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Northeastern University (2012)

Characterization of the Libyan desert in support of vicarious calibration

Brooke, Bridget

Titre : Characterization of the Libyan desert in support of vicarious calibration

Auteur : Brooke, Bridget

Université de soutenance : Northeastern University

Grade : Master of Science 2012

Résumé
Thorough calibration of electro-optical sensors being designed for today’s space-based applications is essential to utilize remotely sensed imagery products. A complete sensor calibration provides in-depth understanding of operation and performance, while verifying that the system meets mission standards. Accurate calibration is crucial in order to give the data physical meaning and allow the imagery to be used and compared for a variety of applications. The use of invariant sites for vicarious calibration has become a valuable tool for the changing design and demands of new instruments. Pseudo-invariant calibration sites provide the opportunity to utilize a much larger site to accommodate the full sensor footprint. Characterizing and understanding these sites is key to successful vicarious calibration.
This study focuses on the common pseudo-invariant test site, Libya 4, located in the Saharan desert and two essential atmospheric parameters necessary for characterizing the surface reflectance : column water vapor and aerosol optical depth. These radiometric effects are explored by using a radiative transfer code (e.g., MODTRAN®) to simulate atmospheric changes within realistic environmental ranges and create look up tables to match real world data. We first estimate the water vapor amount in selected data sets using the Continuum Band Interpolated Ratio technique. The aerosol optical depth is then determined using a look up table scheme, with the first estimations of the water vapor amount as inputs to MODTRAN®. Finally, with the atmospheric parameters determined by this iterative approach, we study the surface reflectance of the test site to be utilized in future calibration.

Mots clés : Hyperion ; Hyperspectral ; Libya ; Vicarious Calibration ; Electrical and Computer Engineering ; Engineering ; Signal Processing

Résumé

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Page publiée le 18 juin 2013, mise à jour le 9 septembre 2017