The world's first high orbit synthetic aperture radar satellite has entered working orbit, observing the Earth's "rain or shine" land | Synthetic aperture radar | High orbit
The National Space Administration (NASA) announced today that the world's first high orbit synthetic aperture radar satellite, Land Exploration 4 01, has successfully entered working orbit recently. The synthetic aperture radar antenna has been successfully deployed, and the satellite is operating normally and in good condition. In orbit testing and other work will continue in the future.
The world's first high orbit synthetic aperture radar satellite has entered working orbit
On August 13th, the Land Exploration No. 4 01 satellite was lifted into space by the Long March 3B carrier rocket at the Xichang Satellite Launch Center, and successfully entered the designated transfer orbit after launch.
It is understood that this satellite is the world's first high orbit synthetic aperture radar satellite, which has innovatively broken through multiple key technologies and can observe China's local and surrounding areas 24/7, meeting the application needs of disaster prevention and reduction, earthquake monitoring, land and resource exploration, as well as industries such as ocean, water conservancy, meteorology, agriculture, environmental protection, and forestry.
Observing the Earth with radar, all weather, all day, no obstruction of wind and rain
The Land Exploration 4 01 satellite is a satellite that can observe the Earth in space, but its observation equipment is not a camera, but a radar. What is the different experience of using radar to take pictures of the Earth?
The observation equipment of the Land Exploration No. 4 01 satellite is synthetic aperture radar. The working principle of this radar is different from that of other optical remote sensing satellites. It emits electromagnetic waves to the Earth, then receives the reflected electromagnetic waves from the Earth and analyzes them, thereby obtaining radar images with a large amount of information.
Zhang Qingjun, the overall developer of remote sensing satellites at the Fifth Academy of Aerospace Science and Technology Group, introduced that it is precisely because synthetic aperture radar is used for imaging, satellites can image without the help of light, and can penetrate clouds to observe the world below. Therefore, the Land Exploration No. 4 01 satellite is not limited by climate or light, and can observe ground to ground 24/7, 24/7, which is very suitable for application scenarios such as disaster prevention and reduction.
The world's highest flying synthetic aperture radar satellite
In addition to using synthetic aperture radar technology, the Land Exploration No. 4 01 satellite has another characteristic, which is that its orbit is particularly high, nearly 40000 kilometers away from the Earth. The higher it flies, the farther it can be seen. What is the difference in observing the Earth at such a high orbit?
The Land Exploration 4 01 satellite operates in a tilted geostationary orbit close to 40000 kilometers from Earth. The satellites in this orbit are like repeating an "8" in the sky, allowing for relatively continuous observation of a large area with a short observation revisit period and a large imaging width.
It is reported that satellites operating in low orbits of 500 or 700 kilometers generally have a residence time of about ten minutes for a certain area. It will take several days for the next observation of this area, and the timeliness is relatively low. On the other hand, when the Land Exploration 4 01 satellite flies high, it will see a larger area, and the efficiency of repeated observations of the same area will be higher, which can complement the functions of low orbit satellites.