43 replies to this topic

[wristwister]

I'm thinking of getting a tablet as a chartplotter. I assumed the new iPad had true, built-in GPS, but when I was checking one out at the Apple store the sales guy insisted that no iPad models had GPS. The specs for the WiFi/Cellular version say "assisted GPS". The guy said this means triangulation off cell towers, the iPad does NOT pick up satelite GPS. I thought this sounded fishy, so he checked with the store's iPad expert who confirmed that even the latest iPad has to be in range of cell towers to pick up positional info.

So I went to Best Buy to check out Android tablets. Same thing. They said none of the tablets they carried (and they carry a BUNCH) had true GPS, only cell tower triangulation.

Now poking around on the interwebs I see there are some Android tablets that claim GPS reception, but I'm even questioning that.

So what's the deal? Are you iPad guys able to navigate when you're out of cell tower range? Do all you tablet/iPad users have to hook into a separate GPS module or some such thing?

[rastus]

I am running cmap on a laptop with an etrex thru a usb. I would assume a tablet would work with this setup

[Navigare]

The 3/4G version of the iPad has a built-in aGPS and it's a "real" gps using satellites to give a position fix. The "a" in aGPS stand for "assisted" and mean its using cell-towers, if present, to shorten the time to establish the position. I would safely assume its the same in Android tablets.
I've been using both iPad 1 and the "new iPad" outside cell coverage with good and accurate position fixes.

[Navigare]

The 3/4G version of the iPad has a built-in aGPS and it's a "real" gps using satellites to give a position fix. The "a" in aGPS stand for "assisted" and mean its using cell-towers, if present, to shorten the time to establish the position. I would safely assume its the same in Android tablets.
I've been using both iPad 1 and the "new iPad" outside cell coverage with good and accurate position fixes.

aGPS link should be; http://en.wikipedia....ki/Assisted_GPS

[ShockValue]

That's ridiculous. I have an Android tablet with NO cell reception (aka, it's wireless only, no cell plan.) and I get satellites JUST fine.

aGPS means it's real gps PLUS assistance from Cell tower and wifi triangulation.

[allen]

My Android tablet has GPS out in the middle of the bay well away from any WiFi. It has no cell phone reception. In addition, both my Android cell phones have GPS and "GPS Test" shows the satellites that they are getting. They definitely have real GPS.

WiFi only devices without GPS, like my iPod, can get location from the WiFi and cell phones can use WiFi or Cell towers to get location before the GPS locks to the satellites but if they have GPS, they have GPS.

That said, I do not know if the new WiFi iPad has GPS, I think that I read that it does not but I don't really know.

Allen

[nroose]

iPads with cell connection have real GPS. Wifi iPads don't, they only have wifi locationing. For Android, there is a huge variety of devices with a huge variety of hardware -- hundreds of different devices with hundreds of different hardware configurations. I am fairly certain the the most popular one that I know of, the Kindle Fire, does NOT have GPS. I think some versions of the Samsung Galaxy Tab and Note do have GPS, but I am not sure all do.

[Ocean View]

Many PC / tablet devices use the gobi or similar chipsets which is an all in one 3g/4g/Gps chip - low cost - does it all

So if the device is not telco / 3G 4G enabled -the GPS chip will not normally be inside it.

If you're into the technical stuff - details on this chip here http://www.gobi.com/

A bit of blurb on Apples change to the latest Gobi 4000 4G GPS chip here http://www.smarthous...G8S9L7D6?page=2


I'd suggest the apple guys is a bit confused in regards to how it works -

If it's telco enabled - it will have the GPS function on board as part of the 4g chip


BUT

In my experience - they work do without a teclo signal - but tend to take a lot longer to find a location -

They also tend to not respond very rapidly to movement in my experience

I'm sure they will get better as time goes on.


But using a dedicated puck like this - which I've used successfully yachting http://www.haicom.co...204III_USB.aspx

You get the sort of figures below - very sensitive

0.1metres / second sensitivity with a location very soon after you power it up.

Same applies to the Tacktick GPS - which is a GM44-UB inside http://www.sanav.com...rs/GM-44-UB.htm

It also responds to very minor movements - which it should do !!!!!

