Engineering topics

Thompson, Owen E.

Publications and source records attributed to Thompson, Owen E..

3 records

NASA NTRS1992

Regularizing the satellite temperature-retrieval problem through singular-value decomposition of the radiative transfer physics

A new technique is derived for retrieving atmospheric temperature profiles from satellite-measured spectral radiance that appears, in first tests, to effectively circumvent certain difficulties of other well-known and implemented techniques. This method provides an effective manner to avoid numerical instability without having to force the algorithm toward adherence to a priori statistics not dependent on the radiance measurements. This provides the opportunity to obtain more information from satellite sounding instruments, without encountering instabilities owing to overlapping weighting functions.

Thompson, Owen E.↗

NASA NTRS1990

Coupling of horizontal, vertical, and temporal resolving power of a satellite temperature sounder

This paper examines the interconnection between the vertical, horizontal, and temporal resolving power of satellite temperature-sounding system. Using a temperature cross section produced by interpolating a set of RAOBs taken at three locations in Texas; Shreveport, Louisiana; Jackson, Mississippi; and Montgomery, Alabama, and an artificially constructed temperature cross section, it was found that the horizontal and temporal resolving power are subject to strong controls imposed by the vertical resolving power of the sounder. Thus, to improve the horizontal or temporal resolving power it is necessary to improve the vertical resolving power' of the satellite instrument itself, or to extend the a priori external information to include correct horizontal and temporal structure.

Thompson, Owen E.↗

NASA NTRS1986

The ill-posed nature of the satellite temperature retrieval problem and the limits of retrievability

The inverse problem of satellite temperature profile retrieval is well known to be ill-posed. This means that not only is a vertical temperature profile solution not unique, but that two solutions can be very different from each other. A set of atmosphere-like, and true atmospheric examples of significantly dissimilar inverse solutions, were sought and found, using an 11-channel simulated HIRS sounding radiometer. Using the Riemann-Lebesgue Lemma for guidance, it is shown that simultaneous, numerical solutions of an atmospheric character may differ by as much as 10 K between 10-1000 mb. However, an empirical search for dissimilar solutions in the natural atmosphere reveals an extremely low probability of finding two significantly different RAOBs which produce radiance measurements whose differences cannot be resolved by the satellite radiometer. The empirical results are used to derive a first estimate of the limits of retrievability, analogous to the limits of predictability derivable from the ill-posed nature of the numerical weather prediction problem.

Thompson, Owen E.↗