INS/GPS Integration with Adaptive Beamforming
F. Berefelt, B. Boberg, F.L.T. Eklof, Johan Malmström, L. Pääjärvi, Peter Strömbäck, S.-L. Wirkander · 2003
The Swedish Armed Forces are evolving towards a Network Based Defense (NBD) where accurate position and timing information will be essential. One important capability in NBD is to use, as well as counteract, long-range precision weapons. To simulate and assess the performance of different robust navigation system realizations and countermeasures in various navigation warfare scenarios, a simulation environment is being developed. In this paper we focus on a long-range precision engagement scenario where an aerial platform is navigating towards a stationary target. The proposed navigation system consists of a tightly coupled INS/GPS where measurements are integrated by means of an Extended Kalman Filter (EKF). The INS/GPS is also integrated with an adaptive beamforming antenna array. The target is protected by multiple airborne low-power mini-jammers and a high-power ground based jammer. All jammers are wideband Gaussian noise jammers. Three different beamforming algorithms, Minimum Variance (MV), Linearly Constrained Minimum Variance (LCMV) and Multi-target LCMV (MT-LCMV), from the class of power minimization algorithms are investigated, two of which are direction-constrained. Navigation accuracy in terms of mean position error over the flight path and position error at the end-point is presented for the beamforming algorithms and different antenna array configurations. The system employing the MT-LCMV beamforming algorithm proved to be the most promising, in terms of position error, for navigation warfare scenarios.