crawl (version 1.0-1)

northernFurSeal: Northern fur seal pup telemetry data set

Description

Northern fur seal pup relocation data set used in Johnson et al. (2008)

Usage

data(northernFurSeal)

source

Alska Ecosystems Program National Marine Mammal Laboratory Alaska Fisheries Science Center National Marine Fisheries Service, NOAA 7600 Sand Point Way NE Seattle, WA 98115

References

Johnson, D., J. London, M. -A. Lea, and J. Durban (2008) Continuous-time random walk model for animal telemetry data. Ecology 89:1208-1215.

Examples

data(northernFurSeal)

argosClasses <- c("3", "2", "1", "0", "A", "B")
ArgosMultFactors <- data.frame(Argos_loc_class=argosClasses,
                               errX=log(c(1, 1.5, 4, 14, 5.21, 20.78)),
                               errY=log(c(1, 1.5, 4, 14, 11.08, 31.03)))
nfsNew <- merge(northernFurSeal, ArgosMultFactors,
                by=c("Argos_loc_class"), all.x=TRUE)
nfsNew <- nfsNew[order(nfsNew$Time), ]

# State starting values
initial.drift <- list(a1.x=c(189.686, 0, 0), a1.y=c(57.145, 0, 0),
                      P1.x=diag(c(0, 0.001, 0.001)),
                      P1.y=diag(c(0, 0.001, 0.001)))

##Fit random drift model
fit <- crwMLE(mov.model=~1, err.model=list(x=~errX, y=~errY), drift.model=TRUE,
              data=nfsNew, coord=c("longitude", "latitude"),
              Time.name="Time", initial.state=initial.drift,
              fixPar=c(NA, 1, NA, 1, NA, NA, NA,NA),
              control=list(maxit=2000,trace=1, REPORT=10))

##Make hourly location predictions
predTime <- seq(ceiling(min(nfsNew$Time)), floor(max(nfsNew$Time)), 1)
predObj <- crwPredict(object.crwFit=fit, data=nfsNew, predTime=predTime,
                      speedEst=TRUE, flat=FALSE)
str(predObj)
predObj <- as.flat(predObj)
head(predObj)
crwPredictPlot(predObj)