VLIDORT User's Guide

corrections, and sphericity corrections for the incoming solar beam and the outgoing line-ofsight.In Chapter 3, we go over the derivation of Inherent Optical Property (IOP) input preparation. Thederivation of the standard set of optical properties required for the computation of the Stokes 4-vector field is outlined, and derivations of linearized optical property inputs for the generation ofatmospheric Jacobians are discussed. Also in Chapter 3, we discuss benchmarking the modelagainst literature datasets, and there is another section on the use of performance enhancements,including the “solution-saving” and “BVP-telescoping” options; these are labor-saving devicesdesigned to eliminate unnecessary computation. We also review the Fourier convergence aspectspertaining to the exact treatments of single scattering and direct beam contributions, and the useof a multiple-SZA facility for look-up table generation.Chapter 4 describes the specifics of the VLIDORT 2.6 package. In section 4.1, we give anoverview of the package; section 4.2 has a description VLIDORT’s source code modules. Insection 4.3, we discuss the input configuration file, “makefile” production of executables, andinstallation of the code. In this regard, a number of tests have been written for this release of thecode, and proper installation of the package will result in the confirmation of the test data set thataccompanies the release. In section 4.4, we summarize the important new software standardsadopted for the code and describe exception handling. This version of VLIDORT is in the publicdomain; copyright and licensing issues are discussed in section 4.5. Chapter 4 concludes withsome acknowledgements in section 4.6. Chapter 5 contains references cited in the guide.Appendices for VLIDORT may be found in Chapter 6. Section 6.1 has important tablesdescribing VLIDORT input and output Fortran 90 type structure variables (both basic andlinearized) along with tables illuminating the association between these variables and the filereadinput strings found in VLIDORT’s input configuration file. Section 6.2 discusses theenvironment programs which serve as package installations tests as well as provide the user withexamples of how to incorporate VLIDORT into his or her desired applications. Lastly, section6.3 gives a complete description of the vector BRDF supplement: information on how theBRDFs are constructed, the inputs and outputs of the supplement software, and descriptions ofthe water and land surface BRDFs included in the package.13