# The Customized Automatic Processing Framework for HY-2A Satellite Marine Advanced Products
## 2 Products and Related Work
### The Ground Application System  
The ground application system is used for receiving, processing, calibrating and validating the data of HY-2A satellite, and is responsible for data applications. Along the data processing chain, the system consists of a mission control subsystem, a data preprocessing subsystem, a processing subsystem, a precise orbit determination subsystem, a calibration and reality check subsystem, a data archiving and distribution subsystem, and a data application subsystem (2015).  
The data preprocessing subsystem is composed of three HY-2 ground receiving stations and a suite of data preprocessing software deployed at the National Satellite Ocean Application Service  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Frequencies** & **Polarization** & **Noise-Equivalent** & **Dynamic** & **Calibration** \\
**(GHz)** & **Polarization** & **Sensitivity (K)** & **Range (K)** & **Precision (K)** \\ \hline
18.7 & & 0.4 & & \\
23.8 & linear polarization & 0.4 & 3–300 & 1.0 (180–320 K) \\
37 & & 0.4 & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: The detailed information of the calibration microwave radiometer.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Frequency** & **Polarization** & **Swath** & **Ground** & **Noise-Equivalent** & **Dynamic** & **Calibration** \\
**(GHz)** & **Polarization** & **Width (km)** & **Resolution (km)** & **Sensitivity (K)** & **Range (K)** & **Precision (K)** \\ \hline
6.6 & VH & & 100 & & & \\
10.7 & VH & & 70 & & & \\
18.7 & VH & 1600 & 40 & Better than 0.5 & 3–350 & 1.0 (180–350 K) \\
23.8 & V & & 35 & & & \\
37 & VH & & 25 & Better than 0.8 & & \\ \hline \hline \end{tabular}
\end{table}
Table 3: The detailed parameters of the scanning microwave radiometer.  
(NSOAS) located in Beijing. Once these ground stations receive the real-time or delayed data, these satellite downlinked data will be transferred to the data preprocessing software for further processing. According to the commands from the mission control subsystem and the parameters from the calibration and reality check subsystem, the data preprocessing software converts the raw data to level-1 products [16].  
The processing subsystem has four processing modules that are used to derive the corresponding data from the radar altimeter, the scatterometer, the microwave radiometer and the calibration microwave radiometer. By using the existing mature geophysical retrieval algorithms and the related ancillary data from the precise orbit determination subsystem, the data can be processed into level-2 and level-3 products which contain the geophysical measurements for different applications [16].  
The data archiving and distribution subsystem mainly provide two functions that can automatically archive the various levels of data, and easily disseminate them to designated users. In order to ensure the data security, the archived data are physically separated from the data distribution system by a network gap. The data archiving module, which is deployed in the inner network, is responsible for automatically collecting the data derived from the data preprocessing subsystem and processing subsystem, and storing them on the data repositories and cataloging them in a spatial database. By synchronizing the cataloging information between inner network and outer network, a user can search and order their desired data by using a data distribution module. As soon as the desired data are ready, users can obtain the data by several means, such as File Transfer Protocol (FTP), Email or CDs [17].  
The data application subsystem has identified six key categories of potential applications of HY-2A data. They are the sea level rise assistant decision-making system, the ocean storm surge monitoring application system, the sea ice monitoring and forecasting system, the marine gravity field application system, the ocean-atmosphere interaction application system, and the ocean fisheries business application system.