Method for separating loran sky and ground waves based on levenberg-marquart algorithm

A method for separating Loran sky and ground waves based on a Levenberg-Marquart algorithm, the method comprising:

• (1) generating, by a LORAN signal simulator of a Long-range navigation system, a plurality of simulated Loran sky-ground wave signals, and collecting, by a LORAN receiver of the Long-range navigation system, a plurality of actual Loran sky-ground wave signals;
• and normalizing, by the LORAN receiver, the plurality of simulated Loran sky-ground wave signals and the plurality of actual Loran sky-ground wave signals to obtain a normalized signal;
• (2) preprocessing, by the LORAN receiver, the normalized signal to obtain an initialization parameter;
• (3) according to the initialization parameter, establishing, by the LORAN receiver, a mathematical model for a Loran received signal in time domain;
• and
• (4) fitting, by the LORAN receiver, parameters in the mathematical model using the Levenberg-Marquart algorithm to obtain a Loran sky-wave time delay, a Loran sky-wave amplitude, a Loran ground-wave time delay, and a Loran ground-wave amplitude;
• separating, by the LORAN receiver, Loran sky waves and Loran ground waves in the Loran received signal according to the Loran sky-wave time delay, the Loran sky-wave amplitude, the Loran ground-wave time delay, and the Loran ground-wave amplitude;
• and
• providing, by the LORAN receiver, positioning for the Long-range navigation system based on the separated Loran ground waves.