TITLE:
Toward Estimating the Variance in Acoustic Surveys Based on Sampling Design
AUTHORS:
Magnar Aksland
KEYWORDS:
Acoustic Abundance Estimation, Line Surveys, Sampling Design, Sampling in the Area, Variance Estimation
JOURNAL NAME:
Open Journal of Marine Science,
Vol.1 No.1,
April
26,
2011
ABSTRACT: This paper develops a sampling method to estimate the integral of a function of the area with a strategy to cover the area with parallel lines of observation. This sampling strategy is special in that lines very close to each other are selected much more seldom than under a uniformly random design for the positions of the parallel lines. It is also special in that the positions of some of the lines are deterministic. Two different variance estimators are derived and investigated by sampling different man made signal functions. They show different properties in that the estimator that estimate the biggest variance gives an error interval that, in some situations, may be more than ten times the error interval computed from the other estimator. It is also obvious that the second estimator underestimates the variance. The author has not succeeded to derive an expression for the expectation of this estimator. This work is motivated towards finding the variance of acoustic abundance estimates.