摘要
受到地物二向性反射的影响,航空遥感数据中存在亮度梯度现象,但目前仍然缺乏针对亮度梯度效应专门开展的实验研究。以美国加利福尼亚州中部的果园为研究区,基于沿太阳主平面方向(along solar plane,ASP)、垂直太阳主平面方向(perpendicularly to solar plane,PSP)和南北方向飞行并扫描成像获取的三景MASTER遥感影像,利用剖面分析研究了不同波段、植被指数的亮度梯度效应,并提出了一种多项式拟合校正方法。结果表明:受到热点现象的影响,PSP图像具有最明显的亮度梯度效应,而ASP图像的亮度梯度效应可以忽略不计;植被指数可以削弱亮度梯度效应的影响,但是在热点方向仍然会存在低估的情况。PSP与ASP的比值图像可以较好地消除地物本身以及背景的影响,利用该比值建立的分段多项式模型可以有效地校正由照射角度和观测角度带来的亮度梯度效应。
The brightness gradient phenomenon commonly exists in aerial remote sensing data due to bidirectional reflectance of anisotropy surface.However,there is still lack of experimental research on brightness gradient effect.Taking the orchards bocks in the middle of California in USA as the study area,the brightness gradient effect in typical spectral bands and vegetation indexes were studied based on the MODIS/ASTER airborne simulator（MASTER）imagery,which acquired flying along the solar plane（ASP）,perpendicularly to solar plane（PSP）,and North-South direction（NS）respectively.A piecewise polynomial correcting method was then provided in this paper according to the ratio between PSP and ASP imagery.The results showed that brightness gradient effect of the PSP image was most obvious,while that of the ASP image was negligible.Vegetation index reduced the brightness gradient effect,but there was still an underestimate nearby the hot direction.Using the piecewise polynomial model based on the ratio between PSP and ASP imagery,the method used in this paper effectively corrected the brightness gradient effect.
作者
陈健
高绍鑫
石满
张雪红
CHEN Jian;GAO Shaoxin;SHI Man;ZHANG Xuehong(School of Geography and Remote Sensing 9Nanjing University of Information Science and Technology tNanjing 210044,China)
出处
《遥感信息》
CSCD
北大核心
2018年第3期1-6,共6页
Remote Sensing Information
基金
国家自然科学基金(41201461)
中国科学院太空应用重点实验室开放基金(LSU-2016-06-02)
关键词
多光谱
亮度梯度
MASTER
植被指数
多项式拟合
multi-spectral
brightness gradient
MODIS/ASTER airborne simulator
vegetation index
polynomial regression
