Tropospheric delay is an important source of altimeter elevation measurement error. Compared to traditional profile altimeters, interferometric imaging radar altimeter (InIRA) has a larger range of antenna viewing angle, and it cannot directly follow its tropospheric delay estimation method. Based on the data of Sentinel-3A, several commonly used vertical tropospheric delay estimation models are compared and screened, and the screened models are improved for InIRA. Combined with the third-party meteorological data to calculate the improved model results and analyze the influence of antenna viewing angle on dry and wet tropospheric delay estimates, the results show that: The estimated value of dry tropospheric delay is significantly affected by the visual angle of antenna, and the estimated value of wet tropospheric delay is less affected by the visual angle of antenna.
