Benefit of a monitoring system in situ for direction finding antennas
Résumé
Antenna arrays works at their peak performance when they are well calibrated at the factory. Once they are employed in a real environment, they might be subject to unpredictable disturbances. That's why recalibration after operational deployment is required but is usually not done due to practical difficulties. In some applications such as Direction Finding (DF), direction of arrival estimation is susceptible to the antenna model errors. However, the evolution of Direction finding antenna, as the pushed integration of an antenna array mounted on a vehicle and the use of more efficient antennas tend to increase this type of disturbances. This paper proposes to evaluate the benefit of an in-situ measurement system for detecting and compensating the disturbance of antenna radiation. The influence of permanent scatters on one hand and variables (open door...) on the other hand in the vicinity of antenna array is investigated. We present a quantitative study of a biased calibration using a model combining 3D electromagnetic simulation, a complete receiver model and a MUSIC direction of arrival algorithm characterization. Two antennas arrays with same height are compared: a standard dipole array and an electrically small UWB antenna array.