Shulou(Shulou.com)11/24 Report--

Satellite remote sensing technology can "see the sea" from another perspective.

Nowadays, all countries in the world have a consensus that "the 21st century is the century of the ocean". Because the ocean can not only provide living space, food and minerals for human beings. Transport and water resources, and will play an important role in the development of new energy.

Ocean energy is a kind of renewable energy with great reserves, which usually includes five types: tidal energy, wave energy, ocean current energy, temperature difference energy and salt energy. as the source of new energy for the earth in the future, marine resources will naturally become the focus of competition among countries all over the world.

The opening and utilization of the ocean will play an increasingly important role in driving the future economic development and energy development, so the development of marine technology is particularly important. Among them, the monitoring and prediction of marine hydrological information using satellite remote sensing technology is very important to the development of marine resources, the development of marine economy, the protection of marine ecology and the maintenance of marine rights and interests. This paper gives a brief overview of the application of satellite remote sensing technology in marine development.

01. Development status of marine remote sensing satellites at home and abroad

The research on the application of ocean satellite abroad started early. The first special ocean satellite in the world was launched by the United States in 1978. The satellite successfully observed the water color of the coastal zone.

In 1997, NASA launched the world's first dedicated ocean color satellite, SeaStar. The "Water" satellite launched in 2002 can measure the sea surface wind speed, and the "Croris" satellite launched in 2003 can measure the sea surface wind field.

The research on ocean remote sensing satellites in Europe is mainly focused on integrated observation satellites. A number of "European remote sensing satellites" were launched from 1991 to 2001. the cold satellite-2 launched in 2010 can accurately observe ocean floating ice and polar ice.

Russia launched five experimental ocean surveillance satellites from 1965 to 1969. from 1967, Russia launched practical ocean surveillance satellites, and a total of 32 launches were carried out in 1989.

Japan first launched the ocean observation satellite Cherry Blossom in 1987 and its follow-up satellite in 1990. In 2012, Japan launched the Global change observation Satellite Waterdrop, which carries an advanced microwave radiometer with a spatial resolution of 15km and a width of 1450km.

The ocean remote sensing satellite launched by India in 1999 is mainly used for the monitoring of sea surface chlorophyll and phytoplankton, and the ocean remote sensing satellite launched in 2009 has added a scanning scatterometer, which can not only detect suspended solids in seawater, but also study atmospheric aerosols.

The research of ocean remote sensing satellite in China started relatively late. China's first ocean color satellite, Ocean No. 1 (HY-1A), was launched in May 2002. the launch of this satellite has greatly improved the extraction level of ocean color information in China. In August 2011, China successfully launched the first marine dynamic environment satellite, HY-2A, to observe a variety of marine dynamic environmental parameters, such as wave height, ocean current, sea surface wind field and sea surface temperature. In August 2016, the GF-3 satellite was successfully launched, which is China's first C-band multi-polarization synthetic aperture radar imaging satellite with a resolution of 1m, which can monitor and monitor global marine and land resources around the clock and around the clock, effectively supporting applications such as marine environment monitoring, marine target surveillance, sea area use management, marine rights and interests protection, and disaster prevention and mitigation.

After rapid development in recent years, China has gradually formed a series of marine remote sensing satellites represented by ocean color satellites, marine dynamic environment satellites and ocean surveillance and monitoring satellites, which provide technical support for China's marine environmental protection, marine resources development, sea area use management, marine rights and interests maintenance and polar ocean management.

02. How can satellites be used to observe the ocean? Satellites are an excellent tool for observing the earth and the blue oceans that cover more than 70% of the earth. By remote sensing from the orbit above the earth, satellites provide us with more information than information obtained only from the surface.

Using satellites, researchers study the ocean carefully. The information collected by satellites can tell us about ocean sounding, sea surface temperature, ocean color, coral reefs, as well as sea ice and lake ice. Scientists also use data collection systems on satellites to transmit signals from ground transmitters to field researchers-for applications such as measuring tidal heights and whale migration. Satellite transmitters also transmit location information from emergency beacons to help save lives when people are in distress on ships, planes or remote areas. Here are a few of the many ways that satellites can help us learn more about the ocean:

Sea surface temperature

The sea surface temperature simulation of the Geophysical fluid Dynamics Laboratory knowing the sea surface temperature can tell scientists a lot about what is happening in and around the ocean. Temperature changes can affect the behavior of fish, leading to coral bleaching and affecting coastal weather.

