Basic principles of remote sensing:
Everything, because of its different types and environmental conditions, has the characteristics of reflecting and radiating electromagnetic waves with different wavelengths. The bands that can be detected by remote sensing technology are ultraviolet, visible light, infrared and microwave. As the source of electromagnetic waves, the light emitted by the sun is also electromagnetic waves.
When sunlight shines on the earth's surface through the universe and atmosphere, objects on the ground will reflect and absorb electromagnetic waves composed of sunlight. Because of the different internal structure and related characteristics of things and the wavelength of incident light, their reflectivity to incident light is also different.
According to this principle, remote sensing is a technology to detect the electromagnetic waves reflected and emitted by the target object, analyze and obtain the required information, and complete long-distance object recognition through interpretation and processing.
The concept of remote sensing:
Remote sensing, broadly speaking, refers to the technology of detecting and sensing objects or things from a distance. In the scientific sense, it refers to all non-contact remote detection.
Generally speaking, it refers to the process of using some device (remote sensor) placed on the carrier (platform) to perceive the characteristic information of the target (generally the reflected radiation or emitted radiation of electromagnetic waves) without direct contact with the studied target, and then extracting the information that people are interested in from it through transmission and processing.
Composition of remote sensing system:
1, information source:
Refers to the monitored thing, that is, the monitored object. All substances have the ability to absorb and reflect electromagnetic waves. According to their different internal structures and related attributes, specific things can be monitored, so as to obtain the relevant information of the monitored objects.
2. Information acquisition:
It refers to the detection process of receiving and recording the electromagnetic wave characteristics of the target by remote sensing technology. The equipment used in this process mainly includes remote sensing platform and sensor. Among them, the sensor is an instrument to detect the electromagnetic wave characteristics of the target, and the working platform is a vehicle equipped with the sensor.
3. Information processing:
It refers to the correction, analysis and interpretation of remote sensing information obtained through certain equipment. Summarize the image characteristics of the detected target, and finally determine the process of extracting the required information.