32 seconds from dead cold it provides a GPS location and is still finding more satellites.

And is doing is at 0.1m movement sensitivity (Velocity)

Check out the velocity - start-up times & number of Channels to see how good they are.


Marine GPS = Very high sensitivity = very accurate positioning.

Tablet - Hmm - Never waited long enough - but not anything like the following on a moving boat in my experience

Tacktick is <2.5 M

Haicom is <10 M

And if you're using a DGPS signal as well -

both the Haicom and Tack-Tick get better results.

More about DGPS here http://ww2.trimble.c...l/dgps-how.aspx

[BuggarTheBone]

You should seriously question anyone who claims better than 5m accuracy with a simple GPS. The mathematics of the solution just don't support it. DGPS and dual frequency receivers are a different story, but for the typical marine or recreational receiver, 5m is about all you will get, and that is probably at a 95% confidence interval.
The reality is, speed of first fix, display options and battery life are about the only differences in what you pay for.
GPS though is a great product and should be used within its KNOWN limitations.

[Tucky]

iPads with cell connection have real GPS. Wifi iPads don't, they only have wifi locationing. For Android, there is a huge variety of devices with a huge variety of hardware -- hundreds of different devices with hundreds of different hardware configurations. I am fairly certain the the most popular one that I know of, the Kindle Fire, does NOT have GPS. I think some versions of the Samsung Galaxy Tab and Note do have GPS, but I am not sure all do.

This is not true. As posted above, you can get an iPad with a gps chip in it. I have one- no wifi, no cell plan, works fine.

[Retired BN]

I have an ACER Android tablet and it has a full function GPS. Got rid of my Tom Tom and use it in the care with a great app I paid for. The maps even reside on the tablet. Will do the same when I find a good Chart plotting app where I can store the charts on the device.

[allen]

iPads with cell connection have real GPS. Wifi iPads don't, they only have wifi locationing. For Android, there is a huge variety of devices with a huge variety of hardware -- hundreds of different devices with hundreds of different hardware configurations. I am fairly certain the the most popular one that I know of, the Kindle Fire, does NOT have GPS. I think some versions of the Samsung Galaxy Tab and Note do have GPS, but I am not sure all do.

This is not true. As posted above, you can get an iPad with a gps chip in it. I have one- no wifi, no cell plan, works fine.

Our WiFi only iPad-1 does not have GPS but our Samsung Galaxy Tab-2 does. The Kindle Fire and many other Android tablets do not have GPS. That is why I was so excited when the Tab-2 came out. I had been waiting for a long time for an inexpensive Android tablet that had GPS.

Allen

[Ocean View]

You should seriously question anyone who claims better than 5m accuracy with a simple GPS. The mathematics of the solution just don't support it. DGPS and dual frequency receivers are a different story, but for the typical marine or recreational receiver, 5m is about all you will get, and that is probably at a 95% confidence interval.<br style="color: rgb(28, 40, 55); font-family: verdana, arial, tahoma, sans-serif; font-size: 13px; line-height: 19px; background-color: rgb(250, 251, 252); ">The reality is, speed of first fix, display options and battery life are about the only differences in what you pay for.<br style="color: rgb(28, 40, 55); font-family: verdana, arial, tahoma, sans-serif; font-size: 13px; line-height: 19px; background-color: rgb(250, 251, 252); ">GPS though is a great product and should be used within its KNOWN limitations.

Agreed -
how accurate - I know of power boat that put in a channel markers gps co-ords as a transit mark and hit it dead centre in the middle of the night - which indicates the levels of accuracy that can be obtained - sometimes

[ShockValue]

Only significant if it's repeatable.

[nroose]

iPads with cell connection have real GPS. Wifi iPads don't, they only have wifi locationing. For Android, there is a huge variety of devices with a huge variety of hardware -- hundreds of different devices with hundreds of different hardware configurations. I am fairly certain the the most popular one that I know of, the Kindle Fire, does NOT have GPS. I think some versions of the Samsung Galaxy Tab and Note do have GPS, but I am not sure all do.

I guess this is not clear. The iPads with the cell capability have real GPS. You don't need to be connected or even have a subscription. But you do need to have the hardware. As Ocean View stated, the cell hardware and the GPS hardware are on the same chip, and the wifi version of the iPads don't have that chip.

