The present disclosure generally pertains to systems and methods for autonomously detecting and correcting anomalies in position information provided to aircraft using radio-frequency signals. By enabling autonomously detecting and correcting for anomalies in the operation of a ground-based solution entirely independent of GPS, systems of the present disclosure can make the provided position information more accurate and robust, thereby enhancing the effectiveness and safety of navigation systems using the provided position information. More precisely, systems of the present disclosure may employ a series of ground-based beacon transmitters to provide radio-frequency (RF) signal pulse with a highly regular frequency. A locating receiver can detect the arrival times of these pulses and use this information to detect and report certain anomalies. These reports may then be used to autonomously correct the detected anomalies.

The present disclosure generally pertains to systems and methods for autonomously detecting and correcting anomalies in position information provided to aircraft using radio-frequency signals. By enabling autonomously detecting and correcting for anomalies in the operation of a ground-based solution entirely independent of GPS, systems of the present disclosure can make the provided position information more accurate and robust, thereby enhancing the effectiveness and safety of navigation systems using the provided position information. More precisely, systems of the present disclosure may employ a series of ground-based beacon transmitters to provide radio-frequency (RF) signal pulse with a highly regular frequency. A locating receiver can detect the arrival times of these pulses and use this information to detect and report certain anomalies. These reports may then be used to autonomously correct the detected anomalies.

Provided herein is a method for separating Loran sky and ground waves based on a Levenberg-Marquart algorithm, including: (1) collecting a plurality of Loran sky-ground wave signals followed by normalization to obtain a normalized signal; (2) preprocessing the normalized signal by inverse Fourier transform method to obtain an initialization parameter; (3) establishing a mathematical model for the Loran sky-ground wave signals in time domain; and (4) solving parameters of the mathematical model using the Levenberg-Marquart algorithm to separate the Loran sky and ground waves.

A transmitter includes a Loran pulse generator, a dispersion filter, an equalizer, a power amplifier, an antenna tuner, and an antenna. The Loran pulse generator is configured to generate a Loran pulse signal. The dispersion filter is coupled to the Loran pulse generator, and is configured to generate a dispersed signal responsive to the Loran pulse signal. The equalizer is coupled to the dispersion filter, and is configured to generate an equalized dispersed signal responsive to the dispersed signal. The power amplifier is coupled to the equalizer, and configured to generate an amplified signal responsive to the equalized dispersed signal. The antenna tuner is coupled to the power amplifier, and is configured to generate a tuned signal responsive to the amplified signal. The antenna is coupled to the antenna tuner, and is configured to radiate a transmitted signal responsive to the tuned signal.