Installed Performance Analysis of a Direction Finding System on Board of a Large Aircraft Platform

The platform integration of antennas for direction finding purposes requires an optimisation of the antenna location onboard the platform in order to minimize interferences and bearing errors. While much effort has been spent building mockups for measurements in the past, the availability of modern simulation methods enable an accurate (full wave) simulation of the platform installed performance of antennas even on electrically relatively large platforms. This contribution demonstrates the application of the Multilevel Fast Multipole Method (MLFMM) to the analysis of a nine-element array antenna for direction finding applications on board of an Airbus A319 platform. The simulated quantities (field strengths and element voltages) are then fed into the interferometer algorithms in order to evaluate the system performance (bearing accuracy) for the antenna installation considered. It is shown, that the engine nacelles of the A319 have a characteristic influence on the bearing error.