Why are marine remote sensing satellites called clairvoyance ?

The earth we inhabit is a large round sphere that has a surface area of about 5. 100 million square kilometers, of which the ocean area is about 3. 600 million square kilometers.

In that vast and boundless ocean, the wind roars, the waves are stormy, and the mystery is unpredictable, attracting many explorers to go on expeditions. The first vehicles to survey the seas were sailboats, which were powered by the wind. Later, the invention of the steamship expanded the scope of oceanographic investigations.

On October 4, 1957, the world's first artificial earth satellite was successfully launched, and since then, mankind has added another advanced tool to study the ocean. Remote sensing satellites used for ocean surveys can really be described as "clairvoyance". It operates at an altitude of hundreds, thousands, or even tens of thousands of kilometers, standing high, seeing far away, and having a clear view of the world's oceans.

In addition, it orbits the earth quickly or in sync with the earth, so it can keep abreast of changes in the ocean.

Remote sensing satellites are equipped with many advanced detection equipment, such as visible light detection systems, infrared detection systems, and microwave detection systems, which can be used to detect the situation on the ocean surface. The visible light detection system has photographic, television and spectral analysis capabilities to measure sea surface conditions, chlorophyll distribution, sediment distribution, pollution status, seawater distribution and surface fish distribution. Infrared detection systems can receive infrared radiation and infrared spectroscopy, which can understand the current status of sea surface water temperature, ocean currents and sea ice distribution.

The microwave detection system is equipped with radiometers, scatterometers and radar altimeters, etc., which can measure waves, tides and sea level heights, current speeds, sea temperatures and sea surface wind fields. The data detected by remote sensing satellites are sent to the surface satellite receiving stations through the transmission system, so that people can keep abreast of the current status of sea level changes. The data measured by remote sensing satellites are extremely useful in navigation, fishery production, and marine environmental protection.

The detected sea surface conditions, wave height, wind field, sea ice and currents will be an important decision-making basis for navigation commanders to decide the course of the navigation personnel. The detected chlorophyll distribution, sea temperature and currents are a powerful basis for judging the distribution of fish stocks, which provides help for improving fishery production. When oil pollution, chemical pollution and red tide distribution are detected, it can buy time for people to control pollution and reduce losses in time.

In addition, the results of remote sensing satellite surveys have research value in a variety of marine disciplines. Of course, the technical requirements of professional ocean remote sensing satellites are also extremely high, because in the information received by satellite sensors, many data are disturbed by the atmosphere, and the real ocean information is very limited. Therefore, the detection equipment on the satellite requires high sensing sensitivity and data processing capabilities.

At present, there are not many remote sensing satellites in the world that specialize in ocean exploration, and only a few countries such as the United States have them.

During the period 1999-2000, China plans to launch an ocean water color satellite to effectively monitor the marine environment such as suspended solids, chlorophyll, sea temperature, pollution, and red tides, so as to provide a scientific basis for decision-making on the protection of marine biological resources and the formulation of plans for marine development and utilization and sustainable development.

Because it can detect a very wide area.

That's because he can monitor the ocean remotely

But because it is able to monitor the ocean remotely,

That's because ocean remote sensing satellites can detect the full range of events on the ocean surface.

Because it can observe a lot of things that people can't observe.

This is because his technology is very advanced.

This is probably a technological advancement.

Because remote sensing satellites can see the situation from a great distance.

Because its technology is powerful and it is clear to see.

I think it's because it can see far away.

Contemporary military reconnaissance satellites can be called a pair of real clairvoyants, which have the following three advantages:

One is that it's fast. How fast is it? If it is a reconnaissance satellite in low-earth orbit, it will fly about seven or eight kilometers per second, and it can circle the earth in about an hour and a half.

Such reconnaissance satellites are hundreds of times faster than trains and automobiles, and more than 10 or 20 times faster than supersonic aircraft. Let's take an analogy. From Beijing, it only takes half a minute to Tianjin, 3 minutes to Shanghai, and 5 minutes to Lhasa.

Not only is the reconnaissance timely, but also the continuity is guaranteed. Generally, long-lived reconnaissance satellites can stay in the air for more than two years, and during this time, they can detect continuous changes in the target.

Second, the scope is broad. Comparing airplanes and satellites, they are also 20-degree perspectives, and the range of 1 square kilometer on the ground can be seen from an aircraft at an altitude of 3,000 meters, and 10,000 square kilometers can be seen from a satellite at an altitude of 300 kilometers, and the range seen is more than 10,000 times different. Someone has made a calculation, saying that it takes 1 million shots to shoot 1 million ** photos of our country on a high-altitude plane, and it will take 10 years; If you shoot with satellites, you only need to take more than 500 shots**, which will not take you a few days.

Third, there are few restrictions. If you shoot the ** of a military target on the ground of the other party, the other party will definitely arrest you and ask you for the crime. You can't take pictures in my air, because if you violate the sovereignty of the airspace, the plane will be knocked down.

Who can control the satellites in the sky? It has the freedom to transcend its borders without the hassle of violating its airspace. Mountains, the sea, the desert Gobi, dense forests, and places that cannot be reached by people cannot stop satellites from conducting reconnaissance.

Of course, military reconnaissance satellites also have shortcomings, which require scientists to constantly study and improve.

I still want to know

Because military reconnaissance satellites operate in different orbits due to their different altitudes, they seem to have two states, moving and immovable, when viewed from the earth.

There are four types of military reconnaissance satellites in terms of performance: photographic reconnaissance satellites; electronic reconnaissance satellites; missile early warning satellites; Ocean Surveillance Satellites.