Welche Umweltfaktoren beeinflussen den kombinierten Einsatz von Optoelektronik und Radar?
Meteorological condition
Rain and fog weather: In rain and fog weather, radar waves will be scattered and absorbed by raindrops and fog droplets. For millimeter wave radar, the size of the raindrop is close to the wavelength of the millimeter wave, which will cause serious attenuation, which will reduce the detection range and accuracy of the radar. For example, in heavy rain, the range of radar detection of targets may be reduced to half or less than normal weather. At the same time, rain and fog will also have an impact on the photoelectric system, and the imaging of optical devices (such as optical cameras) in the visible light band will become blurred, because the light is scattered by raindrops and fog droplets. In the case of dense fog, the clarity of thermal imaging will also be reduced, and the details of the target are difficult to distinguish.
Dust weather: The effect of dust on radar is mainly to absorb and scatter radar waves. A large number of dust particles will weaken the radar echo signal, especially for high-band radar, this effect is more obvious. In the photoelectric system, sand and dust will block the line of sight, so that optical imaging equipment can not work properly. Dust may also scratch the lens of the photoelectric equipment, causing damage to the equipment. Moreover, sand and dust will produce thermal noise under sunlight, which interferes with the detection of the target thermal signal by infrared thermal imaging equipment.
Cloud cover: The effect of clouds on radar varies depending on cloud thickness and type. Thick clouds will have a certain attenuation effect on radar waves, but under normal circumstances, radar can still penetrate the clouds for detection. For photoelectric systems, however, thick clouds can completely block the target, making it impossible for the visible light camera to capture the target. Even thin clouds may reduce the contrast of optical imaging and affect image quality. When the photoelectric equipment in the infrared band is covered by the cloud, there may be misjudgment due to the difference between the temperature of the cloud and the target temperature.
Light condition
Strong light interference: In a strong light environment, such as direct sunlight or strong light irradiation (such as searchlights, etc.), the optical camera in the photoelectric system may overexpose, resulting in the loss of details of the target in the image. It will cause serious interference to the object recognition and tracking function based on optical imaging. In addition, under strong light, the reflected light of the target may cover the characteristics of the target itself, making it difficult for the photoelectric system to accurately identify the target. The radar system is generally unaffected in bright light environments because it is based on electromagnetic signal detection and does not depend on light conditions.
Dark environment: At night or in a dark environment, the photoelectric system needs to rely on its own infrared imaging or low-light imaging capabilities. If there is not enough infrared radiation source or the ambient light is too weak, the low-light imaging equipment may not be able to obtain a clear image. The radar is not affected in the dark environment, and can still work normally to detect and locate the target. However, in the dark environment without photoelectric assistance, radar information alone may not be able to accurately judge some visual characteristics of the target, such as the appearance of the target shape details.
Geographical environment factor
Terrain occlusion: Complex terrain (mountains, valleys, tall buildings, etc.) will have an occlusion effect on radar and photoelectric systems. For radar, when the target is behind the terrain, the radar waves will be obscured and cannot directly detect the target. For example, in a mountain environment, targets in a valley may be invisible to radar because of the surrounding mountains. Similarly, when the photoelectric system is faced with terrain occlusion, the line of sight is blocked, and the obscured target cannot be observed. Even in the urban environment, tall buildings will form a lot of blind spots, affecting the photoelectric system to monitor the target.
Electromagnetic interference environment: In some special geographical areas, such as near large communications base stations, broadcast and television towers, or industrial electromagnetic interference sources (such as high-voltage substations), radar electromagnetic signals may be interfered with. The electromagnetic waves emitted by these interference sources may overwhelm the radar's echo signal, or produce noise in the radar receiver, reducing the radar's detection performance. Photoelectric systems are generally not subject to electromagnetic interference, but if the intensity of electromagnetic interference is too large, it may affect the electronic control part of the photoelectric system, such as resulting in image transmission errors or equipment failures.