# The Customized Automatic Processing Framework for HY-2A Satellite Marine Advanced Products
## 2 Products and Related Work
### The Onboard Sensors of HY-2A Satellite and Their Products
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Frequency (GHz)** & **Swith Width (km)** & \
\begin{tabular}{c} **Accuracy of Sea Surface** \\ **Height at the Nadir Point (cm)** \\ \end{tabular} &
\begin{tabular}{c} **Range of the Significant** \\ **Wave Height (m)** \\ \end{tabular} \\ \hline
13.58/5.25 & \(\leq\)2 & \(\leq\)8 & 0.5–20 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The detailed information of the radar altimeter of HY-2A. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Frequency (GHz)** & **Polarization** & \begin{tabular}{c} **Ground** \\ **Resolution (km)** \\ \end{tabular} & **Swath Width (km)** & \begin{tabular}{c} **Accuracy of Wind** \\ **Speed (m/s)** \\ \end{tabular} & \
\begin{tabular}{c} **Range of Wind** \\ **Speed (m/s)** \\ \end{tabular} &
\begin{tabular}{c} **Accuracy of Wind** \\ **Direction (\({}^{\circ}\))** \\ \end{tabular} \\ \hline
13.256 & HH and VV & better than 50 &
\begin{tabular}{c} H polarization 1350, V \\ polarization 1700 \\ \end{tabular} & 2 & 2–24 & 20 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The technical specifications of HY-2A microwave scatterometer. dependence, the variables can be retrieved from a set of multifrequency, multivariable simultaneous equations. The products of the scanning microwave radiometer are also processed into three levels. The level-1 data are the antenna temperatures after a series of calibration procedures including geolocation analysis, attitude adjustment, along-scan correction and so on. The level-2 products are various geophysical measurements derived from the calibrated brightness temperatures in level 1, including sea surface temperature, water vapor, cloud liquid water and wind speed. The level-3 products are daily and monthly gridded products at global or polar regional scale. The detailed parameters of the radiometer are listed below in Table 3.  
The calibration microwave radiometer is mainly used to provide the essential calibration parameters for water vapor processing of the scanning microwave radiometer and the radar altimeter. With fewer channels and better sensitivity, it can process the atmosphere parameters in real-time. The products can be categorized into two levels. The first level is similar to the corresponding products of the scanning microwave radiometer. The second level is the derived geophysical measurements. The detailed information is listed in Table 4.  
A few studies have been conducted on the quality assessment of HY-2A data. [PERSON] et al. (2013) compared the data of HY-2A with the data of the NDBC (National Data Buoy Center) of the National Oceanic and Atmospheric Administration (NOAA), the data of the European Centre for Medium Range Weather Forecasting (ECMWF), and the data of the advanced scatterometer (ASCAT). The result shows that the quality performances of the HY-2A near-real-time wind vector data (especially the wind speeds) were satisfactory throughout the service period. A cross comparison with JASON-2 data over the same period has been performed in order to compare the sea surface height and sea level anomaly of the HY-2 altimeter (2014). In that paper, [PERSON] et al. found that the precision of HY-2 sea surface height is the same as that of JASON-2.