Evaluation of the Impact of Variable Temporal and Spatial Data Resolution upon IREPS (Integrated Refractive Effects Prediction System)

摘要

Atmospheric refractive index gradients significantly modify the path of electromagnetic (EM) waves as they propagate through the atmosphere. Accordingly, the performance of U.S. Navy (EM) systems can be either degraded or enhanced due to atmospheric conditions which effect atmospheric refractive index profiles. The Integrated Refractive Effects Prediction System (IREPS) version 2.2 is the latest software developed by Naval Ocean Systems Center to predict atmospheric refraction and its resulting effect on EM systems. Specific environmental parameters are used as input data to produce various output products to be used by the tactician in planning the optimum use of naval assets. The quality and accuracy of the resulting output is directly related to the quality and timeliness of the input data. This thesis study shows the importance of timely, high resolution data, for input into the IREPS version 2.2 program, in order to obtain realistic atmospheric refractive and corresponding EM system performance predictions. A continentally derived data set is used to compare the results of using high resolution versus low resolution data as input into IREPS, and to qualitatively show how quickly the refractive structure of the atmosphere can vary with time. A second data set from an ever ocean experiment attacks the horizontally homogeneous atmosphere assumption which appears to be frequently incorrectly applied. Finally, a statistical comparison can result in significant variations of atmospheric refractivity that could affect naval EM systems.