基于ImageStation OrthoPro的数字正射影像自动处理

借助于ImageStation OrthoPro（ISOP）软件,能够对工作区内的影像进行正射纠正、匀光处理、自动生成拼接线以及镶嵌裁图等批量处理,为数字正射影像的大规模制作提供了高效的软件平台。     

过完备字典稀疏表示的云图超分辨率算法

提出一种基于过完备字典稀疏表示的云图超分辨率算法。首先,联合训练针对低分辨率与高分辨率云图块的两个字典Dl和Dh,保证对应的低分辨率与高分辨率云图块关于各自的字典具有相似的稀疏表示;其次,通过求解优化问题,获得待处理云图每个低分辨率云图块关于Dl的稀疏表示,并将表示系数用于Dh以生成对应的高分辨率云图块;最后,运用最速下降算法,得到满足重构约束的高分辨率云图。红外与可见光云图的数值实验验证了本文算法的有效性,表明本文算法在视觉效果及PSNR指标上均优于插值方法。     

无地面控制点条件下卫星摄影测量的发展与现状

无地面控制点条件下, 卫星摄影测量研究与工程实践是世界各国在该领域中所面临的研究难点之一。本文介绍了在无地面控制条件下光学卫星摄影测量的研究发展和工程实践历程, 并对中国“天绘一号”卫星获取的影像实测结果进行分析, 结果表明, 中国在无地面控制条件下的卫星摄影测量研究与工程实践已居于国际领先地位。     

利用嫦娥一号IIM 模拟数据提取月表矿物端元的的精度分析

干涉型成像光谱仪(IIM) 作为中国首颗探月卫星嫦娥一号上的重要载荷之一,已经获取了大量的月球高光谱数据.然而由于IIM 数据的光谱范围被限定在480—960 nm 波谱范围内,很少覆盖月表矿物的波谱吸收特征,利用IIM 数据反演月表矿物信息面临巨大挑战.当前月表地面调查数据或精细矿物分布制图还很缺乏,难以对反演或提取结果进行有效验证.本文利用月表4种主要矿物(斜长石、单斜辉石、橄榄石和钛铁矿)进行线性混合构建IIM 模拟数据,分析月表矿物端元提取的精度,并对真实IIM 数据进行了初步应用.根据斜长石和钛铁矿的不同组合比例分别模拟了月表的月海和高地,模拟数据还加入了与IIM 真实数据分布趋势一致的随机噪声.基于4种端元提取算法(VCA 、ICA 、MVSA 、SISAL) 对模拟数据进行端元提取,并以光谱角距离(SAD) 作为端元提取的精度评价准则.结果显示,MVSA 和SISAL 算法提取的所有矿物端元的光谱角距离都小于0.1 ,一般意味着矿物提取精度可以被接受.斜长石在各种算法下提取端元的光谱角距离都小于0.015 ;单斜辉石和钛铁矿提取端元的光谱角距离都小于0.1 ;橄榄石提取精度最差,在ICA 算法下其光谱角距离高达0.34 .     

Natural occurrence of reidite in the Xiuyan crater of China

The high‐pressure minerals of reidite and coesite have been identified in the moderately shock‐metamorphosed gneiss (shock stage II, 35–45 GPa) and the strongly shock‐metamorphosed gneiss (shock stage III, 45–55 GPa), respectively, from the polymict breccias of the Xiuyan crater, a simple impact structure 1.8 km in diameter in China. Reidite in the shock stage II gneiss displays lamellar textures developed in parental grains of zircon. The phase transformation of zircon to reidite likely corresponds to a martensitic mechanism. No coesite is found in the reidite‐bearing gneiss. The shock stage III gneiss contains abundant coesite, but no reidite is identified in the rock. Coesite occurs as acicular, dendritic, and spherulitic crystals characteristic of crystallization from shock‐produced silica melt. Zircon in the rock is mostly recrystallized. The postshock temperature in the shock stage III gneiss is too high for the preservation of reidite, whereas reidite survives in the shock stage II gneiss because of relatively low postshock temperature. Reidite does not occur together with coesite because of difference in shock‐induced temperature between the shock stage II gneiss and the shock stage III gneiss.     

Unstable Dynamical Properties of Spiral Cloud Bands in Tropical Cyclones

A nondivergent barotropic model （Model 1） and a barotropic primitive equation vortex model （Model 2） are linearized respectively in this paper. Then their perturbation wave spectrums are computed with a normal mode approach to study the instability problem on an appointed tropical cyclone （TC）-like vortex, thereby, the dynamic instability properties of spiral cloud bands of TCs are discussed. The results show that the unstable mode of both models exhibits a spiral band-like structure that propagates away from the vortex outside the radius of maximum winds. The discrete modal instability of the pure vortex Rossby wave can account for the generation of the eyewall and the inner spiral band. The unstable mode in Model 2 has three parts, i.e., eyewall, inner and outer spiral bands. This mode can be interpreted as a mixed vortex Rossby-inertia gravitational wave. The unbalanced property of the wave outside the stagnation radius of the vortex Rossby wave is one of the important reasons for the formation of the outer spiral band in TCs. Accordingly, the outer spiral band can be identified to possess properties of an inertial-gravitational wave. When the formation of unstable inner and outer spiral bands is studied, a barotropic vortex model shall be used. In this model, the most unstable perturbation bears the attributes of either the vortex Rossby wave or the inertial-gravitational wave, depending on the vortex radius. So such perturbations shall be viewed as an unbalanced and unstable mixed wave of these two kinds of waves.     

