iPhone GPS

[Old Koreelah]

Tried out my iPhone 4 for the first time in flight today. A major reason for buying the unit is the many navigation applications available. Since I prefer to read a paper map, I don't at the moment need a full-featured aviation GPS receiver; I just need a reliable second source of altitude, speed and location. The App "GPS" cost a whopping $1.16 and tells me all this plus a few useful statistics about the last flight. This came in handy today when the old battery failed mid flight and I lost all the wired-in instruments. It's easier to read than the display on my old GPS. So far the altitude and location readings have been within a poofteenth of my altimeter and the surveyed data for the airport, but the speed and compass headings have not been as impressive. It's claimed the iPhone 4 has a 12-channel GPS receiver, but I found that mine is lost without a mobile signal.

 

Regards,

 

Lyle

 

 

[wizzard1964]

What was the name of the app? I had a quick look and found several!

 

W G

 

 

[Guest basscheffers]

The iPhone does not give app developers speed and directions, only location updates. So speed and direction quality is up to the developer to deduce will vary between apps. And of course it is highly likely that what is being displayed is true track, not the magnetic heading of your compass!

 

Because it has such a small antenna, iPhone uses "assisted GPS"; it gets a rough fix from the cell towers so it knows which satellites to look for. This allows for a very, very quick fix when that tower is there (much faster than most top of the range Garmins and such) but if the signal is not there, it takes a long time.