analyse_portableOSL {Luminescence}R Documentation

Analyse portable CW-OSL measurements

Description

The function analyses CW-OSL curve data produced by a SUERC portable OSL reader and produces a combined plot of OSL/IRSL signal intensities, OSL/IRSL depletion ratios and the IRSL/OSL ratio.

Usage

analyse_portableOSL(
  object,
  signal.integral = NULL,
  invert = FALSE,
  normalise = FALSE,
  mode = "profile",
  coord = NULL,
  plot = TRUE,
  ...
)

Arguments

object

RLum.Analysis (required): object produced by read_PSL2R. The input can be a list of such objects, in which case each input is treated as a separate sample and the results are merged.

signal.integral

numeric (required): A vector specifying the range of channels used to calculate the OSL/IRSL signal. It can be provided as a vector of length 2 such as c(1, 5), or as a sequence such as 1:5, in which case the lowest and highest values define the range.

invert

logical (with default): TRUE flip the plot the data in reverse order.

normalise

logical (with default): whether the OSL/IRSL signals should be normalised to the mean of all corresponding data curves.

mode

character (with default): analysis mode, one of "profile" (the default) or "surface" for surface interpolation.

coord

list matrix (optional): a list or a 2-column matrix with the x and y coordinates for the sampling positions in meters (m), of the same length as the number of samples measured. For example, the coordinates for one sample could be ⁠coord = list(samp1 = c(0.1, 0.2)⁠. If the x coordinates were not measured, x should be set to 0. Note that, in such case, a surface plot cannot be produced.

plot

logical (with default): enable/disable the plot output.

...

other parameters to be passed to modify the plot output. Supported are run to provide the run name (if the input is a list, this is set automatically). Further plot parameters accepted are main, col, xlim (a named list for profile mode), ylim, ylab, xlab. Additional parameters for mode = "profile" are type, pch, grid (TRUE/FALSE), bg_img (a raster object for the background image, usually a profile photo), bg_img_positions (a vector with the four corner positions, see graphics::rasterImage), zlab (here x-axis labelling). Additional parameters for mode = "surface" are surface_value (character with names of the surfaces to plot), col_ramp, legend (TRUE/FALSE), contour (TRUE/FALSE),⁠ ⁠contour_nlevels⁠, ⁠contour_col⁠, ' zlim⁠.

Details

This function only works with RLum.Analysis objects produced by read_PSL2R. It further assumes (or rather requires) an equal amount of OSL and IRSL curves that are pairwise combined for calculating the IRSL/OSL ratio. For calculating the depletion ratios, the cumulative signal of the last n channels (same number of channels as specified by signal.integral) is divided by cumulative signal of the first n channels (signal.integral).

Note: The function assumes the following sequence pattern: ⁠DARK COUNT⁠, IRSL, ⁠DARK COUNT⁠, BSL, ⁠DARK COUNT⁠. Therefore, the total number of curves in the input object must be a multiple of 5, and there must be 3 DARK_COUNT records for each IRSL/BSL pair. If you have used a different sequence, the function will produce an error.

Signal processing The function processes the signals as follows: BSL and IRSL signals are extracted using the chosen signal integral, dark counts are taken in full.

Working with coordinates Usually samples are taken from a profile with a certain stratigraphy. In the past the function calculated an index. With this newer version, you have two option of passing on xy-coordinates to the function:

If in your profile the x-coordinates were not measured, x should be set to 0. Note that, in such case, a surface plot cannot be produced.

Value

Returns an S4 RLum.Results object with the following elements:

⁠$data⁠
.. $summary: data.frame with the results
.. $data: list with the RLum.Analysis objects
.. $args: list the input arguments

Function version

0.1.3

How to cite

Burow, C., Kreutzer, S., Colombo, M., 2025. analyse_portableOSL(): Analyse portable CW-OSL measurements. Function version 0.1.3. In: Kreutzer, S., Burow, C., Dietze, M., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J., Mercier, N., Philippe, A., Riedesel, S., Autzen, M., Mittelstrass, D., Gray, H.J., Galharret, J., Colombo, M., Steinbuch, L., Boer, A.d., 2025. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 1.1.0. https://r-lum.github.io/Luminescence/

Author(s)

Christoph Burow, University of Cologne (Germany)
Sebastian Kreutzer, Institute of Geography, Heidelberg University (Germany)
Marco Colombo, Institute of Geography, Heidelberg University (Germany) , RLum Developer Team

See Also

RLum.Analysis, RLum.Data.Curve, read_PSL2R

Examples


## example profile plot
# (1) load example data set
data("ExampleData.portableOSL", envir = environment())

# (2) merge and plot all RLum.Analysis objects
merged <- merge_RLum(ExampleData.portableOSL)
plot_RLum(
 object = merged,
 combine = TRUE,
 records_max = 5,
 legend.pos = "outside")
merged

# (3) analyse and plot
results <- analyse_portableOSL(
  merged,
  signal.integral = 1:5,
  invert = FALSE,
  normalise = TRUE)
get_RLum(results)


[Package Luminescence version 1.1.0 Index]