# Batch sampling SDR

I am using RTLSDR on macOS with Cubic SDR, it works great and is very intuitive.

Now I want to do a frequency envelope analysis where I need to basically 3-d plot intensity versus frequency and time. I can probably figure out the math to do that part (or get help). But I need data.

The data I need is 1-second samples across the entire frequency range. What tools are available for loop over the frequency range and save the samples for each band?

• What do you mean "entire frequency range"? The range of the rtl-sdr bandwidth setting (240kHz to 2.4MHz)? Or the frequency range of the tuner (25 MHz to 1.6 GHz)? – hotpaw2 Oct 11 '19 at 19:02
• That sounds very much like what SETI@home did when I first started running it -- they had special hardware to sample a very broad frequency range. – Zeiss Ikon Oct 11 '19 at 19:17
• The entire tuner range. – William Entriken Oct 15 '19 at 19:15

If you want to cover the entire tunable frequency range, you cannot do this all at once — the hardware is not capable of that. Instead, you must tune, take some data, and repeat, stepping across the range. Conveniently, there is already a tool which will do this for you in the rtl_sdr driver package — it is called rtl_power. It will output a CSV file with the data already arranged in columns by frequency and rows by time.
• Thank you! So basically: rtl_sdr -f FREQ -s 2048000 -n 2048000 FREQ.bin – William Entriken Oct 15 '19 at 19:18