Validation of the Significant Wave Height Product of HY-2 Altimeter

Chuntao Chen,Jin Wang,Yili Zhao,He Wang,Mingsen Lin,Jianhua Zhu

doi:10.3390/rs9101016

Chuntao Chen, Jin Wang + Show 4 more

Open Access

https://doi.org/10.3390/rs9101016

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Abstract

HY-2 was launched by China on August 2011, which has provided continuous wave height measurements to monitor ocean dynamic environments for more than 5 years. Before using these data, however, the measurements need to be validated. Based on the in situ buoy data from the National Data Buoy Center (NDBC) and the Jason-2 altimeter data, the HY-2 Ku-band significant wave height (SWH) measurements were validated. The comparisons showed that a linear regression with NDBC measurements can be used to improve the accuracy of the HY-2 SWH measurements. Compared with the NDBC SWH data, the validation results of the HY-2 SWH data show an RMS (root mean square) of 0.33 m, which is similar to that of the Jason-1 and Jason-2 data; the RMS of the HY-2 SWH is 0.30 m, which, corrected via linear regression, is similar to that of the corrected Jason-1 and Jason-2 data (0.27 m and 0.23 m, respectively). Therefore, the accuracy of the HY-2 SWH products is close to that of the Jason-1/2 SWH data.

Highlights

Traditional ocean wave observation is mainly performed via buoys, survey ships, and tide stations, and the coverage is very limited
The HY-2 significant wave height (SWH) data are Level 2 IGDR products distributed by the National Satellite Ocean Application Service (NSOAS), the State Oceanic Administration of China
During Cycle 40, the HY-2 satellite changes its altimeter sensor from the main one (Alt-A) to the backup one (Alt-B)

Summary

Introduction

Traditional ocean wave observation is mainly performed via buoys, survey ships, and tide stations, and the coverage is very limited These methods, cannot meet the needs of the current high-speed development of the economy and of scientific research. Satellite altimeter operation benefits from continuously improving measurement accuracy and calibration and validation methods. The positive impact of the satellite altimeter SWH data assimilation in numerical wave models has been estimated on the coastal scale or global scale [4,5,6]. Calibration and validation plans are usually conducted after operational satellite altimeters are launched Based on these plans, these sea surface height (SSH), SWH, and backscattering coefficient measurements are calibrated and validated during dedicated commissioning phase operations [8,9].

Materials

Methods

Validation with NDBC

Validation with JASON-2

HY-2 SWH Uncertainty Analysis