Airborne observatory for high-resolution land surface temperature and spectral emissivity
6 affiliations
- 1Luxembourg Institute of Science and Technology (LIST), Remote Sensing and Natural Resources Modelling Group, L-4422 Belvaux, Luxembourg; Corresponding authors.
- 2Luxembourg Institute of Science and Technology (LIST), Remote Sensing and Natural Resources Modelling Group, L-4422 Belvaux, Luxembourg
- 3Politecnico di Milano, Department of Civil and Environmental Engineering, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
- 4Global Change Unit, Imaging Processing Laboratory, University of Valencia, Paterna 46980, Spain
- 5Telops Inc., 100-2600 St-Jean-Baptiste Avenue, Quebec City, (QC) G2E 6J5, Canada
- 6Trier University, Remote Sensing and Geoinformatics Department, D-54286 Trier, Germany
Abstract
The Land surface temperature and emissivity Airborne Observatory System (LAOS) provides land surface temperature (LST) and spectral land surface emissivity (LSE) at very high spatial resolutions (0.5–4 m) and flexible (e.g., intraday) acquisition times. LAOS enables: (i) to map spectral variations in LSE—an inherent property of land surface materials—and (ii) to analyse spatial and temporal variations in LST in relation to land surface processes. Here, we present the scientific rationale for developing the system, the components of the hardware and the processing chain, and retrieval and validation results from an agricultural case study. The LAOS hardware consists of a HyperCam-LW (Telops Inc.), a Fourier transformed infrared spectrometer that operates in the long-wave infrared (7.7–11.5 µm) and an associated airborne platform. The processing chain includes radiometric calibration, generation of ortho -photo mosaics, noise removal, atmospheric correction (AC) and temperature and emissivity separation (TES). Key innovations with respect to previous airborne hyperspectral TIR studies are an improved noise filtering step and a recalibrated minimum emissivity—spectral contrast relationship derived from an extended set of ECOSTRESS spectral library spectra . For demonstrating LAOS’ capacities, an extensive survey campaign was conducted over the Burana Irrigation Consortium area near Modena, Italy, on 13–15 July 2022. Images were acquired at 1- and 4-meter resolution during three times of the day. Raw image tiles were processed to LST and LSE mosaics and compared with ground measurements. Validation was performed over agricultural surfaces – wheat stubble, melon, and water –providing a more surface-type-diverse assessment than previous more urban-focused studies. The LST mosaics show good agreement with the in-situ temperatures across all three surface types (within-class R 2 = 0.52–0.86, RMSE = 2.0–3.2 K, global R 2 = 0.96). LSE maps reveal crisp changes at field boundaries and appear relatively constant over time (i.e., both during a day and across multiple days). Airborne LSE spectra show mostly reasonable agreement with ground measurements and reproduce the overall spectral shape. Spectral emissivity remains largely stable both diurnally and across days (average variability ∼ 1.1 %), indicating consistent retrieval performance at field scale. The results demonstrate that LAOS produces LST and LSE maps with accuracies consistent with previous hyperspectral TIR studies, showcasing its potential to address pressing questions in various fields, including agriculture (e.g., irrigation), forestry (e.g., stress detection), defence (e.g., target detection), and urban studies (e.g., urban heat islands). As a high spatial resolution airborne TIR imager, LAOS can also serve as a demonstrator for upcoming satellite missions, such as LSTM (Land Surface Temperature Monitoring, ESA), TRISHNA (Thermal Infrared Satellite for High-Resolution Applications, CNES & ISRO), and Eagle-TIR (Explorer for Artemis Geology Lunar and Earth, NASA).
