Maritime Radar Spherical Projection for Earth Curvature Correction

The patent applies projection error correction to radar target data before the multi-radar track fusion process. Each platform performs spherical projection correction on its own detected targets, converting them to ground spherical positions. This preliminary correction ensures that when data is fused centrally, the projection errors from earth curvature have already been eliminated, improving tracking accuracy without increasing the complexity of the fusion system itself.

The patent changes the coordinate system and projection method from traditional plane projection to spherical projection that accounts for earth curvature. Instead of using sensor position calibration alone, the system transforms target coordinates through spherical projection formulas that incorporate earth radius, radar altitude, and target range. This parameter change makes the system adaptable to long-range maritime surveillance where earth curvature effects become significant.

The patent divides the projection error correction task into independent segments that can be performed by each radar platform individually. Each platform calculates its own projection correction using its specific parameters (altitude, location) and applies it to its detected targets. This segmentation allows single-platform processing to achieve high accuracy without requiring complex centralized correction systems, as each platform independently corrects its own data before sharing.