Diagnosis of Trees from Helicopter by Thermographic System
Diagnosis of Trees from Helicopter by Thermographic System
复制标题
利用热成像系统从直升机上诊断树木
DOI：
10.2525/ecb1963.31.161
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
A. Masuki
中科院分区：
文献类型：
--
作者：
K. Omasa;H. Shimizu;K. Ogawa;A. Masuki
为了诊断生长在城市地区的树木个体的生理活动，从一架直升机使用的热成像系统的遥感进行了检查，在寺庙的“海林寺“和邻近地区的琦玉县。在多云和稳态热条件下，树木的生理功能活动，如气孔运动，蒸腾，光合作用和空气污染物的吸收，从热图像获得的信息。在对个别树木的实地调查中发现的轻微损伤，通过热成像进行了诊断，尽管从彩色航空照片中没有发现。用气孔仪测定的气孔导度（气孔开度的一个指标）随PPFD的降低而降低。在PPFD低于200μmol光子m-2 sec-1时，降低速率较大，但在PPFD高于300μmol光子m-2 sec-1时，降低速率较小且恒定。这一结果表明，在多云天气下，PPFD大于300μmol光子m-2sec-1的条件下，利用热成像系统测量的温度图像可以稳定地诊断树木的轻微损伤。当图像中的高温和低温之间的差（5°C）由锯齿形图案的狭缝给出时，分辨率和误差约为0.5 ° C。300条线，50个狭缝时为5%（0.25°C）。这一结果表明，有必要在300至500米以下的高度进行测量，以获得误差在5%以内的单棵树的准确温度。
In order to diagnose physiological activities of individual trees growing in urban area, a remote sensing using a thermographic system from a helicopter was examined at the temple of“Heirin-ji”and adjascent area in Saitama Prefecture. Under cloudy and steady-state thermal conditions the information about activities of physiological functions such as stomatal movement, transpiration, photosynthesis, and air pollutant absorption was obtained from the thermal image of trees. The slight injury, which was found in the field survey of individual trees, was diagnosed by the thermal image, although it was not detected from aerial photographs in color. The difference in species of trees was also detected by the thermal image.The stomatal conductance of several tree species measured by a porometer, which is an indicator of stomatal opening, decreased with a lowering of PPFD. The decrease rate was large at PPFD below 200μmol photons m-2 sec-1 but it was small and constant at PPFD above 300μmol photons m-2 sec-1. This result means that it is possible to diagnose stably the slight injury of trees from the thermal image measured under a cloudy sky with PPFD above 300μmol photons m-2 sec-1.The resolution and error in temperature image measured by the thermographic system depended on spatial distributions of temperature. When the difference (5°C) between high and low temperatures in the image was given by slits with zigzag patterns, the resolution and error were ca. 300 lines and ca. 5% (0.25°C) at 50 slits. This result shows that it is necessary to measure at a height below 300 to 500 m in order to obtain the exact temperature of individual trees within 5% in error.