Hi Alexis,
You should check out the gr page on metadata [1]. In your flow graph, use a file meta sink. That should write the metadata, including time stamps, to disk. It's not great at high sample rates, though. I maintain gr-analysis [2], which has a program called
specrec, which can handle higher sample rates. To view the time stamps, you can use a file meta source, which will pull out the metadata as tags. Many plotting widgets will show tags. Additionally, there are some command line tools such as gr_read_file_metadata
to display the metadata. Gr-analysis also has read_file_metadata which I think had a better output.
Hope this helps.
Hello!
I am very new to GNU Radio and I have been trying to figuring out how to create a “timestamp” on a incoming signal. I am trying to capture a signal using an Ettus N210 as the USRP source and display it in real time on frequency and waterfall sinks, while also
writing it to a file sink. Later, I would like to be able to “replay” the saved file, but I would like to know the time (preferably in UTC) that the signal was observed. This is important because I need to match up changes in the signal to other events that
might have happened. If possible, I would also like to be able to display the (UTC) time from the file on the GUI somehow.
I’ve mostly been using GNU Radio Companion, but I’ve also tried using Python.
I’ve looked into stream tags and using the Tagged file sink block , but I don’t understand what to use as the key, or how to extract the tag value during the replay. I feel like this should be a simple task, but I’ve looked everywhere for an answer so maybe
there is something else I don’t understand. Thank you in advanced.
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