This is the Split Window Surface Temperature algorithm description derived from the prototype implementation provided by the authors and subsequent conversations and emails. ============================================================================== Algorithm Authors: Aaron Gerace Rochester Institute of Technology email: adgpci@cis.rit.edu Tania Kleynhans Rochester Institute of Technology email: tkpci@rit.edu ============================================================================== Algorithm Description - Overview: 1) Create 2 Landsat emissivity bands based on Landsat top of atmosphere reflectance, ASTER emissivity and ASTER NDVI data. 2) Read TIRS coefficients. 3) Read 2 Landsat TIRS thermal bands. Convert them to thermal radiance, and convert that to apparent temperature. 4) Use the Landsat emissivity bands, apparent temperature bands, and coefficients to make a surface temperature band. ============================================================================== Algorithm Description - Inputs: The primary sources of input to the algorithm are: Landsat L1T thermal bands retrieved from LPGS L1T products ASTER Emissivity and NDVI data Landsat TOA (top of atmosphere) reflectance bands The L1T thermal bands are used to create apparent temperature bands. The ASTER emissivity and NDVI data, as well as the Landsat TOA data from multiple bands, are used to simulate Landsat emissivity bands matching the Landsat scene. ============================================================================== Algorithm Description - Detailed: 1) Read Landsat top of atmosphere reflectance green, red, NIR, SWIR1, and brightness temperature bands for the scene. Generate a Landsat NDVI layer from the red and NIR bands. Generate NDSI and snow layers from the green and SWIR bands. Get projection information from the brightness temperature band. 2) Retrieve ASTER emissivity and NDVI data, and warp them to match the Landsat scene. 3) Calculate a simulated Landsat emissivity layer using the ASTER emissivity values, ASTER NDVI values, Landsat NDVI band, NDSI band, and snow locations. Write the simulated Landsat emissivity layer to a file. Repeat the the process using coefficients for 2 Landsat TIRS bands to produce 2 emissivity files. 4) Read predefined TIRS coefficients. 5) Read metadata for 2 Landsat thermal bands. 6) Use the 2 Landsat L1T thermal bands and metadata coefficients to derive thermal radiance layers, and write band files for those 2 layers. 7) Use the 2 thermal radiance layers and metadata coefficients to compute 2 apparent temperature layers. 8) Calculate Surface Temperature: epsilon = (b10_emissivity + b11_emissivity) / 2 delta_epsilon = b10_emissivity - b11_emissivity b = TIRS coefficients b10 = band 10 apparent temperature b11 = band 11 apparent temperature surface_temperature = b[0] + (b[1] + b[2] * ((1 - epsilon) / epsilon) + b[3] * (delta_epsilon / (epsilon^2))) * ((b10 + b11) / 2.0) + (b[4] + b[5] * ((1 - epsilon) / epsilon) + b[6] * (delta_epsilon / (epsilon^2))) * ((b10 - b11) / 2.0) + b[7] * ((b10 - b11)^2) 9) Scale the surface temperature value to include 1/10 degree precision in the integer product. If intermediate bands are included in the final product, also scale the 2 emissivity bands and 2 thermal radiance bands and convert them to integer.