风云卫星数据服务评价指标的验证分析

简述了目前我国风云卫星数据服务以及气象服务效益评估业务的现状,利用层次分析法提出风云卫星数据服务评价的6个1级指标和19个2级指标。设计了风云卫星数据服务评测量表,并采用分半信度、因子分析等方法对量表作信度和效度分析,结果表明所设计的评测量表具有良好的信度和效度,确定了包括服务平台易用性、服务流程规范性、服务响应及时性、服务内容完整性、服务工作主动性、服务宣传广泛性等6个方面的风云卫星数据服务评价指标。     

上海市PM_(10)浓度四季遥感模型研究

通过分析2001—2012年上海市PM_(10)浓度(由API(Air Pollution Index)转化得到)的变化规律,构建了上海市PM_(10)浓度的遥感反演模型。结果表明:1)上海市PM_(10)浓度存在季节性变化,应分别建立遥感反演模型。2)分析MODIS气溶胶光学厚度(Aerosol Optical Depth,AOD)产品与PM_(10)浓度之间的相关性发现,AOD须经过垂直和湿度订正才可与PM_(10)建立较好的关系。3)结合垂直和湿度订正分别建立的上海市PM_(10)浓度春夏秋冬四季的遥感反演模型均通过了拟合度检验,其中春季模型采用指数函数、夏季和秋季模型采用二次多项式函数、冬季采用幂函数、全年采用二次多项式函数,利用此四季模型反演上海市PM_(10)浓度具有较高的可信度。     

塔河油田奥陶系岩溶储层垂向带发育特征及其识别标准

岩溶储层在垂向上的分带性是岩溶在垂向上发育不均匀的客观表现。根据现代岩溶理论,通过对大量测井资料的统计分析,按照岩溶缝洞系统发育强弱及地下水运动方式、岩溶作用方式,将岩溶储层垂向上划分为表层岩溶带、垂向渗滤溶蚀带、径流溶蚀带、潜流溶蚀带等四个岩溶发育带,并建立了塔河油田奥陶系岩溶储层垂向带划分的测井响应与岩溶成因组合指标体系。测井响应指标包括自然伽玛、电阻率、井径等;岩溶成因指标包括地下水径流方式、岩溶作用类型、充填特征和岩溶个体形态等。根据岩溶储层垂向带划分标准,对塔河油田奥陶系岩溶储层垂向带发育特征进行了统计分析,并对不同地貌区岩溶储层的垂向带发育特征进行分析。分析认为:表层岩溶带以大中型溶蚀孔洞为主,测井显示为高伽玛,低电阻;半充填(或未充填)时测井表现为低伽玛,低电阻;垂向渗滤溶蚀带以高角度溶缝和小型溶蚀孔洞为特征,测井显示为低伽玛,高电阻;径流溶蚀带多发育大型溶洞,测井显示为高伽玛,低电阻;潜流溶蚀带岩溶弱发育,测井显示为低伽玛,高电阻。     

基于GeoSOT剖分编码的不动产单元统一标识模型研究

针对现有不动产单元编码存在空间位置信息模糊的问题,以寻求更加直接反映空间位置的不动产编码为目标,在对现有不动产单元编码深入研究的基础上,提出了基于GeoSOT网格编码的不动产单元模型、编码方法,以及该模型与空间位置信息转换方案。试验证明,基于GeoSOT的不动产单元编码更加直观,具有很好的实用性。     

热红外与可见光数据的云边缘高度匹配

高分辨率数据中云高度的差异性突显,特别是边缘处高度在云阴影识别和地表辐射估算等方面成为需要考虑的重要因素。热红外数据获取云高度分辨率较低、缺乏细部差异性特征,为解决这一问题,首先将对应的热红外和可见光数据进行特征点配准,再将基于热红外数据计算的云高度重采样至高分辨率,然后以基于欧式距离变换的围线搜索方法及距离加权将热红外云边缘高度匹配至对应的可见光图像,最后根据云阴影的相似度匹配方法确定真实云高度。结果表明,算法在遵循热红外云高信息分布变化规律的同时,可以得到较准确的高分辨率云边缘高度,一定程度上解决了热红外技术获取云高在分辨率上的局限,扩展了其在云高反演方面的作用。     

