观测标志稳定性和高压线电磁环境对地壳运动观测影响的研究

发布时间：2018-03-18 04:27

本文选题：精密地壳运动观测　切入点：垂直摆倾斜仪　出处：《中国地震局地震研究所》2013年硕士论文　论文类型：学位论文

【摘要】：精密地壳运动观测可能受到观测技术本身带来的误差、观测设备自身性能、观测标志稳定性、各种外部观测环境等因素带来的影响。本文针对观测标志稳定性和高压线电磁环境对精密地壳运动观测造成的影响进行研究。中国地壳运动观测网络中，在GNSS观测墩上采用了强制归心标志，观测标志的稳定性对地壳运动信息的识别具有不可忽视的影响。影响观测标志稳定性的因素有标志基础、气象条件、所在地域、季节变化及年变化等。本文针对气象因素对基岩观测标志稳定性的影响，利用垂直摆倾斜仪对黄梅和荆门的GNSS观测墩进行观测试验，并对倾斜仪运用于此实验的可行性进行评价。实验发现，观测墩在南北向和东西向上存在回归性的日偏移运动，观测墩南北向的偏移变化大于东西向。南北向的偏移日变幅度和偏移日均值多在3mm和1mm以内，最大可达3.5mm和1.3mm；东西向的偏移日变幅度和偏移日均值多在2mm和0.2mm以内，最大可达2.9mm和0.25mm，且季节变化不显著。日照导致墩体的温差变化是观测墩发生偏移运动的主因，测向(南北向或东西向)上的偏移变化与测向上墩体两面温差变化的相关度较高。降雨、气压变化、地球固体潮等因素对观测标志稳定性没有显著影响。从现有实验数据看，，基岩观测墩的日偏移运动已对精密地壳运动观测造成了一定的影响，特别是在南北向上，其贡献可达1~2mm，需对观测墩采取温度防护措施或采用热膨胀率较低的特殊观测墩设计。通过分析实验数据发现，垂直摆倾斜仪的量程、精度、稳定性和可靠性均达到了实验要求，观测结果可以真实可靠地反映观测墩体的倾斜情况，完全有能力运用于观测标志稳定性的观测实验中。高压输电线路产生的电磁环境，包括工频电场、工频磁场和无线电干扰，以及高压电塔及线路作为大型金属导体对信号的屏蔽、反射和散射，可能会对GNSS接收机的工作性能，接收数据的质量和解算精度产生影响。本文分别在500kv和220kv高压输电线路区域针对高压输电线路对GNSS观测的影响进行实验研究。结果发现，高压输电线路产生的电磁干扰和无线电干扰对GNSS接收机内部噪声没有显著影响。GNSS观测的多路径效应受到高压输电线路的显著影响，距离高压线越近，线路带电电压越高，多路径效应越严重。高压输电线路对接收机捕获数据的性能，接收机钟的稳定性，观测信号L1、L2载波信噪比，观测值周跳，以及基线和点位坐标的解算精度没有显著影响。《全球定位系统（GPS）测量规范》中规定的GNSS观测仪器应离开高压输电线路50米以上有着一定的裕度，在高压输电线路区域进行的GNSS建站及野外观测活动中，可根据实际情况，灵活把握仪器与线路的距离。
[Abstract]:The precision crustal movement observation may be caused by the error caused by the observation technology itself, the performance of the observation equipment itself, the stability of the observation mark, In this paper, the influence of the stability of observation marks and the electromagnetic environment of high voltage line on the precision crustal motion observation is studied. In the crustal movement observation network of China, the forced centring mark is used on the GNSS observation pier. The stability of the observation mark has an unnegligible effect on the identification of crustal movement information, and the factors affecting the stability of the observation mark are based on the criteria. The meteorological condition, the location, the seasonal variation and the annual variation, etc. According to the influence of meteorological factors on the stability of the bedrock observation mark, the vertical pendulum tiltmeter is used to observe and test the GNSS observation piers of Huang Mei and Jingmen. The feasibility of using the tiltmeter in this experiment is evaluated. The migration variation of the observed pier is larger than that of the east-west direction. The diurnal variation amplitude and the daily mean value of the migration are within 3mm and 1mm, the maximum is 3.5mm and 1.3mm, and the daily variation amplitude and the daily average value of the migration in the east-west direction are within 2mm and 0.2mm, respectively. The maximum values can reach 2.9mm and 0.25mm, and the seasonal variation is not obvious. The temperature difference of the pier caused by sunlight is the main cause of the observed pier migration. The correlation between the shift change of direction finding (north to south or east-west) and the variation of temperature difference on both sides of the upward pier is relatively high. There is no significant influence on the stability of the observation sign by the factors such as rainfall, atmospheric pressure change and earth earth tide, etc. From the available experimental data, The diurnal migration of bedrock observation piers has had a certain effect on the precise crustal movement observation, especially in the north and south direction. Its contribution can reach 1 ~ 2 mm. It is necessary to take temperature protection measures on observation piers or to design special observation piers with low thermal expansion rate. Through analysis of experimental data, it is found that the measuring range, accuracy, stability and reliability of vertical pendulum tiltmeter meet the experimental requirements. The observed results can truly and reliably reflect the tilt of the observed piers and can be used in the observation experiments of the stability of the observation marks. The electromagnetic environment generated by high voltage transmission lines, including power frequency electric field, power frequency magnetic field and radio interference, and the shielding, reflection and scattering of signals by high voltage towers and lines as large metal conductors may affect the performance of GNSS receivers. The quality of received data and the accuracy of calculation are affected. In this paper, the effect of high voltage transmission line on GNSS observation is studied in 500kv and 220kv HV transmission lines, respectively. The electromagnetic interference and radio interference produced by HV transmission line have no significant effect on the internal noise of GNSS receiver. The multipath effect observed by GNSS is significantly affected by HV transmission line. The closer to the high voltage line, the higher the live voltage of the line. The more serious the multipath effect is, the more the performance of HV transmission line to the acquisition data of receiver, the stability of receiver clock, the signal-to-noise ratio of L _ 1 / L _ 2 carrier, the cycle slip of observation value, And the accuracy of the calculation of baseline and point coordinates is not significantly affected. The GNSS observation instrument specified in the GPS Measurement Code has a certain margin to leave the HV transmission line above 50m. The distance between the instrument and the transmission line can be flexibly grasped according to the actual situation in the GNSS station building and field observation activities in the area of HV transmission line.
【学位授予单位】：中国地震局地震研究所
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P227

【参考文献】