Recent Upgrades to MODTRAN - New Solar Irradiance and Instrument Scanning Functions

摘要

Recent upgrades are intended to make MODTRAN a more accurate, convenient and versatile atmospheric modeling tool. The current default solar irradiance database due to Kurucz was corrected in the 310-340 nm region using measured data. Several other data sets are also made available to the user. The user can also use his/her won data residing in a file. Examination confirms that the corrected Kurucz data is still the best overall among all currently available data sets. MODTRAN can now be run using frequency inputs which are in wavenumber, nm or micron. Additionally, there is now the capability of obtaining radiance and transmittance which are convolved with an appropriate instrument scanning function. Several choices of scanning functions are available including a user-defined option. This upgrade is helpful to users who would like to model satellite data which are gathered as a function of wavelength and have undergone instrument degradation. All upgrades are accomplished while maintaining strict compatibility of TAPE5 with earlier versions of the code. Work is currently in progress to incorporate NOVAM (Navy Oceanic Vertical Aerosol Models) into MODTRAN.