Accession Number : ADA262381


Title :   Algorithms for Interpolating and Approximating Radiance Profiles


Descriptive Note : Final rept. 1 Oct 88-30 Sep 89


Corporate Author : SOUTHEASTERN MASSACHUSETTS UNIV NORTH DARTMOUTH DEPT OF MATHEMATICS


Personal Author(s) : Leon, Steven J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a262381.pdf


Report Date : 02 Apr 1990


Pagination or Media Count : 15


Abstract : Using radiative transfer theory it is Possible to relate the Planck intensity to the upwelling intensity of the atmosphere. The infrared upwelling intensity can be measured by remote sensing from satellites. Using the H- function inversion theory of Chandrasekhar it is possible to represent the radiance function and the Planck function as transform pairs. In this paper we present methods for obtaining a rational function approximation to the radiance profile. The approximation is obtained using rational interpolation and nonlinear least squares techniques. The Planck function can then be determined as an inverse transform. We also consider regularization methods for solving the radiative transfer equation. In this from the problem is transformed into a linear system with quadratic constraints. Two algorithms are given for solving the constrained problem. In practice, however, one cannot obtain meaningful solutions because the matrices involved have low numerical ranks. A singular value analysis is given for matrices derived from data obtained from the NOAA TIROS Operational Vertical Sounder.


Descriptors :   *ALGORITHMS , *TEMPERATURE , *RADIATIVE TRANSFER , *INTERPOLATION , LINEAR SYSTEMS , THEORY , INTENSITY , PROFILES , APPROXIMATION(MATHEMATICS) , RADIANCE , LEAST SQUARES METHOD , ARTIFICIAL SATELLITES , INVERSION , VALUE , ATMOSPHERES , MEASURE THEORY , RATIONAL FUNCTIONS


Subject Categories : Numerical Mathematics
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE