Explain the concept of aerial photography.

Remote sensing technology is a technology to detect and identify targets by using electromagnetic waves, visible light and infrared rays reflected or radiated by remote sensing targets. For example, aerial photography is a kind of remote sensing technology. The success of artificial earth satellite promotes the development of remote sensing technology. Modern remote sensing technology mainly includes information acquisition, transmission, storage and processing. The complete system that completes the above functions is called remote sensing system. Its core component is a remote sensor for obtaining information. There are many kinds of remote sensors, including cameras, TV cameras, multispectral scanners, imaging spectrometers, microwave radiometers, synthetic aperture radars, etc. Transmission equipment is used to transmit remote sensing information from remote platforms (such as satellites) to ground stations. The information processing equipment includes a color synthesizer, an image interpreter and a digital image processor.

principle

Any object has spectral characteristics, specifically, they all have different absorption, reflection and radiation spectra. In the same spectral region, different objects reflect different situations, and the same object also reflects different spectra. Even the same object has different reflection and absorption spectra at different times and places due to different angles of sunlight. Remote sensing technology is based on these principles to judge objects.

Remote sensing technology usually uses three spectral bands of green light, red light and infrared light for detection. Green belts are generally used to detect the characteristics of groundwater, rocks and soil. The red light part detects plant growth, change and water pollution; The infrared part detects land, minerals and resources. There is also a microwave section, which is used to detect meteorological clouds and fish downstream.

The characteristics of remote sensing are simple, easy to use, convenient, fast and economical.