2019-01-22, 03:29 AM
(2019-01-22, 12:54 AM)seandepagnier Wrote: Are you detecting radar from other vessels? What frequencies are you using? Why would 4 inputs help? Couldn't you use multiple rtlsdr dongles instead?
No you are using a known large radio source as a reference point. TV or Radio station. With a semi directional or directional antenna pointed at the station. You are using another antenna to listen for the same fm station but from a reflection slightly later than the first known reference signal. The dongles need to be altered so they are all using the same clock timing. Not individual clock timings to accurately measure the Delay. You need at least 2 inputs but I was thinking with 4 you would have better coverage and a better idea of the exact direction of the target as you would have different reflection rates. My other thought was writing a quick scan every 30 seconds of the reference signal strength to change the reference antenna on the fly Incase you changed course and a different antenna should now be the reference antenna.
Hope that makes sense.
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