Can the iPad really be used as an out-of-signal range, off-road GPS device?

Howard70

Adventurer
For AZ what is the best Gaia topo to download? Confused with different subscription options.

In general I prefer the USFS 2016 Topos, but they only cover National Forests or the immediate surroundings. Otherwise I prefer the USGS Topo as it is the same as the old quad sheets and has a lot of additional information - springs, old trails etc. - the sort of stuff that helps you explore. The US Topo is vector and thus smaller, but doesn't have as much old information as the USGS Topo. Most other topo maps aren't significantly better than the GaiaTopo which I have downloaded for nearly everywhere as it is my general basemap.

The most costly subscription provides ESRI World Imagery which I've found the be the highest resolution satellite imagery of GAIA's choices. If you really like to explore that is extremely helpful but can definitely eat up your storage space for offline use. The Public Lands layer is also great - I don't recall which subscription offers it. If you head into areas that are covered, the various National Geographic layers provide good general information but usually lead you to pretty popular destinations.

Howard
 
Considering the new iPad Air 10.9" with 256gb and WiFi+LTE. I've currently got an in-dash headunit in my 80 series that accepts CarPlay. While it "works" with Gaia, it's just at such a poor angle and well below my line of sight.

While I understand the cellular is required to get GPS, is it required to get an actual data plan? I have no intention of using it and want it for GPS only. If needed, I will use my cell phone as a hotspot.

Also, any Apple folks need to talk me into getting the Pro instead? My use will be for exploring using Gaia, the periodic lounge in a chair at home over coffee and catching up on things, and may mount it behind the seat in the 200 for my daughter on the family trips. Concerned the 12.9" is just too big.
 

WanderingBison

Active member
Considering the new iPad Air 10.9" with 256gb and WiFi+LTE. I've currently got an in-dash headunit in my 80 series that accepts CarPlay. While it "works" with Gaia, it's just at such a poor angle and well below my line of sight.

While I understand the cellular is required to get GPS, is it required to get an actual data plan? I have no intention of using it and want it for GPS only. If needed, I will use my cell phone as a hotspot.

Also, any Apple folks need to talk me into getting the Pro instead? My use will be for exploring using Gaia, the periodic lounge in a chair at home over coffee and catching up on things, and may mount it behind the seat in the 200 for my daughter on the family trips. Concerned the 12.9" is just too big.

Doesn’t sound like you need the Pro for your use.

You also don’t need a LTE/cellular model. You could use a WiFi only model but will need a separate, external GPS receiver.

If you are going to use the iPad on a paddling or backpacking trip, that might be inconvenient but if it’s for vehicle use, an external GPS receiver might be perfect.

I use a Dual Pro external Bluetooth GPS receiver which provides GPS location to multiple devices (up to five - think iPad, your phone, etc.) and in addition to being more accurate, only the GPS receiver needs to sit on the dash. The iPad can be anywhere. It also has the ability to record and export a track on its own.

A very good option!


Sent from my iPad using Tapatalk
 
@WanderingBison I like the sounds of it! That said, price delta goes in favor of choosing an LTE optioned iPad based on a brief Google search, right? I imagine the benefits lie with the external GPS supplying location to a variety of devices?
 

DaveInDenver

Middle Income Semi-Redneck
@WanderingBison I like the sounds of it! That said, price delta goes in favor of choosing an LTE optioned iPad based on a brief Google search, right? I imagine the benefits lie with the external GPS supplying location to a variety of devices?
I'm not sure what the price difference might be, but if you don't already have either the iPad or the external GPS I'd think about just getting the cell-capable model and be done with it. There's not going to be any significant increase in position accuracy.

I will say one reason to get the stand-alone puck is flexibility in mounting. A device with built-in GPS no matter what it is - iPad, phone, Android tablet - needs to see the sky for GPS to work. This means on the dash or near a side window. Deeper inside the vehicle the performance *may* degrade. Not definitely will but could. With an external puck on the dash you can put the tablet anywhere you want as long as it can reach however you choose to connect, e.g. local Bluetooth or WiFi.

Another reason you might use an external is if you need higher than 1Hz refresh. Most GPS receivers for decades have updated their position once per second, e.g. 1Hz and this is still true of phones and tablets. Higher performance receivers can now update 5 or 10 times a second, e.g. 5Hz or 10Hz. Normally this is excessive and many of the additional points could get filtered later as redundant but in very twisty places or at high speeds (55 MPH is about 80 feet per second) the track will be more faithful to the actual route. I don't know that all external pucks offer 5 or 10Hz update but if they do and you want it then that's how you get it.
 
