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Thermal remote sensing in the framework of the SEN2FLEX project: field measurements, airborne data and applications

2008; Taylor & Francis; Volume: 29; Issue: 17-18 Linguagem: Inglês

10.1080/01431160802036516

1366-5901

José A. Sobrino, Juan C. Jiménez‐Muñoz, G. Sòria, M. Gómez, A. Barella Ortiz, M. Romaguera, M. M. Zaragoza, Y. Julien, Javier Cuenca, Mariam Atitar, Vanesa Hidalgo, B. Franch, Cristián Mattar, Ana B. Ruescas, Luis Morales-Salinas, A. R. Gillespie, L. Balick, Zhongbo Su, Françoise Nerry, Leonardo F. Peres, Renata Libonati,

Calibration and Measurement Techniques

Abstract A description of thermal radiometric field measurements carried out in the framework of the European project SENtinel‐2 and Fluorescence Experiment (SEN2FLEX) is presented. The field campaign was developed in the region of Barrax (Spain) during June and July 2005. The purpose of the thermal measurements was to retrieve biogeophysical parameters such as land surface emissivity (LSE) and temperature (LST) to validate airborne‐based methodologies and to characterize different surfaces. Thermal measurements were carried out using two multiband field radiometers and several broadband field radiometers, pointing at different targets. High‐resolution images acquired with the Airborne Hyperspectral Scanner (AHS) sensor were used to retrieve LST and LSE, applying the Temperature and Emissivity Separation (TES) algorithm as well as single‐channel (SC) and two‐channel (TC) methods. To this purpose, 10 AHS thermal infrared (TIR) bands (8–13 µm) were considered. LST and LSE estimations derived from AHS data were used to obtain heat fluxes and evapotranspiration (ET) as an application of thermal remote sensing in the context of agriculture and water management. To this end, an energy balance equation was solved using the evaporative fraction concept involved in the Simplified Surface Energy Balance Index (S‐SEBI) model. The test of the different algorithms and methods against ground‐based measurements showed root mean square errors (RMSE) lower than 1.8 K for temperature and lower than 1.1 mm/day for daily ET. Acknowledgements We thank to the European Union (EAGLE, project SST3‐CT‐2003‐502057), the Ministerio de Ciencia y Tecnología (DATASAT, project ESP2005‐07724‐C05‐04), the European Space Agency (SEN2FLEX, project RFQ 3‐11291/05/I‐EC) and the Generalitat Valenciana (Conselleria d'Empresa, Universitat i Ciència, project ACOMP06/219) for financial support. We also thank the INTA team for pre‐processing the AHS imagery and for technical assistance.