Comment The inventor's 2 cents worth (Score 5, Informative) 336
Dear All,
Wow! Thank you very much for all your comments on this mobile phone navigation system. I thought I'd throw in my 2 cents worth since I'm one of the people who invented it! Forgive the lack of structure in what follows, but I'm trying to address several different issues raised throughout this discussion...
Yes, another way of doing this is radio signal triangulation (including GPS). But actually, this method doesn't work too well in cities because of things like multipath effects and satellite visibility (BTW our system isn't designed to work outside urban environments). GPS car navigation systems rely on a combination of GPS and inertial sensors, i.e. they take a sort of average of a large number of inaccurate readings to get a good fix on position. But the simpler positioning strategies are unlikely to give good enough acccuracy to establish on which side of the street you are standing (and in any case, they don't tell you whhat direction you're looking in). GPS is also expensive: most people would not be prepared to pay more for a phone with an in-built GPS receiver - but camera phones are already selling well.
No, we're not going to build a database of every building in the world! But a good place to start would be large city centres. FYI what motivated us to invent this system was the familiar problem of getting lost outside London tube stations. Obviously I know which tube station I'm at but I don't usually know which exit I took or what direction I'm facing. Of course I can retrieve a local map via my mobile phone. But the problem is I'm missing that critical "you are here" dot that tells me where to start. This is where our system comes in: by providing the dot (well, an arrow actually because it tells you which direction you're looking in too).
In practice, builing a database is easier than you might think. Probably we could do it with nothing more than a video camera attached to a car. Granted someone will have to drive down the streets of interest but only once (and this shouldn't be too difficult in somewhere like New York).
Finally, no, movable objects don't cause too many problems. The system uses a feature based strategy that is robust to 'clutter' in the form of things like cars, pedestrians, changing shop window displays, etc. That being said, there will always be ways of confusing it, e.g. by demolishing a building. But supposing that picture messages will one day cost as little as text messages do now, a system that works almost instantaneously and gets it right 99% of the time sounds as if it might have some commercial potential at least. And what if the hypothetical tourist isn't lost but just interested? For example, the system could return information about the history of any building of interest in the middle of Venice.
Yours,
Duncan Robertson
Wow! Thank you very much for all your comments on this mobile phone navigation system. I thought I'd throw in my 2 cents worth since I'm one of the people who invented it! Forgive the lack of structure in what follows, but I'm trying to address several different issues raised throughout this discussion...
Yes, another way of doing this is radio signal triangulation (including GPS). But actually, this method doesn't work too well in cities because of things like multipath effects and satellite visibility (BTW our system isn't designed to work outside urban environments). GPS car navigation systems rely on a combination of GPS and inertial sensors, i.e. they take a sort of average of a large number of inaccurate readings to get a good fix on position. But the simpler positioning strategies are unlikely to give good enough acccuracy to establish on which side of the street you are standing (and in any case, they don't tell you whhat direction you're looking in). GPS is also expensive: most people would not be prepared to pay more for a phone with an in-built GPS receiver - but camera phones are already selling well.
No, we're not going to build a database of every building in the world! But a good place to start would be large city centres. FYI what motivated us to invent this system was the familiar problem of getting lost outside London tube stations. Obviously I know which tube station I'm at but I don't usually know which exit I took or what direction I'm facing. Of course I can retrieve a local map via my mobile phone. But the problem is I'm missing that critical "you are here" dot that tells me where to start. This is where our system comes in: by providing the dot (well, an arrow actually because it tells you which direction you're looking in too).
In practice, builing a database is easier than you might think. Probably we could do it with nothing more than a video camera attached to a car. Granted someone will have to drive down the streets of interest but only once (and this shouldn't be too difficult in somewhere like New York).
Finally, no, movable objects don't cause too many problems. The system uses a feature based strategy that is robust to 'clutter' in the form of things like cars, pedestrians, changing shop window displays, etc. That being said, there will always be ways of confusing it, e.g. by demolishing a building. But supposing that picture messages will one day cost as little as text messages do now, a system that works almost instantaneously and gets it right 99% of the time sounds as if it might have some commercial potential at least. And what if the hypothetical tourist isn't lost but just interested? For example, the system could return information about the history of any building of interest in the middle of Venice.
Yours,
Duncan Robertson
