READ ME File For 'Ultra-stable speckle-based optical fiber sensing demonstrated on an uncrewed aerial vehicle platform - dataset'

Dataset DOI: https://doi.org/10.5258/SOTON/D3800

Date that the file was created: January, 2026


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GENERAL INFORMATION
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ReadMe Author: PRZEMYSLAW FALAK, University of Southampton [ORCID: 0000-0002-2970-0700]

Date of data collection: SEPTEMBER 2024 - OCTOBER 2024, OCTOBER 2025 - NOVEMBER 2025

Information about geographic location of data collection: Southampton, UK

Related projects:
EPSRC grant 'Novel flat fibre sensors for application in process control, evaluation and health monitoring of high value composite assets' (EP/Y016920/1).
EPRSC grant 'Impact Acceleration Award' (EP/X525807/1)
Swedish Research Council (Vetenskapsradet) project (2022-06180)


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SHARING/ACCESS INFORMATION
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Licenses/restrictions placed on the data, or limitations of reuse: No restrictions. Can be used based on CC-BY.

This dataset supports the publication:
AUTHORS: PRZEMYSLAW FALAK, TOBY KING-CLINE, AKOS MARADI, TIMOTHY LEE, BRUNO MOOG, PAWEL MANIEWSKI, ROBERT ENTWISTLE, MARTYNAS BERESNA, CHRISTOPHER HOLMES
TITLE: Ultra-stable speckle-based optical fiber sensing demonstrated on an uncrewed aerial vehicle platform
JOURNAL: Communications Engineering


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DATA & FILE OVERVIEW
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This dataset contains one archived file .zip with the following content:
1) This README.txt file,
2) Subfolder "01_System_vibration_and_temperature_performance"
3) Subfolder "02_System_flight_performance"
4) Subfolder "03_FBG_characterisation"

This dataset consists of 3 sub-folders titled "01_System_vibration_and_temperature_performance", "02_System_flight_performance" and "03_FBG_characterisation" and 10 .fig files in total.

The "01_System_vibration_and_temperature_performance" folder contains the following 8 sub-files:

a) "01_Strained_FBG_responsitivity_BFD_PC1_OSA.fig" - this file contains comparison of the responsivity to the strained FBG in range 0-160 microstrains for: a) speckle baseline dissimilarity (BFD) method, where the first speckle pattern image at 0 microstrains is treated as the reference, b) PC1 projection method (using the first principal component from the principal component analysis to visualise the changes between the speckle paterns related to the microstrain applied) and c) direct Bragg wavelength shift measured by an optical spectrum analyzer (Yokogawa AQ6370D), used as industry-wide standard. This figure also shows the linbear trendlines and R^2 factors of the models fit for each method.

b) "02a_Shaking_BFD_FBG_strain_cycle.fig" - this file contains BFD-derived strain experienced by the FBG, during tensile stretching-release cycles with industrial vertical shaker operation. Colours of the backorudnd determine the shaker activity - white/no colour - no shaker operating (0Hz,-1G), red - (5Hz, +-4G), green - (10Hz, +-6G), purple - (30Hz, +-7G) and yellow - (60Hz, +-6G).

c) "02b_Shaking_PC1_FBG_strain_cycle.fig" - as above, but first principal component (PC1)-derived strain was investigated.

d) "02c_Shaking_error_BFD_FBG_strain_cycle.fig" - this is statistical analysis of the BFD-based strain reconstruction for different shaker frequencies (please read in conjunction with 02a_Shaking_BFD_FBG_strain_cycle.fig).

e) "02d_Shaking_error_PC1_FBG_strain_cycle.fig" - as above, but for the PC1-based strain (read in conjunction with 02b_Shaking_PC1_FBG_strain_cycle.fig).

f) "02e_PCA_1_5_sample_index_wise.fig" - this contains unmodified, first 5 principal components (PC1-PC5) over sample number for the stretching-release test with shaker (as above).

g) "03_BFD_cold_start_and_shaking.fig" - this is the BFD metric registered from the cold start of the system (STASIS) over the time lapsed. It also shows the trend equation and detrended data (showing removal of the temperature trend form the measurement. The orange patch (Vibration) indicates here 30Hz +-4G mechanical shaker operation.

h) "03a_cold_start_CPU_temperature.fig" - this is the readout of the temperature sensor located by the device CPU over the time lapsed. This shall be read in conjunction with 03_BFD_cold_start_and_shaking.fig


The "02_System_flight_performance" folder contains the following 6 sub-files:

a) "04_flight_PCA_1_5_results.fig" - this file contains registered first 5 principal components (PCs) registered over test flight of the device on board of the UAV. The colours/letters here signify disrtinct flight phases: (A, white)-idle aircraft at the runway, (B, red)-take-off and altitude climbing, (C, green)-autonomous circular orbiting, (D, blue)-aerobatics and (E, yellow)-landing and touchdown). 

