共查询到17条相似文献,搜索用时 218 毫秒
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《地球物理学进展》2017,(2)
目前卫星重力梯度测量精度主要受限于核心载荷重力梯度仪的噪声.要提高卫星重力梯度测量的精度,首先要发展更高精度的星载重力梯度仪.在该背景下,本文一方面针对已成功搭载GOCE卫星飞行的静电式重力梯度仪,基于静电控制的工作原理,探讨了静电式重力梯度仪测量精度的根本受限因素,分析表明,通过改进敏感探头的设计以及降低动态范围,静电重力梯度仪的极限测量分辨率可达0.3 m E/Hz1/2;另一方面,建议发展原子干涉型的星载重力梯度仪,在空间微重力环境下,其潜在测量灵敏度高达0.03 m E/Hz1/2,有望为未来完善50~100 km空间分辨率的全球重力场模型提供一种可能的技术途径. 相似文献
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卫星重力梯度测量与地球引力场的精度研究 总被引:1,自引:0,他引:1
本文根据地球引力位的球谐函数展开式,利用重力梯度张量各分量导出了位系数模型的精度估计公式.从三方面进行了研究:假定卫星重力梯度仪测量精度,探讨用重力梯度数据确定地球重力场模型的精度;求出位系数模型和大气阻力引起的重力梯度卫星的轨道误差;最后,反求轨道误差和位系数误差对重力梯度测量值的影响.数值计算表明,与地面技术和常规卫星方法相比,卫星梯度测量可使重力场模型的精度至少提高3-5倍;利用重力梯度张量全分量求得的重力值精度比单用径向分量Vrr的结果提高40%以上;若仅顾及位系数模型和大气阻力误差,则轨道误差对梯度测量值的影响△Vi3(i=3,2,1)至少可分别在1/4和1/3弧圈内达到△Vi3≤σ(仪器精度). 相似文献
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随着仪器科学的进步和发展,使移动平台式地球物理测量方法成为可能.移动平台式的物探测量作为一种高效的地球物理勘探手段,在地质调查、油气资源勘探和固体矿产资源勘探等相关领域扮演着重要的角色.地形情况良好区域的资源已经探明的情况下,地球物理学家们将眼光着眼于未知陆地和海洋资源,随着国家"十三五计划"的进行,未知陆地和深海资源勘探得到了人们的广泛重视.与此同时,航空、航海重力仪器和重力梯度仪器的发展,使地球物理学家们有了可以应对未知陆地、深海以及深远海资源勘探的重要武器.相比于未知陆地和海洋地震勘探,航空、航海重力和重力梯度数据测量具有快速、稳定、低成本的特征,可以快速圈定异常区域,为进一步更高精度的资源探测提供良好靶区. 相似文献
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The past few years have witnessed significant advances and unparalleled interest in gravity gradiometer instrument technology as well as new deployment scenarios for various applications. Gravity gradiometry is now routinely considered as a viable component for resource exploration activities as well as being deployed for global information gathering. Since the introduction of the torsion balance in the 1890s, it has been recognized that gravity gradient information is valuable – yet difficult and time-consuming to obtain. The recent acceptance and routine use of airborne gravity gradiometry for exploration has inspired many new technology developments. This paper summarizes advances in gravity gradient sensor development and also looks at deployment scenarios and gradiometer systems that have been successfully fielded. With projected improved system performance on the horizon, new challenges will also come to the forefront. Included in these challenges are aspects of instrument and system intrinsic noise, vehicle dynamic noise, terrain noise, geologic noise and other noise sources. Each of these aspects is briefly reviewed herein and recommendations for improvements presented. 相似文献
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Hasan Yildiz Rene Forsberg Carl Christian Tscherning Daniel Steinhage Graeme Eagles Johannes Bouman 《Studia Geophysica et Geodaetica》2017,61(1):53-68
An airborne gravity campaign was carried out at the Dome-C survey area in East Antarctica between the 17th and 22nd of January 2013, in order to provide data for an experiment to validate GOCE satellite gravity gradients. After typical filtering for airborne gravity data, the cross-over error statistics for the few crossing points are 11.3 mGal root mean square (rms) error, corresponding to an rms line error of 8.0 mGal. This number is relatively large due to the rough flight conditions, short lines and field handling procedures used. Comparison of the airborne gravity data with GOCE RL4 spherical harmonic models confirmed the quality of the airborne data and that they contain more high-frequency signal than the global models. First, the airborne gravity data were upward continued to GOCE altitude to predict gravity gradients in the local North-East-Up reference frame. In this step, the least squares collocation using the ITGGRACE2010S field to degree and order 90 as reference field, which is subtracted from both the airborne gravity and GOCE gravity gradients, was applied. Then, the predicted gradients were rotated to the gradiometer reference frame using level 1 attitude quaternion data. The validation with the airborne gravity data was limited to the accurate gradient anomalies (TXX, TYY, TZZ and TXZ) where the long-wavelength information of the GOCE gradients has been replaced with GOCO03s signal to avoid contamination with GOCE gradient errors at these wavelengths. The comparison shows standard deviations between the predicted and GOCE gradient anomalies TXX, TYY, TZZ and TXZ of 9.9, 11.5, 11.6 and 10.4 mE, respectively. A more precise airborne gravity survey of the southern polar gap which is not observed by GOCE would thus provide gradient predictions at a better accuracy, complementing the GOCE coverage in this region. 相似文献
