Many years ago, Chu Qian studied the spectra of ground objects and detected changes in topography and landforms in the Teng River area. Observe where vegetation decreases or increases, where hills rise or fall, where waters widen or narrow.
The spectrum is a pattern in which the dispersed monochromatic light is arranged in sequence according to the wavelength (or frequency) after the complex-colored light is split by a dispersion system (such as a prism and a grating). It is called the optical spectrum. Simply put, it is the separated and displayed data of the seven colors of light visible to the human eye: red, orange, yellow, green, cyan, blue, violet, as well as invisible infrared, ultraviolet and X-rays.
The spectral characteristics of ground objects are that any ground object in nature has its own electromagnetic radiation rules, such as the ability to reflect and absorb certain bands of external ultraviolet, visible light, infrared and microwaves, and they all have the ability to emit certain infrared and microwaves. Characteristics; a few ground objects also have the characteristic of transmitting electromagnetic waves. This characteristic is called the spectral characteristics of the ground objects.
Different ground objects have different reflection capabilities for incident electromagnetic waves, which are usually expressed by reflectivity. When electromagnetic radiation energy reaches the interface of two different media, part or all of the incident energy returns to the original medium, which is called reflection. When the wavelength of the incident electromagnetic wave is constant, ground objects with strong reflective ability have a large reflectivity and will appear lighter in black and white remote sensing images. On the contrary, ground objects with weak ability to reflect incident light have low reflectivity and appear dark in black and white remote sensing images. The difference in hue in remote sensing images is an important symbol for interpreting remote sensing images.
When an electromagnetic wave is incident on the interface of two media, part of the incident energy passes through the interface of the two media. called transmission. When the transmitted energy passes through the medium, it is often partially absorbed by the medium and converted into heat energy before being emitted. In general, most ground objects have no transmittance to visible light. Infrared rays only have certain transmission capabilities for ground objects with semiconductor characteristics. Microwaves have obvious transmission ability to ground objects, and this transmission ability is mainly determined by the wavelength of the incident wave. Therefore, in remote sensing technology, appropriate sensors can be selected to detect information about certain features under water and ice based on their characteristics.
While in Qiong City, Chu Qian met Qi Yanliang. At that time, Qi Yanliang was still asking him how various substances were detected. For example, how are plants tested?
Since plants all perform photosynthesis, all types of green plants have very similar reflection spectrum characteristics: in the visible light band 0.55 μm, that is, there is a peak with a reflectivity of 10%-20% near the green light; in the near-infrared band 0.8 There is a steep slope of reflection between -1.0μm and a peak near 1.1μm, forming the unique characteristics of vegetation.
How is the soil tested?
The reflection spectrum characteristics of soil have no obvious peaks and troughs. The finer the soil, the higher the reflectivity. The higher the organic matter content and the higher the water content, the lower the reflectivity.
How are waters tested?
The reflection of water body is mainly in the blue-green band, and the absorption of other wave bands is very strong, and the near-infrared absorption is stronger.
When passing through Qiong City, Chu Qian discovered that the spectrum near Qiong City was quite special. However, the accuracy of the instruments used at that time was not very high, so the specific location could not be determined yet.
Chu Qian lived in Qiongcheng for a while. The spectral lines do not correspond to ordinary rocks and soil. There are relatively obvious changes.
The special spectral lines are actually due to the influence of the concentrated energy field. At first I didn't know it was because of the energy gathering field.
After the concentrated energy field was damaged, the spectrum of the ground objects returned to its original state, and no abnormalities could be seen.
The wavelengths of electromagnetic waves, from short to long, include X-rays, ultraviolet rays, visible light, infrared rays, microwaves, radio waves, etc.
Radio waves are used for communications and more. Microwaves are used in microwave ovens. Infrared rays are used in remote controls, thermal imagers, infrared guided missiles, etc. Visible light is what all living things use to see. Ultraviolet rays are used for medical disinfection, verification of counterfeit banknotes, distance measurement, engineering flaw detection, etc. X-rays are used in CT photography. Gamma rays are used for treatment, causing atoms to transition to produce new rays, etc. Radio waves are used for radio broadcasting. In radio broadcasting, people first convert sound signals into electrical signals, and then these signals are carried by high-frequency oscillating electromagnetic waves to the surrounding space.
While Chu Qian was analyzing the landforms near the Teng River, he was also studying whether electromagnetism affects light. He consulted some information. There are several main possibilities for magnetic fields to affect light: Faraday effect, Zeeman effect, and Kerr effect.
The Faraday effect (Faraday rotation, magneto-optical rotation) is a magneto-optical effect, which is an interaction between light waves and magnetic fields in a medium. The Faraday effect causes a rotation of the plane of polarization that is linearly proportional to the component of the magnetic field toward the direction of light wave propagation. In 1845, Faraday discovered that when linearly polarized light propagates in a medium, if a strong magnetic field is added parallel to the propagation direction of the light, the vibration direction of the light will be deflected, and the deflection angle is proportional to the product of the magnetic induction intensity and the length of the light traveling through the medium. .
Chu Qian thought that it might be that the polarized light was affected by the electromagnetic field of the concentrated energy field, causing the deflection angle to change.
Dutch physicist Zeeman discovered that atomic spectral lines split in an external magnetic field. Later Lorentz theoretically explained the reason why the spectral line split into three. This phenomenon is called the "Zeeman effect". Further research found that the spectrum of many atoms is split in a very complicated manner in a magnetic field, which is called the anomalous Zeeman effect. A complete explanation of the Zeeman effect requires the use of quantum mechanics. The orbital magnetic moment and spin magnetic moment of the electron are coupled into the total magnetic moment, and the spatial orientation is quantized. The additional energy under the action of the magnetic field is different, causing energy level splitting. In an external magnetic field, atoms with a total spin of zero exhibit the normal Zeeman effect, and atoms with a non-zero total spin exhibit the anomalous Zeeman effect. The Zeeman effect confirms the spatial quantization of atomic magnetic moments. The Zeeman effect can be used to measure the charge-to-mass ratio of electrons. In astrophysics, the Zeeman effect can be used to measure the magnetic field of celestial bodies.
Chu Qian thought that it might be that the spectral lines were split under the influence of the magnetic field of the concentrated energy field. Celestial objects can also be detected using the Zeeman effect.
Kerr discovered the phenomenon of electrically induced birefringence proportional to the square of the electric field. When a substance is placed in an electric field, its molecules are oriented (deflected) due to the action of the electric force, showing anisotropy. As a result, birefringence occurs, that is, the substance has different refractive abilities for light along two different directions. Later generations called it the Kerr electro-optical effect.
Chu Qian thought that it might be that the refractive index of other light-transmitting materials changed under the influence of the magnetic field of the concentrated energy field. The refractive index can also be detected using the Kerr electro-optical effect.
To sum up, the deflection angle of polarized light, spectral lines, and the refractive index of light-transmitting materials may all change under the influence of the electromagnetic field of the concentrated energy field. Therefore, the signal detected by the light sensor will change.