b) "05a_flight_BFD_strain.fig" - BFD-based strain of the wing, registered over the flight of the UAV. The lettering/colour marks are the same as above.

c) "05b_flight_PC1_strain.fig" - as above, but for PC1-based strain over the flight of the UAV.

d) "05c_flight_ residuals_PC1_BFD_strain.fig" - this file contains difference (residuals) between the PC1 and BFD-derived strains toghetehr with the statistical analysis (mean and standard deviation (STD)), plotted over time (same colour and lettering legend apply as before).

e) "05d_flight_acceleration_on_board.fig" - this is on-board accelerometer reading of the accelration (in Gs) experienced by the aircraft (UAV) durig distinct flight phases.

f) "05e_flight_PC1_BFD_with_acceleration_CC.fig" - this is cross-correlation between the PC1 and BFD-derived strains as well as between the PC1 and acceleration and BFD with acceleration.


The "03_FBG_characterisation" folder contains the following 2 sub-files:

a) "06a_FBG_spectrum_characterisation.fig" - this is the fully annotated spectrum of the FBG sensor from the Optical Spectral Analyser (OSA Yokogawa AQ6370D).

b) "06b_FBG_tension_stretching_characterisation.fig" - relation between the tensile strain applied to the FBG and the relative wavelength shift (FBG sensor characterisation).

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METHODOLOGICAL INFORMATION
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Description of methods used for collection/generation of data: The raw data was collected as speckle patterns captured by IR camera (.png files) and further processed by MATLAB scripts (where annotated). 

Methods for processing the data: Generated data was processed by computational MATLAB scripts and saved as MATLAB figure files (.fig).

Software- or Instrument-specific information needed to interpret the data, including software and hardware version numbers: 
All files within this dataset are MATLAB(C) MathWorks Inc. figure files (.fig). 
All files were created in MATLAB R2021a and shall be opened by any MATLAB version, starting from R2014b.
The .fig files contain the data which can be accessed by using MATLAB commands.

People involved with sample collection, processing, analysis and/or submission: PRZEMYSLAW FALAK


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DATA-SPECIFIC INFORMATION 
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Filename: 01_Strained_FBG_responsitivity_BFD_PC1_OSA.fig

Number of variables: 2

Number of cases: 3

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- strain applied (µε, microstrain),
- Response (BFD, PC1, λ/λ0) (arbitrary units, dimensionless).
Cases:
a) Responsitivity of the strained FBG to the:
- investigated STASIS system (BFD metrics),
- investigated STASIS system (PC1 metrics),
- external OSA (Optical Spectrum Analyser, λ/λ0 metrics) - acting as industry-wide standard.
b) also linear fitting models and their R^2 factors for each case are displayed.

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DATA-SPECIFIC INFORMATION
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Filename: 02a_Shaking_BFD_FBG_strain_cycle.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- reconstructed strain from the BFD metric (BFD Strain (µε), microstrain),
- sample number - sequentional sample numbers.
Cases:
- BFD-derived strain experienced by the FBG, during tensile stretching-release cycles with industrial vertical shaker operation. Colours of the backorudnd determine the shaker activity - white/no colour - no shaker operating (0Hz,-1G), red - (5Hz, +-4G), green - (10Hz, +-6G), purple - (30Hz, +-7G) and yellow - (60Hz, +-6G).

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DATA-SPECIFIC INFORMATION
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Filename: 02b_Shaking_PC1_FBG_strain_cycle.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
As above, the only difference is the PC1-derived strain is being registered (PC1 Strain (µε), microstrain).

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DATA-SPECIFIC INFORMATION
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Filename: 02c_Shaking_error_BFD_FBG_strain_cycle.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- reconstructed strain from the BFD metric (BFD Strain (µε), microstrain),
- industrial vertical shaker vibrating frequency (Shaking frequency (Hz)).

This is statistical analysis of the BFD-based strain reconstruction for different shaker frequencies (please read in conjunction with 02a_Shaking_BFD_FBG_strain_cycle.fig). It includes the mean and standard deviation (STD).


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DATA-SPECIFIC INFORMATION
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Filename: 02d_Shaking_error_PC1_FBG_strain_cycle.fig

Number of variables: 2

Number of cases: 1

As above, but for the PC1-derived strain. (please read in conjunction with 02b_Shaking_PC1_FBG_strain_cycle.fig).


