Tomographic Correction Techniques For An Enhanced Tropospheric Effects Compensation System

"Propagation Research Associates (PRA) introduces two innovative tomographic techniques, based on ground based GPS satellite signal measurements, that significantly improve angle of arrival error correction for radars tracking long range, low elevationtargets. These tomographic techniques provide real-time updates to existing 3-D refractivity field data sets over a 360 degree field of view, enabling an order of magnitude reduction in error when compared to existing model based refractivity fieldestimators. PRA proposes to expand the capabilities of the Enhanced Tropospheric Error Compensation (ETEC) system concept, developed for BMDO by PRA under contract number DASG60-01-P-0042, with the addition of an Enhanced 3-D Refractivity Fieldmeasurement system. This system will incorporate Ray Tracing Tomographic Correction and Diffraction Tomographic Correction methods to allow real-time measurements of the tropospheric refractivity field for the mitigation of tropospheric error effects dueto large scale bending and turbulence. Phase I will demonstrate the feasibility of the Ray Tracing Tomographic Correction and Diffraction Tomographic Correction technique to estimate bending error and establish a system error budget for integration intothe ETEC system. A Phase I Option is proposed that will develop a prototype design that can be integrated into either GMD XBR or NTW HPD-X for real-time operation. The anticipated results from the prop