estNv: Estimate the Number of Targets in the Acoustic Beam

In JVAdams/EchoNet2Fish: Estimate Fish Abundance from Acoustic Echoes and Net Catch

Description

Estimate the number of targets in the acoustic sampling volume.

Usage

estNv(c = 1450, tau = 4e-04, psi, R, rhov)

Arguments

c	Numeric scalar, sound speed in m/sec, default 1450.
tau	Numeric scalar, pulse duration in sec, default 0.0004.
psi	Numeric scalar, two-way equivalent beam angle in steradians.
R	Numeric vector, range to target in m.
rhov	Numeric vector, volumetric fish density in number per m^3, same length as R, typically the result of a call to estrhov.

Details

The number of targets in the acoustic sampling volume is estimated according to Sawada et al. (1993) as Nv = c * tau * psi * R^2 * rhov / 2.

Value

A numeric vector the same length as R containing the estimated number of targets in the acoustic beam.

References

Sawada, K., Furusawa, M., and Williamson, N.J. 1993. Conditions for the precise measurement of fish target strength in situ. Fisheries Science (Tokyo) 20:15-21.

See Also

estrhov

Examples

mypsi <- 0.008
myrange <- c(10, 20, 30)
myrhov <- c(0.0001, 0.01, 0.0006)
estNv(psi=mypsi, R=myrange, rhov=myrhov)

JVAdams/EchoNet2Fish documentation built on Feb. 15, 2021, 4:27 a.m.