【作者】 程晓；

【导师】 徐冠华； 邵芸；

【作者基本信息】 中国科学院研究生院（遥感应用研究所） ， 地图学与地理信息系统， 2004， 博士

【摘要】 南极冰盖的物质平衡和海平面变化是全球变化研究的一个重要内容。南极的地理环境和恶劣的自然条件给科学家赴现场考察带来了重重困难。微波遥感技术是监测整个南极冰盖变化的最佳手段。微波传感器具有全天时和全天候的观测能力，可以获取极地冰盖表面和次表面的详细信息。国内目前在极地遥感研究方面所做工作甚少，本文工作属国内首次较为系统的尝试。 合成孔径雷达干涉测量是测量南极地区数字高程模型和冰流的有效工具。目前的研究重点主要在西南极沿岸冰架地区，东南极内陆冰盖地区涉足很少。 散射计和辐射计数据具有较大的空间覆盖和快速重访率，这使其成为联系监测南极冰盖的极好工具。对长期积累的散射计和辐射计数据开展时序分析可以研究南极冰盖的变化趋势与异常。 本论文开展了利用干涉雷达技术在南极内陆冰盖地区提取数字高程模型和测量复杂冰流的研究，另利用大尺度的微波散射计和辐射计数据开展了冰盖冰架地区的变化监测研究。 主要研究内容包括： (1)格罗夫山地区数字高程模型提取 利用星载雷达干涉技术提取东南极内陆格罗夫山地区的数字高程模型，与GPS现场测量结果进行对比，取得了较好的精度。深入分析内陆冰盖地区重复轨道INSAR测量地形的精度和可行性。 (2)冰盖地区干涉去相干研究及应用 通过处理多种时相与空间基线的L波段和C波段干涉SAR数据，从干涉结果研究南极冰盖干涉各去相干源的影响特性。蓝冰区的相干性通常较好。冰盖地区临界基线短于平常值，空间垂直基线对干涉去相干影响大，L波段雷达干涉在保持相干性方面具有独特的优势。 (3)差分干涉雷达技术冰流测量模型研究与应用 研究差分干涉测量消除地形相位的方法以及雷达视线向位移与真实冰流位移之间的关系，详细阐述单向和升降轨双向观测测量冰流的模型及计算方案，并结合多组雷达数据采用多种方案在格罗夫山地区开展研究试验，其中基于JERS-1和ERS-1／2 SAR的四路差分干涉处理获得了很好的结果。论文还就冰流测量的误差来源进行了深入的分析。 (4)基于缠绕相位的冰流参数计算 提出基于缠绕相位的冰流参数计算模型，使得研究人员无需进行相位解缠即可获得冰流应变率等重要参数信息，提高了局部相位梯度大、相位解缠难度大的干涉图的可用性。 (5)基于ENviSAY-ASAR的干涉处理研究 利用格罗夫山地区最新的ENVISAI二ASAR数据进行干涉处理研究，生成干涉条纹，条纹中的冰流模式与前述ERS一1/2和JERS一1的结果基本一致。 (6)基于星载微波散射计和辐射计数据的冰盖特性及变化监测研究 结合微波与冰雪相互作用的理论，研究了南极冰盖的微波散射、辐射特征与地形、温度等的关系。通过比较同季sAAS与NSCAT观测数据，发现Ku波段不同观测方向对冰面微地形取向的敏感性。选取8个典型冰盖和冰架试验区，利用ESCAT和SSMI历史数据(1992一2000)进行后向散射与亮温变化的时间序列研究，得出南极大陆周围冰架与南极半岛地区处于融化加剧状态的初步结论。更多还原

【Abstract】 Mass balance of Antarctic ice sheet and mean sea level are the factors in global change study. The atrocious geographical and natural conditions in Antarctica make it quite difficult for the scientists to carry out more and frequent field expeditions. Microwave satellite remote sensing is a practical way of monitoring long-term changes in the properties of the entire Antarctic ice sheet. Data acquired from microwave instruments can be acquired day and night in all weather conditions and provides detailed information on the surface and subsurface of polar glaciers and ice sheets.Synthetic Aperture Radar(SAR) is proved to be an effective tool to generate high-accuracy digital elevation model (DEM) generation and to measure ice flow on Antarctic glaciers. Presently, most research is concentrated on the coastal ice shelves of WAIS (West Antarctic Ice Sheet), very few work has been done for in-land glaciers in East Antarctica.Scatterometer and radiometer image data have a greater spatial and more frequent coverage, albeit at a lower spatial resolution, making these instruments ideal for monitoring the Antarctic ice sheet. The long-term continuous scatterometer and radiometer image data are best for time series analysis to study the trend and abnormity of Antarctic ice sheet.The dissertation investigates application of SAR interferometry in Antarctic inland glacier for DEM and complex ice flow measurement, also large-scale scatterometer and radiometer data for ice sheet monitoring.Main research topics and initiatives in this dissertation include:(1) DEM generation in Grove MountainsDigital elevation model (DEM) of Grove Mountain in East Antarctica is generated by means of SAR Interferometry (InSAR), as is validated partly using the pre-existed GPS DEM mapped in 2000. It is proved to be accurate. The error source and feasibility of INSAR DEM construction on inland ice sheet is well analyzed.(2) Research and application of interferometric decorrelation on Antarctic ice sheet.The impact of several decorrelation factors on interferometric correlation is studied through interferometric experiments with multiple SAR image pairs (different baseline, L-band and C-band). The critical baseline here is much shorter than the normal length. The long spatial perpendicular baseline is a main deccorelation factor. Also are found that high correlation can always be seen in blue ice region and L-band interferometry is preponderant in keeping fine correlation within long interval.(3) Modeling and Applications of DINSAR ice flow measurementsDifferent topographic phase removal methods in differential SAR interferometry, the relations between radar look-of-sight displacement and actual ice motion are studied. The models of derive actual ice displacement from single-direction and bi-directional (ascending and descending flight) INSAR measurements are described in detail. Multi-source L-band (JERS-1) and C-band (ERS-1/2, ENVISAT) SAR data are used for ice motion measurements in Grove Mountain. The 4-pass differential interferometric combination of JERS/ERS gets good result. The possible error sources are given and discussed in detail.(4) Study of deriving ice flow parameters from wrapped interferometric phase The calculation models of deriving ice flow parameters from wrappedinterferometric phase are given. Thus we could get the ice flow information regardless of the interferometic phase is unwrapped or not, which widens the usability of high-gradient and failing-to-unwrap interferogram.(5) Research of SAR interferometry based on ENVISAT-ASAR dataThe latest ENVISAT-ASAR SLC data are put to interferometric experiment, which produced high-quality interferogram. The pattern of ice flow fringes presented is coincident with the former ones in ERS and JERS interferograms.(6) Ice sheet monitoring with space-borne microwave scatterometer and radiometer data.Starting from the theory of interaction between microwave and snow, the behavior characteristics of microwave scattering and radiation of fim layers更多还原