3 ms·
The only advantage GPS would have is that you don't have to install something (eg, a powered RFID tag) in each station. And yet, they've had to install "GPS rep
by TillE 12y ago
The only advantage GPS would have is that you don't have to install something (eg, a powered RFID tag) in each station. And yet, they've had to install "GPS repeater beacons" to work around this problem. Sounds like a typical case of bad design.
- mikeash 12y agoSomebody decided that GPS was a good idea here, and didn't think about problems underground. Silly, but understandable. Somebody else decided that having doors controlled by location was a good idea here, and didn't think somebody would specify a system that doesn't work at some stations. At some point during procurement and installation of the equipment you'd think somebody would have raised a red flag. Unless, of course, they were simply told to install GPS equipment, and not why. Or they were told why but nobody listened to them when they explained why it wouldn't work right. Sounds to me more like bad organization than bad design, although of course it's hard to tell from this distance.
- tjoff 12y agoThe GPS solution should have been shot down on sight - regardless of where in the process it was made up. The only sensible reason for this is that someone responsible had a friend that sold GPS-beacons.
- rcthompson 12y agoI don't think the choice of GPS for a train system is understandable at all.
- kalleboo 12y agoThe buses where I'm from started using the odometer to show the next station on a digital sign some time in the 90's. This ought to work even more accurately on a train.
- mike_hearn 12y agoOnly on underground stations. Possibly most of the stations this class of train stops at are above ground, and it made sense there to avoid big station upgrade works. Just one little GPS receiver on the train instead. You can see how it could happen.
- amelius 12y agoRFID tags don't necessarily need power. And they can be quite cheap.