iNGENET - La comunidad de la ingeniería mexicana

There is no electronic telescope, the following is the principle of ordinary telescope:
How does the telescope move the distant scene to our eyes? This relies on the two lenses that make up the telescope. In the front of the telescope, there is a convex lens with a large diameter and a long focal length, called the objective lens; the rear lens with a small diameter and a short focal length is called an eyepiece. The objective lens converges the light from the distant scene into an inverted and reduced real image behind it, which is equivalent to moving the distant scene closer to the imaging place. And the inverted image of this scene happened to fall on the front focus of the eyepiece. Looking into the eyepiece like this, it is like looking at something with a magnifying glass. You can see a virtual image magnified many times. In this way, scenes far and far away look as if they are close in front of the telescope.
Telescopes are the same as other optical instruments. After a long history of development, telescopes of various structures have come out one after another. According to optical principles, it can be classified into two categories: refraction and reflection. Refracting telescopes, commonly used with prism binoculars, are often used in military and field investigations because of their short lens, large field of view, and convenience to carry; reflective telescopes are made of concave mirrors and convex lenses as eyepieces for observing celestial bodies. At present, the largest mirror has a diameter of 6 meters, and the entire telescope is as high as a building with more than a dozen stories! The light it “captures” is 10 million times more powerful than the natural light that enters the human eye; it can be used to observe celestial bodies at a distance of up to 10 billion light years (the distance traveled by a light year is equal to approximately 9,460.8 billion kilometers). There are billions of stars in
The principle of a radio telescope is much the same as that of a satellite TV antenna receiver. It conducts research by receiving electromagnetic radiation signals from distant celestial bodies and analyzing their intensity, frequency spectrum and polarization. It mainly has two basic indicators-resolution and sensitivity. From optics, we know that the resolution of a telescope is proportional to the wavelength λ and inversely proportional to the aperture D of the telescope. Since optical telescopes work on the order of micrometers in wavelength, while radio telescopes work on the order of millimeters with a difference of 10,000 times, the aperture (aperture) of radio telescopes must be larger than that of optical telescopes to achieve the same resolution. Ten thousand times. Fortunately, because of the use of a radio interferometer, the linear distance between two radio telescopes far apart can be used to replace the true aperture of the telescope. This technique is called very long baseline interference. It can make the effective aperture as large as several thousand kilometers or even farther, which greatly improves the resolution and makes it possible for people to see the fine structure of celestial bodies. However, there are gains and losses, and the sensitivity is reduced while the resolution is improved. The sensitivity depends on the effective area of ​​the radio telescope. The larger the antenna, the higher the sensitivity. However, due to the use of radio interferometers, we used the length of the straight line (baseline) between the two telescopes to replace the real aperture, but did not increase the effective area of ​​the corresponding antenna, so that the sensitivity of the radio telescope decreased exponentially. Determines the research object of radio astronomy-mainly the observation of high-energy celestial bodies and the analysis of radio astronomy spectral lines.