?How to use iPhone as a GPS, other cool bc uses?

I found this app for the iPhone to be a useful BC tool.
www.mammut.ch/safetyapp

I used MotionX GPS app on my iPhone 3GS and it works well. Ditto about putting your phone in airplane mode and, since the GPS app seems to suck juice, I bought an external battery for my iphone that will let me recharge it 2.5 times or so. Also, you don't need your phone / GPS on the whole time, power off you phone until needed periodically. Be sure to download the maps ahead of time for the area you'll be in, which is free and easy, just select the area on the map and then decide how far you want to be able to zoom in or out, which determines the number of tiles (and resulting file size) which are downloaded. Then preload your waypoints in, such as what I didn't for the key bearings up to Camp Muir for navigating and you can also record your track and then navigate back the same path during whiteout conditions, etc (if caught in one, not that you should plan to do it, obviously). The GPS app also includes an altimeter and compass (true and mag north) and probably cost around $5 or so, perhaps it was $9.95, still a steal though. However, I'm not just relying on my iPhone to do all that, I also have a real compass, altimeter, as well as printout of topo maps just in case.

My $.02 anyway.

Brian

I have been using the app "Topo Maps" on my iPhone 4 for a quite a while now, in the backcountry, with very good success. I don't know if it's a newer chip than the 3GS, but the GPS chip in the 4 is shockingly good....I'd say you'd have to spend over $200 on a handheld GPS to get a better chip that has more antennae and can pick up WAAS satellites. WAAS only helps with accuracy though, not locating, and the iPhone does fine to within ~20ft, (real world testing, deep in a glacial cirque & forested valley). Frankly unless your going pretty high end, I see no reason to own a separate GPS unit.

Here's some tips:
Previously mentioned Airplane mode as a "sleep mode". I'd turn it off though if you weren't going to use it for more than a few hours (overnight, etc..)
Settings --> General --> Network --> Disable 3G (this also gives you farther reaching cell reception!)
you can also turn off data.
Settings --> Wifi --> disable
I'm having a tough time relocating it, but I found a site once that detailed how to turn off the cellular module altogether, and did that on Rainier on a 3GS model for a 3 day trip. Because it wasn't even looking for signal, that REALLY saved on battery life.
Finally, Garmin was making a case for the 3GS that cost $200; it made your phone waterpoof, tripled the battery life, and extended the GPS capability with a longer antenna coupled to a processor I think. Dunno if they made one for the iPhone 4

Another fun app, "ski tracks". I've used it on backcountry skis. This will suck the batteries down pretty hard though.

Thanks all. So it sounds like there is a handful of decent GPS apps available: GaiaGPS, Topo, and MotionX.

I'll do a little more research and try one or two out. If anyone is absolutely certain one is better than the others for backcounty use, including uploading tracks to topo maps, please let us know.

Good to know about "airplane mode" as a battery conservation technique. I also found this posted on Amazon (sold by a third party). It gets good reviews and seems like a reasonable way to keep devices charged while off-grid.

Any more tips tricks for seasoned users?

I was under the impression that a cell phone will interfere with a beacon device. Is this still true?

I always turn my phone off when avalances are a concern.

Interesting. I had never heard that and did some reading up on it. Here's one of the discussions:

www.tetongravity.com/forums/showthread.p...e-with-beacon-signal .

In summary, if you have a smart phone on you and go into "search" mode with a Digital beacon (anything post 2001-ish) turn off the phone or throw it in your backpack. iPods, 2 way radios, and some other all other electronics to varying extent will also screw it up, but not as bad as a data-transmitting smartphone. Near field radiation only extends about 12", so throwing it in your backpack on the other side of your body in a search scenario should be fine.

Pertinent points:
1. Does not screw up transmitting/send signal
2. Does not affect older analog transceivers at all
3. Affect is worst if radio/phone is sending out a call while DSP beacon is trying to search right next to it.

Thanks for making me research that, CJM720