Precise starlight refraction navigation observation model based on LS-SVM

The precise observation model for stellar refraction navigation using the least squares support vector machine (LS-SVM)is introduced.The process involves high fidelity simulations of stellar refraction via ray tracing,considering changes of atmospheric parameters with altitude,to determine the nonlinear mapping between true altitude and refraction angle.The LS-SVM algorithm is applied to fit this relationship accurately,creating a precise model for refracted apparent height.Simulations show the model achieves high precision,with an average absolute error of 0.986m.When integrated into a stellar navigation system,it significantly enhances navigation accuracy,reducing the average positioning error to 130.7 m and velocity error to 0.1479 m/s,thereby validating the effectiveness of the modeling approach.This approach is significant for the high-precision study of autonomous navigation using stellar refraction.