jeffa: Laake's availability correction factor calculation for a...

In david-borchers/hmltm: Line transect estimation with hidden Markov availability models

Laake's availability correction factor calculation for a single 2-state Markov model.

Description

Calculates the probability that an animal is availabel at least once whil within detectable region, using the method of Laake et al. (1997), Eqn (4).

Usage

jeffa(Pi, ymax, spd = NULL, E = NULL)

Arguments

Pi	is Markov model transition matrix (state 1 is UNavailable).
ymax	is maximum forward distance things can be detected.
spd	is observer speed. If NULL ymax is assumed to be in the units of the Markov chain.
E	is mean times unavailable (E[1]) and available (E[2]) (in units of Markov chain). If E is not NULL, it is used in preference to Pi for calculations, else it is ignored.

Details

See Laake et al. (1997), Eqn (4), or Borchers et al. (2013) for details of the method.

References

Borchers, D.L., Zucchini, W., Heide-Jorgenssen, M.P., Canadas, A. and Langrock, R. 2013. Using hidden Markov models to deal with availability bias on line transect surveys. Biometrics.

Laake, J., Calambokidis, J., Osmek, S., and Rugh, D. 1997. Probability of detecting harbor porpoise from aerial surveys: estimating g(0). Journal of Wildlife Management 61, 63-75.

david-borchers/hmltm documentation built on Oct. 29, 2023, 9:07 p.m.