Finding interesting signals: heat maps and callsigns https://medium.com/@rxseger/finding-interesting-signals-heat-maps-and-callsigns-a269392a4168
Example Commands
rtl_power -f 144M:146M:100 -g 50 -i 1s -e 30m data.csv
Captures from 144MHz to 146Mhz in 100Hz intervals with a gain of 50, taking samples every 1 sec, for 30 minutes, and saving into the file "data.csv"
Parameters
-f lower:upper:bin (Hz)
Frequency range and the size of the bin
-i
Amount of time to integrate for each sample
-g
Gain for the sdr
-e
Amount of time to collect for
!rtl_power -f 95M:97M:100 -g 50 -i 1s -e 10m data.csv
Number of frequency hops: 1 Dongle bandwidth: 2000000Hz Downsampling by: 1x Cropping by: 0.00% Total FFT bins: 32768 Logged FFT bins: 32768 FFT bin size: 61.04Hz Buffer size: 65536 bytes (16.38ms) Reporting every 1 seconds Found 1 device(s): 0: Realtek, RTL2841UHIDIR, SN: 00000001 Using device 0: Generic RTL2832U OEM Found Rafael Micro R820T tuner Tuner gain set to 49.60 dB. Exact sample rate is: 2000000.052982 Hz [R82XX] PLL not locked! User cancel, exiting...
python script called "heatmap" by Kyle Keen. This converts the csv file into an image.
python heatmap.py <data_file.csv> <output_image.png>
!python heatmap.py data.csv image.png
loading x: 32766, y: 600, z: (-30.650000, 8.370000) drawing labeling saving
from IPython import display
display.Image("./image.png")