaves himself if challenged, then that makes it alright, doesn't it ?

Mullet · Frequent Visitor Joined: Dec 12, 2005 Posts: 1051

lamplight · Regular Visitor Joined: Sep 13, 2004 Posts: 130

philip4242 · Regular Visitor Joined: May 26, 2004 Posts: 123

Well, we fly tomorrow, so here's what I WILL and WON'T be doing:-

I WILL be keeping my GPS turned OFF during take-off and landing.

I WILL be asking permission from the cabin staff before I turn my GPS on.

I WILL respect what they say in response.

I WON'T be the one possibly (however slightly) putting the aircraft at risk.

I WON'T be the one causing the flight to be diverted so the Authorities can detain an uncooperative passenger.

I WILL be enjoying the flight, and I WILL (hopefully !) be posting the aircraft's velocity and altitude when I return (or earlier, if the wireless technology at our destination lets me !)
_________________
Getting older and more senile by the minute !

Philip

mikealder · Posted: Sun Apr 02, 2006 10:15 pm Post subject:

Philip, sound ideas without a doubt. I do not mind people on aircraft giving the GPS unit a try when it is a built in device at the correct phase of flight (i.e. not the take-off or landing phases), its the units that transmitt via Bluetooth that I don't agree with, I know of one rep who was flying onboard a small (ish) 18 seater who turned on the laptop wifi and the plane went into a dive, not advisable during landing - if the crew are OK about it and give their permission then enjoy the experiance - its far better than the onboard "entertainment".
I have used some of my equipment on internal flights on company owned aircraft (with permission) and its quite amusing to see the countryside wiz past on a topo map (Memory map using OS).
Like I said in my OP in this thread try and get a window seat to give the unit a chance when in flight, it could take some time to obtain a fix, finally don't be too surprised when the metal detector goes off on the way through to the aircraft they pick out phones/ PDA's and PND's with ease - Mike

madtam · Regular Visitor Joined: Jul 09, 2005 Posts: 78

As far as I understand it, a GPS device is a receiver only and doesn't transmit any signal (other than the limited EMC that a small electrical device does when switched on) This being the case then I don't see what the problem would be in trying one when cruising. If other electrical devices such as laptops and games consoles are OK then why should a GPS be different?
If the GPS is not hard wired and uses bluetooth then that is entirely different as this is a specific radio transmission which potentially could have a harmful effect on other systems.
I will admit to trying (and failing) to get a fix on a flight a few weeks ago. I also struggled to get a fix on the train journey following but on a different train on my return I picked up the signal without problem.

lbendlin · Posted: Mon Apr 03, 2006 11:12 pm Post subject:

Absolutely correct - the GPS signal is not the issue. The problem (if any) is the Bluetooth transmitter. Hopefully that one is CE or FCC certified, but with some of the cheaper versions you don't know what the output power is.

The SiRF III receivers get a fix through the coated window, others will probably struggle too much with that metallic shielding.
_________________
Lutz

Report Map Errors here:
TomTom/TeleAtlas NAVTEQ

portman · Posted: Tue Apr 04, 2006 5:32 pm Post subject:

this is what the Civil Aviation Authority have to say:

http://www.caa.co.uk/default.aspx?categoryid=884&pagetype=70&groupid=890&faqid=637
FAQ Details | Cabin Safety | Safety Regulation

http://www.caa.co.uk/default.aspx?categoryid=3&pagetype=90&pageid=1347
Mobile phones and personal electronic equipment | Safety Regulation

This is what the Americans have to say:
http://faa.custhelp.com/cgi-bin/faa.cfg/php/enduser/std_adp.php?p_faqid=261&p_created=1094733474&p_sid=MORakb4i&p_lva=285&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MiZwX3Byb2RzPSZwX2NhdHM9MTgsMjImcF9wdj0mcF9jdj0yLjIyJnBfcGFnZT0xJnBfc2VhcmNoX3RleHQ9Z3Bz&p_li=&p_topview=1
Answer

laracroft1 · Occasional Visitor Joined: Mar 10, 2006 Posts: 5

Tried this with a Garmin eTrex on a flight to the Maldives but unfortunately it could not get a fix Sad

philip4242 · Regular Visitor Joined: May 26, 2004 Posts: 123

Well, we are now in sunny - No ! - Make that SNOWY Toronto, after a quite interesting journey.

Once we were at cruising speed en route from Manchester to Paris (CDG) airport, I put the GPS near the window in the aircraft door (no window seats were available) and was quite surprised to get a GPS lock after only a few minutes.

Unfortunately, I haven't any screen capture software on the PDA, but the speed was about 950kph and our altitude was about 7000m.

On the leg from CDG to Toronto, I did the same thing and saw 650mph and 10000m (different program, hence the 'mix' of units).

I also changed TomTom's map from UK to Canada, as we overflew the coast of Newfoundland - It was wierd to see the 'overview' map scrolling so quickly !

However, a number of incidences of turbulence cut short any further GPS fixes being obtained.

We also had quite an incident-packed final approach, when the plane was struck by lightning no less that 3 times !!

After clearing Immigration (1 1/2 hours) and retrieving our luggage (1 hour, with the handle of 1 case found broken), then queueing for a taxi (3/4 hour), I wasn't much in the mood for checking the GPS out at the hotel.

But next day, I was quite perturbed to see that the GPS showed the hotel room as being about 100m off shore, in Lake Ontario !

However, a couple of soft reboots sorted that out OK, and the GPS has since worked OK around the city.

We're going up the CN tower tomorrow - I'll get an altitude when we're at the top of that, I think !
_________________
Getting older and more senile by the minute !

Philip

SteveTheLight · Occasional Visitor Joined: Dec 23, 2005 Posts: 12

I am not suggesting that the rules on using equipment on planes should be ignored but, in these days of heightend security, I cannot believe that the authorities would allow anything to be carried onto an aircraft, let alone be used covertly, accidentally or othewise, that may make the aeroplane crash.

	PocketGPS
	Web