User Manual - pancroma

using the PANCROMA TM ‘Preprocess’ | ‘ Resize Images’ | ‘Resize One Image’utility. Note that in order to get an exact match, you may have to resize all ofyour images downward. The TIR band of the scene used in this example had arow count of 4783 and a column count of 4503. Band 1 had a row count 9566 ofand a column count of 9005. In order to get the correct ratio, it was necessary toresize the TIR band to 4783 by 4502 and band 1 (and other masked bands) to9566 by 9004.IMPORTANT NOTE: If there is only one TIR band, its resolution will match thatof the other multispectral bands exactly.After adjusting the row and column sizes (if necessary) open the files byselecting the ‘Gap Fill’ | ‘Mask Clouds’ | ‘Three File Method’ menu selection.After reading the three files, you will be presented with a data input box. Thisbox will let you set the two comparison thresholds and the cloud buffer radius.The algorithm will select all pixels with DNs below the band1 threshold andabove the band6 threshold. You can also set the Cloud Mask Buffer Width.Because the edges of clouds tend to be diffuse, the algorithm will add all pixelswithin a radius of the Cloud Mask Buffer Width of each selected pixel to themask.The thresholds must be determined empirically. This can best be done byinspecting the band 1 image and the TIR image and interrogating it using thecursor to determine the DNs of the cloud areas. Once this is done, the correctthresholds can be estimated. However, it may take some trial-and-error to getacceptable results.Note that if you wish to mask band 1, you must select the file twice, i.e. ‘File’ |‘Open’ | band1; ‘File’ | ‘Open’ | band1; ‘File’ | ‘Open’ | band6.The images below show an input image with clouds followed by the maskedimage.130