The Toolkit
Software Defined Radio
Software-defined radio moves the radio into software. Instead of a fixed-purpose receiver, you use a general SDR dongle to capture raw radio across a wide range of frequencies, and let programs on your computer decode whatever’s there — aircraft transponders, weather sensors, pagers, IoT devices, trunked radio, satellites. For security work it opens up a whole layer most tools never touch: the wireless protocols that aren’t Wi-Fi.
This is the largest category in the toolkit because SDR is a stack. At the bottom are the hardware drivers and utilities for the common dongles (RTL-SDR, HackRF, Airspy, LimeSDR) and the SoapySDR layer that abstracts across them. Above those sit the general-purpose receivers and analyzers — waterfalls, spectrum tools, and the visual environments where you actually explore a signal. Then the decoders that turn a captured signal into data.
You need a compatible SDR device plugged in for any of this to do something; the cheap RTL-SDR dongle is the usual starting point.
Hardware drivers & utilities
| Tool | Source | Device |
|---|---|---|
| rtl-sdr | official | The ubiquitous RTL2832U dongles — the entry point to SDR. |
| hackrf | official | HackRF One — transmit-capable, wide range. |
| airspy | official | Airspy receivers — higher performance than RTL. |
| limesuite | official | LimeSDR — full-duplex, transmit-capable. |
| soapysdr | official | A vendor-neutral layer so tools work across all of the above. |
Receivers, analyzers & environments
| Tool | Source | What it’s for |
|---|---|---|
| gqrx | official | Graphical receiver with a live waterfall. |
| cubicsdr | AUR | Cross-platform SDR receiver. |
| sdrangel | AUR | A full-featured multi-mode SDR workstation. |
| gnuradio | official | The signal-processing toolkit and flowgraph environment. |
| inspectrum | official | Offline analysis of captured signal files. |
| urh | official | Universal Radio Hacker — reverse-engineer unknown protocols. |
| qspectrumanalyzer | official | A spectrum-analyzer GUI over various backends. |
Decoders
| Tool | Source | What it decodes |
|---|---|---|
| rtl_433 | official | 433/868/915 MHz IoT and sensor devices. |
| multimon-ng | official | Pagers (POCSAG), AIS, and other digital modes. |
| dump1090 | AUR | Aircraft ADS-B transponders. |
| supersdr | AUR | A client for networked KiwiSDR receivers. |
All live under Security → Software Defined Radio. The Webapps category adds KiwiSDR’s public-receiver directory and the SIGIDWiki signal-identification guide.