Questions about digital signal processing, whether of RF, audio, or digital signals. For RF, consider [software-defined-radio].
Use this tag when the topic includes Digital Signal Processing. This can be either RF signals or audio signals, or perhaps post-processing like decoding of protocols.
software-defined-radio is a perfect example of DSP-based radio. Similarly, recording of signals for later processing (like manipulating satellite imagery to assign false colors and the like) could be considered to fall under this category.