vector of sunrise/sunset times (e.g. 2008-12-01 08:30).
tSecond
vector of of sunrise/sunset times (e.g. 2008-12-01 17:30).
type
vector of either 1 or 2, defining tFirst as sunrise or sunset respectively.
twl
data.frame containing twilights and at least tFirst, tSecond and type (alternatively give each parameter separately).
known.coord
a SpatialPoint or matrix object, containing
known x and y coordinates (in that order) for the selected measurement
period.
plot
logical, if TRUE a plot will be produced.
lnorm.pars
logical, if TRUE shape and scale parameters of the twilight error (log-normal distribution)
will be estimated and included in the output (see Details).
Details
Optionally, shape and scale paramters of the twiligth error (in minutes) can be estimated. The error is assumed
to follow a log-normal distribution and 0 (elev0) is set 0.1 below the minimum sun elevation angle of estimated twilight times.
Those parameters might be of interest for sensitivity analysis or further processing using the R Package SGAT (https://github.com/SWotherspoon/SGAT).
References
Lisovski, S., Hewson, C.M, Klaassen, R.H.G., Korner-Nievergelt,
F., Kristensen, M.W & Hahn, S. (2012) Geolocation by light: Accuracy and
precision affected by environmental factors. Methods in Ecology and
Evolution, DOI: 10.1111/j.2041-210X.2012.00185.x.