Target strength

The target strength or acoustic size is a measure of the reflection coefficient of a sonar target. This is usually quantified as a number of negative decibels. For fish such as salmon, the target size varies with the length of the fish and a 5 cm fish would have a target size of about -50 db.

Target strength (TS) is equal to 10 log₁₀(σ_bs), where σ_bs is the backscattering cross section.