This paper aims to quantify the precision of retracked Jason-2 altimeter sea level data (2008–2016) in the 0–5 km Australian coastal zone. A new retracking strategy has been developed to achieve the highest possible precision of coastal sea-level data. Coastal waveforms were classified into four groups according to the adaptability of dedicated coastal retrackers, from which each group was reprocessed using an optimal retracker. A modified Brown model was introduced to reprocess the quasi-specular waveforms over calm waters. A seamless transition of sea surface heights from different retrackers was achieved by estimating and removing the significant wave height dependent height differences. In order to generate the 20-Hz sea level anomaly (SLA) and total water level envelope (TWLE) at the coast, the regional along-track mean sea surface (MSS) with a high spatial resolution (~300 m) was estimated. Compared to the global MSS model, the use of the along-track MSS has dramatically reduced the SLA variance by 140 cm² in the 0–15 km coastal strip.

The results from the evaluation of data precision for Jason-2 ground tracks and the validation against tide gauges show that this new retracking strategy can retrieve more reliable sea level data nearshore. The precision of 20-Hz sea level data in the 0–5 km Australian coastal strip ranges typically from 5 cm to 6 cm in most coastal areas, which is only ~1 cm lower than that beyond 5 km off the coastline. However, in Northwest Australian and some coastal regions, the data precision drops to ≥7 cm due partly to the specific coastal sea states and topography. In addition, it is found that the altimeter and tide gauge TWLE time series have a high correlation (>0.8) in the 0–5 km distance band, indicating that coastal sea-level data are useful for applications such as estimation of river plumes, long-term variation of water level in lakes and rivers, and the analysis of storm surges.

本文旨在量化澳大利亚 0-5 公里沿海地区重新跟踪的 Jason-2 高度计海平面数据（2008-2016 年）的精度。已开发出一种新的重新跟踪策略，以实现沿海海平面数据的尽可能高的精度。根据专用沿海再跟踪器的适应性将沿海波形分为四组，使用最佳再跟踪器对每组进行再处理。引入了修改后的 Brown 模型来重新处理平静水域上的准镜面反射波形。通过估计和消除与波高相关的显着高度差异，实现了来自不同重新跟踪器的海面高度的无缝过渡。为了生成海岸的 20 Hz 海平面异常 (SLA) 和总水位包络 (TWLE)，估计了具有高空间分辨率（~300 m）的区域沿航迹平均海面（MSS）。与全局 MSS 模型相比，沿轨道 MSS 的使用显着降低了 SLA 方差 140 cm²在 0-15 公里的沿海地带。

Jason-2 地面航迹数据精度评估和潮汐计验证结果表明，这种新的重新跟踪策略可以检索到更可靠的近岸海平面数据。澳大利亚沿海地带 0-5 公里的 20 赫兹海平面数据的精度在大多数沿海地区通常为 5 厘米到 6 厘米，仅比离海岸线 5 公里以外的精度低约 1 厘米。然而，在澳大利亚西北部和一些沿海地区，由于特定的沿海海况和地形，数据精度下降到≥7 cm。此外，发现高度计和潮汐计 TWLE 时间序列在 0-5 公里距离范围内具有较高的相关性（>0.8），表明沿海海平面数据对于河流羽流估计、