I’m using FlightR 0.4.7 to analyse geolocation from Arctic-nesting birds.
Because my study site is located above the Arctic circle, I did a rooftop calibration in the “south” prior to the field season. This works well and the make.calibration function gives good estimates.
+ lon=-68.21627, lat=48.57245)
calibration.start calibration.stop lon lat
1 2016-05-07 2016-05-17 -68.21627 48.57245
> Calibration<-make.calibration(Proc.data, Calibration.periods)
checking dusk 10
calibration method used: parametric.slope
likelihood correction switched to TRUE
estimating correction function...
Further on, the make.prerun.object function works fine if I keep the same geographic coordinates in start=c(lat, lon) than the coordinates I used for the calibration. But the calibration site is then considered to be the location where the birds were released (i.e. the start of the migration). And when I change the coordinates in start=c(lat, lon) for the real location of the study site I get this error:
> all.in<-make.prerun.object(Proc.data, Grid, start=c(-79.88566, 72.89986), Calibration=Calibration)
Error in `$<-.data.frame`(`*tmp*`, "Dusk", value = c(FALSE, TRUE, FALSE, :
replacement has 772 rows, data has 735
Is there a solution that would allow me to use the real coordinates of my study site as the start location? or at least to avoid using the coordinates of the calibration site?
Advice would be much appreciated!