I’ve been doing a considerable amount of hacking with the iPhone SDK, mainly to get the iPhone communicating with our Foundation product. Last night I was trying to display the horizontal accuracy from the iPhone’s CoreLocation API in our Foundation user interface. The horizontal accuracy is the radius of uncertainty of the iPhone’s location (and it’s measured in meters). The uncertainty I was dealing with at the time of development was 1618 meters. I’ve seen the iPhone come close to 100m and even better when connected via WiFi, but more on that later.

As part of our Foundation product we provide some simple JavaScript functions that make it easy to draw geofences on Google Maps. If you’re not familiar with a geofence, it’s basically a virtual boundary you can create to receive a notification if a device moves into or out of it. In most circumstances a circular geofence is used. So I spent an hour trying to understand why I couldn’t get the geofence overlay to display on Google Maps. Here’s my initial screen:

After a considerable amount of time and frustration passed (1 hr to be exact) I decided to zoom nearly all the way out and was surprised to see that I geofenced all of North America. Then I came to the realization that units were keeping me down (m vs mi). I was passing 1618 meters into our function, which was expecting miles. This yielded the following screen:

My geofence was only 1,617 miles off. It turns out that 1618 meters is just a tad bit more than a mile. Finally, I ended up with exactly what I needed:

Ah yes, much better. The image above shows the reading from inside our office building where we’re surrounded by all sorts of windows, walls, cubes, etc. Because of triangulation we’re able to get readings indoors and even underground. Even though the accuracy isn’t all that precise it’s enough to do some really interesting things. If you’d like to get your iPhone hooked up to the Ublip Foundation for development and testing purposes please feel free to comment or drop us a line.

In a couple of previous posts I used the term “iPhone GPS” and then went on to describe that it’s accomplished through doing cell tower triangulation. Let me state that I’m well aware that there’s no GPS chip inside of the iPhone, but for the purposes of my posts I state “iPhone GPS” meaning that the iPhone can get it’s current position (regardless of whether it uses satellites or not). Okay, with that being said I’d like to share some more of my recent discoveries.

Previously, I stated that the iPhone is not a viable solution for GPS tracking for several reasons. Right now, I’d like to ignore the current limitations of the OS (app can’t be started automatically and run in the background) and focus on retrieving the device’s current location. This is done with limited accurancy, but I’ve explicitly coded our iPhone tracking application to provide the most accurate readings as possible. There’s also a property that can be set to tell the device to report continuously when it moves.

If you’re unaware, we sell GPS tracking products for small fleets and families. All Ublip employees have a fleet tracking device installed in their car and we track each other 24/7 (because we’re geeks like that). This morning as I drove to work I decided to compare the accuracy of the iPhone’s GPS to our fleet tracking device. The Ublip fleet tracking device reports several times a minute while moving and I only let the iPhone report once/minute. This was done manually so there were a couple instances where I missed the mark. When I got to work I logged into our web application and compared my car’s breadcrumbs to those of my iPhone. Here are the results:

The red blip represents our office, where my trip ended. You can see the consistency of reports (evenly spaced) from our fleet tracking device, while the iPhone was somewhat spotty (due to human error). At a quick glance you’ll notice that the breadcrumb trails in both cases are very similar. We’ll be working to continuously improve our iPhone tracking application as well as continue to test against a more accurate and reliable device. With that being said I’m more optimistic about the possibilities of using the iPhone as a GPS tracking device, but this is only one part of the equation. There are still many, many things to figure out.

What do you think? Based on the image above does the iPhone provide enough detail for the types of applications you would use?

I recently posted about using the iPhone as a GPS tracking device. After doing more testing today I’ve come to the conclusion that using the iPhone (in its current state) for a traditional fleet tracking device is out of the question. Let me explain by first providing a visual:

The first thing you’ll notice is that the speed as displayed by our GPS tracking system is zero. The iPhone uses cellular triangulation to estimate the device’s current position. With that being said there’s no speed information that is accessible from the CoreLocation API. That doesn’t necessarily mean it can’t be done, but currently its next to impossible.

If you look at the map image you’ll see a bunch of blips within a 2-3 mile radius of my house. I drove around today and frantically pushed the “Update Location” button within the Ublip iPhone application. You can see there’s no way to discern a real route between location readings. I had the thought of using Google’s directions API to get a route between two points, but I’m skeptical this will provide the level of detail necessary. I’ll be sure to post my findings once I run a few tests. Overall, the accuracy of location information isn’t bad if you need to know the whereabouts of your iPhone (or iPhone owner) and there’s still a few things I’ll be testing to improve the results.

I can think of a few circumstances where knowing the vicinity of the iPhone can prove useful, but most are consumer or socially oriented:

- Knowing the whereabouts of my friends and family

- Searching for businesses/information within a vicinity of the iPhone

- Geocaching: finding geocaches within a vicinity of the iPhone

- Publishing location information from the iPhone to FireEagle (this ties into the first item listed above)

- Geotagging: taking a photo and sending the whereabouts of the photo to Flickr (although there are more accurate ways to do this)

Those are just a few appliations that come to mind and I’m sure there are several others, none of which rely on GPS accuracy to the meter. I’ll be experimenting with sending location data to the Ublip system on an automated interval and share my findings here. For now I can press the “Update Location” button on a one minute interval while driving to work. 1, 2, 3, 4, 5…..60 press. 1, 2, 3, 4, 5….60 press.

