Bushwalk Australia

hello there fellow bush walkers

please forgive me if this has been covered i did attempt the search function to no avail

i am keen on getting a GPS unit to use in conjunction with my iphone if this is possible to more accurately pinpoint me on a map, i already have maps on my phone run with a program called memory maps now predominantly it is a 4wd map program but has 25k topo maps with walking tracks

any information would be great

cheers
phil

Not sure what you are trying to achieve or thinking as the iPhone already has GPS and altimeter functionalities built in, quite good too. Just need to have back up battery juice for more than a long day's use.


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I think the OP is looking for something that may operate beyond his phone reception capabilities, perhaps a little like the sat sleeve for iPhone only for GPS.

I don't believe such a device exists. As I mentioned above there is a sleeve that turns your iPhone into a satellite phone but call costs, service range and annual fees make that really for the more hard core user. Interesting thought though, I could actually see a market for something of this nature that lets you use your iPhone as the interface to the GPS information.


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The iPhone GPS will still operate without a 4G connection. The idea is to have your maps preloaded in Maps or Google Earth so you can access them when you won't have a connection.

Memory maps can pre-load topo maps (as the OP has done). The iphone has a good GPS chip (at least since the iphone 4 - the earlier iphones were not so accurate) so you don't need any other add-on as it will be accurate to around 5 metres (horizontal) in most environments. Add-ons like the Bad Elf will not improve accuracy because the iphone has a GPS chip that is as good the Bad Elf chip.

The main reasons to get a dedicated GPS are battery life and rugged construction. My GPS (a magellan) sits unused in a cupboard at home.

If having a GPS-like display on the iPhone is what you want, and topo maps as well, get the GPSKit app.

Tintin wrote:The iPhone GPS will still operate without a 4G connection. The idea is to have your maps preloaded...

+1.

Just get a big external battery pack on longer walks and have an app that can cache map data. There are quite a number of apps available and have been discussed. I'd recommend MotionX-GPS as a starter.

Are you thinking of something like the Magellan Toughcase? That fits iPhone 3G and has its own gps chip and antenna.

The 3G was not at all accurate without a connection (it once put me in Siberia instead of Sydney), but newer iPhones don't have that problem.

You do need offline map software though. I use avanza pdf map and pocket earth.

Thanks for the replies
From what I gather iPhones will not pin point accurately enough to be used on walking trails, dunno know if it's going to help being used for bash walking navigation ect. well that was what I was told thus the market for products like bad elf ect. Which will guarantee your location within 2.5m

Just thought some one on here may have some hand on experience to lead me in the right direction

phs wrote:Thanks for the replies
From what I gather iPhones will not pin point accurately enough to be used on walking trails, dunno know if it's going to help being used for bash walking navigation ect. well that was what I was told thus the market for products like bad elf ect. Which will guarantee your location within 2.5m

Just thought some one on here may have some hand on experience to lead me in the right direction

I don't believe any consumer GPS device will guarantee your location within 2.5m.

If you depend on 2.5m resolution in the bush, you are in serious trouble!

Seriously, the iPhone's GPS resolution without Wifi/mobile services is no worse than a latest consumer Garmin or Magellan unit. It gets better than those when in mobile network coverage with its aGPS functionality.

If you already have an iPhone with a built in GPS chipset, I can't see any advantage to getting a Bad Elf type plug-in GPS product.

This older thread might have information that could be of interest to you viewtopic.php?f=21&t=20044. It discusses using the iPhone 6 for bushwalking, and one member took theirs to Scandanavia and used it as a GPS.

The Bad Elf plug in GPS uses a Mediatek (MTK) GPS chipset. I'm not sure which model they use as I've not dug into it. But the usual MTK GPS chipset models have specs with an horizontal Estimated Positional Error (EPE) of around 3m without aid, and around 2.5m with Differential GPS (DGPS) aid. In Australia, we don't have a reliable DGPS signal for consumer GPS usage (we can't receive space based WAAS or EGNOS here) but some chips can see GAGAN and MSAS satellites.

