Scanning the Airwaves

As I mentioned in one of my earlier posts , I work for TSA, the Transportation Security Administration , the federal agency charged with protecting the nations transportation systems. Today, I'm going to give you a little overview of the agency's two-way radio systems. Sensitive Security Information Before I begin though, I must go over Sensitive Security Information or SSI . SSI is a designation used by TSA which is coded in federal regulation that states that SSI "is information that, if publicly released, would be detrimental to transportation security." SSI is essentially sensitive but unclassified information. As I work for TSA, I am automatically a "covered person" who is required to protect such information. Therefore, I am limited in what I can I use and say on anything that is considered SSI. However, most of the sources I'm using for this blog post are publicly available third-party sources which are not SSI or if it is a TSA source...

In February of this year, using a leftover Lenovo ThinkCentre M73 Tiny, that was original intended to be used a home theater PC, I made a "scanner" using it and 3 RTL-SDR USB dongles. All thanks to Luke Berndt's Trunk Recorder project . Trunk Recorder Trunk Recorder is open source software written by Luke, that using various SDRs such as the HackRF, RTL-SDR-based USB dongles and Ettus USRPs among others, allows the capture and recording of Project 25 (P25) and Motorola SmartNet trunked radio systems plus conventional systems that are P25 or analog too. It runs on Linux, macOS and even on a Raspberry Pi (although it's recommended to be a Pi 3 because the rest probably won't be able to keep up). You can either build it yourself from the source code or use Docker like I did to get it up and running. After configuring a JSON file that sets all the parameters for the instance you plan on running, a CSV file that defines the talkgroups you want to record, you...