[craigiri]

I guess this is not clear. The iPads with the cell capability have real GPS. You don't need to be connected or even have a subscription. But you do need to have the hardware. As Ocean View stated, the cell hardware and the GPS hardware are on the same chip, and the wifi version of the iPads don't have that chip.

+1
I think you need a "3G plus wifi" model, and then it works with or without that 3G cellular connection.
https://discussions.apple.com/thread/2718534?start=0&tstart=0

I am thinking about buying the lowest cost refurb 1st generation ipad for this - doing only bay (day) cruising in RI and already know the waters pretty good, so this is really just as a glorified map. I'll get a waterproof enclosure and mount it somewhere......maybe get a solar charger since new boat (corsair tri) has no built in power or batter. I can always bring along one of those extra dongle chargers if need be - as mentioned, I don't really "need" a chartplotter anyway - this is just for some fun, and while I am at it could check email or SA!

I can't think of any reason why the slower older model with 16 GIGs would not do the job well. If anyone else can, let me know!

I can pick up one of these for about $275.00 and then subscribe to the low data plan ($15 mo) during the sailing months if I want internet access out there.

I have an old iphone, but the screen is so small it sucks for this particular purpose.

[eric e]

our asus transformer 101 has a true gps chip

http://www.techrepub...t;siu-container

the 200 series transformer also has onboard gps, but they screwed up its sensitivity by putting an alloy case on...

the 300 series also has gps

and presumably the forth coming 700 series

[allen]

The Samsung Galaxy Tab-2 7 inch has a wonderful GPS chip. Works great. Still hard to read out in the sun although it is readable. My wife's iPad v.1 WiFi only does not have GPS.

Allen

[Roleur]

We have non-3G iPad and then use a bluetooth puck like this - http://www.amazon.co...s/dp/B004M3BICU

To me that has a few nice advantages. It is cheaper than just a 3G iPad, it will also work with our laptops, and I'm not positive, but I think the GPS is better than what is found in an iPad.

We already had the iPad before we even considered using it for nav, so this was an easy upgrade. It works well for us, so far.

[baybilly]

I used a GPS receiver by BAD ELF that plugs into iPAD that provides my wifi only 1st Generation iPAD GPS capabilities. The only issue was the device is so small it is easily lost, which we did. I am looking to upgrade to new iPAD and will get version with built in CELL DATA capabilities even though I will not subscribe to the plan so that I get the GPS.

Long term I am looking at interfacing iPAD with boats primary GPS. I understand the reception is better and what I see on the iPAD will be what the rest of the intruments display.

Link to BAD ELF: http://bad-elf.com/products/gps/

[Tige]

I used a GPS receiver by BAD ELF that plugs into iPAD that provides my wifi only 1st Generation iPAD GPS capabilities. The only issue was the device is so small it is easily lost, which we did. I am looking to upgrade to new iPAD and will get version with built in CELL DATA capabilities even though I will not subscribe to the plan so that I get the GPS.

Long term I am looking at interfacing iPAD with boats primary GPS. I understand the reception is better and what I see on the iPAD will be what the rest of the intruments display.

Link to BAD ELF: http://bad-elf.com/products/gps/

NavNet TZ will treat an iPad as a smart repeater. Unless furuno, garmin etc etc comes out soon with a sole purpose tablet chart plotter I'll get one of them when it's time to update to a new nav suite.

[Sailabout]

do any tablets receive Diff data, WAAS in the US?

[A Florida Redneck]

iPads with cell connection have real GPS. Wifi iPads don't, they only have wifi locationing. For Android, there is a huge variety of devices with a huge variety of hardware -- hundreds of different devices with hundreds of different hardware configurations. I am fairly certain the the most popular one that I know of, the Kindle Fire, does NOT have GPS. I think some versions of the Samsung Galaxy Tab and Note do have GPS, but I am not sure all do.

Samsung Galaxy Note and SG Tab 10.1 have GPS.

[Balder]

I brought my OLD (2 years anyway) google android phone with me here to Hong Kong. I cant get service for it here, no bars ever show for reception. I can connect to wifi to download google maps, and then use the GPS to navigate wherever I want.

