| 基于半分析模型的太湖春季水体漫衰减系数Kd(490)估算及其遥感反演 |
| 摘要点击 2705 全文点击 1456 修订日期：2011-05-09 |
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| 中文关键词 漫衰减系数 半分析模型 环境一号卫星 光学闭合 太湖 |
| 英文关键词 diffuse attenuation coefficient semi-analytical model HJ-1 satellite optical closure Lake Taihu |
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| 中文摘要 |
| 漫衰减系数是水体重要的光学参数,是水生态系统的重要影响因素.利用2009年4月和2010年5月太湖实测数据,基于光学闭合原理,首先求解出490 nm处水体总的吸收系数[a(490)]和后向散射系数[bb(490)],进而研究了其与模拟的环境一号卫星多光谱数据不同波段遥感反射率之间的关系,在此基础上构建了太湖春季水体Kd(490)反演的半分析模型并将其应用到环境一号卫星影像上进行了太湖春季水体Kd(490)的遥感反演.结果表明,1基于光学闭合原理,可以较为准确地求解出a(490)和bb(490),a(490)实测值与求解值的平均相对误差为17.1%,bb(490)与模拟的环境一号卫星第四波段的遥感反射率具有很好的指数关系; 2 本研究所构建的模型具有较好的精度和稳定性,利用与卫星影像准同步的地面采样点对模型进行验证,得出模型反演的平均相对误差为21.6%,均方根误差为1.68 m-1; 3太湖春季水体Kd(490)具有较强的空间差异性,太湖北部和东太湖大部分区域为Kd(490)的低值区,太湖西部和南部为Kd(490)的高值区,而太湖中部大部分区域介于两者之间. |
| 英文摘要 |
| Diffuse attenuation coefficient is not only an important optical parameter, but also an important factor of water ecological system. Two datasets measured in April 2009 and May 2010 were firstly used to calculate absorption coefficient [a(490)] and backscattering coefficient [bb(490)] at 490 nm, and then, the relationship between bb(490) and simulated remote sensing reflectance at different bands of HJ-1 was studied. The semi-analytical model of Kd(490)in Lake Taihu in spring was constructed based on this basis, and it was used to estimate Kd(490) of Lake Taihu via an image of HJ-1 finally. The results show that: 1 The values of a(490) and bb(490) can be calculated accurately based on optical closure principle, and the mean absolute percent error (MAPE) of a(490) between calculated and measured is 17.1%. In addition, the backscattering coefficient at 490 nm [bb(490)] exponentially relate with the simulated remote sensing reflectance at the fourth band of HJ-1; 2 The semi-analytical model constructed in this study has good accuracy and stability. The MAPE is 21.6% and RMSE is 1.68 m-1 by comparing inversion result and quasi-synchronous measured data; 3Kd(490) of Lake Taihu in spring differs a lot in space distribution. The values are relatively smaller in north and east part of Lake Taihu, but larger in west and south part. |
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