森林航空摄影比例尺和森林判读像片放大倍数的研究

为了确定森林航空摄影的最佳比例尺和波段以及判读像片的放大倍数,我们在广东省南昆山林业遥感试验场,测定了地物光谱,拍摄了不同比例尺的多光谱片和彩色红外片,进行了内业判读、野外检测和综合分析。本文讨论了航空摄影机、胶片、地物光谱反射系数和摄影位移等因素对像片分辨力的影响,用经验关系式估算了南昆山像片的影像分辨力,阐述了内业判读和实地检测的情况。试验表明,在所试验的波长附围内绿波段表达森林影像的效果最佳,用于森林判读的影像分辨力宜放大到3.5线/毫米,若用新型航空摄影机和高分辨力胶片,则用于森林资源调查分类判读的像片比例尺可缩小到1:4.8万。

A Research on Forest Aerialphotographic Scale and Enlarging Times of Aerialphoto Interpretation

In order to determine the optimum scale and band of forest aerial photography, determine-the enlargement of photo, interpretation in the experimental sites of Nankunshan, Guangong province carried out the following tests, namely determination of the spectrum of ground objects, multiple spectrum and colour infrared photograph in different scales, office interpretation, field survey and complex analyse. This article discussed the influence of aerial camera, film, coefficient of reflection of object spectrum and photographic displacement on resolving power. It also estimated the resolving power of photo image in Nanjunshan with the experimental relationship-formula and illustrated the interpretation in room and field survey. The breif conclusions are as follow: 400-800um in green band is the best for aerial forest photograph. The resolution of photo for forest interpretation is enlarged to 3.5 line/mm. If new type camera and film with high resolving power are used, photo-scale for classfication of forest resource will be decreased to 1:48000.