Satellite images of sea surface temperature also show the pattern of the water cycle. Examples include the location of upwelling, which is characterized by cold water rising from the depths, usually near the coast, and warm water streams, such as the Gulf Stream.

The most commonly used instrument for collecting sea surface temperature is the visible Infrared Imaging Radiometer Kit (VIIRS) instrument on satellite. The sensor captures new data every day, enabling scientists to piece together a series of maps showing how sea surface temperatures change over time in different parts of the world.

Sea surface color

The satellite also provides information about the color of the ocean. For example, color data can help researchers determine the effects of coastal floods, detect river plumes, and locate the proliferation of harmful algae that may contaminate shellfish and kill other fish and marine mammals.

Ocean color data from satellites can not only determine the location of algal blooms, but also predict where they may drift in the future. The treatment plant also uses the algal bloom prediction created by NOAA to determine when to change its water treatment formula to deal with algae.

Sea level change

Map of total sea level change since 1993 one of the most important potential impacts of climate change is sea level rise, which can lead to the inundation of coastal areas and islands, coastline erosion and the destruction of important ecosystems such as wetlands and mangroves.

Satellite altimeter radar measurements can be combined with accurate known spacecraft orbits to measure sea levels globally with unprecedented accuracy. Measuring the long-term change of global average sea level provides a method for testing climate models to predict global warming.

Mapping

The ocean surface bulges outward and inward, mimicking the topography of the ocean floor, which are too small to detect and can be measured by a radar altimeter on a satellite.

Satellite images can also be used to draw features in water, such as coral reefs. The geology of the seafloor is much simpler than that of the continent because of its low erosion rate and because the continent has suffered multiple collisions related to the opening and closing of ocean basins.

Although it is relatively simple geologically, much of the deep ocean floor is still poorly understood because it is covered by the ocean. So far, ships have drawn only a small part of the bottom of the sea. But because of gravity, there are wide bumps and depressions on the ocean surface, mimicking the topography of the ocean floor. These bumps and drops can be mapped using a very accurate radar altimeter installed on the satellite.

Weather

Before Hurricane Ivan hit the Gulf Coast of the United States on September 15, 2004, the oceans played an important role in regulating the earth's weather and climate. Weather data is perhaps the most well-known application of satellite technology.

The meteorological satellite system consists of two types of satellites: the geostationary operational environment satellite (GOES) for short-range forecasting, warning and observation, and the polar orbit satellite for long-term prediction. Both types of satellites are necessary to provide a complete global weather monitoring system.

Tracking

A satellite that fishery scientists manipulate a marked sea turtle to the end of the ship's ramp to provide images of the environment can also be used in conjunction with other instruments that receive data from various sensors.

For example, marine animals, such as sea turtles and manatees, can install launchers to transmit information about their location to orbiting satellites. Similar technologies are also used in human search and rescue.

03. How can satellites be used to observe the ocean? The influence of marine satellite remote sensing technology on the field of marine resource management and environmental monitoring is increasing day by day, which provides rich data for research, development, utilization and protection of the ocean, and has become a key technology for human beings to recognize the ocean.

With the development of remote sensing technology and the increasingly close combination of remote sensing technology and GIS technology, remote sensing technology will be more widely used in various fields.

The 21st century is the century of the ocean. To transform the scientific and technological productivity of satellite remote sensing technology into the real productivity of marine management departments, satellite remote sensing technology is the best way to make full use of existing data and information resources. it is the key technology and important means to realize the sustainable development of marine resources and environment. It plays an irreplaceable role in global change, resource survey, environmental monitoring and prediction. At the same time, in the process of maintaining the sustainable development of marine resources and environment, it will greatly promote the development of information science and technology, space science and technology, environmental science and technology and earth science.

With the development of science and technology, ocean remote sensing satellites have been launched one after another, ocean exploration technology is becoming more and more advanced, and underwater topographic survey and gravity survey instruments are constantly updated, which provides a guarantee for the acquisition of marine basic data.

This article comes from the official account of Wechat: new Research (ID:chuxinyanjiu), author: Tang Shi

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