Glossary

Glossary#

Symbol	Definition	Units	Notes
\(s_\text{a}\)	area backscattering coefficient	m²m^-2
\(s_\text{A}\)	nautical areal backscattering coefficient	m²nmi^-2	Also commonly abbreviated as \(\textit{NASC}\)
\(s_\text{v}\)	volume backscattering coefficient	m^-1
\(S_\text{v}\)	volume backscattering strength	dB re 1 m^-1	Sometimes called the mean volume backscattering strength (\(\textit{MVBS}\) when averaged over a finite volume of water)
\(\sigma_\text{bs}\)	backscattering cross-section	m²
\(\sigma_\text{sp}\)	spherical scattering cross-section	m²
\(TS\)	target strength	dB re 1 m²

Symbol	Definition	Units	Notes
\(\alpha\)	age	year
\(B\)	biomass	kg
\(L\) or \(\ell\)	length of animal	m or cm
\(n\)	sample size
\(N\)	abundance
\(\rho_\text{v}\)	volumetric animal number density	animals m^-3
\(\rho_\text{a}\)	areal animal number density	animals m^-2	Metric units
\(\rho_\text{A}\)	areal animal number density	animals nmi^-2	Nautical units (same as \(\rho_a\) but in nautical miles)
\(\rho_\text{B}\)	biomass density	kg nmi^-2	Nautical units
\(s\)	animal sex
\(w\)	animal weight	kg

Symbol	Definition	Notes
\(\text{Cov}\), \(\mathbb{C}\)	covariance	Units are the product of the units of the two variables (e.g., m·s)
\(\text{CV}\)	coeffficient of variance
\(\mathbb{E}\)	expected value	Units are the same as the variable’s units
\(\gamma\)	semivariance	Units are the square of the variable’s units (e.g., m²); often denoted as \(\gamma(h)\) for lag distance \(h\)
\(\text{KS}\) test	Kolmogorov-Smirnov test
\(\mathbb{R}\)	real value
\(\theta\)	set of parameters
\(\mathbb{V}\), \(\sigma^2\)	variance	Units are the square of the variable’s units (e.g., m²)
\(Z\)	random field or spatial process

Symbol	Definition	Units	Notes
\(A\)	area	km² or nmi²
\(d\)	distance	km or nmi
\(g\)	haul/trawl
\(i\)	stratum
\(\text{INPFC}\)	International North Pacific Fisheries Commission		Used interchangeably to denote latitude-based stratification
\(k\)	along-transect interval		Sometimes also referred to as the elementary distance sampling unit, or \(\textit{EDSU}\)
\(t\)	transect
\(x, y\)	geospatial location		Units can be \(\degree\) in the case of longitude and latitude, or something else depending on how data are georeferenced or projected

Symbol	Definition	Units	Notes

| \(r_n\) | number proportion | | | | \(r_w\) | weight proportion | | |