A multi-channel approach for automatic microseismic event association using RANSAC-based Arrival Time Event Clustering (RATEC)     

《地震研究进展（英文）》2021,1(3):100008

In the presence of background noise, arrival times picked from a surface microseismic data set usually include a number of false picks that can lead to uncertainty in location estimation. To eliminate false picks and improve the accuracy of location estimates, we develop an association algorithm termed RANSAC-based Arrival Time Event Clustering (RATEC) that clusters picked arrival times into event groups based on random sampling and fitting moveout curves that approximate hyperbolas. Arrival times far from the fitted hyperbolas are classified as false picks and removed from the data set prior to location estimation. Simulations of synthetic data for a 1-D linear array show that RATEC is robust under different noise conditions and generally applicable to various types of subsurface structures. By generalizing the underlying moveout model, RATEC is extended to the case of a 2-D surface monitoring array. The effectiveness of event location for the 2-D case is demonstrated using a data set collected by the 5200-element dense Long Beach array. The obtained results suggest that RATEC is effective in removing false picks and hence can be used for phase association before location estimates.  相似文献   

IMU/DGPS supported photogrammetry in China     

李英成  LI Xue-you  ZHAO Ji-cheng  GONG Xun-ping  TANG Liang 《测绘科学》2004,29(Z1):42-46

<正>People'sRepublicofChinaisoneofthemostrapidlydevelopingcountriesintheworldtoday.Thereisagreatdemandonhighlyactualandaccuratespatialinformationofthewholecountry,especiallyofWestChinawhichbecomesthefocusofdevelopmentoftheChinesegovernmentrightnowandinthenextyears,butwherestillnotenoughtopographicmapsareavailable.ThisraisesgreatchallengestothesurveyingandmappingcommunityinChina.FacingthenewchallengestheChineseAcademyofSurveyingandMapping(CASM)starteditspioneerworkearly2002toexplorenewtechniquesandtechnologiesavailabletodaytowardincreasingthemapproductivity.WithimportofaCCNS/AEROcontrolsysteminNovember2002,thefirstDGPS/IMU-basedphotogrammetricprojectinChinawassuccessfullyaccomplishedjointlybyCASM,theGermany-basedcompaniesIGIandTechedge.Twophotogrammetricblocksof1:4,000and1:20,000photoscales,respectively,wereflowninAnyang,China.Directgeoreferencingandintegratedsensororientationwereconducted.Resultsachievedwereprovenbyusinggroundcheckpointsandcomparedwiththoseofaerialtriangulation.Orthophotosgeneratedbasedondir  相似文献   

世界遥感技术发展现状及其地质应用   总被引：4，自引：1，他引：3  

张义彬  曲家惠 《国土资源遥感》1998,9(4):73-81

本文概括了世界各国的航空航天遥感器技术的现状及未来,重点阐述了它在岩性填图、构造勾绘、蚀变带圈定、岩石矿物识别、含金石英脉确定、找矿靶区圈定以及成矿远景预测等遥感地质应用方面的研究成果。  相似文献   

大气温湿廓线反演问题的研究     

王颖  黄勇  黄思源 《国土资源遥感》2008,(1):23-26

介绍了反演大气温湿廓线的主要传感器特性,阐述了ATOVS、MODIS和AIRS这3个卫星传感器的仪器特征及其相应的大气温湿廓线反演原理和方法,对其利弊进行初步分析,总结了大气温湿廓线反演问题的发展趋势.  相似文献   

长输埋地管道振动台试验传感器布置方案研究     

韩俊艳  万宁潭  李立云  侯本伟  赵密  杜修力 《震灾防御技术》2018,13(1):13-22

在进行长输埋地管道振动台试验的过程中,针对数据信息的采集量测以及传感器的布置位置进行了研究。采用三维数值模拟的方法对管-土相互作用体系进行了地震反应分析,内容包括埋地管道结构纵、横向在非一致地震动作用下的地震响应及受力变形特征。根据计算结果确定了主观测断面及辅助观测断面的位置及观测断面上传感器布置的位置,在满足基本信息采集要求的前提下,对可供采用的信息采集通道进行了优化分配,由此确定本次试验的观测断面以及传感器的具体测量部位与数目。成果对试验获得成功起到了保障作用,可为同类试验提供参考。  相似文献   

Coaxial coil towed EMI sensor array for UXO detection and characterization     

Haoping Huang  Bill SanFilipo  Alex Oren  I.J. Won 《Journal of Applied Geophysics》2007,61(3-4):217-226

