How do satellites capture people's faces on earth through thick clouds?

There are generally two methods for satellites to acquire ground images: the first method is to shoot negatives with a camera, put the camera with negatives on the satellite, send the satellite into a designed orbit to shoot the ground, and then take it back after shooting. After a series of photographic processing, the negative can be obtained, which can be digitized by image scanning, thus obtaining digital satellite images; The second is "digital imaging", and the imaging principle is similar to that of a digital camera.

The application of satellite images is like setting up a super camera in space, and the "eye of the sky" will be able to see everything on the ground. Photographic reconnaissance satellite is a satellite that uses optical remote sensors and microwave remote sensors to shoot objects in a certain range on the ground and produce high-resolution images. It is mainly used for strategic intelligence collection, tactical reconnaissance, arms control verification and strike effect evaluation.

Extended data

Advantages of satellite images:

1, with large image area and strong macro.

2. Multi-band

3. Multi-temporal

4. Approximate vertical projection with small error and consistent scale.

5, the time is unified, which is convenient for image analysis.

6, digital information, easy to handle.

7. Free from geographical and national boundaries.

8. Low cost

Baidu Encyclopedia-Satellite Pictures