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Time of arrival of signal

 Hi All,


I am trying to measure the Time of Arrival of a radio signal (CW) or the time I saw the signal on my graph. I will compare signal from different sources to see the dalay in arrival of the same signal from different sources. I wish to measure in Nanoseconds.


I will basically connect my DAQ to a radio to receiver this satellite signal.


Can anyone advice how I can measure the Time of arrival of the singal? Which module can I use. Labview has example modules. Which one fits my project?

Please Help!!


Thank You

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If you read a Waveform from the DAQmx Read function, part of the waveform data typ is "T0" which is the timestamp of the first element in the waveform.  Also in the waveform is "dt" which is the time for each sample.  Based on those two, you can easily determine the time of a given sample.  It is just a matter of figuring out which sample is the start of your signal.  Usually a simple threshold check would work.

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Great thanks for the comment.

But now the configuration has changed. I am not using DAQ.
I have an Software Defined Radio ( HACKRF) and a GPS clock for Timing signal pulses and synchronization. I am thinking of connecting these two directly by USB to labView ( VI/VISA). Is this possible? If it is then I can see two signals on LabView which are GPS clock pulses and the Radio signal from the Software Defined Radio. Now I am going to receive a single pulse ( CW) with the radio and I want to measure the time accuracy in Nanoseconds of arrival of this signal.
I am guessing I can judge this arrival time using the GPS clock signals.
If not what other way can I do it?
I am new to LabView but I can see some example projects on the Help. Which one can I use for this. I am guessing a correlation program.

Please Advice
Please Help.
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