A new broadband electromagnetic induction (EMI) array sensor, GEM-5, for detecting and characterizing Unexploded Ordnance (UXO) has been developed in order to provide high production rates for EMI surveys. The sensor consists of a single rectangular loop transmitter around a linear array of seven pairs of coaxial receiver coils, with each coil in a pair located at the same vertical distance above and below the loop transmitter. The coil pairs are wired in an inverted series so that the signal consists of the difference between the voltage induced in the upper and lower coils. This particular configuration provides a high degree of primary field cancellation, dense spatial sampling rate due to simultaneous and continuous operation of all sensors, suppression of motion-induced and environmental noise, and strong source fields at typical UXO burial depths providing deep detection range. Our prototype tests indicate that the array yields a lower static and motion-induced noise over the critical low frequencies than that of existing sensors, and in particular, the signal-to-noise ratio at 90 Hz is 32 dB higher. Environmental noise can be largely removed from the difference measurements. The field test results from UXO test sites show that the prototype sensor has smoother background and appears to detect more seeded targets than the GEM-3 concentric sensor, however some of that gain can be attributed to higher power transmitter electronics.  相似文献   

徕卡ADS 80数字航空相机空三精度分析     

王江  武吉军 《测绘与空间地理信息》2011,34(5):231-233

徕卡ADS 80数字航空相机采用POS/GPS精确导航定位技术进行航空摄影,通过对GPS差分数据进行常规布设控制点、少量布设控制点甚至无控制点的内业空三解算结果的对比分析,探讨外业像片控制点的布设方案对IMU/DGPS辅助航空摄影测量加密精度的影响,利用不同地形类别的加密数据,分析在保证成图精度的情况下如何减少外业工作量,降低生产成本,缩短生产周期。  相似文献   

Silicon-on-Insulator-Based Single-Chip Image Sensors: Low-Voltage Scientific Imaging     

Vyshnavi Suntharalingam  Barry E. Burke  Michael J. Cooper 《Experimental Astronomy》2002,14(2):91-98

A low-voltage (≤3.3 V) imaging technology has been developed to enable scientific-grade imagers with low-power complex functions on chip. A 128 × 128 CCD imager with on-chip clocking and charge-domain analog-to-digital conversion, as well as an exploratory active pixel sensor have been demonstrated. A 640 × 960 CCD imager with optimized 12 bit charge-domain conversion and an improved active pixel sensor are presently in fabrication. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

A miniature laser anemometer for measurement of wind speed and dust suspension on Mars     

J.P. Merrison  H.P. Gunnlaugsson  J. Jensen  K. Kinch  P. Nørnberg  K.R. Rasmussen 《Planetary and Space Science》2004,52(13):1177-1186

Suspended dust is a dominant component of the Martian environment. It has a major influence on atmospheric circulation and it is deposited widely over the planetary surface causing a serious hazard to instrumentation. In order to study dust transport, quantification of the wind flow and dust concentration are vital. A simple laser-based anemometer system is presented that is able to measure suspended dust grain velocity and turbulence from a landed spacecraft. This system has advantages over other techniques of wind speed determination in being insensitive to contamination or atmospheric conditions such as temperature, pressure or composition. For the first time it would allow direct measurement of the suspended dust concentration on Mars. A prototype instrument has been constructed and successfully tested in a wind tunnel facility under simulated Martian conditions. The optics are simple in design, light weight and the instrument has low power consumption. It is also robust and the output signal is easily interpreted, producing only a small data volume. Future improvements will be discussed, specifically modification to measure wind direction, the possibility of obtaining information about dust grain size and the construction of a flight model.  相似文献   

瞬变电磁探测系统(CASTEM)试验对比——安徽颖上大王庄铁矿          下载免费PDF全文

武欣  薛国强  陈卫营  吴凯  齐林  刘富波  方广有 《地球物理学报》2016,59(12):4448-4456

为推进国产电磁勘探设备的高端化进程,自主研发了CASTEM瞬变电磁系统.在前期系统开发、测试及集成基础上,开展野外试验研究,以检验CASTEM系统的稳定性及探测能力.选择已取得显著勘探成果的安徽颖上县大王庄铁矿进行试验,试验内容包括大功率发射机性能、接收系统噪声性能、实测响应曲线和反演效果,并与国际高端瞬变电磁仪在上述几方面进行了对比.试验结果表明CASTEM系统的各项指标性能稳定、可靠,已达到国际先进水平;探测成果与高端瞬变电磁仪器探测成果以及钻孔资料相吻合,表明CASTEM系统可以用于深部勘探.  相似文献