Omega Wind-Error Estimation.

摘要

The estimation of winds and their errors for Omega radiosonde soundings has been addressed by several authors in the past years. Major improvements over an earlier wind error model have been in modeling VLF propagation for estimation of phase variances of Omega signals and the use of a smoothing improvement factor. The formulation for the phase variance estimation incorporates the distance and direction of propagation,the ground conductivity,noise level around the world,and empirical data collected at Majuro. This has resulted in an extensive tabulation of Omega wind errors. However,with understanding there has also grown a deeper respect for the magnitude of the general problem of adequately modeling VLF disturbances,be they sferic noise on one extreme to a hard X-ray flare on the other. To make this a single source document on Omega windfinding and its errors,the authors have included derivations of basic equations for linear mean-square estimation,and some relevant work on this subject done by the authors.