This unit is the most common unit used to express the front-to-back ratio of an antenna. A meteorological quantity (10[1])called this (-5[1])unit relative to Z (10[1])is a normalized expression (10[1])for the equivalent reflectivity of a hydrometeor. The steepness of a filter’s transfer function is written as the change in this unit per decade or (10[1])octave, (10[1]-5[2])which (10[1])is a quantity called the roll-off. (10[3])The frequency (10[1])at which gain drops (10[1])off by approximately 3 of this unit (10[1])determines the cutoff (10[1])frequency. (10[8])In its most common (10[1])application, (10[1])a reference (10[1])pressure equal to 20 micropascals defines (10[1])a value (10[1])of 0 for this unit. (10[4])This (10[1])unit is (10[1])defined so that multiplying intensity (10[1])by a factor (10[3])of 10 (10[4]-5[1])corresponds (10[3])to an increase (10[4])by (10[1])10 (10[2])of (10[1])this unit. (10[8])For (10[1])10 points, name this unit (10[1])that defines a logarithmic (10[1])scale (10[1])of sound (10[4])intensity. (10[1])■END■ (10[6])