Hi all,
I’m now using USRP N200 with LFRX daughterboard.
I’m trying to detect radio signals produced by lightning discharges.
When
lightning does not occur, the system just detect the signal but does not
record data. When lightning happens, it triggers the system and the
system
starts to write data into a file.
Each triggered record comprises pre-trigger part and post-trigger part.
For
example, if lightning triggers the system at time 0, the triggered
record
should starts from time -100 ms to 900 ms. In other word, the system has
to
record some part of data before the trigger point.
I’m now using GNURadio to construct the software, but I’m really new to
it.
I’ve been working on it for two weeks. I’m now using vector_sink_x to
store
signal of each second, find the maximum of the vector and compare it
with
the trigger point, and if the maximum value is larger than the trigger
point, use file_sink to record the data. However, this process seems to
be
slow.
One of my colleagues told me that usually such system provides
pre-defined
function for recording triggered signal, and the function can control
pre-trigger time. But so far I have not found any related function or
module. Does anyone know what function or module may be useful, or any
example that may be similar, or any idea for recording triggered data?
Thanks in advance.
Wu