Modeling and Inversion in Thermal Infrared Remote Sensing over ...

10 Modeling and Inversion in Thermal Infrared Remote Sensing 25110.4.1 Fundamentals in TIR Remote Sensingird-00392669, version 1 - 9 Jun 2009The use of TIR remote sensing to infer the temperatures of interest involves anaerodynamic issue for the related temperature, and a radiative issue for the othertemperatures.10.4.1.1 Aerodynamic IssueAerodynamic temperature T aero is not radiative based and cannot be remotelysensed. It is required for one source modeling of surface energy fluxes, since itcorresponds to the value of the logarithmic based air temperature profile T air (z) atthermal roughness length z oh [110]. For a negligible displacement height, sensibleheat flux H is expressed from the air temperature gradient between z oh and referencelevel z re f :H = T air(z oh ) − T air (z re f )r ah (z oh ,z re f )with T aero = T air (z oh ) (10.1)where r ah (z oh ,z re f ) is aerodynamic resistance for heat between z oh and z re f [111].Due to larger resistance for heat transfers, z oh is lower than mechanical roughnesslength z om [112]. The link between both is the aerodynamic kB −1 parameter [113]:( )kB −1 zom= ln(10.2)z ohThe physical meanings of T aero and z oh are equivocal. T aero is an effective temperaturefor heat sources that are soil and vegetation [114]. z oh is an effective level forwhich T air = T aero . Their retrieval from remote sensing is not trivial (Section 10.6.3).Nevertheless, T aero can be unequivocally derived from soil and vegetation temperaturesT soil and T veg , by merging one source and two source modeling [20, 115]:T aero =T soilr+ T vega,soil r a,veg+ T air(z re f )r ah1r+ 1a,soil r a,veg+ 1r ah(10.3)where r a,soil (respectively r a,veg ) is aerodynamic resistance from the soil (respectivelyvegetation) to z om , and r ah is aerodynamic resistance from z om to z re f [111].10.4.1.2 Radiative IssueApart from aerodynamic temperature, the land surface temperatures inferred fromTIR remote sensing are radiative based. Then, fundamentals deal with the TIRradiative regime within atmosphere and over land surfaces. This includes threemechanisms which drive the wave matter interactions: emission, absorption, andUncorrected Proof