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WanderingBison

Active member
@WanderingBison I like the sounds of it! That said, price delta goes in favor of choosing an LTE optioned iPad based on a brief Google search, right? I imagine the benefits lie with the external GPS supplying location to a variety of devices?

I'm not sure what the price difference might be, but if you don't already have either the iPad or the external GPS I'd think about just getting the cell-capable model and be done with it. There's not going to be any significant increase in position accuracy.

I will say one reason to get the stand-alone puck is flexibility in mounting. A device with built-in GPS no matter what it is - iPad, phone, Android tablet - needs to see the sky for GPS to work. This means on the dash or near a side window. Deeper inside the vehicle the performance *may* degrade. Not definitely will but could. With an external puck on the dash you can put the tablet anywhere you want as long as it can reach however you choose to connect, e.g. local Bluetooth or WiFi.

Another reason you might use an external is if you need higher than 1Hz refresh. Most GPS receivers for decades have updated their position once per second, e.g. 1Hz and this is still true of phones and tablets. Higher performance receivers can now update 5 or 10 times a second, e.g. 5Hz or 10Hz. Normally this is excessive and many of the additional points could get filtered later as redundant but in very twisty places or at high speeds (55 MPH is about 80 feet per second) the track will be more faithful to the actual route. I don't know that all external pucks offer 5 or 10Hz update but if they do and you want it then that's how you get it.

It’s probably very close to six of one, a half a dozen of the other.

Here’s why I like the external GPS receiver even though I chose a cellular iPad:

First and foremost, I can position the GPS receiver to get the best reception possible. You could even get an external antenna. We’re in a van, so that useful because the “cockpit” is blocked by a large chunk of metal to the rear.

Second, I can use the signal regardless of where I have the iPad. In my case, it’s sitting below the dash, between the seats where it wouldn’t get a great signal from the built in receiver. It works but I can certainly notice the difference.

Third, I use the tracks that GPS receiver records on its own to keep track of our routes, which doesn’t require running the iPad at all if I don’t need it.

Fourth, I can share the signal between devices - I use the GPS receiver for my iPad running GAIA and a few other navigation apps, my iPhone for accuracy and for a rig running my APRS setup. It also provides geolocation to a couple of other systems (solar, router) but that’s more complicated- this is not likely a very common use case.

From a cost stand-point, you can buy a quality, GPS/Glonass receiver once for a little more than the cost difference between a non-cell iPad and one with, and use it for many more years than the iPad. So buy once and use for multiple generation of your iPad.

It is a little more complicated, sometimes it doesn’t pair to my iPad on its own and requires you to keep another battery on another device.

So, it’s really about what you think you need and will use.


Sent from my iPad using Tapatalk
 

roving1

Well-known member
For me its total no brainer as signal is not an issue at all these days. Go take your phone into the basement and see how good the GPS signal still is. The fact you can stick a SIM in the tablet and use it as a backup phone also trumps the GPS receiver.
 

skyfree

Active member
I'm unable to test this at the moment, but I read that you can tether your iPad Wi-Fi only version with any iPhone using the iPhone as a hotspot, and the iPad will receive the GPS coordinates from the phone. I have the huge iPad Pro though, which is a bit too big for mounting anywhere near the dash for me.

So rather than use an iPad, I'll just use Gaia GPS on my iPhone 12 Pro and Apple Carplay. IMG_0278.jpg
 

Rando

Explorer
I use a Wifi only iPad Pro with an inReach to provide the GPS position to the iPad. This works seamlessly. I also regularly (as in most of the time) forget to grab the inReach out of my backpack after a hike and will leave the backpack either in the back seat of my crewcab, or in my fourwheel camper. It still tracks perfectly on my iPad and I can't tell a difference in performance between this and it being on my dash. Point being, with new high sensitivity GPS receivers, having the receiver mounted on your dash is no longer such a big deal.
 

Rando

Explorer
I'm unable to test this at the moment, but I read that you can tether your iPad Wi-Fi only version with any iPhone using the iPhone as a hotspot, and the iPad will receive the GPS coordinates from the phone. I have the huge iPad Pro though, which is a bit too big for mounting anywhere near the dash for me.

