【摘要】 卫星图像辐射质量与其对地观测能力息息相关,GF-1是我国高分辨率对地观测系统的首发星,在山区积雪监测中有着重要的应用价值。使用新疆天山玛纳斯河流域积雪区GF-1图像与相同区域、相近时间(2d内)成像的国外同类高分辨率卫星SPOT-6和RapidEye图像进行评价与比较,衡量GF-1在山区积雪区域的图像辐射质量水平,为GF-1的应用以及后续高分系列卫星载荷的研制提供参考。利用遥感图像辐射质量评价中常用的图像统计特征、平均梯度、信息熵和信噪比(SNR)指标对3种卫星图像进行比较,结果表明:GF-1图像与其他两种卫星的图像相比在图像统计特征和平均梯度方面表现最佳;但由于辐射量化级数的制约,其信息熵相比其他两种卫星还存在一定差距;GF-1在对积雪成像时局部会出现过饱和现象,从而导致部分区域的局部标准差值为0,在去除这些异常值后对GF-1图像的SNR进行重新估计,发现其在蓝光、红光和全色波段显著优于其他卫星,但绿光波段和近红外波段与SPOT-6有一定差距,与RapidEye相仿。总体来说,GF-1在山区积雪区的图像辐射质量基本达到了国际同类卫星的水平,部分指标甚至显著优于其他卫星,但在辐射量化级数和传感器所接受辐射能量范围方面还有一定差距,在部分积雪区会出现过饱和现象,后续可针对这些方面进行改善。更多还原

【Abstract】 Radiometric quality of satellite’s image is closely related to its monitoring capability.GF-1 is the first satellite of China’s high-resolution earth observation system and has an important application value in monitoring mountain snow.In this paper,we compare the radiometric quality of GF-1 satellite image to the similar overseas high-resolution satellite SPOT-6 and RapidEye in snow-covered area of Manasi River Basin.The results could provide some advices for future GF series satellites’ development in China.Using the image statistical features,average gradient,information entropy,and SNR,the radiometric quality of the three satellite images is compared.The results show that the GF-1’s image statistical features and average gradient has the best performance.However,the information entropy has a certain gap compared with the other two satellites due to the depth of radiation.GF-1 partially supersaturated during snow imaging,resulting in part of region having zero value.After removing these outliers,GF-1 image’s SNR is re-estimated and found to be significantly superior to other satellites in the blue,red,and panchromatic bands,whereas,the green and near-infrared bands still have a certain gap compared to SPOT-6,but similar to RapidEye.Overall,the radiometric quality of GF-1 image in the mountainous snow-covered area has basically reached the level of similar satellites in the world and some indicators are even better than other satellite images.Limited to the depth of radiation and the range of radiation energy accepted by the sensor,an over-saturation phenomenon will appear in some snow-covered regions,the follow-up can be further improved in this regard.更多还原