It worked in the US also when out of cell range.

We just got an IPhone 4s here and are racing to Macau this weekend. we will turn off the roaming and I will let you know if it worked.

[EDIT- just noticed you said pads/tablets, not phones. but other than the size of the screen I think there is little, if any, difference]

[wristwister]

Thanks for all the input folks. JUst to close this thread out, I figured I'd post an update on what I ended up buying and how it's working.

Got a Samsung Galaxy Tab 2, 10.1" version. The geniuses at Best Buy insisted it didn't have true GPS . They said it MUST have WiFi enabled and picking up signals in order to get position fix. They proved this by shutting off WiFi, leaving GPS only on, and sure enough, Google Maps puked.

But ... I wasn't convinced so I bought one anyway (despite the efforts of their crack team of salesmen to talk me out of it). Then, being the cheap sumbitch I am, I downloaded a free marine navigation app (Marine Navigator Lite) along with a bunch of free charts from NOAA. I've been out on a weekend trip with the boat and tried it all out, and ... drum role please ... it works spectacularly, even with WiFi shut off. I'm so thrilled with how well it works I'm even considering actually PAYING for an app that gives me more capabilities than my freebie app.

[nroose]

Um... Google Maps uses the internet to get the map tiles. That is why it doesn't work with wifi off.

[Elite324]

Just to clear up some points in this thread:

Google Maps will work without an Internet connection on an Android tablet if you download the area in advance. I am not sure if this working on iPads yet.

Most Android tablets have GPS regardless of 3G or 3G capability.
Most Android tablets also have a magnetic compass.
AGPS is not a lesser version of GPS, it is the ability to get a fast first fix by gathering the GPS satellite data from the network. This is requirement for E911 to improve the location speed and accuracy.
The GPS on my Galaxy TAB 10.1 will track indoors, I have not tried it on a boat, but it should work fine.

[allen]

Just to clear up some points in this thread:

Google Maps will work without an Internet connection on an Android tablet if you download the area in advance. I am not sure if this working on iPads yet.

Most Android tablets have GPS regardless of 3G or 3G capability.
Most Android tablets also have a magnetic compass.
AGPS is not a lesser version of GPS, it is the ability to get a fast first fix by gathering the GPS satellite data from the network. This is requirement for E911 to improve the location speed and accuracy.
The GPS on my Galaxy TAB 10.1 will track indoors, I have not tried it on a boat, but it should work fine.

All true. Just to add, the Galaxy TAB-2 7 inch has a nice GPS just as you describe as well but be aware that the book store tablets do not have GPS. The only problem I have with the phone/ tablet GPS chips is that they are not WAAS so their accuracy is not as good. In some testing I did, I saw peak to peak errors of about 80 feet. I got a bluetooth BPS that is WAAS and that went down to about 35 feet. This number is the worst case point to point difference over 3 hours. The positional error seemed to be pretty much half that as I traced out the path of walks and bike rides and compare them to the Google Earth locations.

[knobblyoldjimbo]

AGPS is not a lesser version of GPS, it is the ability to get a fast first fix by gathering the GPS satellite data from the network.

I think the A is the fixing of initial, or rough initial position from the cellular network using the current cell as the starting lat/long.

If you use an in car gps and then turn it off and go somewhere else it'll take quite a long time to work out where it is now from sat fixes.

Allen, if you're testing with walking or cycling remember that when you go under trees etc the gps won't get a fix and then uses the next fix to work out where you've been. During a walk in the Botanical Gardens in Sydney I found that I was doing 70kph - clearly because it loses signal under the trees.

I also noticed our TomTom (proper in car one) got very distracted when we drove out of the Daintree Forest, occasionally it'd have us driving in the sea! When we then got to Cairns Airport and flew back to Sydney it was computing our route home (110km) as over 4000ks because it hadn't yet got the proper fix of its current position (and this took about 15 mins) so the Agps would have helped enourmously except that I only haver a Nokia N97 and it's crap for nav.

Out on the open sea or lake, while assisted may not be available because you're out of cell once the gps kicks in it should be fairly accurate except the smartphone versions don't sample fast enough presumably because of power consumption issues.

