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inspectrum

Offline visualiser for captured radio signals — read a waveform by eye

What it does

Opens a recorded IQ capture and displays it as a spectrogram you can zoom, measure and annotate, with cursors for reading off symbol rates and decoding simple modulation by hand.

Why you would want it

It is how you work out what an unknown signal is before writing any code to decode it. Nothing else makes the structure of a capture -- preamble, symbol period, modulation -- as immediately visible, and it is entirely offline, so it needs no hardware at all.

Before it will work

A recorded IQ file. Nothing transmits and no receiver is required, which makes it a good first tool for someone who owns no hardware yet.

How it installs

  • apt: inspectrum

Known problems

Large captures are memory-hungry; a multi-gigabyte recording will struggle. It reads raw IQ and expects you to know the sample format and rate of the file, which is not stored in a bare .cfile.

Keeping it current

  • probe: apt policy
  • strategy: apt_upgrade

Source: catalog/packages/inspectrum.yaml