In the meantime, with the help of the satellite, people can choose fish breeding areas more rationally, which will help improve the efficiency of the mariculture industry.

On April 11, 2007, China's second ocean satellite HY-1B was launched. It made up for the shortcomings of HY-1A, optimized technical indicators and improved other functions. With its launch, China achieved real-time dynamic monitoring over the 3-million-square-km sea areas under the jurisdiction of China. Also, it got real-time environmental information of the Arctic, the Antarctic and other areas such as the Gulf of Aden.

It has now been joined by HY-2. It cooperates with HY-1B to form a three-dimensional monitoring system covering both outer space and underwater areas, through the comprehensive use of microwave and optical observations and a combination of dynamic oceanic environmental monitoring and marine resource detection.

Functions

The new satellite has greatly enhanced China's ocean monitoring capabilities. Meanwhile, because it can observe nearly 90 percent of the ocean's wind fields, its observation data is an effective complement to the data of global microwave remote sensing satellites.

To be specific, researchers can determine the environmental information of the fisheries through a combined analysis of the temperature and sea levels monitored by HY-2 and the chlorophyll—an element decisive for marine primary productivity—monitored by HY-1B. Thanks to the joint information, researchers are able to get accurate environmental information about the fisheries.

In addition, devices on the HY-2 can tell the frontal surface and the mesoscale eddies in the ocean. This information provides meteorological support for fishing activities.

The HY-2 satellite can obtain various ocean dynamic parameters across the world, including the wind fields, wave, circulation of the oceans and sea surface temperatures.

It can directly assist in marine environmental monitoring and prediction, oceanographic research, marine pollution monitoring and oceanic environment changes.

The HY-2 contributes significantly to disaster prevention and mitigation. It can provide information on winds, waves, streams, tides and sea ice for navigation. The satellite effectively monitors changes in the global sea level, the El Nino phenomena, and changes of polar ice caps as well as extreme oceanic phenomena including storms, typhoons, tsunamis and heavy surfs.

The HY-2 will greatly improve the accuracy and timeliness of the marine environmental forecast. Unlike HY-1A and HY-1B, which rely on infrared rays and visible light detection, the HY-2 depends on active and passive microwave remote sensor for detection.

Microwave remote sensing is a new means of observing the Earth from space. Compared with visible light and infrared rays remote sensing, microwave remote sensing has unique advantages because it will not be affected by cloud, thunder and rain—it can work around the clock in all kinds of weather.

"An active microwave remote sensing device is like radar, whose sensor proactively emits electromagnetic waves and receives reflected or scattered electromagnetic waves. Passive microwave remote sensing device is like a camera which receives the electromagnetic wave emitted by the surface of the ocean," said Jiang Jingshan, chief scientist of the National Space Science Center of the Chinese Academy of Sciences (CAS).

HY-2 carries four main instruments: a radar altimeter, microwave scatterometer, scanning microwave radiometer and correction microwave radiometer. The first two are active microwave remote sensing devices and the last two are passive microwave remote sensing devices. These four instruments, together, play the major role in monitoring and surveying the ocean dynamic environment.