A Method for Along-Track Interferometric Phase Elimination of Large Baseline Imaging Radar Altimeter

Abstract

The large baseline imaging radar altimeter (LB-IRA), deployed in a dual-satellite formation, enhances altimetric accuracy to sub-centimeter levels through the use of helical orbits to extend the interferometric baseline. However, for critical oceanographic tasks such as seafloor topography mapping and ocean eddy detection, the along-track baseline can introduce coupled phase interference due to ocean currents. This study examines the impact of ocean currents at various scales on altimetric accuracy from both qualitative and quantitative perspectives. An along-track interferometric phase measurement strategy based on a dual-array system is proposed to eliminate significant altimetric errors caused by ocean currents. Simulation results demonstrate that after accounting for the effects of ocean currents, the relative altimetric accuracy of the LB-IRA can achieve 0.5 cm at 1 km $\times 1$ km resolution, fulfilling the data requirements for high-precision seafloor topography inversion. This research provides a foundation for the practical application of dual-satellite interferometric imaging radar altimeters in oceanographic studies.

Keywords

• Dual-satellite formation
• along-track interferometric phase
• relative altimetric accuracy