VLIDORT User's Guide

Finally, in vlidort_aux, there are standard numerical routines for the eigenproblem solution(based on ASYMTX as used in DISORT) and Gauss quadrature evaluation. This module alsocontains the input file-read tool FINDPAR, and some exception handling software.The module lapack_tools is a compilation of LAPACK subroutines used in VLIDORT(eigensolver DGEEV, linear algebra modules DGETRF/DGETRS and DGBTRF/DGBTRS, plusother routines). More details in Section 4.5Module files required for Jacobian calculations.The module vlidort_lcs_masters calculates column atmospheric Jacobians and surfaceproperty Jacobians in addition to the radiance and mean-value fields, while the modulevlidort_lps_masters returns profile atmospheric Jacobians and surface property Jacobiansin addition to the radiance and mean-value fields. All linearized input functions are contained invlidort_l_inputs.Module vlidort_la_miscsetups and vlidort_lpc_solutions are shared by the twolinearization masters and apply to both types of atmospheric property Jacobian. The firstcomputes linearizations of the delta-M, single-scatter albedo, and transmittance setups for eachlayer optical property and are called early in the main Fourier loop, while the second giveslinearizations of the eigenvalue and particular integral RTE solutions. Setups and source termsrequired for linearized thermal computations are located in the module vlidort_l_thermalsup.Module vlidort_la_corrections and vlidort_lpc_bvproblem are also shared by the 2linearization masters and apply to both types of atmospheric property Jacobian. The firstcomputes linearizations of Z-matrices for the linearization of the single-scatter correction indifferent scenarios, while the second contains help subroutines used in solving the linearizedboundary-value problem. Subroutines to write linearized inputs received by VLIDORT arelocated in vlidort_l_writemodules.The complete generation of column weighting functions is governed by the following fivemodule files, namely: vlidort_lc_bvproblem, vlidort_lc_wfatmos,vlidort_lc_miscsetups, vlidort_lc_corrections, and vlidort_lc_solutions. The firstsolves the linearized boundary-value problem (constants of integration) in a multi-layeratmosphere; this requires only the setup of linearized vectors for the L-U back-substitution (alsocontains modules dealing with linearization boundary value telescoping). The second is the postprocessing solution - generation of column Jacobians at arbitrary optical depths and user line-ofsightangles, the Fourier cosine-series convergence for these Jacobians, and the derivation ofweighting functions for the mean-value fields. The third generates transmission-relatedquantities for the column weighting functions while the fourth generates weighting functions forthe exact single scatter components of the radiation fields. The last develops the linearized beamsolutions for the linearized column RT problem. These routines are only called by the mastersubroutine vlidort_lcs_master.The complete generation of profile atmospheric weighting functions is similarly determined byfive module files: vlidort_lp_bvproblem, vlidort_lp_wfatmos, vlidort_lp_miscsetupsvlidort_lp_corrections, and vlidort_lp_solutions. These routines are only called by themaster subroutine vlidort_lps_master.60