Related
- Reconciling Arctic sea ice roughness across four observing platforms: a resolution transfer function and the stability of spectral shape over six decades
- Steering Diffusion Priors with Sparse Observations for High-Resolution Temperature Downscaling
- High-resolution mapping of urban wet-bulb temperature and its intra-urban variability: A London case study
- A 45-year high-resolution wave hindcast for the Fijian archipelago: mean climate, spectral characteristics, and long-term trends
- Downscaling land surface temperature to high resolution using Sentinel-2 and Landsat in Google Earth Engine: a case study in Da Nang City
BibTeX
@article{gerhards2026airborne,
title = {{Airborne observatory for high-resolution land surface temperature and spectral emissivity}},
author = {M. Gerhards and T. Hu and F. Ronellenfitsch and P. Pinheiro and C. Corbari and D. Skokovic and J. Sobrino and M. Chamberland and T. Udelhoven and L. Hoffmann and M. Schlerf},
journal = {International Journal of Applied Earth Observations and Geoinformation},
year = {2026},
month = oct,
doi = {10.1016/j.jag.2026.105636},
url = {https://doi.org/10.1016/j.jag.2026.105636},
note = {CC BY},
}
RIS
TY - JOUR
TI - Airborne observatory for high-resolution land surface temperature and spectral emissivity
AU - M. Gerhards
AU - T. Hu
AU - F. Ronellenfitsch
AU - P. Pinheiro
AU - C. Corbari
AU - D. Skokovic
AU - J. Sobrino
AU - M. Chamberland
AU - T. Udelhoven
AU - L. Hoffmann
AU - M. Schlerf
PY - 2026
DA - 2026/10/30
JO - International Journal of Applied Earth Observations and Geoinformation
DO - 10.1016/j.jag.2026.105636
UR - https://doi.org/10.1016/j.jag.2026.105636
AB - The Land surface temperature and emissivity Airborne Observatory System (LAOS) provides land surface temperature (LST) and spectral land surface emissivity (LSE) at very high spatial resolutions (0.5–4 m) and flexible (e.g., intraday) acquisition times. LAOS enables: (i) to map spectral variations in LSE—an inherent property of land surface materials—and (ii) to analyse spatial and temporal variations in LST in relation to land surface processes. Here, we present the scientific rationale for developing the system, the components of the hardware and the processing chain, and retrieval and validation results from an agricultural case study. The LAOS hardware consists of a HyperCam-LW (Telops Inc.), a Fourier transformed infrared spectrometer that operates in the long-wave infrared (7.7–11.5 µm) and an associated airborne platform. The processing chain includes radiometric calibration, generation of ortho -photo mosaics, noise removal, atmospheric correction (AC) and temperature and emissivity separation (TES). Key innovations with respect to previous airborne hyperspectral TIR studies are an improved noise filtering step and a recalibrated minimum emissivity—spectral contrast relationship derived from an extended set of ECOSTRESS spectral library spectra . For demonstrating LAOS’ capacities, an extensive survey campaign was conducted over the Burana Irrigation Consortium area near Modena, Italy, on 13–15 July 2022. Images were acquired at 1- and 4-meter resolution during three times of the day. Raw image tiles were processed to LST and LSE mosaics and compared with ground measurements. Validation was performed over agricultural surfaces – wheat stubble, melon, and water –providing a more surface-type-diverse assessment than previous more urban-focused studies. The LST mosaics show good agreement with the in-situ temperatures across all three surface types (within-class R 2 = 0.52–0.86, RMSE = 2.0–3.2 K, global R 2 = 0.96). LSE maps reveal crisp changes at field boundaries and appear relatively constant over time (i.e., both during a day and across multiple days). Airborne LSE spectra show mostly reasonable agreement with ground measurements and reproduce the overall spectral shape. Spectral emissivity remains largely stable both diurnally and across days (average variability ∼ 1.1 %), indicating consistent retrieval performance at field scale. The results demonstrate that LAOS produces LST and LSE maps with accuracies consistent with previous hyperspectral TIR studies, showcasing its potential to address pressing questions in various fields, including agriculture (e.g., irrigation), forestry (e.g., stress detection), defence (e.g., target detection), and urban studies (e.g., urban heat islands). As a high spatial resolution airborne TIR imager, LAOS can also serve as a demonstrator for upcoming satellite missions, such as LSTM (Land Surface Temperature Monitoring, ESA), TRISHNA (Thermal Infrared Satellite for High-Resolution Applications, CNES & ISRO), and Eagle-TIR (Explorer for Artemis Geology Lunar and Earth, NASA).
SN - 1569-8432
SN - 1872-826X
ER -