结合多尺度纹理特征的遥感影像面向对象分类

地物具有多尺度的特点,单一尺度难以准确描述遥感影像包含的地物纹理信息。利用我国自行研发的高分一号遥感影像数据,采用灰度共生矩阵对第一主成分进行纹理特征提取,利用Jeffries-Matusit距离选择多尺度组合,并通过单一纹理结合多光谱数据的分类精度,以及纹理特征间的相关性,最终选择多尺度纹理特征组合进行面向对象分类。研究结果表明:结合多尺度纹理特征组合的面向对象GF-1影像分类能有效提取地物信息,总体分类精度达到81.75%,Kappa系数0.78。     

Precise orbit determination of BeiDou constellation: method comparison

Chinese BeiDou navigation satellite system is in official service as a regional constellation with five geostationary earth orbit (GEO) satellites, five inclined geosynchronous satellite orbit (IGSO) satellites and four medium earth orbit (MEO) satellites. There are mainly two methods for precise orbit determination of the BeiDou constellation found in the current literatures. One is the independent single-system method, where only BeiDou observations are used without help from other GNSS systems. The other is the two-step GPS-assisted method where in the first step, GPS data are used to resolve some common parameters, such as station coordinates, receiver clocks and zenith tropospheric delay parameters, which are then introduced as known quantities in BeiDou processing in the second step. We conduct a thorough performance comparison between the two methods. Observations from the BeiDou experimental tracking stations and the IGS Multi-GNSS Experiment network from January 1 to March 31, 2013, are processed with the Positioning and Navigation Data Analyst (PANDA) software. The results show that for BeiDou IGSO and MEO satellites, the two-step GPS-assisted method outperforms the independent single-system method in both internal orbit overlap precision and external satellite laser ranging validation. For BeiDou GEO satellites, the two methods show close performances. Zenith tropospheric delays estimated from the first method are very close to those estimated from GPS precise point positioning in the second method, with differences of several millimeters. Satellite clock estimates from the two methods show similar performances when assessing the stability of the BeiDou on board clocks.     

基于最优分割分级法的月球撞击坑分级及其演化分析

撞击坑是月球表面广泛分布的重要构造形态,占据了月球表面的大部分面积。撞击坑的直径差别很大,从几微米到数百千米,其退化程度与形成年代具有密切关系。为了研究不同地质年代形成的撞击坑直径大小及其演化规律,需采用量化分级方法对大小不同的撞击坑进行定量分级和统计分析。本文在月表撞击坑数据库LU60645GT和Lunar_Impact_Crater_Database(2011)的基础上,结合数据库中撞击坑的直径、深度和年代信息,利用最优分割分级法对撞击坑直径进行定量化分级,并根据分级结果,综合分析撞击坑几何形态特征及其演化规律。研究结果表明,撞击坑形态特征的演化与年代有密切的关系。在相同级别、相同地体下,撞击坑形成的年代越早,其形态特征的精细结构退化程度越明显,只保留了大体的几何形状;而在不同级别、相同地体、相同年代下的撞击坑形态特征则由简单逐渐变为复杂,坑物质也逐渐变得复杂。     

河岸带潜流层温度示踪流速计算方法

为揭示低温水影响下的河岸带潜流层的温度场和流场分布特性,利用野外水温水位实时监测试验,研究河岸带潜流层温度场在不同季节、不同空间位置上的分布特性,并利用水温资料计算获得地下水流速。结果表明:河岸带潜流层温度场在夏季和冬季分别呈现出"上暖下冷"和 "上冷下暖"的温度分层现象;通过对温度示踪方法的4种计算方法进行分析比较,得到Hatch相位法计算的地下水流速具有较高的准确性,在2014年12月15—31日时段内流速大小为1.03×10-4~7.96×10-4m/s,在空间上,断面深度增加,地下水流速降低,且不同深度流速曲线接近平行。     

Comparative Study of the Carbon Emission Situation and Goals between China and India

As the two large developing and populous countries, China and India face the dual challenges of economic development and climate change. Both of them are active in carbon emissions reduction, while India also bears the pressure of being “benchmarked” against China. With taking China and India as the sample of a comparative analysis, and the statistical value of a long sequence as the basic analysis data, based on the detailed analysis and comparison of carbon emissions history, the carbon emissions situation of the two countries from various dimensions including economic development, energy reserves and consumption, etc. were comparatively analyzed. The carbon intensity and energy structure after achieving the objectives were measured and compared by focusing on the carbon emissions reduction targets in China and India. The comparative results show that: China’s total carbon emissions are greater than India’s, but the growth rate of emissions, per capita emissions are significantly lower than India’s, while the carbon intensity decreases significantly faster than that of India. China has taken more efforts to make commitments to carbon reduction than India. With India’s energy structure adjustment, the situation will be gradually better than that in China.