The EPE of the newer iPhone GPS chips (they use a combined wifi/telephony/GPS chipset) is pretty close to that already without Assisted GPS (agps). So using a plug-in doesn't do any more than the inbuilt chipset, and will use more of your phones power instead.

Of course, if you have an older iPhone that does not have a GPS chipset (did they ever make these?) or an iPod or iPad that didn't have a built in GPS, the plug in GPS units will do the trick. But otherwise, I reckon just use an app with your iPhone and get an external battery for longer life.

RonK wrote:

phs wrote:Thanks for the replies
From what I gather iPhones will not pin point accurately enough to be used on walking trails, dunno know if it's going to help being used for bash walking navigation ect. well that was what I was told thus the market for products like bad elf ect. Which will guarantee your location within 2.5m

Just thought some one on here may have some hand on experience to lead me in the right direction

I don't believe any consumer GPS device will guarantee your location within 2.5m.

Bad elf pro accurate within 2.5m

Not that I need that. I just want sorting they will show me on a 25K map where I am.

So any one have any experience with this on an iPhone 6s ?

Thanks Keithy

I think you summed it up for me the IPhone 6s gps will do just fine

I think when I was looking at this years ago it was with an iPhone 4 obviously they have come along way

Cheers

I've been using a 6S. Accuracy is not a problem unless there is some reason you want it to show which side of the track you are walking along. It can take a second or so to get an accurate position when you turn it on.

I set it to low power mode when in the bush and usually have about 30% battery left after an overnight trip - the battery lasts pretty well when it isn't powering a big screen or streaming video.

I strongly recommend some sort of case though - I found out the hard way that it doesn't take kindly to being dropped repeatedly in rocky creeks.

phs wrote:I think you summed it up for me the IPhone 6s gps will do just fine

I think when I was looking at this years ago it was with an iPhone 4 obviously they have come along way

No worries. These things have improved quite significantly in the past few years. I noticed it with the GPS chipsets in Android phones especially. I haven't tested any iPhone GPS since the iPhone 4, but I have noticed that they have improved accordingly as well.

It's just a matter of:

• your battery life, which can be resolved with an external USB battery pack or two,
• getting a waterproof case/protective cover for it and
• finding an app that does what you want for offline use.

Also, it's important to note that the EPE mentioned above - like the 2.5m of the Bad Elf product (referring to it's MTK GPS chipset) is not a guarantee of absolute positional accuracy, but an estimate of the positional error being within something like >95% of being within the actual location. There is no standard for this accuracy figure from manufacturer to manufacturer. The accuracy figure is derived from DRMS (Distance Root Mean Square), and Garmin for example while they have not released their formula for the calculation of EPE, but have said that they also include other error factors into their calculations. For Garmin handhelds, they usually quote 10-15m accuracy without DGPS corrections (which is pretty standard for consumer based GPS receivers). With DGPS, Garmin states their accuracy comes down to 3m. With most of my kit, in optimum situations, I get around the 3m accuracy. On newer Android devices, with AGPS, it can come down further.

There's been a few threads here on what apps people use with iPhones on bushwalks. I have mainly Android devices now, and have been quite impressed with Oruxmaps as posted here: viewtopic.php?f=21&t=22380

keithy wrote:Also, it's important to note that the EPE mentioned above - like the 2.5m of the Bad Elf product (referring to it's MTK GPS chipset) is not a guarantee of absolute positional accuracy, but an estimate of the positional error being within something like >95% of being within the actual location.

Exactly - what can be guaranteed is that the observable error of my iPhone 6 is often significantly more than 2.5m.

phs wrote:Thanks Keithy

I think you summed it up for me the IPhone 6s gps will do just fine

I think when I was looking at this years ago it was with an iPhone 4 obviously they have come along way

Cheers

It's been accurate enough for walking navigation since the iPhone 3GS, which would reliably get mewithin 10m most of the time, and 5m often (exceptions being when there is not much clear-sky view for satellite reception). Each version since has improved, and these days, I get 5m accuracy most of the time on a 6s, even in moderately dense forest.