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.
analyse_portableOSL(
object,
signal.integral = NULL,
invert = FALSE,
normalise = FALSE,
mode = "profile",
coord = NULL,
plot = TRUE,
...
)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
RLum.Analysis (required): RLum.Analysis object produced by read_PSL2R. The input can be a list of such objects, in such case each input is treated as a separate sample and the results are merged.
numeric (required): A vector of two values specifying the lower and upper channel used to calculate the OSL/IRSL signal. Can be provided in form of c(1, 5) or 1:5.
logical (with default): TRUE flip the plot the data in reverse order.
logical (with default): TRUE to normalise the OSL/IRSL signals
to the mean of all corresponding data curves.
character (with default): defines the analysis mode, allowed
are "profile" (the default) and "surface" for surface interpolation. If you select
something else, nothing will be plotted (similar to plot = FALSE).
list matrix (optional): a list or matrix of the same length as
number of samples measured with coordinates for the sampling positions. Coordinates
are expected to be provided in meter (unit: m).
Expected are x and y coordinates, e.g.,
coord = list(samp1 = c(0.1, 0.2). If you have not measured x coordinates, please x should be 0.
logical (with default): enable/disable 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 are
surface_values (character with value to plot), legend (TRUE/FALSE), col_ramp (for
surface mode), contour (contour lines TRUE/FALSE in surface mode), grid (TRUE/FALSE), col, pch (for profile mode), xlim (a name list for profile mode), ylim,
zlim (surface mode only), ylab, xlab, zlab (here x-axis labelling), main, bg_img (for
profile mode background image, usually a profile photo; should be a raster object),
bg_img_positions (a vector with the four corner positions, cf. graphics::rasterImage)
0.1.1
Christoph Burow, University of Cologne (Germany), Sebastian Kreutzer, Institute of Geography, Ruprecht-Karl University of Heidelberg, Germany , RLum Developer Team
Burow, C., Kreutzer, S., 2024. analyse_portableOSL(): Analyse portable CW-OSL measurements. Function version 0.1.1. 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., 2024. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 0.9.25. https://r-lum.github.io/Luminescence/
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. If you have written a different sequence, the analysis function will (likely) not work!.
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:
(1) Add coordinates to the sample name during measurement. The form is rather
strict and has to follow the scheme _x:<number>|y:<number>. Example:
sample_x:0.2|y:0.4.
(2) Alternatively, you can provide a list or matrix with the sample coordinates.
Example: coord = list(c(0.2, 1), c(0.3,1.2))
Please note that the unit is meter (m) and the function expects always xy-coordinates. The latter one is useful for surface interpolations. If you have measured a profile where the x-coordinates to not measure, x-coordinates should be 0.
RLum.Analysis, RLum.Data.Curve, read_PSL2R
## 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)
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