GPS - Do You Use Them
 

Anyone have a GPS and do you use one? Also, are they legal to use in flight (sorry, I don't have page 82 of the magazine in front of me). What brand/model would you recommend?

GPS use is ok on United and British Airways, but not on several other airlines. http://joe.mehaffey.com/ is the main resource for GPS questions and has a list of which airlines allow GPS and which don't.

It can take a while for a GPS to sync up at an airplane window (due to poor satellite configuration, multipath, and doppler shift) but it usually works. It has to be right at the window (though the blind can be closed). I was having difficulty one time (in United FirstSuite, where the seat is a long way from the window) and an FA lent me an external amplified antenna--which significantly improves reception (who says you don't get great service from the FAs on United?). I bought an external antenna for myself after that, but seldom take it now, even though it offers the conveience of attaching directly to the window with suction cups, 'cos it's one more thing to carry.

I don't use GPS inflight so much now that map displays are common on the IFE.

Garmin are the most popular brand. I use a Garmin IIIplus, the Garmin Emap is another popular choice. A GPS receiver is the most complicated consumer device you will encounter--it takes months to learn to use all the functionality (waypoints, routes, tracklogs) to full advantage. It's also one of the most fun toys there is.

A good place to buy Garmin stuff (no connection, just a satisfied customer) is http://www.tvnav.com/navhome.html

[Edited to add TVNAV link]


[This message has been edited by someotherguy (edited 12-16-2000).]

Someotherguy:

Thanks for the link, I've always wondered if they were allowed or not. I was told several several years ago (by a pilot) that if you tried to turn one on once in flight, it would never get a "fix". But, you are the second person in a week to tell me that they will work if you hold them up to the window.

BTW. OfficeDepot has the Garmin GPSIII+ (usually $345) on closeout at $99. To get full benefit, you also need Garmin Mapsource maps (downloadble streetlevel detail), which cost $80 per country.

The only time I've not got a "fix" was on Concorde. The FA suggested it might work better in the cockpit, but it didn't http://www.flyertalk.com/forum/smile.gif .

Do you have documentation from official UA docs or the UA web site that says that GPSs are allowed? The reason I figured they were not is that their announcement says "any device that transmits or receives is not allowed at any time". This is in contrast to Alaska, which explicitly states that you must shut off GPS receivers at takeoff and landings.

I've regularly used my GPS on board for several years. I also regularly connect it to my laptop and run StreetAtlas. It's really cool to look out the window and say "Hmmm... SR50 and SR6, East Ely, NV." On most planes, I can "stick" my external antenna between the window and the shade. Sometimes I get a solid lock right away. Other times it takes 30-45 minutes, and then only for an intermittant fix.

I used to always ask the crew if I could use it, but it just got the point where the answer was always "yeah, sure." The best response, after the FA asked the captain, was "Sure, and if you could figure out where we are, please let us know."

I use a Garmin eMap on board Delta flights all the time. As long as I hold it next to the window, I never have a problem getting good reception from the satellites.

My second flight with my eMap was from SJC to SLC. I had just boarded and pulled out the eMap and was holding it up to the window to get a fix -- I've found it syncs up faster if it has been recently turned on.

I heard this voice say: "We are at the airport."

I turned to the aisle and saw a FA standing there. Not knowing what she meant, I responded "Huh?". OK, so it was early in the morning.

She pointed at my GPS and said: "In case you were trying to figure out where we are, we are still at the airport."

Cute.

--John

How 'bout for driving, say in a rental car? Any recommendations for GPS in the USA? I always get lost and I don't rent from Hertz, preferring Avis
http://www.flyertalk.com/forum/frown.gif

Have also used a friends GPS on board AA, no problems from the flight crew to use.

I routinely use my Garmin eMap during flights, and have never been told to turn it off. Several flight attendants have asked what it is, and several have asked jokingly "Are we going the right direction?"

The 2-dimensional locator is quite accurate, but you can't get a lock on enough satellites from the tiny window to get an accurate elevation. 35,000 Feet often varies by 500 feet or more.

The inflight maps tend to only show wide area maps. You still need a GPS to know what a particular road, town, or river is.

