Abstract:

Using Level-2 low-rate expert-level data obtained from the Surface Water and Ocean Topography (SWOT) satellites, this study calculates the positions of crossover points using a gridding method, quantitatively analyzes self-crossover discrepancies, and investigates the impacts of various factors—the time difference between the crossover points, crossover distance, distance from the coast, and latitude—on these discrepancies.Results show that in most regions, discrepancies fall within the range of -0.2 m to 0.2 m, indicating good data consistency, although notable discrepancies are observed in specific regions. Further analysis reveals that the distance between the crossover points has a minimal impact on discrepancies; discrepancies near the coastline are relatively dispersed, while those observed in regions farther from the coastline tend to decrease and stabilize. In high-latitude regions, discrepancies decrease. The time difference shows a certain degree of dispersion in its influence on discrepancies. In a certain range (within 2 km), the distance between the crossover points has a minimal impact on discrepancies. The findings of this study provide a scientific basis for improving the accuracy and reliability of altimetry data obtained from SWOT satellites.

Key words: surface water and ocean topography satellite, self-crossover discrepancies, latitude, time difference