On Saturday 02 September 2006 01:16 pm, Rony wrote: > > Lets do it from the bottom first. We are getting into very high > precision navigation apparatus, something which may not be > necessary for local use in a locality. Lets start with simple > directional TX RX systems. They will give the direction and area > information on the basis of where the user is standing. you can get area information - "u are at Century bazar" left, right, front and back is relative to YOUR postion, orientation and distancefrom the beacon - something which u are trying to find out with your gadget. To do so u need a time stamped signal from threebeacons. You could be standing 2 mtr to the left of the beacon and facing north and sombody could be .5 mtr from the beacon facing south. The system has to resolve these distances. Remember u have no visual clue.
> The need > for the RF system would be limited to helping the user make a > choice of direction and its destination. The guide railings and > audio beeps at traffic signals will provide the `last meter' > connectivity. If u have guide railings and the user walks up to that point all problems are resolved. U have location, orientation and distance. The beacon can transmit proper info at the additional cost of having several rails and beacons -eg 7 at prabhadevi signal. Also now they cannot be used at a distance. > > I was also wondering about the use of optical Tx and Rx devices impractical. Try waving a remote in front of the tv and see. -- Rgds JTD -- http://mm.glug-bom.org/mailman/listinfo/linuxers