An analysis on observed and simulated PNA associated atmospheric diabatic heating

This study examines the PNA associated atmospheric diabatic heating by linearly isolating the influence of ENSO. The analysis is based on the NCEP–NCAR and ERA-40 reanalyses and a 1,000-year-long integration of the CCCma coupled climate model. Both the vertically integrated and three-dimensional diabatic heating are examined. The Rossby wave sources in association with the PNA are also diagnosed. The PNA-related heating is confined outside the tropics and is dominated by anomalies in the eastern Pacific, with a north–south dipole structure in mid-latitudes and the northern subtropics. The heating anomalies change sign with height in mid-latitudes but have the same sign throughout the troposphere in the northern subtropics. Relatively weak heating anomalies also appear in mid-latitudes, downstream of the heating dipole over North America and the western North Atlantic. The heating anomalies are largely supported by the advections related to the mean state throughout the troposphere, and partially damped by the advections related to the eddy effect, particularly at the upper troposphere over the North Pacific. Broadly similar patterns are seen from the NCEP–NCAR and ERA-40 reanalyses. Yet anomalous heating centers are generally located at relatively lower troposphere for the ERA-40 with respect to the NCEP–NCAR. The tropical heating anomalies are rather weak, remarkably different from those related to ENSO variability. In addition, the Rossby wave source collocates with the atmospheric diabatic forcing in the mid-high latitudes over the PNA sector, and shows no forcing source in the tropics. The results demonstrate possible forcing in the mid-high latitudes, regardless of tropical heating for the PNA teleconnection. The modeled heating and wave forcing anomalies in association with the modeled PNA compare reasonably well with the reanalysis-based estimates, increasing confidence in the observational results. The analysis provides further evidence of the independence of the PNA on ENSO from the diabatic heating point of view.     

基于MODIS资料的贵州植被叶面积指数的时空变化及其对气候的响应

利用2000～2006年MODIS(Moderate Resolution Imaging Spectroradiometer)卫星遥感观测的植被叶面积指数月平均资料以及相应时段的月平均气温、降水的观测资料对贵州植被的时空变化进行了分析.结果表明贵州2000～2006年植被分布受水热条件控制表现出对气候因子不同的响应关系,其中对降水的响应关系比气温明显,特别是冬季和春季,而植被在夏季和秋季的分布主要受气温的制约,与降水的关系并不明显.从季节和年际尺度的时间变化角度而言,植被对气温的响应比对降水明显,季节变化和年际变化的相关系数分别为0.89和0.73(分别通过99.9%和95%信度检验).     

十堰市气候干旱分析及预报指标

利用十堰市7个代表站1953-2006年的降水资料和气温资料,用降水距平百分率（R指标）这一传统的干旱等级划分方法,并考虑到气温引入了P指标对干旱等级进行了划分,揭示了该区域干旱发生的基本特征。结果表明：十堰是我国中部地区干旱频发地区之一,干旱存在自身的周期性和连续发生的规律,地理分布是北部重于南部。造成十堰干旱的主要天气系统是东亚大槽、副热带高压和青藏高压（大陆高压）。这3个系统交替影响并控制该市：春季主要是东亚大槽稳定;夏季副热带高压控制为主、大陆高压控制次之;秋季大陆高压控制为主、副热带高压控制次之。根据不同季节和不同类型的干旱,给出了具体的预报指标。     

1951-2008年辽宁冰雹的时空分布特征

选取1951-2008年辽宁省56个站气象资料和中国气象灾害大典等资料,对冰雹时空分布进行了统计分析。结果表明：辽宁冰雹日数以山地为最多,丘陵次之,平原和沿海最少。移动路径基本与山脉、河流、海岸线等地形走向一致。冰雹具有明显的季节变化,主要出现在4-10月。5-6月为冰雹多发期,6月为最多,5月次之。近30a辽宁省年冰雹日数呈减少趋势。冰雹发生主要集中在中午至傍晚。辽西走廊、辽宁中部平原及辽东半岛南部大连地区为冰雹灾害重点防御区。产生冰雹的天气系统按高空形势分类主要有4种：冷涡、冷涡后部横槽、高空槽和槽后西北气流,对应地面形势多为低压冷锋。