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DATA-SPECIFIC INFORMATION
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Filename: 02e_PCA_1_5_sample_index_wise.fig

Number of variables: 2

Number of cases: 5

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Sample number - sequential number of the sample,
- PC (1-5) - principal components in abstract, unitless dimensions.

Cases:
- Monitoring PC 1-5 (first five principal components) over sample number during the FBG stretch-release cycles with and without shaker operation.

The colour patches meaning is identical as in previous figures.

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DATA-SPECIFIC INFORMATION
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Filename: 03_BFD_cold_start_and_shaking.fig

Number of variables: 2

Number of cases: 2

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- time (seconds),
- BFD (baseline frame difference, unitless)
Cases:
- monitoring speckle pattern BFD from the cold start of the STASIS system (integratet), using the first captured speckle as the reference. After warmup, 30Hz, +-4G shaking was applied.
- applying detrending of the temperature drift, resulting in detrended data. 

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DATA-SPECIFIC INFORMATION
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Filename: 03a_cold_start_CPU_temperature.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- time (seconds),
- temperature of the STASIS CPU (in Celsius)
Cases:
- readout of the temperature sensor located by the device CPU over the time lapsed (together with the BFD from the previous file). This must be read in conjunction with 03_BFD_cold_start_and_shaking.fig


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DATA-SPECIFIC INFORMATION
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Filename: 04_flight_PCA_1_5_results.fig

Number of variables: 2

Number of cases: 5

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Time lapsed (seconds),
- PC (1-5) - principal components in abstract, unitless dimensions.

Cases:
- Monitoring PC 1-5 (first five principal components) from the FBG sensor at the aircraft wing over time lapsed during the UAV flight. The colour patches/letters meaning is as follows: (A, white)-idle aircraft at the runway, (B, red)-take-off and altitude climbing, (C, green)-autonomous circular orbiting, (D, blue)-aerobatics and (E, yellow)-landing and touchdown).


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DATA-SPECIFIC INFORMATION
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Filename: 05a_flight_BFD_strain.fig
Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Time lapsed (seconds),
- BFD Strain (µε) - BFD strain obtained during the flight of the UAV.
Cases:
- Monitoring BFD-derived strain of the aircraft wing over time lapsed during the UAV flight. The colour patches/letters meaning is identical as in the previous file.


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DATA-SPECIFIC INFORMATION
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Filename: 05b_flight_PC1_strain.fig
Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Time lapsed (seconds),
- PC1 Strain (µε) - PC1 strain obtained during the flight of the UAV.
Cases:
- Monitoring PC1-derived strain of the aircraft wing over time lapsed during the UAV flight. The colour patches/letters meaning is identical as in the previous file.


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DATA-SPECIFIC INFORMATION
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Filename: 05c_flight_ residuals_PC1_BFD_strain.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Time lapsed (seconds),
- Residuals PC1-BFD (µε) - residuals (difference) between the PC1 and BFD-derived strains, obtained during the flight of the UAV.
Cases:
- Monitoring residuals of the two reconstruction methods (BFD vs PC1) for the expereinced strain. The colour patches/letters meaning is identical as in the previous file.


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DATA-SPECIFIC INFORMATION
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Filename: 05d_flight_acceleration_on_board.fig

Number of variables: 2

Number of cases: 1

- Time lapsed (seconds),
- Acceleration (G) - acceleration expereinced by the UAV, measured by the on-board accelerometer.
Cases:
- Monitoring acceleration expereinced by the aircraft using on-board accelerometer. The colour patches/letters meaning is identical as in the previous file.


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DATA-SPECIFIC INFORMATION
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Filename: 05e_flight_PC1_BFD_with_acceleration_CC.fig

Number of variables: 2

Number of cases: 3

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- time/cross-correlation time lag (Δt, seconds),
- cross-correlation (unitless)
Cases:
- computing cross-correlation betwen:
a) the PC1-derived strain and acceleration readings,
b) the BFD-derived strain and acceleration readings,
c) the PC1 and BFD derived strain.


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DATA-SPECIFIC INFORMATION
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Filename: 06a_FBG_spectrum_characterisation.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Reflection (dBm),
- wavelength (nm)
Cases:
- Measurement and spectral characterisation of an idle (unstrained) reflection from FBG via OSA Yokogawa AQ6370D.


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DATA-SPECIFIC INFORMATION
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Filename: 06b_FBG_tension_stretching_characterisation.fig

Number of variables: 2

Number of cases: 1

Variable list, defining any abbreviations, units of measure, codes or symbols used:
- Tensile strain applied (Strain (ε), strain)
- relative wavelength shift (Δλ/λ0, unitless)
Cases:
- Measurement of the FBG sensor response (reflected wavelength shift) to the applied strain via OSA Yokogawa AQ6370D.
This figure includes trendline and the model equation.