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Topic: Has anyone ever tried to build own GPS-System? (Read 6 times) previous topic - next topic

-horn-

Hi,

has anyone of you ever tried to build an own positioning system like gps with arduino? I would like to know whether or not arduino is fast enogh for doing such things.

I would like to build some kind of reverse gps, where a small beacon is sending a time-stamp signal and 4 stations will receive that signal and where you can triangulate the position of the beacon, because you know the exact position and reception time of the receiver-antennas.
but because the signal is travaling sat such high speeds the resolution of the receiver hardware has to be very high and thus the frequency/tackting of the analog-to-digital-converter.

do you think such a project can be done with arduino? because at the end, I want to have receiving antennas ata distance of 10m and the beacon should be detectable in between with a decent resolution in between.

best regards,

Andreas

CrossRoads

Are the receivers all talking to each other to indicate what time they got a common signal?
They need to be in sync with a common time source also.

How far is the signal, transmitted at 299,792,458 metres per second, 186,282 miles/Sec,
going to travel in the arduino's 62.5nS per clock cycle?
18.73m.
Say you just recorded the time a simple pulse occured - how accurately can you tell when that pulse occurred?
Every clock pulse that your time is off increases the circle of error in your triangulation calculation.

So in my mind you need a few things to test this out:

- transmitter
- min 3 receivers, all able to communicate with each other, and spaced far enough apart to have a meanigful result that won't envelop your receivers.
- software to take in the data and do the math.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

-horn-

#2
Oct 17, 2011, 06:33 am Last Edit: Oct 17, 2011, 07:09 am by -horn- Reason: 1
Hi,

Time synching of the receiver stations do I want to do with gps time itself or with the radio signal for radio controlled clocks. Both need the antennas as well but the sender still doesn't need more then a clock and radio.

I just wanted to know how accurate arduino and a shield can be with this task and a minimum distance of 18m sounds allmost okay but should be better.

Processing of the data of all 4 receiver stations can be done with the math that you can find in the gps article in wikipedia. Realtime processing would be nice but when the single arduinos at the receiver antenna will strore the data for later processing, that is fine. I just want to track the beacon.

Andreas

CrossRoads

I would think you'd want all devices used to be sync'ed to the same time source.
I am thinking like phase-lock-loop synced, so when they get the 1Hz GPS time pulse they are all dead-on.
If the receivers are 1 or 2 clock pulses different, then you kiss your accuracy goodbye.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

-horn-


I would think you'd want all devices used to be sync'ed to the same time source.
I am thinking like phase-lock-loop synced, so when they get the 1Hz GPS time pulse they are all dead-on.
If the receivers are 1 or 2 clock pulses different, then you kiss your accuracy goodbye.


hi,

the linking of 4 antennas, that will be deployed at distances where I can't connect them via cable or even radio will be dificult at the end.
so the time-synching via gps-time will be one of the few ways left.
and a 1hz time pulse isn't that much, but perhaps interpolation in betwwen 2 of them will solve that.

Andreas

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