Direction Finding for the SESAM-System. Digital and Electronic Support Systems(Pejlalgoritmer foer SESAM-Systemet)

摘要

The purpose with this report is threefold. First, an eight-element Adcock antennasystem is studied and expressions for azimuth and elevation angle estimates are derived. Second, the squaring receiver is studied together with the Adcock antenna and an expression for the azimuth angle estimate is derived. This setup is used for direction finding of SS-DS (Spread Spectrum--Direct Sequence) signals with BPSK (Binary Phase Shift Keying) signaling. Third, a three-element antenna system is also studied and expressions for the azimuth and elevation angle estimates are derived. In this report, the authors will concentrate on the theoretical derivation of the direction finding algorithms and not focus on practical direction finding problems. To be able to verify and test the derived finding (DF) algorithms, MATLAB-based antenna simulators were developed. The key component in these simulators is a fractional delay FIR filter that accurately delays radio signals an arbitrary delay time.