Hello,
I've taken Marcus's suggestion to use the integration block to average samples taken with my loop antenna, and that is working extremely well for my purposes! However, I do have a question about something I don't quite understand - I'm hoping someone can point me in the right direction.
I've attached the flowgraph I'm using to this email. My sampling rate is set to 614400 samp/s, and input from the source is run through a "Stream-to-Vector" block and a 2048 point FFT block. I then take the power of the output from the FFT block, and pass that on to an Integrate block, with decimation set to 18000.
So, my question is this. I took data for about hour with this setup, and then mapped the resulting file to a numpy array. I took the len() of an element of that array, and it was 2048, as expected. However, the length of the whole array was 111 (i.e. there were 111 vectors of 2048, or 227328 samples total), and I was expecting it to be 60 based on my calculations.
Here is how I got the value 60: I multiplied 3600*614400=2211840000 to get the total number of samples I would expect to collect in an hour without decimation. Then, I divided this by 2048 to get the number of vectors produced in an hour (1080000). Since decimation is set to 18000, I divided 1080000 by 18000 to determine how many vectors would result from the integration block, which turned out to be 60. But this is obviously wrong - it's only about half of the actual number of vectors saved to the file. I'm sure I'm probably making some kind of silly error with my math or reasoning, so I would really appreciate hearing anyone's input on this.
Thanks in advance!
Ellie
rtl-sdr.grc