Measurements of horizontal or vertical gradients of the magnetic field intensity can add a new dimension to high resolution aeromagnetic surveys of shallow basement areas. Although a number of vertical, horizontal and triaxial aeromagnetic gradiometers are in operation throughout the world, very little has been documented on the relative merits of horizontal and vertical gradiometer measurements or of measured versus calculated gradients. Our results demonstrate that there are differences in spatial resolution and bandwidth between measured and calculated gradients and that horizontal and vertical gradients provide complementary information. Finally our results indicate that better geo-referencing of horizontal gradiometer data is needed before we can derive reliable vertical gradient data from the measured longitudinal and transverse gradients Development of short-baseline aeromagnetic gradiometers began in 1975 with construction of the Geological Survey of Canada vertical gradiometer. The success of current short-baseline gradiometers depends on the use of high sensitivity optical pumping magnetometers, usually caesium vapour sensors and effective compensation for aircraft manoeuvre noise. Practical advantages of measured gradients include elimination of the diurnal problem and improved spatial resolution of small shallow sources. Transient signals have the same effect on all the magnetometer sensors so the effects are cancelled out in the gradients and diurnal-free total magnetic intensity can then be reconstructed by integrating the gradient data. The gradient data effectively remove the main field of the earth and enhance smaller scale, shallow anomalies while attenuating longer wavelength, deeper seated anomalies. In addition, measurement of the transverse horizontal gradient provides extra information between flight lines, leading to a reduction in flight line dependency of magnetic anomalies and a reduction in aliasing effects. The vertical gradient can also be derived from the longitudinal and transverse horizontal gradients with less line dependence and probably lower noise levels than the measured vertical gradient. Data from a conventional Canadian vertical gradiometer system, an Australian horizontal gradiometer system and a Southern African triaxial gradiometer system are evaluated. The measured vertical gradient data appear to provide better resolution of shallow sources than the vertical gradient calculated from the total field. The horizontal gradient data allow us to derive the vertical gradient from the horizontal gradients and provide much improved enhanced total magnetic intensity grids. The choice of a vertical or horizontal gradiometer system depends on survey objectives and both systems have their advantages. The vertical gradient appears to be marginally easier to measure and simpler to interpret. A triaxial gradiometer system provides the advantages of both at the cost of an additional sensor and retractable boom installation, compared to a horizontal gradiometer. Unfortunately, in Australia, CAA certification of a retractable tail boom may prove difficult. The viability of deriving the vertical gradient profiles from measured horizontal gradients needs more research, but if this can be done routinely, we think this would tilt the balance towards the horizontal gradiometer system. The improvement in total magnetic intensity grids using the transverse gradient information can be quite dramatic in many cases and there is always some improvement in the data. The combination of transverse gradient enhanced total magnetic intensity data and high spatial resolution 'texture' filters provides excellent definition of lower amplitude anomalies. In contrast, the calculated vertical magnetic gradient is often very similar to the measured data and the benefits of the measured vertical gradient may be small in many cases. Gradiometer performance deteriorates rapidly as the source becomes deeper and existing gradiometers are probably close to the noise level at 500m depth. Rugged topography also causes fixed wing gradiometer performance to deteriorate.

评介了澳大利亚BHP比利顿矿产勘查公司和矿产发现技术公司的航空矢量磁测,美国地质调查所研制的地面张量磁梯度仪(用磁通门磁力仪),德国耶拿物理学高技术研究所的航空全张量磁力梯度仪系统(用LTS-SQUID),美国橡树岭国家实验室和特瑞斯坦技术公司(Tristan Technologies,Inc.)研究和开发的航空全张量磁力梯度仪系统(用HTS-SQUID),澳大利亚联邦科学工业研究组织(CSIRO)正在研制的航空张量磁梯度仪GETMAG和MAGSAFE(用HTS-SQUID),后者由CSIRO和澳大利亚国防科学与技术组织(DSTO)共同研制.提出了关于研究和开发我国航空磁测技术的建议.

我国航空物探的成就与展望乔日新，王守坦（地矿部航空物探遥感中心，１０００８３）我国航空物探工作起始于五十年代初期，至今已有四十多年的历史。这项技术主要是在二个部门（系统）中发展的：一是地质矿产部以区域地质研究、各类固体矿产和油气普查为主的综合航空物探...

<FONT face=Verdana>本文概要介绍了我国航空磁力测量方法技术现状,近年来测量技术与解释方法方面的最新进展.首次介绍了我国引进国外航空重力测量系统以来的最新测量技术成果.分析了我国航空物探技术与国际上先进国家的差距,并对我国航空物探的发展趋势进行了分析与预测.</FONT>

<p>在异常选编工作中，往往需要剔除掉区域背景场的干扰，从而寻找浅部异常的一些信息，因为区域背景场往往是由一些火山岩、侵入岩所引起，当然也不排除大型矿床所引起的可能性，航磁总场是区域场和局部场的叠加，因此异常往往会因为某种方式被忽略掉.梯度数据具有压制深部异常体、突出浅部异常体信息的特点，这就为梯度数据能够方便地提取异常提供了理论支持.在中国的北部某地区进行了航磁全轴梯度测量飞行，获得了横向梯度、纵向梯度和垂向梯度数据，利用实测数据总结出梯度数据与地质体异常之间的关系，确定了异常选编原则，为今后梯度数据确定异常奠定了基础，同时分析了实测的垂向梯度数据相比于转换的垂向梯度数据在异常反映上信息更丰富.</p>

China Aero Geophysical Survey and Remote Sensing Center successfully developed AGS-863 Three Axis Airborne Magnetic Gradiometer with self-owned intellectual property rights, and carried out gradient measurements of aeromagnetic survey in Inner Mongolia recently. To analyze the key indicators of gradiometer and corroborate instrument performance, the authors designed the testing method for key indicators. It has been proved that the aeromagnetic gradiometer is stable and reliable during survey. The test result shows that the system has excellent synchronism, consistency, long-term stability and compensation precision.

