A Hammurabi simulated Faraday spectrum and the associated Faraday depth and field parameters as a function of physical depth. a) The Faraday spectrum along the LOS at Galactic coordinates (90°, − 15°) in arbitrary units. b) Faraday depth in rad m^-2. c) The product of the LOS magnetic field and thermal electron density, which is proportional to the Faraday depth in code internal units. d) The perpendicular magnetic field component squared, which is proportional to the synchrotron emissivity again in code internal units.