It’s been a while since I’ve been heavily involved with mobile phone development. About 5 years to be exact. During that time I’ve hacked all sorts of projects together in search for the ultimate GPS tracking phone. One project was called BlueGPS for both Symbian and Windows Mobile. Both of these mobile GPS apps depended on an external Bluetooth GPS receiver. There are many other devices that have built-in GPS receivers, some of which I’ve programmed, but most have limitations. One of the more capable devices was the basic Motorola i415 that runs on the Boost Mobile network. This phone is programmable in Java (J2ME) and costs a mere $29 with no contract. This should be a sign of where the industry is headed when you can get a mobile phone with GPS capabilities for such a nominal fee.

The main reason behind this post is to evaluate using the iPhone as a GPS tracking device. As you’re probably aware, Ublip sells low-cost GPS tracking solutions with a focus on simplicity. Our goal is to provide a Foundation that makes it simple to integrate practically any GPS tracking device with our core software stack. The term Foundation (with a capital “F”) is a product that we’re getting ready to publicly launch and we believe it provides tremendous value to any developer or organization building location based M2M applications. For more details on our Foundation check out this post.

Over the past couple of weeks I’ve been dabbling with the recently announced iPhone SDK. I’m a Mac fanboy and purchased the iPhone to help minimize the number of devices I carry around in my backpack (phone, iPod, GPS receiver, digital camera, and PowerBook). With the latest version of the iPhone firmware all iPhone users have the ability to triangulate their current location using cellular towers and WiFi access points. It’s not true GPS, but for a lot of applications (such as location based search) it’s good enough. So when I downloaded the SDK I was optimistic that Apple would expose the iPhone location API to developers. Thankfully, my assumption was correct.

Downloading the SDK was a beast. A 2GB beast. After my 8 hour download (mainly because Apple’s servers were getting hammered at the time) I had the installer sitting on my desktop. My first hurdle was the fact that the iPhone SDK was designed to run on Intel based Macs. Unfortunately, I purchased my PowerBook in 2005 and was frustrated that I didn’t have the latest hardware to run the iPhone SDK. If you’re a Windows developer then you had better switch or continue developing J2ME, Windows Mobile, and Symbian applications. The thought of having to spend $2,500 to upgrade to a MacBook Pro was out of the question, but the thought definitely crossed my mind. Luckily I stumbled across this great blog post about running the iPhone SDK on a PowerBook. About 4 hours later my iPhone dev environment was up and running.

At this point I was a bit skeptical that anything would actually work since this was an unsupported hack. But lo and behold, I was able to compile and run the good ole “Hello World” application in the iPhone simulator. As with any mobile phone development project the next logical step was to see the actual application running on the device. There’s something to be said for the instant gratification you get when holding a mobile phone in your hand with the application running on it (even if you only changed one line of code). I quickly found out that developing on the real device costs money and requires Apple’s approval. The registration fee is nominal ($99 for developers and $299 for enterprises), but the approval process takes time. Just this past week our application was approved and we now have the ability to deploy applications to our company iPhones.

During the beta period Apple limits developers to test on five iPhones. I think this is due to the fact that you have to reflash the iPhone with the beta version of the 2.0 iPhone firmware. So I went through this process, which scrubbed all the data from my device (not a big deal since everything was backed up in iTunes). There are some nifty enhancements to the 2.0 iPhone OS, but I won’t go into detail right now. After loading the new firmware, signing the application, and creating a provisioning profile for each iPhone, I was able to load the “Hello World” application on my device. Instant gratification.

The next logical step for me was to figure out how to integrate the iPhone with our web-based GPS tracking software. After several hours of hacking (spanning multiple evenings), learning a bit about Objective C and Xcode, I was able to get my iPhone integrated with the Ublip system. Now when I’m on the go I can report my location to our system just like any other GPS tracking device (Enfora, Orbit One, Digi, and CalAmp to name a few).

After getting the data into the system I was interested in seeing the accuracy of the location reading. If you look at the image below you can see the blip my iPhone reported (the one with the bubble window), while the blip below and to the right represents my actual location (as reported by my car). So the accuracy is within a couple hundred meters. Not too shabby. You actually have control of the accuracy through the iPhone CoreLocation framework, but for testing purposes I set this to 100 meters.

As for using the iPhone as a GPS tracker I think we’ll need to tweak, test, tweak, test and possibly wait for the next hardware version, which could possibly have an internal GPS receiver. Or maybe they’ll find a way to provide better accuracy using WiFi access points. There are a few other limiting factors that I’d like to point out:

- 3rd party applications developed for the iPhone cannot be run in the background
- When a user presses the home button on the iPhone the application is automatically terminated
- 3rd party applications cannot be automatically started when the iPhone boots

The reality is that each of the items mentioned above are essential for any successful GPS tracking application, but can be addressed in a future firmware update. That’s one of the beautiful things about the iPhone platform: a majority of limitations can be addressed in software. I’d also like to point out that all location readings that I’ve generated from the iPhone have been indoors. Because of using cellular and WiFi positioning technology the device doesn’t need a clear view of the sky. All in all, the iPhone SDK has tremendous possibilities and we’ll be working hard to tightly integrate it with the Ublip system.

If you’re interested in becoming a beta user of our iPhone application feel free to contact us our post a comment below. Also, if you have any suggestions on what type of location based applications you’d like to see on the iPhone then please feel free to share your thoughts.