Most people are going to lose their cell phone somewhere inside. Indoor location requests have long proven difficult for GPS trackers. The problem arises from the weakness of the GPS signals emitted by the satellites in orbit above us and the interference that roofs and walls create. Cell phones often perform better since they can get information from cell towers in addition to GPS signals, making them, generally speaking, more accurate than standalone GPS devices. What you will find below is how Plan B faired in locating our phone in a series of indoor locales.
As we mentioned above, a red dot indicates our best guess of exactly where we were when activating the app. All distances between Plan B coordinates, which are indicated by the green arrows, and my estimates using Google Maps were calculated using this coordinate distance calculator)
The results for testing inside a home or apartment were very interesting. Instead of providing a coordinate that was closer to the actual location of the phone it actually provided worse results as the position because more “refined.” We started the home test at 9:41 PM and received location emails at 9:41 PM, 9:41 PM again, 9:44 PM, and 9:47 PM for a total of 4 locations. We only included locations 1, 2, and three since location 3 and 4 were only 5 feet apart and represented the least accurate coordinates for our phone. According to the emails the 4 tracking coordinates were 32 m (105 ft), 48 m (157.5 ft), 6 m (19.67 ft), and 6 m (19.67 ft) away respectively. Our estimate had each of the locations the following distances away: 15 m ( 49 ft), 12 m (40 ft), 18 m (59 ft), and 16 m (54 ft). As you can see the 2 location was to closest.
Key Takeaway: The last result is not always going to be the most accurate. I would liked to have seen a little bit better results with this since it could be difficult to tell where the phone is if it is in a home and has been stolen. Google Maps did give me the correct address for all the tests, so that is a plus but can’t be relied upon as your only information on the location of the phone.
Time App Started: 9:41 PM
Time to First Result: 9:41 PM
Most accurate result: Within 40 feet
The next test was we did was on the bottom level of a three story building. We chose to place the phone closer to the interior of the building to be away from any windows that might help the phone get a decent fix on its location. Under these conditions is was difficult for the phone to know exactly where it was. We only received one location email shortly after the app was downloaded, right at 3:23 PM. The email gave us a approximate distance of 96 m (315 ft), but the location generated by the phone was closer than that. According to our approximations, the location given by Plan B and our phone was only 13.4 m (44 ft) away.
Key Takeaway: This app had decent results at the bottom of an multistory building. It wasn’t able to know exactly where it was, but the location it provided was enough to give you a good idea of where the phone was if you left it somewhere accidentally, just not if you needed a pinpoint location because the phone was stolen.
Time App Started: 3:23 PM
Time to First Result: 3:23 PM
Most accurate result: Within 45 ft
We found it difficult to make it downtown during the initial round of testing for the Plan B app. We plan on getting out there sometime soon.
This cell phone recovery app did a good job at finding where our phone was “lost”. The phone was located in the glove compartment of a Honda Odyssey parked in the space indicated above. We received an email from Plan B telling us that the app was downloaded at 3:48 PM and then received 3 different position updates. The first claimed an accuracy of 24 m (79 ft), then 12 m (39 ft), and then 4 m (13 ft). According to our calculations the measurements were off by 32 m (106 ft), 31 m (102 ft), and 12 m (41 ft). Since the first tracking locations were so close together I only included one in the results pictured above. We received the final, most accurate location at 3:50 PM, just 2 minutes after the phone downloaded the app.
Key Takeaway: If you misplaced your mobile in a car then you can have a reasonable expectation that Plan B going to be able to help you find your phone. It got to within 41 ft, or about 6 spaces, away from my lost phone.
Time App Started: 3:48 PM
Time to First Result: 3:48 PM
Most accurate result: Around 40 ft
We had really mixed results with Plan B when trying to find our location inside this Walmart. As you can tell from the picture, we activated the app inside the store. After entering the doors I walked all the way down the aisle immediately in front of the entrance until I got to the end of that aisle. After activating the app and receiving the confirmation email from Plan B at 2:36 PM I just waited to get a location email. I continued to wait for several more minutes, but still no email arrived from this GPS tracking app. Finally, I despaired of the app working and proceeded to check out at the front of the store – my receipt shows a checkout time of 2:45:15 PM. It was only after checking out that I received the two emails from the app, both at 2:46 PM. I will give my phone (and Plan B, but mostly my phone) the benefit of the doubt and say that it found my position at the front of the store before I actually got outside but it looks like it didn’t find me until I was outside.
Key Takeaway: If you loose your phone somewhere in a grocery store you should hope that an employee finds the phone and turns it into the customer service center, which is usually in the front of a store. If it fell low and got kicked under the aisle you are probably out of luck.
Time App Started: 2:36 PM
Time to First Result: 2:46 PM
Results: GPS tracking didn’t kick in until the phone was at the front of the store