KO

[allen]

AGPS is not a lesser version of GPS, it is the ability to get a fast first fix by gathering the GPS satellite data from the network.

I think the A is the fixing of initial, or rough initial position from the cellular network using the current cell as the starting lat/long.

If you use an in car gps and then turn it off and go somewhere else it'll take quite a long time to work out where it is now from sat fixes.

Allen, if you're testing with walking or cycling remember that when you go under trees etc the gps won't get a fix and then uses the next fix to work out where you've been. During a walk in the Botanical Gardens in Sydney I found that I was doing 70kph - clearly because it loses signal under the trees.

I also noticed our TomTom (proper in car one) got very distracted when we drove out of the Daintree Forest, occasionally it'd have us driving in the sea! When we then got to Cairns Airport and flew back to Sydney it was computing our route home (110km) as over 4000ks because it hadn't yet got the proper fix of its current position (and this took about 15 mins) so the Agps would have helped enourmously except that I only haver a Nokia N97 and it's crap for nav.

Out on the open sea or lake, while assisted may not be available because you're out of cell once the gps kicks in it should be fairly accurate except the smartphone versions don't sample fast enough presumably because of power consumption issues.

KO

I didn't see much difference between slight tree cover and hiking on the top of a mountain. I did find that, although the unit I am using reports lock in 15 seconds, it really takes much longer (maybe the better part of an hour) to really get accurate. I am not sure how long, but many minutes and not seconds for sure. My latest testing uses a Qstarz BT-Q1000XT. It is very sensitive relative to many models. The accuracy spec is 8 feet with WAAS RMS. That would be about twice that peak or 4 times that peak to peak for a start line application. I am seeing better than that across my 3 hour test periods so maybe I am not waiting long enough.

[Elite324]

AGPS is not a lesser version of GPS, it is the ability to get a fast first fix by gathering the GPS satellite data from the network.

I think the A is the fixing of initial, or rough initial position from the cellular network using the current cell as the starting lat/long.

That is sort of correct, the AGPS messages contain enough GPS ephemeris (data describing the orbits of the satellites) to enable a fast lock on the GPS signal. It does not use the position of the cells or wifi AP to do this. There is a completely separate process used by e911 to generate a rough position but this is not related to AGPS at all.

[GOGO Gadget]

Seems like Garmin has seen the light.
GLO Bluetooth GPS
https://buy.garmin.c...p.do?pID=109827
GLONASS and 10x second output and can run on USB or ships power. Not super cheap at $99 but if I have an issue I can scream at someone in the US for product support.
Seems like a good deal just for that feature.
I have had issues with drivers and such with the China brand GPS units.
Gadget

[GOGO Gadget]

Seems like Garmin has seen the light.
GLO Bluetooth GPS
https://buy.garmin.c...p.do?pID=109827
GLONASS and 10x second output and can run on USB or ships power. Not super cheap at $99 but if I have an issue I can scream at someone in the US for product support.
Seems like a good deal just for that feature.
I have had issues with drivers and such with the China brand GPS units.
Gadget

[Mogle]

I got a iPad 2 with wi-fi and 3G. Even when out of 3G range it picks up the GPS coordinates. I would not trust the information. Get a wi-fi interface to you instruments and get the details from your onboard instruments. Use the iPad just as a display.

[Navigare]

I would not trust the information.

Why not? If the tablet has a proper position fix I see no reason it's precision would be less than an "expensive" plotter.
I have in fact been using an iPad as navigation aid in parallel to my Raymarine plotter all summer and the be impressed by the speed and accuracy, but at the same time the screen on the tablet is really hard to read in direct sunlight and I've also had it overheat a couple of times which makes it shutdown.

[fastyacht]

This is an interesting thread. BUT...

Can someone explain to me what the great attraction is for trying to use these devices rather than bona fide marine GPS units? I can only see downsides and no upsides to using tablets or phones as compared to a marine GPS. Perhaps I am mistaken--please enlighten me.

Secondarily, back in the early days of GPS, the "Datum" issue was no small issue. Has this been completely sorted out with respect to the tablets relative to paper charts?

[Mogle]

Can someone explain to me what the great attraction is for trying to use these devices rather than bona fide marine GPS units?