So rather than use an iPad, I'll just use Gaia GPS on my iPhone 12 Pro and Apple Carplay. View attachment 649328

I am pretty sure that is NOT actually the case. See the discussion here:

However, I would be very happy to be shown to be wrong on this one.
 

skyfree

Active member
I am pretty sure that is NOT actually the case. See the discussion here:

However, I would be very happy to be shown to be wrong on this one.

Hmm, that thread talks about connecting via Bluetooth. I'm talking about using the iPhone as a hotspot and connecting the iPad via Wi-Fi.

Anyway, I tried it by tethering and walking around the neighborhood and it works. I turned off the iPhone Wi-Fi so it wasn't getting anything from my home network. I did have cell service though.

The one caveat which is that locational accuracy on the iPad is pessimistic. GAIA was showing 213 ft. I believe this is because the iPad is using Wi-Fi positioning, which it assumes is less accurate even though in this case it is not. It also doesn't pass along elevation data.

I'd like to try it in a place where there is no cell signal to exactly reproduce a backcountry scenario, but that's hard to do without travelling pretty far so maybe later on that one. I'm specifically wondering if the hotspot continues to pass on GPS even when the iPhone has no data access. I'm going to guess that it will, but I'll test it when I can to be sure. I may decide I want a bigger map in the truck.
 

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Rando

Explorer
Hmm, that thread talks about connecting via Bluetooth. I'm talking about using the iPhone as a hotspot and connecting the iPad via Wi-Fi.

Anyway, I tried it by tethering and walking around the neighborhood and it works. I turned off the iPhone Wi-Fi so it wasn't getting anything from my home network. I did have cell service though.

The one caveat which is that locational accuracy on the iPad is pessimistic. GAIA was showing 213 ft. I believe this is because the iPad is using Wi-Fi positioning, which it assumes is less accurate even though in this case it is not. It also doesn't pass along elevation data.

I'd like to try it in a place where there is no cell signal to exactly reproduce a backcountry scenario, but that's hard to do without travelling pretty far so maybe later on that one. I'm specifically wondering if the hotspot continues to pass on GPS even when the iPhone has no data access. I'm going to guess that it will, but I'll test it when I can to be sure. I may decide I want a bigger map in the truck.

That is the iPad using the Wifi positioning based on recognizing WiFi networks. It has nothing to do with the phone GPS. If you look at Gaia on the phone, you will notice that it is using GPS in this scenario, so clearly it is available but not passing it on to the iPad.

I use my Gaia on my iPad tethered to an iPhone (via wifi) all the time in the backcountry, and without also being connected to an inReach for GPS position, it cannot locate itself. It is a real pity that the phone doesn't pass on the GPS position, but unfortunately that is the way it works and I have not found a way around this.
 
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DaveInDenver

Middle Income Semi-Redneck
That is the iPad using the Wifi positioning based on recognizing WiFi networks. It has nothing to do with the phone GPS. If you look at Gaia on the phone, you will notice that it is using GPS in this scenario, so clearly it is available but not passing it on to the iPad.

I use my Gaia on my iPad tethered to an iPhone (via wifi) all the time in the backcountry, and without also being connected to an inReach for GPS position, it cannot locate itself. It is a real pity that the phone doesn't pass on the GPS position, but unfortunately that is the way it works and I have not found a way around this.
So the iPhone<->iPad tether is passing location implicitly via WiFi location, e.g. perhaps some sort of Apple version of SpotFi or RSSI triangulation technique? Or is it just a serving the location of the iPhone, which presumably would have to be within the margin of RF range. That would explain the +/- 213 feet error just because your device would have to be within a range on the order of 213 feet to be able to connect to a hotspot.

If the phone and pad are in the came vehicle or house the position for practical purposes is interchangeable, although that would not be sufficient for controlling navigation it would be fine to put yourself on a digital map or alert EMS. By reporting a gross error of 213 feet it's pretty obvious it didn't come from a trusted primary location source such as built-in GPS. Even with poor reception if a GPS receiver has enough signals it will be better than that and if it doesn't see strong enough signals from enough sources it simply gives no position at all. But if you're getting a location repeated you can't be sure of errors so the safe thing is to assume you're 200 feet away even if you're only a foot.

This same problem arises when presenting things like a network time to your local network. If you use a USB GPS puck to determine time there's latency and timing issues that could create tens of milliseconds of error compared to a serial port connected puck. For setting your DVR clock that's not a problem but does present problems for encryption, for example.
 
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