--------------- MODIS PRODUCTS v1.1 ---------------------------------- Date: May 2002 Version: MODIS Products v1.1 Changes: Initial release of products: cloud mask (MOD35) cloud top properties (MOD06) flatfile extractors ancillary data extractors ---------------------------------------------------------------------- --------------- MODIS PRODUCTS v1.2 ---------------------------------- Date: October 2002 Version: MODIS Products v1.2 Changes: Initial release of atmospheric profiles software (MOD07) Note: This release consists of the atmospheric profiles product. No other Level 2 products are included in this release, nor do they need to be updated prior to using this software. This release includes software for use with MODIS Terra data only. ---------------------------------------------------------------------- --------------- MODIS PRODUCTS v1.3 ---------------------------------- Date: January 2003 Version: MODIS Products v1.3 Changes: 1) Terra and Aqua compatible. Platform name a required input for flatfile extractions, cloud mask and cloud top properties execution. See the text below for more explicit details on the changes made in this release. This direct broadcast cloud mask release is concurrent with DAAC cloud mask operational MOD35 version 4.2.0. This direct broadcast cloud top properties and cloud phase release is concurrent with DAAC MOD06CT version 4.0.4. 2) Software release to correct striping in Band 26 (1.38 micron) called DESTRIPE_BAND26.tar 3) To reduce the size of the software tar files, test data is no longer included in the product data directory. Test input data is available separately from the ftp site. This means that the modis_cloudmask.csh script has been modified to look for data in new locations. -------------------------------------------------------------------------- This release of the CLOUD MASK contains several changes from version v1.1: The software now works for both Aqua and Terra datasets. There is a Satellite Platform Keyword required as input to run the algorithm and the modis_cloudmask.csh script. This also means there are separate Aqua and Terra thresholds files. There are checks in the software to make sure that the Platform Keyword and the thresholds file used are consistent. The modis_cloudmask.csh script had been modified to include a call to destripe the band 26 data. This is not required, but the thin cirrus detection in the algorithm will work correctly when this is used. The modis_cloudmask.csh has also been changed to point to certain directories when locating data sets. Follow the !!! symbols to direct you to what needs to be modified to work operationally on your system. An IDL routine is included in this delievery which can convert the mod35.img and mod35qa.img files into a MOD35 HDF file. Please see instructions for use in the cloudmask/README file. The ecosystem file (goge1_2_img.Z) is no longer included as part of the CLOUDMASK.TAR file. It can be found as a separate file on the ftp site. Changes have have been made to improve the quality of the cloud mask: - Added switch for Aqua vs. Terra processing. Use band 6/7 for calculation of NDSI (snow) for Terra/Aqua and adjusted thresholds accordingly. Added reflectance threshold test for band 6/7 for Terra/Aqua. This is an additional test for screening out cloudy pixels incorrectly identified as snow. - Defined small portion of Greenland to be "high elevation" even though it is below 2000 meters. This to eliminate false clouds generated by the 1.38 um test. - Adjusted daytime, land clear sky restoral test thresholds for Aqua data. - Fixed logic error in polar, daytime processing - very small impact on results. - The nighttime land 3.9-11 um brightness temperature difference (BTD) low cloud test threshold is now a function of the 11-12 um BTD. Allows better discrim- ination between low clouds and clear sky especially in humid atmospheres. - A new 7.3-11 um BTD test for mid-level clouds has been included for nighttime land scenes. Clouds with temperatures in the 240-260K range are sometimes very difficult to detect without solar illumination. - The polar night 3.9-11 um cloud test for snowice surfaces will also be used for other polar night land surfaces not explicitly listed as snow-covered by ancillary data. More low clouds will be identified as a result. - A nighttime land 11 um clear-sky restoral test was introduced. It is similar to the daytime 11 um clear-sky restoral test but uses lower thresholds. Aids in identifying clear-sky pixels. - Fixed minor code bug in get_pxldat.f. The error had little or no impact on quality. -------------------------------------------------------------------------- This release of the CLOUD TOP PROPERTIES and CLOUD PHASE ALGORITHM contains changes from version v1.1: The software now works for both Aqua and Terra datasets. There is a Satellite Platform Keyword required as input to run the algorithm and the modis_cloudtop.csh script. Coefficients and noise thresholds are chosen based upon the satellite platform name. Different noise thresholds are now used for Aqua and Terra. Aqua CO2 channels are less noisy; more co2 slicing solutions are expected as a result. The modis_cloudtop.csh script had been modified to include a call to destripe the band 26 data. This is not required, but the thin cirrus detection in the cloud mask algorithm will work correctly when this is used. The modis_cloudtop.csh has also been changed to point to certain directories when locating data sets. Follow the !!! symbols to direct you to what needs to be modified to work operationally on your system. An IDL routine is included in this delievery which can convert the mod06.img files into a MOD06 HDF file. Please see instructions for use in the cloudtop/README file.