Secondarily, back in the early days of GPS, the "Datum" issue was no small issue. Has this been completely sorted out with respect to the tablets relative to paper charts?

It come down to cost and how easy it is to use.

On my yacht we got all three systems, paper, marine GPS and tablets. We use and trust the tools in that order.

[Tucky]

This is an interesting thread. BUT...

Can someone explain to me what the great attraction is for trying to use these devices rather than bona fide marine GPS units? I can only see downsides and no upsides to using tablets or phones as compared to a marine GPS. Perhaps I am mistaken--please enlighten me.

Secondarily, back in the early days of GPS, the "Datum" issue was no small issue. Has this been completely sorted out with respect to the tablets relative to paper charts?

I think that Datum issues have become almost automatic in most populated areas of the world, just as magnetic derivation is automatic. This is true for plotters and should be true for any decent program on a tablet as well.

[wristwister]

Can someone explain to me what the great attraction is for trying to use these devices rather than bona fide marine GPS units? I can only see downsides and no upsides to using tablets or phones as compared to a marine GPS. Perhaps I am mistaken--please enlighten me.

Pretty simple really. I'm not going to buy some piece of marine electronics that costs more than I paid for my whole boat when a tablet for a few hundred bucks does the trick just fine. Plus, can you play Angry Birds on your fancy chart plotter? Huh? Can you?

[Bump-n-Grind]

Just to clear up some points in this thread:

Google Maps will work without an Internet connection on an Android tablet if you download the area in advance. I am not sure if this working on iPads yet.

Most Android tablets have GPS regardless of 3G or 3G capability.
Most Android tablets also have a magnetic compass.
AGPS is not a lesser version of GPS, it is the ability to get a fast first fix by gathering the GPS satellite data from the network. This is requirement for E911 to improve the location speed and accuracy.
The GPS on my Galaxy TAB 10.1 will track indoors, I have not tried it on a boat, but it should work fine.

Do you have a waypoint set for your refrigerator?

[Whisper]

This is an interesting thread. BUT...

Can someone explain to me what the great attraction is for trying to use these devices rather than bona fide marine GPS units? I can only see downsides and no upsides to using tablets or phones as compared to a marine GPS. Perhaps I am mistaken--please enlighten me.

Secondarily, back in the early days of GPS, the "Datum" issue was no small issue. Has this been completely sorted out with respect to the tablets relative to paper charts?

What downsides?

I happen to have dedicated marine nav gear. But I bought it before iPhones were equipped with GPS.

Most people already have smart phones and/or tablets, so the marginal cost to convert them to marine navigational use is only $50 for iNavx, and much less for Navionics. Add a lifeproof case, and you can dunk your iDevice in the water.

For those with dedicated systems, you can have nmea info broadcast to your devices. While off watch, you wake up and want to see where you are, or what conditions are like--but don't want to leave your bunk? Glance at the iPhone.

For those who already have the devices, it's a no-brainer.

[craigiri]

Goog Nexus tablet 7" is $199.

It contains a true GPS chip. You can use it as a GPS for your car - IF you go to goog maps first and download the area(s) where you drive.

I know you can use it with EarthMC
http://earthnc.com/
and I assume other such devices. You also download the charts you need into it first.

If I had a new $500,000+ yacht, I'd probably fork over for the latest real plotter......just to be sure. But my sailing grounds are within a few dozen square miles, so the Nexus and my Iphone do the job fine.

[allen]

I used my Samsung Tab-2 7 today to deliver my boat to Berkeley. It was very nice to have the Navionics app running right there in the cabin where I can see it without glare. I liked the line that shows where you are headed and for all the shortcomings of that app, I picked it over the one that was the most "desk friendly" when actually on the water. Of course, the app I am developing for racing was the best for reading our speed and course :-)

Allen

[fastyacht]

Pretty simple really. I'm not going to buy some piece of marine electronics that costs more than I paid for my whole boat when a tablet for a few hundred bucks does the trick just fine. Plus, can you play Angry Birds on your fancy chart plotter? Huh? Can you?

Angry Birds LOL (haven't played that. I don't own a glowphone.)

I happily paid $170 a few years ago for a good 5" real box compass. It doesn't require batteries and it glows in the dark :-)