We were recently looking at an application called “Private-I” for the iPhone: it’s designed to look interesting to someone who’s stolen (or found) the phone. When they open the application, it cunningly says it’s “loading” things; but what it’s really doing is transmitting its GPS coordinates to a preconfigured email address. As the inquisitive thief waits in vain for the thing to load, the GPS fix gets better and better, so additional emails are sent, pinpointing the phone so you* can retrieve it.

It’s cute but in most cases it’s somewhat irrelevant because the amateur thief is not going to get through the access control system unless they get lucky (be it a PIN, a password, a biometric lock, or whatever). It makes sense therefore to dispense with the subterfuge of the cute application and just link the access control system of the device with a system for transmitting GPS coordinates.

i.e.

• Each time the correct pin is entered, the phone unlocks.
• Each time an incorrect pin is entered, the phone transmits its location.

This simple change won’t stop a professional thief (they can still break the device up for parts, or reset it to factory defaults), but anyone who finds a phone that’s been dropped or accidentally left somewhere will have a strong deterrent against trying to use it … what’s more all the police have to do is switch it on when it’s kindly handed in and the owner will know where to collect it.

1. Firstly, we, the collective public of mobile phone users, have coped without such a pop-up on all previous mobile phones, we’re happy with a little icon telling us how much signal we have, so it’s cute, but redundant.
2. Secondly the iPhone is a computer – its so much more than a phone, so a pop up message indicating network loss interrupts other applications and thus gets in the way.

A good example is in the car when using InstaMapper‘s GPS Tracker.   Once interrupted, the tracker is no longer the foreground application, so it can no longer stop the phone from sleeping: consequently the screen goes off, and position and speed can’t be read without turning the screen back on and unlocking the phone – not something to be doing whilst driving.

There has to be some way of disabling this that I’m missing; or it needs to be an option in the next OS release!

The camera is already set-up so that whenever it’s in range of my computer the photos are automatically uploaded, stored for posterity and (most importantly) available to be viewed and enjoyed. What’s more, the software we use for managing our ever increasing pile of digital memorabilia (Picasa) already includes a tool for adding geo-tags to photos after they’ve been taken. They can then be viewed within Google Earth or Google Maps: so almost unsurprisingly, when I got home after work the other day, the photos I’d taken appeared dotted around Google Earth without me having to do a thing.

Geo-tagging is a wonderful thing; but it’s not yet photography nirvana – there are several issues that still need to be tackled:

Battery

GPS units eat battery, so regular use of geo-tagging is not particularly useful if you’re not able to charge your camera several times per day. One strategy is to keep the GPS circuitry switched off until it’s needed, however, it can take several minutes to get a GPS fix, which is useless for photos that capture the moment. In these circumstances the software I’ve been using appears to retrospectively tag photos as soon as a fix is obtained (which may be several minutes and some distance later).

GPS Accuracy

GPS accuracy in urban areas tends to be haphazard because tall buildings with solid flat walls bounce the satellite signal around before it reaches the phone. Unlike automobile GPS units, it’s not feasible to use a roadmap to correct for such anomalies and predict where the unit might really be when signal is poor.

An approximate tag is still infinitely better than no tag at all, but it’s far from perfect. I took a few photos whilst walking between Waterloo and the City of London the other day, which serve as a good example – the pictures appear clustered around certain spots rather than being spread out along the riverside.

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Enriched GPS Detail

Recording latitude and longitude is a natural starting point, but there’s other information that would be similarly useful. Several of the photos in the example set were taken fourteen floors up a building, so altitude information would also be good. What would be really cool however (and I’ve said this before) would be if some kind of compass and attitude sensor could be combined so that the camera direction could also be captured with the photo.

What originally gave me this idea was wandering around the fields of Glastonbury festival after we’d lost our disposable camera (whilst crowd-surfing – there’s a lesson there). We were rather gutted that we’d lost our pictures and I found myself thinking that even though we’d lost our pictures, we’d certainly be in lots of other peoples photos. So to get a photographic record of our time at the festival we’d just have to solve the problem of (a) sharing the photos and (b) making the photo search tractable. If there were 50,000 cameras used during the weekend and each of took 20 photos, there would be one million potential images that we may have wandered through so the search would be impossible. Surely GPS could help! If we had a GPS trail log of where we’d been, and if every camera position and direction could be recorded, then the intersection of those two data sets would predict which photos we might feature in. Comparing GPS trails alone is not enough in heavily populated events, it’s necessary to know not just if you are near the camera at the time the photo is taken, but also if the camera is pointing at you. For example, person b, is nearer the camera in the diagram, but person a is in the image. It’s still a pipe-dream until someone comes up with a camera that can record pitch, roll and yaw against polar coordinates, but when that’s possible it’ll open up some really interesting new query possibilities!

There’s a happily-ever-after for this tale too. We returned to the pyramid stage after the crowds were gone and scoured the floor, eventually finding the camera trodden into the mud, just inside the security fence in front of the stage (we were able to identify it because we’d written our postcode on it), so we got out photos back!

Some commuters always catch the same train, at the same time, so a time based alarm might do the job, but for anyone with more flexible train usage, and for the times when the train is running late, or cancelled, a simple alarm clock doesn’t cut the mustard. So how about an alarm system that you could configure to go off every time you come within a set distance of a specific point? I’m sure it’s something my GPS phone could no doubt do quite successfully, and it would solve the problem of arriving at the same train station at different times.

A proximity alarm is not the kind of application you could leave running on the phone and just forget, because it would fire every time you got near the station. If you happen to live near the station the alarm would be going off at all times. This could be solved if the alarm were based on a series of way-points. i.e. If you pass near points a, b and c in sequence then the alarm should trigger. This solves the problem of the alarm going off when it’s not necessary. The main problem is that the application still cannot be left running and forgotten because of the battery usage – the Nokia N95 for example, has a good battery and during normal phone usage it lasts well, but the circuitry that does the GPS appears to have a far more significant draw on power than the rest of the device, killing the phone in a matter of hours.

There is, however, a suitable alternative to GPS. Rather than base the alarm on GPS locations, it can be based on cellphone mast IDs. As the commuter moves through the country, the phone detects, and negotiates with different telephone masts. If the alarm system were to be configured to work with masts, then it could work quite successfully without the need for any GPS circuitry to be used.

It’s certainly a less accurate positioning solution than GPS, so the multi-stage trigger for the alarm would be a necessity, but this could be a fairly low-power service because the application would merely have to be woken up whenever a new cell is discovered by the phone, checked for relevance (i.e. does this new cell match an alarm? are any alarms satisfied for triggering?). It’s still not perfect though. What’s needed is a minimal battery solution for that we need to remove the application altogether.

The perfect solution, would remove the need for the phone based application altogether. If the phone company could monitor the phone as it travels between cells, and send an SMS to the phone when the the trigger criteria are met. This solution would work for all phones, even old ones which can’t have applications added to them. No commuter need ever miss their stop again.