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Marine gravimeters mounted on stabilized platforms are commonly used in aircraft to perform airborne gravity measurements. The role of the stabilized platform is to level the sensor mechanically, whatever the aircraft attitude. However, this compensation is generally insufficient due to the sensitivity of modern gravity sensors. Correcting the offlevel error requires that an offlevel correction calculated from positioning data be added to gravimeter measurements, which complicates not only the processing, but also the assessment of precision and resolution. This paper is a feasibility study describing the levelling of a completely strapped‐down LaCoste and Romberg gravimeter for airborne gravimetry operation, by means of GPS positioning data. It focuses on the calculation of the sensor offlevel correction needed for the complete gravity data processing. The precision of the offlevel correction that can be achieved, in terms of GPS data precision and gravity wavelengths, is theoretically studied and estimated using the gravity and GPS data acquired during the Alpine Swiss French airborne gravity survey carried out in 1998 over the French Western Alps. While a 1 cm precision of GPS‐determined baseline coordinates is sufficient to achieve a 5 mGal precision of the offlevel correction, we maintain that this precision has to reach 1 mm to ensure a 1 mGal precision of the offlevel correction at any wavelength. Without a stabilized platform, the onboard instrumentation becomes significantly lighter. Furthermore, the correction for the offlevel error is straightforward and calculated only from GPS data. Thus, the precision and the resolution of airborne gravity surveys should be estimated with a better accuracy. 相似文献
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G.J. Barnes 《Geophysical Prospecting》2019,67(6):1620-1625
In airborne gravity gradiometry, the Gravity Module Assembly is an optional gravimeter unit that is mounted on the same stabilized platform as the Full Tensor Gradiometer. Direct measurements of the gravity field are needed from this device to constrain the long wavelengths when gradient data are integrated mathematically to form high-resolution gravity fields. The Gravity Module Assembly is, however, capable of providing independent gravity data with a specification approaching that expected from a dedicated airborne gravity system. Presented here is an error analysis of data from this instrument collected alongside the Full Tensor Gradiometer during an airborne survey. By having both gradiometry and gravity datasets, comparisons of the information content in these two types of measurement are made. 相似文献
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Improved preconditioned conjugate gradient algorithm and application in 3D inversion of gravity-gradiometry data 总被引:1,自引:0,他引:1
With the continuous development of full tensor gradiometer (FTG) measurement techniques, three-dimensional (3D) inversion of FTG data is becoming increasingly used in oil and gas exploration. In the fast processing and interpretation of large-scale high-precision data, the use of the graphics processing unit process unit (GPU) and preconditioning methods are very important in the data inversion. In this paper, an improved preconditioned conjugate gradient algorithm is proposed by combining the symmetric successive over-relaxation (SSOR) technique and the incomplete Choleksy decomposition conjugate gradient algorithm (ICCG). Since preparing the preconditioner requires extra time, a parallel implement based on GPU is proposed. The improved method is then applied in the inversion of noisecontaminated synthetic data to prove its adaptability in the inversion of 3D FTG data. Results show that the parallel SSOR-ICCG algorithm based on NVIDIA Tesla C2050 GPU achieves a speedup of approximately 25 times that of a serial program using a 2.0 GHz Central Processing Unit (CPU). Real airborne gravity-gradiometry data from Vinton salt dome (southwest Louisiana, USA) are also considered. Good results are obtained, which verifies the efficiency and feasibility of the proposed parallel method in fast inversion of 3D FTG data. 相似文献
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Gary J. Barnes John M. Lumley Phill I. Houghton Richard J. Gleave 《Geophysical Prospecting》2011,59(1):176-187
Noise levels in marine and airborne full tensor gravity gradiometer surveys together with conventional land, marine and airborne gravity surveys are estimated and analysed in gridded form, resulting in relations that detail how these different survey systems can be compared analytically. After defining survey parameters including line spacing, speed and instrument bandwidth, the relations estimate the noise levels that result on either grids of gravity (gz) or gravity gradient (Gzz) as a function of the spatial filtering often applied during geological interpretation. Such comparisons are believed to be a useful preliminary guide for survey selection and planning. 相似文献
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GOCE卫星由于加速度计的特殊安装方式,其非保守力主要由普通模式的组合加速度提供,使得单个加速度计的特征更难提取.本文首次采用实测数据,研究了单加速度计模式下的高低跟踪数据处理.利用GOCE任务2009年(2009-11—2009-12)的实测数据,分别以GOCE卫星梯度仪坐标系三个坐标轴正向的加速度计为研究对象,利用1s间隔的高采样轨道数据,采用动力法同时进行卫星重力场建模和加速度计的精密校准.为了克服两极地区的数据缺失对重力场模型低次系数的影响,即所谓的极空白问题,引入同期GRACE卫星的观测数据,采用方差分量估计方法,建立了GRACE/GOCE卫星跟踪卫星重力场模型WHU-GRGO-SST.该模型完全到100阶次,经6169个美国GPS水准点数据检验,在同阶次上与EGM2008和GGM05S的精度水平相同.分析发现,GOCE卫星的加速度计偏差参数存在显著的漂移,也显示了单加速度计模式处理GOCE高低跟踪数据的优势.本文的研究成果为建立静态高分辨率、高精度的GRACE/GOCE重力场模型提供了更严密的模型与技术方案,同时也为GOCE卫星梯度仪校准,以及梯度数据的深入分析提供了重要的参考信息. 相似文献