Where Did My GPS Go?
I thought it would be great to use my iPad 2 WiFi as a GPS device. Its big screen and computing power would most certainly be a big improvement over the aging Droid cellphone I had been using to find my way around Southern California. After considering this for awhile, my iPad 2 WIFi went with me on my next trip. Once in the car, I fired up the iPad, clicked on Google Maps, then created a destination and a route. I backed my car out of my driveway, drove about 10 yards, and my great idea, fizzled and died. No GPS at all. I rechecked everything. My entries into the mapping program looked good. I drove the car back into my driveway, and the map program seemed to come to life. Great, so I backed the car into the street again, and my iPad GPS adventure once more stalled. Then it hit me: when I backed the car into the street, my WiFi signal went away, and my GPS tracking went with it. Clearly, a “cause” and “affect”. How can this be, I should still be receiving a signal from the satellites? I shut off my iPad, entered my destination data into the old Droid cell phone, and off I went, with no additional GPS issues.
When I returned from my trip, I did some investigating. It seems that if you have a WiFi only iPad, you do not have a GPS chip inside your shiny aluminum iPad case. I could see, when I attempted to use the iPad as a GPS device, that a little “positioning” was taking place while the car sat in my driveway. Unfortunately, the “positioning” quickly evaporated when I rolled the car into the street. This is because my local area network from my home was providing the information, through the network itself and/or WiFi triangulation. When I left the range of my network, any Geo-location for me and the iPad became unavailable. To get GPS for a WiFi iPad, some additional hardware will be necessary.
Conversely, if you have a 3G or 4G iPad, then you have a built-in GPS chip that becomes part of a hybrid GPS system, called A-GPS (Assisted GPS). A-GPS, uses WiFi triangulation, cell towers, and satellites to track you and perform the location finding. There are several advantages to A-GPS when compared to GPS:
- By using your data plan, maps (like those from Google, Waze, etc.) are automatically added and cached for you as you merrily drive to your destination. It may seem to you that you are drawing information from one big map. You are, but that “big map” is located in a server somewhere. In fact, you are actually operating on a number of “portions” of that larger map, now cached in your cellphone (or other iOS device). As you begin to “run off” the the existing map, the next appropriate map portion is downloaded to you through your cellular network. The end result is a large saving in storage space on your cellphone or tablet, because you only have downloaded what you use, not what is available.
- Another advantage of A-GPS is that you have two other sources of data to provide your location. If there is some obstruction between your device and the GPS satellites, you will still know where you are.
- Many mapping programs now use and display information downloaded from your cellular network. Some examples of this data are: traffic information, and street names to be used in turn-by-turn navigation.
- Finally, A-GPS devices can determine location faster, because they simply are not relying only on satellites.
GPS has some advantages of its own:
- Though it takes longer to determine location coordinates, GPS is more accurate than A-GPS.
- The GPS device receives signals from satellites for FREE, so your only cost is for the GPS device itself.
- GPS devices work where there are no cell towers or cellular service.
- When the GPS receiver is configured to use WAAS (Wide Area Augmentation System), GPS signal corrections are up to 5 times better than a GPS not using WAAS. WAAS corrects for GPS signal errors caused by ionospheric disturbances, timing, and satellite orbit errors, and it provides vital integrity information regarding the health of each GPS satellite. The following is Garmin’s description of how WAAS works: “WAAS consists of approximately 25 ground reference stations positioned across the United States that monitor GPS satellite data. Two master stations, located on either coast, collect data from the reference stations and create a GPS correction message. This correction accounts for GPS satellite orbit and clock drift plus signal delays caused by the atmosphere and ionosphere. The corrected differential message is then broadcast through one of two geostationary satellites, or satellites with a fixed position over the equator. The information is compatible with the basic GPS signal structure, which means any WAAS-enabled GPS receiver can read the signal.” With WAAS you can get position accuracy to within 3 meters, 95% of the time. Another great benefit, if the GPS is WAAS-enabled, you don’t have to purchase additional receiving hardware, and there is no service contract or cost, – the system is free to use.
- You might also want your GPS to be EGNOS-enabled (European Geostationary Navigation Overlay Service). Working much like WAAS, EGNOS augments the US GPS satellite navigation system and makes it suitable for safety critical applications such as flying aircraft or navigating ships through narrow channels. EGNOS is the first pan-European satellite navigation system. The European Space Agency describes the way EGNOS works: “Consisting of three geostationary satellites and a network of ground stations, EGNOS achieves its aim by transmitting a signal containing information on the reliability and accuracy of the positioning signals sent out by GPS. It allows users in Europe and beyond to determine their position to within 1.5 meters.” Also, free to use. For more information about EGNOS, click this link: http://www.esa.int/Our_Activities/Navigation/The_present_-_EGNOS/What_is_EGNOS
- As WAAS is a GPS augmentation system for the US, and EGNOS is the same type of system for Europe, there is also the MSAS (Multi-function Satellite Augmentation System) utilized in Japan. Like its US and European counterparts, it is also free to use.