首次明确指出文献中长方体ΔT场及其梯度场理论表达式在上半无源空间存在某些点的场值无法计算的解析“奇点”问题．通过详细的理论推导，深入分析了出现解析“奇点”的原因，并在此基础上导出新的长方体ΔT场及其梯度场在上半无源空间无解析“奇点”的理论表达式．对比模型正演计算结果表明，新导出的ΔT场及其梯度场无解析“奇点”理论表达式的正确．

中国国土资源航空物探遥感中心成功研制出具有完全自主知识产权的航磁全轴梯度勘查系统,在中国的北部某地区进行了航磁全轴梯度测量飞行,获得了横向梯度、纵向梯度和垂向梯度数据.本文简要介绍了测区地质概况、飞行方案及数据处理等,重点对梯度数据在断裂构造划分等方面进行了探讨,认为航磁梯度数据比总场数据更加清晰显示构造走向,并比较了实测和转换的垂向梯度数据,结果表明实测垂向梯度在反映地质体边界等方面具有一定优势.

完全国产化的航磁全轴梯度勘查系统已开展了测量工作,并获得了比较理想的梯度数据,但是如何利用梯度数据进行磁性地质体边界圈定还处于研究阶段。笔者先给出了航磁全轴梯度测量原理;然后着重从利用梯度数据尤其是垂向梯度数据进行岩体边界圈定等方面进行了讨论研究,认为航磁梯度数据相比于总场数据在地质体边界判断方面可提供更加丰富的地球物理信息;接着提出了梯度数据需要在判断磁性地质体边界上进行化极处理,并根据垂向梯度数据零值线确定地质体边界的原则,圈定磁性地质体的边界位置。与实际地质情况的对比表明,利用梯度数据圈定磁性地质体边界的应用效果比利用总场数据的效果明显。

本文概略介绍了航空三维磁梯度 测量的发展现状,指出了实施航空三维磁梯度测量所应着力解决的几个问题,包括基本装置及其计算方法、探头一致性、探头姿态以及固定翼磁补偿问题等,并针对 当前状况提出了用于大比例尺或中-大比例尺航空三维磁梯度测量的具体方案,大胆引入了正四面体测量装置,并将陀螺仪数据同步至原航测数据之中,既可大幅度 提高测量精度及数据稳定性,同时可解决同点三梯度的数值计算问题,对后续数据处理、成图、解释均具有重要意义。

简单介绍了航磁梯度测量的方法原理、优点及数据处理技术,并将该方法应用于砂岩型铀矿勘查中,对浅层断裂的识别、铀成矿环境的识别及磁性层体埋藏深度反演等方面进行了初步探讨,认为航磁梯度测量可在砂岩型铀矿勘查中发挥重要作用.

A general treatment of end corrections in gravity and magnetic modeling is presented. The well-known 2-D formulae of Talwani and Talwani and Heirtzler become slightly changed to represent a 2 1/2–D body, i.e. a body of polygonal cross section with the tails In the strike direction cut off.

ABSTRACT Presents a deconvolution for automated magnetic interpretation based on Werner's (1953) simplified thin-dike assumption which leads to the linearization of complex nonlinear magnetic problems. Statistical decision, numerical iteration, and a 7-point operator are used to improve approximations of susceptibility, dip, depth, and horizontal location of the source. Marquardt's nonlinear least-squares method for inverse modeling is then used to refine automatically the first approximation provided by the deconvolution. Synthetic and real total-field data are used to demonstrate the process.-from Authors

给出了２５Ｄ多边形截面棱柱体重磁异常的简化表达式及其偏导数；提供了实用的可视化模型建立、修改、实时正反演中的一些具体方法技术。借助这一操作方便、功能强大的图形化实时反演系统，资料解释工作者可以综合利用各种地质资料对计算过程实现引导和控制，使其解释思想及技术方案得到充分体现，从而提高计算速度和质量。

为了了解航磁测量中测量起伏对航磁异常的畸变影响规律，首先，提出研究起伏飞行对航磁异常影响的必要性。然后，对起伏航迹模拟和多边形截面棱柱磁性体正演的方法原理进行简要介绍。最后，设计理论模型，针对不同类型的起伏航迹进行正演计算。计算结果表明：起伏飞行对磁异常的影响明显，其影响程度和起伏高差有很强的相关性，即起伏高差越大，对磁异常峰值和定位的影响越大，峰值最大相对变化达239．1％。这些工作可为大比例尺、高分辨率航磁数据的精细解释提供一定的帮助。