# An adaptive fusion algorithm for coastal sea altimetry based on dual-frequency Beidou-R carrier phase

## TL;DR

This paper introduces a new method using Beidou satellite data to improve the accuracy of measuring sea surface height in coastal areas.

## Contribution

A novel adaptive fusion algorithm using dual-frequency Beidou-R carrier phase data for enhanced coastal sea altimetry.

## Key findings

- The proposed method achieved an RMSE of 2.85 cm and 2.89 cm for SSH estimation using PRN 04 and PRN 33.
- The method demonstrates effectiveness in coastal altimetry through a field experiment at Shenxian River.
- The study analyzed the impact of elevation angle on measurement accuracy.

## Abstract

This article proposes an integer ambiguity determination method based on Beidou system-reflectometry (Beidou-R) observations of the carrier phase at the B1I and B3I frequencies. To enhance the accuracy of sea surface height (SSH) estimation, this study introduces a parallel filtering algorithm and an adaptive iterative fusion algorithm, enabling data fusion based on the variance at B1I and B3I frequencies. To validate and evaluate the proposed method, a coastal experiment was conducted at the Shenxian River. In this experiment, reflected signals from GEO and IGSO satellites were collected. Data analysis reveals that the method is effective, demonstrating that the root mean square error (RMSE) of SSH achieves 2.85 cm and 2.89 cm for PRN 04 and PRN 33, respectively. Furthermore, the impact of the elevation angle on measurement accuracy is analyzed. This study aims to propose a method to enhance coastal sea surface height estimation, offering potential advancements in sea surface altimetry.