A low-cost and open-source approach for supraglacial debris thickness mapping using UAV-based infrared thermography

Additional code and data for the paper by Jérôme Messmer and Alexander R. Groos entitled "A low-cost and open-source approach for supraglacial debris thickness mapping using UAV-based infrared thermography"

Correspondence: Alexander R. Groos (alexander.groos@fau.de)

The repository contains

(1) visual and thermal UAV images, in situ measurements, visual and radiometric thermal orthophotos, and surface temperature and debris thickness maps from the Kanderfirn in the Swiss Alps

(2) a QGIS project with all datasets (coordinate reference system: WGS 84 / UTM zone 32 N; EPSG code: 32632)

(3) an open-source pipeline for the processing of thermal imagery and the modelling of supraglacial debris thicknesses

Description of sub-folders:

- debris_thickness:

-- kanderfirn_hd_diff_2021-09-28_emp-seb.tif  # debris thickness (in meter) difference map (empirical model vs. physical model)

-- kanderfirn_hd_empirical_2021-09-28.tif  # predicted debris thickness (in meter) using the empirical model

-- kanderfirn_hd_global_rounce_et_al._2021.tif  # global debris thickness (in meter) dataset of Rounce et al. 2021 (https://doi.org/10.1029/2020GL091311)

-- kanderfirn_hd_k0.5_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.5 W m -1 K -1

-- kanderfirn_hd_k0.6_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.6 W m -1 K -1

-- kanderfirn_hd_k0.7_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.7 W m -1 K -1

-- kanderfirn_hd_k0.8_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.8 W m -1 K -1

-- kanderfirn_hd_k0.9_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 0.9 W m -1 K -1

-- kanderfirn_hd_k1.0_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.0 W m -1 K -1

-- kanderfirn_hd_k1.1_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.1 W m -1 K -1

-- kanderfirn_hd_k1.2_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.2 W m -1 K -1

-- kanderfirn_hd_k1.3_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.3 W m -1 K -1

-- kanderfirn_hd_k1.4_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.4 W m -1 K -1

-- kanderfirn_hd_k1.5_2021-09-28.tif  # predicted debris thickness (in meter) using the inverse surface energy balance model with a thermal conductivity of 1.5 W m -1 K -1

-- kanderfirn_hd_measured_2021-09-28.csv  # table with the in-situ debris thickness measurements

- dsm:

-- kanderfirn_dsm_2021-09-28_odm.tif  # digital surface model of the surveyed debris-covered area on the Kanderfirn created with OpenDroneMap

-- kanderfirn_dsm_2021-09-28_pix4d.tif  # digital surface model of the surveyed debris-covered area on the Kanderfirn created with Pix4Dmapper

- exif_data:

-- kanderfirn_thermal_images_exif_data_2021-09-28.csv  # positional information of the thermal UAV images from 2021-09-28

-- kanderfirn_visual_images_exif_data_2021-09-28.csv  # positional information of the visual UAV images from 2021-09-28

- gcp_files:

-- kanderfirn_gcp_list_thermal_2021-09-28.txt  # ground control file for the processing of the thermal images with OpenDroneMap

-- kanderfirn_gcp_list_visual_2021-09-28.txt  # ground control file for the processing of the visual images with OpenDroneMap

-ice-snow-debris_mask:

-- kanderfirn_debrismask_2021-09-28.gpkg  # debris mask for the surveyed debris-covered area on the Kanderfirn

-- kanderfirn_emissivity_2021-09-28.tif  # emissivity map for the Kanderfirn (ice and snow = 0.97; debris = 0.95)

-- kanderfirn_ice-snow-debris_mask_2021-09-28.tif  # binary mask (0 = debris; 1 = ice or snow)

-- kanderfirn_icesnowmask_2021-09-28.gpkg  # ice-snow mask for the surveyed debris-covered area on the Kanderfirn

- orthophotos:

-- kanderfirn_orthophoto_radiometric_2021-09-28_odm.tif  # radiometric orthophoto created with OpenDroneMap using the radiometric UAV images

-- kanderfirn_orthophoto_radiometric_2021-09-28_pix4d.tif  # radiometric orthophoto created with Pix4Dmapper using the radiometric UAV images

-- kanderfirn_orthophoto_visual_2021-09-28_odm.tif  # visual orthophoto of the surveyed debris-covered area on the Kanderfirn created with OpenDroneMap

-- kanderfirn_orthophoto_visual_2021-09-28_pix4d.tif  # visual orthophoto of the surveyed debris-covered area on the Kanderfirn created with Pix4Dmapper

-- odm_quality_report.pdf # OpenDroneMap quality report

- R_scripts:

-- copy_metadata.R  # script to copy exif metadata from radiometric jpegs and visual images (with gps data) to raw thermal images (without any metadata)

-- jpg2raw.R  # script to convert radiometric jpegs into 16 bit raw thermal images using exiftool

-- raw2temp.R  # script to compute distributed surface temperatures from a radiometric orthophoto

-- temp2hd.R  # script to derive debris thickness from mapped surface temperature using the theoretical model of Evatt et al. 2015 (https://doi.org/10.3189/2015JoG14J235)

- study_area:

-- kanderfirn_perimeter_2021-09-14.gpkg  # perimeter of the Kanderfirn in 2021

-- kanderfirn_studyarea_2021-09-28.gpkg  # outline of the study area on the Kanderfirn

- surface_temperature:

-- kanderfirn_ts_2021-09-28_odm.tif  # debris surface temperatures in °C calculated from the radiometric orthophoto created with OpenDroneMap

-- kanderfirn_ts_diff_2021-09-28_pix4d-odm.tif  # difference between the OpenDroneMap and Pix4Dmapper surface temperature map (in °C)

-- kanderfirn_ts_e0.95_2021-09-28_pix4d.tif  # debris surface temperatures in °C (thermal emissivity = 0.95) calculated from the radiometric orthophoto created with Pix4Dmapper

-- kanderfirn_ts_e0.97_2021-09-28_pix4d.tif  # ice/snow surface temperatures in °C (thermal emissivity = 0.97) calculated from the radiometric orthophoto created with Pix4Dmapper

-- kanderfirn_ts_measured_2021-09-28.csv  # in-situ temperature measurements  in °C

- thermal_images:

-- radiometric  # selection of radiometric thermal images captured with the FLIR Vue Pro R 640 during the two UAV surveys (2021-09-28)

-- raw_data  # raw data extracted with the Exiftool from the radiometric thermal images

- visual images: