论文部分内容阅读
1.勘测森林资源方面:在这一方面,主要是绘制森林图,调查森林的分布,区分森林的种类,估算木材的蓄积量。例如:美国一些林业工作者利用“阿波罗—9号”和“双子星座”载人宇宙飞船拍摄的地面照片,可以划分出针叶林、阔叶林和混交林的分布范围。这是由于叶肉组织比较厚的阔叶林对太阳光的反射要比针叶林强得多的缘故。利用此技术,区分树木种类,在将来也是可能的。例如:在试验中人们了解到,松树和云杉在可见光摄影的照片上无法区别。如果用0.7微米左右的光谱段拍摄,它们在照片上的反映就大不相同,松树显得明亮,云杉则比较暗。这样就容易把它们区分开来。同样,老龄林和幼龄林的叶子的光泽度和粗糙程度各不相同,所以在多光谱遥测试验中,也能够把它们划分出来。据报道,资源卫星将提供第一张全球森林勘测情况的图片。2.探测森林火灾方面:世界各地森林火灾,据统计每年多达20万起。美国每年由于森
1. In surveying forest resources: In this area, the main tasks are drawing forest maps, surveying the distribution of forests, distinguishing the types of forests and estimating the stock of wood. For example, some foresters in the United States use the ground photographs taken by the Apollo -9 and Gemini manned spaceships to classify the distribution of coniferous forests, broad-leaved forests and mixed forests. This is due to the fact that the broad-leaved forest with thicker mesophyll reflects the sunlight more strongly than the coniferous forest. Using this technique, it is possible in the future to differentiate tree species. For example, in experiments, people learned that pine trees and spruces are indistinguishable in photos of visible light. When taken with a spectral range of about 0.7 microns, they reflect quite differently in the photos, the pine trees appear bright, and the spruce trees darker. This makes it easy to distinguish between them. Similarly, the leaves of aged and young forests have different degrees of gloss and roughness, so they can also be divided in multispectral telemetry. According to reports, Resources Satellite will provide the first picture of the global forest survey. 2. Detection of forest fires: Forest fires all over the world, according to statistics, up to 200,000 each year. America every year due to Mori