Does anyone have a favorite GPS?

FYI, there are three reasons that GPS altititude varies from the aircraft's altitude.

The primary reason is that above 18,000 ft., airlines change the barometric pressure on the altimeters to 29.92. Altitudes above 18,000 ft. are called Flight Levels, indicating that the altitude is not true, but is the altitude that cooresponds to this barometic pressure. Among other advantages, using 29.92 universally above 18,000 ft. allows airlines to maintain appropriate vertical separation without having to adjust the barometric pressure every 100 miles or so.

Secondarily, GPS altitude variation is roughly twice the level of horizontal variation. If you get an EPE of 100 ft., the altitude error can be as much as 200 ft.

And finally, GPS altitude is the altitude over a theoretical simplified spheroid of the Earth and can vary from the real altitude over the Earth.

Also, I wholeheartedly recommend http://joe.mehaffey.com for comprehensive info on GPS!

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My Aviation Pages
My Travel Pages

I am a big fan of the Garmin handhelds. I like the GPS III Plus for the technical information you can get out of it, but the eMap is also nice for step by step directions.

I've got a couple of GPS pages, if you're interested: http://www.bollar.org/garmin.htm

AA, unfortunately, banned GPS use earlier this year. The form letter they sent me back that it's banned for the same reason as cellular phones, which is a specious argument. I wrote back asking for clarification & did not receive a good response.

Any 12 channel GPS, connected to a laptop running Street Atlas. There are other mapping programs, but I prefer (and I think most do) the Delorme products. Not perfect, but very effective.

The new "Road Warrior" edition looks interesting, with voice commands and responses. A big improvement while driving.

Does anyone have any experience using a GPS hooked up to a PDA? I have always thought that this would be a great use for a handheld.

I know that there are solutions for this, but wonder if anyone has any direct experience.

From Dave Barry's column today: ( long link )

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I became aware of how useful a GPS can be when I was on a plane trip with a literary rock band I belong to called the Rock Bottom Remainders, which has been hailed by critics as having one of the world's highest ratios of noise to talent. On this trip were two band members whom I will identify only as ``Roger'' and ``Steve,'' so that you will not know that they are actually Roger McGuinn, legendary co-founder of the Byrds; and Stephen King, legendary legend.

We were flying from Chicago to Boston, and while everybody else was reading or sleeping, ``Roger'' and ``Steve,'' who are both fully grown men, were staring at their GPS devices and periodically informing each other how far we were from the Boston airport. ``Roger'' would say, ``I'm showing 238 miles,'' and ``Steve'' would say, ``I'm showing 241 miles. Then ``Roger'' would say, ``Now I'm showing 236 miles,'' and ``Steve'' would come back with another figure, and so on. My wife, who was confident that the airplane pilot did not need help locating Boston, thought this was the silliest thing she had ever seen. Whereas I thought: I NEED one of those.

So I got a GPS for Christmas, and I spent the entire day sitting on a couch, putting it to good use. Like, I figured out exactly where our house is. My wife told me this was exciting news. I think she was being sarcastic, but I couldn't be sure, because I had to keep watching the GPS screen, in case our house moved. I also used my GPS to figure out exactly how far my couch is from LaGuardia airport (1,103 miles). There is NO END to the usefulness of this device! If you're a guy, you need to get one NOW, so you can locate yourself on the planet. While we still have one.

Well, I ended up getting one for Christmas, which was incredible. I have a Garmin III+ and absolutely love it. I also hook it up to my laptop and already have about 30 waypoints, some of which are airports, in it. I also have my two homes (LA/Seattle) and more. This device is absolutely incredible. And its fairly accurate. I was on a DL flight last week that had the moving map display. I set it up so it would track while I worked on my computer. Every so often, I would glance at the speed, and it matched what the moving map display said every time. It's the best Christmas present I have ever received.

I used a GPS for a recent project...It was the garmin GPS-12XL, which I can heartily reccomend. It has an external antenna connector, and a serial connection for uplink to computer. With an external antenna and a half hour to stabilize , accuracy was great!

[This message has been edited by terminalcity (edited 01-25-2001).]

