Inter-Sensor Calibration between HY-2B and AMSR2 Passive Microwave Data in Land Surface and First Result for Snow Water Equivalent Retrieval.

Shuo Gao,Zhen Li,Wu Zhou,Xiaobin Yin,Quan Chen,Mingsen Lin

doi:10.3390/s19225023

Abstract

The self-designed HaiYang-2B (HY-2B) satellite was launched on 24 October 2018 in China at 22:57 UT in a 99.34° inclination sun-synchronous orbit. The Scanning Microwave Radiometer (SMR) on the core observatory has the capability to provide near-real-time multi-channel brightness temperature (Tb) observations, which are designed mainly for improving the level of marine forecasting and monitoring, serving the development and utilization of marine resources. After internal calibration and ocean calibration, the first effort to retrieve land surface snow parameters was performed in this study, which obtained extremely low accuracy both in snow extent and snow mass. Accordingly, land inter-sensor calibration was carried out between SMR and the Advanced Microwave Scanning Radiometer 2 (AMSR2) in order to broaden the research and application of SMR data on the Earth’s land surface. Finally, we evaluated the consistency of the snow extent and snow mass derived from the initial and land-calibrated SMR data. The results indicated that a systematic SMR cold deviation whose magnitude depends on the channel is present for all the compared channels. After intercalibration, the conformity of the snow extent and snow mass were substantially improved compared to before; the relative bias of the snow extent and snow mass decreased from −49.97% to 2.97% and from −51.71% to 3.01%, respectively.

Highlights

Geophysical parameters including snow depth/snow water equivalent (SWE), soil moisture, sea ice concentration, and precipitable water vapor are key quantities in the study of terrestrial water cycles and play an important role in the study of Earth energy balance [1,2,3,4]
Advanced Microwave Scanning Radiometer 2 (AMSR2) sensors daily brightness temperatures were compared for the typical large-scope region (Figure 1) in continental Asia and were extremely close to the 1:1 line to different extents, respectively
The Scanning Microwave Radiometer (SMR) radiometer relies on the stable calibration of the HY-2B satellite to meet its many scientific and social application goals

Summary

Introduction

Geophysical parameters including snow depth/snow water equivalent (SWE), soil moisture, sea ice concentration, and precipitable water vapor are key quantities in the study of terrestrial water cycles and play an important role in the study of Earth energy balance [1,2,3,4]. The Earth system is a complex, dynamically changing system. Researches on the changing trends of the Earth system rely on long-term, stable, high-quality datasets of surface parameters [5,6]. Long-term sequence observations of surface data are of great significance for studying changes and predictions in the Earth’s environment [7,8]. Spaceborne passive microwave sensors play an important role in Earth observation, providing valuable data for retrieving a various range of critical land-surface parameters and studying changes in the Earth’s environment for time series [9].

Objectives

Methods

Results

Conclusion