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DC9ST / tdoa-evaluation-rtlsdr

Matlab Scripts for Evaluation of a TDOA System based on RTL-SDRs
http://www.panoradio-sdr.de/tdoa-transmitter-localization-with-rtl-sdrs/
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No reference TX #2

Open pietrotedeschi opened 2 years ago

pietrotedeschi commented 2 years ago

What happens if you do not have a Reference TX like the Rotenberg DAB (i.e. tx_ref_lat = tx_ref_long = NULL)? For example, we can assume that each RX is provided with a GPSDO oscillator without assume a reference like this.

JonathanAppriou commented 2 years ago

Hello @pietrotedeschi , did you find a solution for this ?

In the context of the TDOA, what is the purpose of a TX reference? Don't we just need three RX like RTL-SDR or HackRF ?

RFHunterSeeker commented 2 years ago

I might be going out to left field on this and please correct me if I’m wrong. There are two reasons for the TX reference that I can think of. One being for frequency accuracy for making sure that the frequencies your SDR receive are accurate as well. To reduce the possibility of multiple SDR’s looking at different frequencies. The second reason I believe the purpose of the TX reference is for accuracy of plotting receive frequency’s location. This would help in tuning or dialing in your SDR’s for each specific SDR’s characteristics. IE: antenna gain, antenna type, line loss, connector loss and so-forth. So, as in an exaggeration, that when you use two, three or more SDR’s you don’t have a location inaccuracy of half a mile.

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Hello @pietrotedeschihttps://github.com/pietrotedeschi , did you find a solution for this ?

In the context of the TDOA, what is the purpose of a TX reference? Don't we just need three RX like RTL-SDR or HackRF ?

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DC9ST commented 1 year ago

The signal from the reference TX is used to synchronize the receivers in time, which is a requirement for TDOA localization. All three receivers get the same signal from the reference TX and so can align their receptions of the measurement signal. In the current version of the code you need a reference TX otherwise localization is not possible.