User Manual - pancroma

SPOT Top of Atmosphere RadiancePANCROMA TM can also compute atmospheric radiance values for SPOT. Theprocedure is similar to Landsat radiance calculation. Open a single input file andthen input the band number, the image scale factor, and the Absolute CalibrationGain from the metadata. Click ’OK’ and the band radiances will be computed.ASTER Top of Atmosphere ReflectancePANCROMA TM can also compute TOA Reflectance for ASTER band files usingASTER L1B data in either GeoTiff or HDF file format. The procedure is nearlythe same as for Landsat band files. Conversions must be made one ASTERband file at a time. Open a band file by selecting ‘File’ | ‘Open’. Then select‘PreProcess’ | ‘Compute Radiometric Corrections’ | ‘Compute ASTER TOAReflectance’. The TOA Reflectance Data Form will become visible. This formwill ask you to input the parameters that are needed to compute and render (ifdesired) the TOA data. The Solar Elevation Angle and Acquisition Date arerequired. Additional parameters include the ASTER band number and a graphicsimage scale factor. It is necessary to check the ASTER metadata for the correctGain setting. There are four: High, Normal, Low1 and Low2. The default settingis Normal. There are six ASTER multispectral bands, similar to Landsat. Thesebands are numbered 4 through 9. Band data for ASTER is given in Section 30 ofthis manual. The form has check boxes for writing the TOA reflectance data tofile and for rendering it as an image.ASTER Top of Atmosphere RadiancePANCROMA TM can also compute atmospheric radiance values using ASTERL1B data in either GeoTiff or HDF file format. The procedure is similar toLandsat radiance calculation. Open a single input file and then input the bandnumber, and the image scale factor. It is necessary to check the ASTERmetadata for the correct Gain setting. There are four: High, Normal, Low1 andLow2. The default setting is Normal. Click ’OK’ and the band radiances will becomputed.ASTER L1B Surface Temperature HDF File FormatPANCROMA TM can also compute atmospheric radiance values for ASTER L1BHDF format files. ASTER surface temperatures, like Landsat surfacetemperatures are computed from spectral radiance, so PANCROMA TM begins byconverting DNs to radiance. The equation relating the two is given by:L λ = (DN – 1 ) X UCCWhere L λ is the spectral radiance, DN are the TIR band digital numbers, andUCC are the published Unit Conversion Coefficients.193