R: Correct for drift in instrument clock

undriftTime {oce} | R Documentation

## Correct for drift in instrument clock

### Description

It is assumed that the instrument clock matches the real time at the start of the sampling, and that the clock drifts linearly (i.e. is uniformly fast or slow) over the sampling interval. Linear interpolation is used to infer the values of all variables in the `data` slot. The data length is altered in this process, e.g. a slow instrument clock (positive `slowEnd`) takes too few samples in a given time interval, so `undriftTime` will increase the number of data.

### Usage

    undriftTime(x, slowEnd = 0, tname = "time")

### Arguments

`x` | an object of `oce-class`.
`slowEnd` | number of seconds to add to final instrument time, to get the correct time of the final sample. This will be a positive number, for a "slow" instrument clock.
`tname` | Character string indicating the name of the time column in the `data` slot of `x`.

### Value

An object of the same class as `x`, with the `data` slot adjusted appropriately.

### Author(s)

Dan Kelley

### Examples

    ## Not run:
    library(oce)
    rbr011855 <- read.oce(
     "/data/archive/sleiwex/2008/moorings/m08/pt/rbr_011855/raw/pt_rbr_011855.dat")
    d <- subset(rbr011855, time < as.POSIXct("2008-06-25 10:05:00"))
    x <- undriftTime(d, 1)	  # clock lost 1 second over whole experiment
    summary(d)
    summary(x)

    ## End(Not run)

[Package oce version 0.9-20 Index]