Sea-skimming Flight Helicopter Adaptive Wave Filter

In this paper, the design of adaptive filter of the helicopter skimming sea and the application of LMS and RLS on this question is studied. In order to simulate and research easily, the sea spectra in kinetic coordinate system is derived. The simulations of the sea adaptive filter adopting LMS, NLMS and RLS are given. In order to solve the numerical instability of RLS, by Square-root information Kalman filter, An algorithm of RLS based on QR-decomposition (QRRLS) is derived, and the simulation of this filter is also given. In the final, to reduce the complexity of the Information filter based on QR-decomposition, QRDLSL (Least-squares order-recursive lattice adaptive filter based on QR-decomposition )is introduced, and the simulation is also given.It can be drawn from the simulation of the sea adaptive filter adopting various algorithms mentioned that the LMS, NLMS, QRRLS and QRDLSL are all effective to denoise the sea noise. While considered from the complexity of algorithm and denoising effect, the QRDLSL is best.