【作者】 杜庆丰；

【导师】 管志宁；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息技术， 2008， 博士

【摘要】 瞬变电磁法具有电磁法穿透高阻层能力强、对低阻体反映灵敏等优点,且该方法简单易行、信息丰富、精度高、投资少、见效快,被广泛应用于资源与工程勘查等众多领域。在其应用领域被迅速拓宽的同时,一些急需解决的实用的技术问题也逐步突显出来——装置技术、数据预处理(数据组合滤波,弱信息增强处理,异常分离)、快速反演技术、地形影响改正技术、成图技术等。解决好这些问题对推动TEM被更好、更广泛地应用将非常必要。装置与仪器的良好匹配及与被勘查目标物的良好耦合,是取得良好勘查效果的前提。论文探讨了如何进行装置匹配及如何设计最佳地耦合探测目的物的装置,以有效地提取响应信号。TEM观测的是二次场,常表现出信号弱,噪声水平相对偏高的特点,虽然这一问题可通过数据采集的多次叠加及使用抗干扰装置等手段得到一定程度的克服,但却不可能完全解决;再则,在TEM观测中有时还存在着非涡流因素直接引起的瞬变响应,其“响应”的结果使异常复杂化,甚至出现负响应。而这些可以导致反演计算的无法正常进行,为此,必须对TEM观测数据进行预处理,在此,作者提出了“数据组合滤波”、“弱信息增强处理”及特殊的“异常分离”的概念,通过试算及实际应用,该方法可较好地解决上述问题。目前,常规一维反演,多为迭代反演,不仅需要用户提供初始模型参数,且运行速度不快,二维、三维的运算速度则更慢,为使TEM更好地普及推广,论文工作建立的一套多参数的快速反演,为用户提供了包括全域、晚期公式,烟圈理论……等多种理论模式下的视电阻率,纵向电导等参数,供其选择使用,具有实用价值。虽然在电法勘探中,TEM是受地形影响较小的方法。但当地形起伏较大时,如不进行地改,则可能造成严重后果,论文对地改问题进行了较系统的探讨。以往的TEM结果图件,基本以视电阻率断面图为主。但目前许多工作为面积性工作,自然需要更精确的空间分布图。为此,论文工作开发了水平及垂直方向的切片图,该图具实用价值。作者在就上述问题进行系统研究探讨的同时,编制了一套相应的实用的瞬变电磁数据预处理及反演解释的软件系统,该系统已可应用于瞬变电磁的实际数据处理。更多还原

【Abstract】 As an electromagnetic method, the Transient Electromagnetic Method (TEM) has several advantages such as outstanding penetrating ability through high resistance layers and high sensitivity to low resistances. Furthermore, TEM is widely used in many fields like resource and engineering exploration because of its easy application, abundant information, high precision, low cost and quick effects.Simultaneously, a few technical problems which need to be solved urgently have emerged, for e.g. data pretreatment (data composite filter, enhanced process for weak information and anomaly separation), rapid inversion technology, landform rectification technology and mapping technology, etc. It is absolutely necessary to solve these problems so that TEM will have a better and broader application.TEM observes the secondary field and weak signals and comparatively high noise level are visible traits, especially with more interference caused by humanities in many engineering geophysical applications. Although multiple stacking of data acquisitions and anti-jamming devices are able to help, it can’t be settled completely. Besides, sometimes there are transient responses directly caused by non-eddy current factors in TEM observations, and the "responses" will lead to an extraordinarily complex result, even with appearance of negative responses. All these may encumber normal inverse calculation. Therefore, data of TEM observation must be pretreated. The author hereof use the means of "data composite filter", "enhanced process for weak information" and special "anomaly separation" to solve the problems mentioned above, the effect has been proved by theoretical calculation and practical applications.At present, conventional one-dimensional inversions are mostly iterative inversions, which require users to provide initial model parameters and computational speed is not fast. Two-dimensional and three-dimensional inversions are even slower. In order to promote TEM’s applications, it’s meaningful to establish a multi-parameter rapid inversion system and offer parameters as apparent resistivities and vertical conductivities of various theoretical models including all fields, terminal formula and smoking ring theory.The terrain factors don’t have a major impact on observed data; as a result, TEM is less influenced by terrains in electrical prospecting. However, lack of landform rectification may cause serious consequences in interpretation of anomaly. In the past, most TEM maps were contour maps of apparent resistivity section, which can’t reach the precision required by spatial distribution maps of modern areal work; thereby development of horizontal and vertical slicing maps has practical value.The author hereof had a systemic study of all the before-mentioned issues and wrote a relevant and practical TEM data processing system simultaneously. The system which can be used for TEM actual data processing has achieved applicatory successes.更多还原