Tracking using RTL-SDR

One of the more exciting add-ons to our BBB satellite and object tracking recipes is an extremely low-cost USB dongle called RTL-SDR. RTL is short for Realtek RTL2832U controller and tuner chipset, which is inside this dongle and can be purchased for around USD $20.00.

Besides being cheap, the best part of the story is SDR, which stands for Software Defined Radio. SDR is kind of what it sounds similar to: instead of using hardware components, such as amps, mixers, filters, and modulators, it is radio with its key functions driven by software.

SDR can receive signals over a very wide band of frequencies (for example, from 50 to 2500 MHz) without actually requiring specialized hardware. Using various software modules, SDR also performs different radio protocols. The result is that this software—in conjunction with an RTL dongle—now replaces what used to be a wide variety of specialized radio components.

For radio enthusiasts (including old school ham radio operators) and...