I picked up the small Garmin ETREX: it only weighs around 6oz, and connect it to my notebook and watch my own inflite moving map... It works really well, but you can not connect an external antenna.
I use microsoft streets and trips, but the DeLorme Road Warrior with voice seems interesting to try for use in the car.
I tried the Sony Skymap for use in the car, but it does not correct itself if you make a wrong turn: it has since been "e-bayed".

I enjoyed the Dave Barry column. I bought my husband a GPS for Christmas and it reminded me of him quite a bit. Between he and my son, they have so far used the GPS to:

* park the car in the garage in the exact same spot it was removed from

* plot out our property lines, even though there are survey stakes all over the place

* from the backseat of the car, tell us exactly how fast we're traveling

* backtrack to the marina the same course we left the marina on in our boat. If the Coast Guard had been around, we would have been boarded for sure.

Don't know how we ever got along without it. http://www.flyertalk.com/forum/smile.gif

does anyone know if there are...

any standalone units that actually work, to give you right and left turn street level type directions? Comparable to those fouond in new Acuras, BMWs, etc.?

I don't like to connect stuff to my laptop during travel because I find it cumbersome.

According to AA's American Way inflite magazine, GPS are not allowed to be used inflite http://www.flyertalk.com/forum/frown.gif
(This is the latest issue, with Anthony Hopkins on the cover: sorry, I did not get the issue date.)

If any airline or pilot allows the use of GPS, then why don't they allow the use of FM or AM
radios, shortwave radios, TV's or anything else with a local oscillator?

Personally, banning receivers might be a little too much on the careful side, but I would certainly
be upset if any one thought they could use a tranmitter, such as a cell phone.

I do wish that the FAA would change the official 'verbage' from "put away your cell phone"
to something like "make sure it is powered down and fully turned off", or "turn it off so that
the display is balnk". I'm sure a lot of non-technical travellers think it is OK as long as
they are not actually talking into the thing.

It looks like GPS has temporarily 'fallen into a crack' and forgotten by some airlines, but
as some posters have mentioned, airlines are including them in their prohibited from use list.
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Admittedly drifting off-topic, but US allows radio receivers.

I have been real happy with my Magellan Meridian Platinum.

It worked well on the Concorde. The downside is that the speedometer did not work beyond 999 mph. - or at least I did not know how to expand the field.

Nothing like looking out the window and knowing exactly where you are. A short while back on a flight back from San Diego I was able to follow some back roads I took in the Four Corners region. It has been two years too long since I have been there.

http://www.flyertalk.com/travel/fttr...orum/frown.gif

That's a good question. I don't know the real reason, but I can tell you that a GPS signal is a 50 watt signal from a satellite 20,000 miles in space. The am/fm radio bands are 50,000 watt signals, or much greater, from a much shorter distance.

By the way, thanks for bringing this thread back up. I got my GPS shortly hfter I posted it and have loved using it on board flights for a long time.

There are many threads in the AA and DL forums if you search "GPS"

My car is the second Acura I've owned with a nav system. It is basically a GPS, gyro, color screen, and DVD, integrated with the car. It is marvelous to never get lost. I don't bother with the coordinates.

I suppose there is a GPS in my cellphone. I have it turned off except for 911 calls, you can't disable GPS for 911 calls anyway.

The GPS systems that I am interested in have street maps associated with them although a handheld GPS such as those discussed here would be a fun toy!

jeffreyt:
"I can tell you that a GPS signal is a 50 watt signal from a satellite 20,000 miles in space. The am/fm radio bands are 50,000 watt signals, or much greater, from a much shorter distance."


FYI, the problems with operating electronics inflight are the emissions from the device (in
this case, the receiver). Quoting the transmitter power does nothing to relate to the problems
with the emissions from the receiver (usually due to the local oscillator).

So, unfortunately, your figures do not relate to this situation.

As the GPS site link (earlier in the thread) says, there are documented cases of interference
from AM/FM radios. My concern is about the LO (local oscillator) emmissions in GPS receivers ,
which are much higher in frequency than for AM/FM radios, and may be more problematic.
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