Infrared attitude phase compensation for mountain interference using beta distribution and hyperbolic tangent function

In the field of infrared attitude measurement, ensuring measurement accuracy is a complex yet fundamental task. The complexity of mountainous terrain can interfere with the measurement results of infrared sensors, making correction of interference a critical research topic. Mountain surface infrared radiation, induced by abrupt terrain variations, leads to spatial occlusion and manifests as abnormal infrared emission. This anomaly causes infrared sensors to misinterpret targets, a phenomenon referred to as mountain interference in infrared attitude measurement. To improve the accuracy and reliability of infrared attitude measurement affected by mountain interference, a compensation algorithm based on the Beta distribution and hyperbolic tangent function (Beta-HTC) is proposed. First, an infrared radiation theoretical model for mountain interference is derived to accurately characterize the impact of terrain on infrared signals. Then, the overall and the local skewness are calculated to extract mountain features and identify affected regions. Using extracted characteristics, phase compensation is performed with the HTC correction method to mitigate interference effects and enhance measurement accuracy. Semi-physical experiments were conducted under mountain interference conditions at angles of 30°, 60°, and 90°, verifying the accuracy of the infrared radiation theoretical model. The Beta-HTC method was then applied to correct data for three mountain inclination angles, significantly reducing interference. Comparative experiments showed that the Beta-HTC method achieved best overall performance, with the lowest root mean square error (RMSE) of 0.6859, the mean absolute error (MAE) of 0.55, and the highest R2 value of 0.92, reducing the error by 0.6523 compared to the best-performing traditional model, confirming effectiveness of the method.