This page documents usage of the RTL Power tool. It is a command line only tool that generates .csv files with the power levels of each fft bin over time. This allows a large swatch of spectrum to be monitored. With a python script, a waterfall image can be generated.
rtl_power is included with the rtl-sdr drivers so no extra installation is needed.
rtl_power -f 144M:146M:100 -g 50 -i 1s -e 30m two_meter_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 "two_meter_data.csv"
-f lower:upper:bin (Hz)
Frequency range and the size of the bin
-i <integration interval>
Amount of time to integrate for each sample
-g <gain value>
Gain for the sdr
-e <exit timer>
Amount of time to collect for
I used a python script called "heatmap" by Kyle Keen. This converts the csv file into an image. To use, just download the python code from the github repo and have python installed. To call the program:
python heatmap.py <data_file.csv> <output_image.png>
The script can take a while to run sometimes and the files it generates can be fairly large.