Also the fixed stations can not have OCXO? On Fri, Feb 1, 2013 at 5:37 AM, Rick Harold <rickhar...@gmail.com> wrote:
> To time experts/EE's. > > I would like to triangulate a position of a device which moves using 3 > fixed positions devices of known location. > The idea is to have these operate on 915mhz or 434mhz or 2.4ghz or > appropriate frequency. > These two type of devices (fixed and mobile) are all under my control and > thus customized as needed. > > The mobile device (not a phone, custom device) would be the least expensive > item. I'd like a range of 150 feet or better and accuracy of 3 feet or > better. > When manufactured these items they can be calibrated in order to adjust for > any variation in IC's, discrete components etc... > We can assume for now the temperature is constant 70 degree temperature. > Cost is the key design factor. > > The general flow is: > > 1. base station 1 indicates we are determining position of device A. > 2. Each base station 1, 2, 3 take turns pinging the device to determine > distance. > 3. A ping consists of (something like, e.g. frequencies as examples) > -send 915mhz signal from base station to device > -device response ASAP on different frequency > -station waits and counts 'time' for return > -this is repeated N? times to get best avg/accuracy. > -The mobile device does not move very fast > 4. Since delays of the process on each unit is calibrated the device and > base station would subtrack that time out from the results. > 5. obviously with 3 distances we can determine the 2D position of the > mobile device > > I know the time accuracy is the key to count time = feet, 1ns. This > overall project is not new concept. How to make it "inexpensive" is key. > how inexpensive, very ;-) no OCXO or expensive components like that. > > That's my goal, and I'm looking for help on the design/thought process of > getting there. > I am open to a consulting arrangement for a fee, please email if you like. > I've worked with 'regular' EE's (I'm a software guy) but this time > accuracy is too much for them. > Esp. finding a way to do it inexpensively. > > Thanks for any thoughts. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.