地球岩石圈及其板块运动的现代测定——大西洋扩张的初步结果

自20世纪70年代末国际上开始实施了第一个地壳动力学计划,至今在全球范围内已测定了500多条洲际间的基线长度变化率,得到了全球约550个地面观测站的地心坐标及其变化率,实现了用现代空间测地技术观测资料分析得到的高精度地球参考架;证实了全球板块运动的存在,为测地学、地球物理学、海洋学和地震灾害学等的进一步研究提供了可靠的科学依据;我们分析得到了大西洋中脊海底扩张速率的初步结果。

固体潮Love数的基本理论和数值结果

滞弹微椭、自转无海洋、横向均匀地球模型的固体潮模拟理论,已能很好地解释空间大地测量技术的观测成果,但这一地球模型中还没有考虑的一些物理因素(地球横向不均匀和各向异性等),目前在理论上已被人们所重视.本文在毫微伽和毫米精度上,研究了Love数的基本理论,给出了其解析表达式;利用空间大地测量技术对Love数解析表达式的拟合结果,计算了2阶潮汐各个波段内的Love数.研究表明空间大地测量技术观测精度的提高,是精确测定Love数的必要途径之一.

Automatic Change Detection of Geo-spatial Data from Imagery

The problems and difficulty of current change detection techniques are presented. Then, according to whether image registration is done before change detection algorithms, the authors classify the change detection into two categories:the change detection after image registration and the change detection simultaneous with image registration. For the former, four topics including the change detection between new image and old image, the change detection between new image and old map, the change detection between new image/old image and old map, and the change detection between new multi-source images and old map/image are introduced. For the latter, three categories, i.e. the change detection between old DEM, DOM and new non-rectification image, the change detection between old DLG, DRG and new non-rectification image, and the 3D change detection between old 4D products and new multi-overlapped photos, are discussed.