Automatic Heatmap Logging on a Raspberry Pi using an RTL-SDR and RTL_POWER

Amateur radio hobbyist DE8MSH recently wrote in to let us know about a project he has been working on. His project involves using a Raspberry Pi B and RTL-SDR to automatically log a wide band heatmap using rtl_power. Rtl_power is a command line tool that will log signal strengths to a csv file using the RTL-SDR over a very large definable bandwidth.

To do the automatic logging the Raspberry Pi runs rtl_power for 23 hours constantly writing data to a mounted hard drive. After 23 hours the heatmap image is calculated and then uploaded to a webpage at The scheduling is performed by a cron job.

DE8MSH has also been working on a second related project over at The heatmap on this page shows various transmissions from weather balloons. As you mouse over those transmissions, the QTH (location) of those weather balloon transmissions is shown as well as the frequency and time of where the mouse pointer currently is.

Raspberry Pi Automatic Heatmap Logging with rtl_power
Raspberry Pi Automatic Heatmap Logging with rtl_power


  1. Joe

    I’m a DB pro and I like contributing to open source project by upgrading their CSV logging to proper database logging. If the data set is really large and needs to be stored over a period of time, let me know. Putting it into db tables would be much more optimal.

  2. Mario

    really cool project! I cannot connect my RPI to the web cause of my provider limitations, but if you are interested, I’ve been experimenting with 3D viz of rtl_power recorded data using python processing and gnuplot. In March I posted some output on Google+ here

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