- Finally, A-GPS is designed to work in mobile devices, such as cell phones and tablets. GPS is used in devices that are mobile, such as cars, boats/ships, and airplanes. If you are reading this article while traveling in a commercial jet, your plane is probably using GPS right now.
What To Do?
For me there were clearly three options: Either use the old Droid cellphone that uses A-GPS , add GPS to my iPad, or buy a dedicated GPS device for cars, like the Garmin, Magellan, or TomTom devices.
I decided to add GPS to my iPad 2 WiFi because: I wanted the bigger screen offered by the iPad; GPS is more accurate, and I can use it in a car, boat, plane, or while walking in a secluded forest; it is cost effective; I could further GPS accuracy by getting a device WAAS/EGNOS/MSAS enabled; and finally, I could do it with my budget ($100).
GPS Options For The iPad
GPS devices have two ways to get satellite location information to your iPad: Bluetooth, and through the iPad’s built-in 30 pin connector. Here are some examples of both types:
The Dual Electronics XGPS 150 Universal GPS Receiver uses a temporary mount in your car to hold and secure the GPS receiver, and transmits vital location information from GPS satellites wirelessly to your Bluetooth enabled mobile device. The Dual GPS receiver is both WAAS and EGNOS compatible. It uses a 65 channel chipset, and updates positions at least once per second. It can acquire and lock satellite signals on planes traveling a maximum of 1150 m.p.h., and at a maximum altitude of 59,000 feet. The device carries its own rechargeable power supply. Street price around a $100 (US).
The Emprum Ultimate GPS Accessory is designed for the iPad, iPhone, and iPod Touch. It plugs into the iOS device’s 30 pin connector. It is diminutive in size, about 1″ square. The Emprum’s chipset has a 5Hz update rate, and is A-GPS enabled (assuming of course you have a data plan, but will still work without it – minus the A-GPS features available in your mapping software). The device uses 51 satellite tracking channels, and has a maximum altitude for functionality at 59,000 feet. The Emprum’s power comes from the iOS device it is attached to. The Emprum is enabled for WAAS, EGNOS, and MSAS. Configuration software is a free download from The App Store. Street price around a $100 (US).
The Bad Elf BE-GPS 1000, like the Emprum, is designed for the iPad, iPhone, and iPod Touch. Also, like the Emprum, the Bad Elf uses the iOS device’s 30 pin connector. It supports WAAS, EGNOS, and MSAS. It has a 10Hz position update rate, and uses a 66 channel chipset. The Bad Elf has maximum functionality at an altitude of 60,000 feet, and a 1000 mph maximum as well. All this from a little cube, roughly 1″ square. Power comes from the iOS device. A free app for firmware upgrades and configuration is available from The App Store. Street price the Bad Elf is $85 (US). This is the device I purchased for my iPad.
All of the external GPS devices mentioned above claim they will work with any maps available from The App Store that use GPS functionality. That statement is correct, providing your definition of “work with” covers a data plan on your iOS device. Here, the devices circumvent the internal GPS of the iPad, and iPhone, use the A-GPS functionality available through your data plan, and use the map “portion” approach mentioned earlier in this article (portions of the map are downloaded to your mobile device as you need them).
If you have a WiFi only enabled iPad, then you need maps that can be used “offline”. These will be an entire maps of the country, or a specific area of the country, as there is no network to support the downloading of map “portions” while you drive to your destination. Here is a list of “offline” map programs available for use with the external GPS units mentioned above (all are available from The App Store):
Garmin, TomTom, Europe iGo Primo, Navigon, Magellan RoadMate, MotionX GPS Drive, Navfree GPS, and CoPilot Live USA.
The CoPilot Live USA app was my selection. Only Navfree is cheaper (free). CoPilot cost $14.99 (US). Like many of the maps listed above, you can download entire maps to your iOS device (all free with the program purchase). On A-GPS enabled iOS devices, you can get free traffic updates for a year, and for all types of iOS devices, you get free map updates for life. At left is a sample map that is from a screenshot from my iPad.
How It All Works
Though I have not tried my new external GPS/iPad system on any long trips, I have used it on several excursions locally. It does take it a minute or so to acquire all the satellites it needs to function, which is between 8 and 12 (many “car” dedicated GPS systems use only 4 satellites).
CoPilot works well with The Bad Elf GPS. The maps offer both 2D and 3D views. I have purposely avoided following CoPilot’s directions to test how quickly it adjusted and developed another course to my destination. It developed every new route nearly instantaneously and seamlessly, without any of the annoying verbal “recalculating” remarks found in most GPS devices. The overall look of the maps is fine, though not the level of detail found in Google Maps. On the other hand, it is much easier to track the movement of my car on CoPilot, and see where it is in relation to turns, cross streets, etc.
In my car, I created a removable console mount for the iPad, and the big screen (when compared to my old Droid cell, and dedicated GPS devices) is great. I have yet to loose a satellite signal when driving around. The total cost for the GPS device and software came to $100, – my budget. Overall, I am very pleased with the entire system, – just wish I had done it sooner.