Algorithm optimization of piecewise polynomial modeling for ionospheric perturbation correction

Ionosphere phase perturbation made the clutter spectrum spread and influenced the precision of parameter inverse analysis for sky wave sea state radar. Recently, an algorithm based on piecewise polynomial signal (PPS) phase model and high-order ambiguity function has been applied to resolve this problem. The determination of the order for the polynomial phase is critical in the applications of the algorithm. Two order-selecting methods based on self-adaptive polynomial model are proposed and verified by simulation. The results indicated that the new methods (frequency-domain and time-domain) based on the characteristics of high-order ambiguity function (HAF) transformation improved greatly in accuracy and that the amount of calculation is reduced. The polynomial order can be judged exactly, especially at low signal-to-noise ratio (SNR) when employing the frequency-domain method.