analyse_SAR.NCF: Compute SAR palaeodoses using natural sensitivity correction...

In Luminescence: Comprehensive Luminescence Dating Data Analysis

Compute SAR palaeodoses using natural sensitivity correction (NCF)

Description

The function computes the natural sensitivity correction factor (NCF) for the assessment of single aliquot regeneration based palaeodoses. This allows to produce D_e values that account for sensitivity changes that may occur during the preheat and readout of the natural OSL.

Usage

analyse_SAR.NCF(object, TL_peak_range = 15, method_control = NULL, ...)

Arguments

object	RLum.Analysis or list of RLum.Analysis objects (required): input object containing data for analysis. If a list is provided the functions tries to iterate over each element in the list.
TL_peak_range	numeric (with default): size of the integration window in deg. C on each side of the identified peak.
method_control	list (optional): parameters to control the peak-finding step (see Details).
...	further arguments that will be passed to fit_DoseResponseCurve, plot_DoseResponseCurve or calc_OSLLxTxRatio (the latter only supports background.count.distribution, sigmab, sig0, od_rates). Additionally, supported are legend.cex and legend.pch to modify the legend symbols. Note: If you consider using the early light subtraction method, sigmab should be provided. Note: od_rates can be used to treat uncertainties in Lx/Tx according to Bluszcz et al. (2015) instead of the standard approach of Galbraith (2002, 2014). See calc_OSLLxTxRatio for details.

Details

This function is a wrapper around analyse_SAR.CWOSL: it works in a similar way, but corrects the natural OSL signal according to Singhvi et al. (2011) and by implementing the MatLab code reported in Kaushal et al. (2022).

The NCF procedure

The NCF protocol modifies the standard SAR protocol by adding a small dose before the readout of the natural signal; the corresponding 110 deg. C TL peak in quartz is monitored and compared to the TL peak recorded during the typical cutheat measurement. The additional dose used for the NCF TL curves is subtracted automatically. The published NCF sequence structure must be followed, otherwise the correction will not work.

The natural sensitivity correction factor (NCF) is measured as the ratio of the 110 deg. C TL peaks before and after the measurement of natural OSL, accounting for an integration range around the peak, typically 15 deg. C or the full width at half maximum (FWHM).

TL peak finding

The TL peaks are found automatically by finding the position with highest counts below 160 deg. C (after some smoothing has been applied to the counts data) for each of the two TL curves.

The peak search parameters can be controlled via the method_control argument. If used, this must be a list with one or more of the following named arguments (e.g. method_control = list(search.threshold.degrees = 130)):

• peak.temperature: this can be used to set the temperature of the TL peak manually; if set to NULL (default), the peak is found automatically

• search.threshold.degrees: threshold in deg. C below which the peak is searched (160 by default); this is ignored if peak.temperature is not NULL

The identified TL curves and the chosen signal integral are shown in the graphical output.

Value

Plots (optional) and an RLum.Results object is returned containing the following elements:

DATA.OBJECT	TYPE	DESCRIPTION
..$data :	data.frame	Table with corrected D_e values
..$LnLxTnTx.table :	data.frame	Corrected LnLxTnTx values
..$rejection.criteria :	data.frame	Rejection criteria
..$Formula :	list	Function used for fitting of the dose response curve
..$data_uncor :	data.frame	Table with the uncorrected data
..$LnLxTnTx.table_uncor :	data.frame	Uncorrected LnLxTnTx values
..$NCF_settings :	list	Setting used for TL peak finding

This output is similar to the output of analyse_SAR.CWOSL extended by a few more elements.

Function version

0.1.1

How to cite

Colombo, M., Kreutzer, S., 2026. analyse_SAR.NCF(): Compute SAR palaeodoses using natural sensitivity correction (NCF). 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., Steinbuch, L., de Boer, A., Bluszcz, A., 2026. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 1.3.1. https://r-lum.github.io/Luminescence/

Note

This function is a beta version.

Author(s)

Marco Colombo, Institute of Geography, Heidelberg University (Germany)
Sebastian Kreutzer, LIAG Institute for Applied Geophysics (Germany) , RLum Developer Team

References

Kaushal, R.K., Chauhan, N., Singhvi, A.K., 2022. Luminescence dating of quartz: A MATLAB-based program for computation of SAR paleodoses using natural sensitivity correction (NCF). Ancient TL, 40 (2), 1-7. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.26034/la.atl.2022.561")}

Singhvi, A.K., Stokes, S.C., Chauhan, N., Nagar, Y.C., Jaiwal, M.K., 2011. Changes in natural OSL sensitivity during single aliquot regeneration procedure and their implications for equivalent dose determination. Geochronometria, 38 (3), 231-241. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2478/s13386-011-0028-3")}

See Also

analyse_SAR.CWOSL, fit_DoseResponseCurve

Examples

## Load example data
file <- system.file("extdata/NCF.binx", package = "Luminescence")
ncf <- read_BIN2R(file, fastForward = TRUE)

results <- analyse_SAR.NCF(
 object = ncf,
 signal_integral = 1:2,
 background_integral = 100:250,
 dose_rate_source = 0.1)

Luminescence documentation built on Sept. 18, 2026, 9:07 a.m.