dB''Z

(Sometimes written dBz.) The logarithmic scale for measuring radar reflectivity factor, referred to a value of 1 mm⁶ m^-3, defined by

where Z is the reflectivity factor (mm⁶ m^-3), Z₁ is 1 mm⁶ m^-3, and ζ is the reflectivity factor in dBZ.

See decibel.