Abstract

Long-range localization of maritime infrared targets is challenging due to Earth’s curvature, installation deviations, sensor inaccuracies, and environmental noise.This paper proposes an Earth ellipsoid model-based localization algorithm with a two-stage error compensation mechanism. The algorithm constructs a collinearity equation in the geocentric Cartesian coordinate system to intersect the camera’s secondary optical axis with the WGS-84 ellipsoid, obtaining target coordinates. The first stage uses a dual-target-point calibration method to correct installation angle and hardware-induced secondary optical axis pointing errors. The second stage applies an adaptive Kalman filter to dynamically suppress random errors from environmental disturbances.Experiments on shore-based, shipborne, and airborne platforms show that when the observation device is above 80 m sea level, the proposed method achieves a localization accuracy within 5% of the detection range for distant infrared targets.The algorithm effectively compensates multi-source errors, significantly improving positioning precision under complex sea conditions, and is suitable for engineering deployment.