The information security community has long suffered from a lack of effective and affordable tools and techniques for locating radio devices. Many methods are available, but most of them require multiple radio receivers and/or physical motion of one or more antennas. Pseudo-doppler is an old technique that implements Direction Finding (DF) by rapidly switching between multiple fixed antennas connected to a single radio receiver.
We have taken a modern approach to the implementation of pseudo-doppler DF with Software Defined Radio (SDR). Our open source solution enables low cost DF of bursty, packet-based target systems using arbitrary digital modulations. Additionally we will discuss our future work toward asymmetric pseudo-doppler approaches that eliminate the need for direction calibration and that can be used as a countermeasure against targets that attempt to spoof direction.
Michael Ossmann (@michaelossmann) is a wireless security researcher who makes hardware for hackers. Best known for the open source HackRF, Ubertooth, and GreatFET projects, he founded Great Scott Gadgets in an effort to put exciting, new tools into the hands of innovative people.
Schuyler St. Leger (@docprofsky) is a young maker in Arizona. He enjoys working with both hardware and software. His interests include 3D printing, electronics, hardware and software programming, Software Defined Dadio (SDR), robotics, computers, and more. He is always interested in how things work.