Application I - Hydrocarbon Pollution consequent to 1991 Gulf War

Monitoring near surface existence of hydrocarbon polluted surfaces in the Burgan Oil field area was attempted by Saif ud din et al. [20, 21]. The researchers used the land surface temperature (LST) as an indicator for hydrocarbon pollution. 

The LST and total petroleum hydrocarbon (TPH) are positively correlated. The methodology followed is based on the fact that most of the satellites carry a thermal infra-red band which can be used for LST estimation. The spatio-temporal variation in the thermodynamic properties of surface material has been mapped in order to identify hydrocarbon polluted surfaces using Landsat TM data. Emissivity is a strong indicator of compositional variation in silicate minerals which make up the bulk of the earth s surface material. Emissivity affects the apparent temperature due to changes in the thermal properties of materials (conductivity, density, capacity, and inertia). There are several algorithms proposed to estimate LST from remotely sensed data. The most common of these are mono-window and split window methods [22-25], the latter was used initially to estimate sea surface temperature. 

The mono-window algorithm proposed by Qin et al. [25] is based on the thermal radiance transfer equation to calculate LST. It utilizes transmittance and mean attnospheric temperature to estimate LST. The LST estimation is done considering the fact that brightness temperature at satellite can be computed by estimation of radiance from Dn value and conversion of radiance into brightness temperature. The radiance calculation from Dn of TM data utilizes an equation developed by Markham and Barker [31], shown below. 

The ATCOR Program of PCI uses the constants defined by Schneider and Mauser [32], where the average wavelength for Landsat TM band 6 is taken as 11.475 [tm, min(A)= 0.1238 mWcm sr xm for Dn value 0 and L ( ,=1.56mWcm sr 4m for Dn value 255. Substituting these values in the equation above 

The brightness temperature correction for true LST is based on the radiative transfer equation [33]. The concept accounts for thermal emittance from an object in accordance with the blackbody theory, which states  

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