新型质子旋进磁传感器的研制

新型质子旋进磁传感器在传统探头的基础上,根据新的观测环境要求对探头进行了改进,在实现无向性观测的同时,进一步提高了探头线圈的Q值及抗干扰能力,为提高观测系统的信噪比、降低仪器功耗创造了重要的条件。     

感应式磁探头及数据采集系统的设计

感应式磁力仪是观测变化磁场,特别是地磁脉动的有力工具。它的探头由高导磁合金棒、长螺线管线圈及铝屏蔽筒构成。本文记述了探头的设计,并提出了一种新的标定探头绝对灵敏度的简单方法。此外,本文还将介绍数字化感应仪——智能地磁数据采集装置的研制工作。     

FHDZ—M15地磁组合观测系统OVERHAUSER探头对FGE探头的影响初探

受记录室和观测系统自身因素的限制,FHDZ-M15地磁组合观测系统的OVERHAUSER磁力仪探头和FGE磁力仪探头相互之间存在一定的磁影响。本文在湖北省恩施地震台作了相互影响的模拟实验,结果表明,OVERHAUSER探头和FGE探头之间的相互影响与两者之间的距离和方位有关。当FGE探头和OVERHAUSER探头呈东西向放置时,影响水平较大,H分量表现更加明显,距离大于1.5m时,影响基本消失。     

新30井不同深度下的水温观测试验及其结果

本文通过在新30号观测井孔里重新放置一套新的测温仪, 使新、 老水温监测仪在不同深度同时观测, 发现在同一井孔中, 不同深度的水温探头所记录到的井水温度变化曲线形态是不一样的, 也就是观测井放置探头的深度与部位对井水温观测结果有明显的影响。 通过对新30井水温试验仪观测数据分析, 可以确定探头放置180～185 m处, 水温日变化有规律, 有潮汐显示, 而且与同井观测的井水位在日变形态上具有一定的同步性, 表现为水位上升时水温上升, 水位下降时水温也下降。 另外, 分析了该井水温探头在不同深度的日变形态和映震灵敏度, 并初步确定该井放置水温探头较为合理的观测深度为180 m。     

大同地震监测中心站GM4-XL磁通门磁力仪观测数据漂移分析

大同地震监测中心站配备2套GM4-XL磁通门磁力仪进行地磁观测,探头置于同一地下地磁房。自2017年以来,2套仪器每年夏秋季均存在不同程度的数据漂移现象。从数据连续率、完整率及台站背景噪声、数据预处理等角度,对2017年以来观测数据进行质量评价。通过与山西省其他台站地磁数据进行差值检测,结合地磁房附近地质条件、地下地磁室及观测墩建设、降雨等因素,分析认为,大同地震监测中心站地磁观测数据漂移的原因在于,夏秋季降雨致土层渗水,玻璃钢罩密封性较差,探头室地面积水,造成观测墩基不稳,使得置于观测墩上的仪器探头水平状态改变,进而引起观测数据发生漂移。     

漳州台深井应变不变量同震响应分析

在解决钻孔应变观测加衬模型的待定常数的基础上,巧妙地利用不变量与坐标系选择无关的性质,推导出了5组观测组合计算不变量的简洁表达式,并以玉树地震为例,选取漳州台深井观测系统的探头上、下端面8分量应变观测单元的观测资料,采用加衬模型分别根据探头上下端面的5组观测组合公式计算了地震当天的最大主应变、最小主应变、最大主应变相应...     

SSY-1型多址数字水位遥测设备

SSK-1型数字水位记录仪和SSY-1型多址数字水位遥测设备是近来新研制成功的包括探头在内的全数字化水位观测装备。本文将扼要介绍该设备的基本组成和工作原理,并对目前水位仪器设计和水位观测中普遍存在的问题——水位观测仪器的精度、误差分析及传输中的抗扰问题做了讨论     

观测构造应力场及其变化的新型系统

一、简况电阻式地应力就是以电阻型敏感元件,如丝式应变片、箔式应变片、半导体应变片以及其它电阻型力敏元件,制作成传感装置(传感器,即探头),配之以相应的二次仪表(测试仪),来测量地下应力—应变信息。此项试验观测工作开始于一九七六年。当时,对各种换能器的特征、线性范围、测试精度.使用条件     

深井探头密封技术的初步研究

本文是1973～1985年天津地震局在研制“井下短周期地震仪”和“深井综合观测系统”过程中,在室内高温、高压模拟试验和野外下井观测试验的基础上,提出了六种深井探头密封方法,即(1)矩形环自紧式密封,(2)“0”形环自密式密封,(3)插管型密封,(4)瓷头型密封,(5)硫化型密封,(6)组合型密封.     

地磁房湿度对地磁观测的影响及解决方案

地磁房湿度变化较快或过大都易引起地磁数据的异常变化,且室内湿度不易控制,地磁房、磁通门磁力仪探头湿度智能在线分析监控系统,可以实时显示监控地磁房、磁通门磁力仪探头湿度的变化,超过湿度阈值则发出报警信号,进而可以采用科学的方法控制探头观测环境的湿度,提高观测数据的稳定性、可靠性。本文介绍了该系统的设计思路和主要功能。     

Comparison of methods for estimating earth resistivity from airborne electromagnetic measurements

Earth resistivity estimates from frequency domain airborne electromagnetic data can vary over more than two orders of magnitude depending on the half-space estimation method used. Lookup tables are fast methods for estimating half-space resistivities, and can be based on in-phase and quadrature measurements for a specified frequency, or on quadrature and sensor height. Inverse methods are slower, but allow sensor height to be incorporated more directly. Extreme topographic relief can affect estimates from each of the methods, particularly if the portion of the line over the topographic feature is not at a constant height above ground level. Quadrature–sensor height lookup table estimates are generally too low over narrow valleys. The other methods are also affected, but behave less predictably. Over very good conductors, quadrature–sensor height tables can yield resistivity estimates that are too high. In-phase–quadrature tables and inverse methods yield resistivity estimates that are too high when the earth has high magnetic susceptibility, whereas quadrature–sensor height methods are unaffected. However, it is possible to incorporate magnetic susceptibility into the in-phase–quadrature lookup table. In-phase–quadrature lookup tables can give different results according to whether the tables are ordered according to the in-phase component or the quadrature component. The rules for handling negative in-phase measurements are particularly critical. Although resistivity maps produced from the different methods tend to be similar, details can vary considerably, calling into question the ability to make detailed interpretations based on half-space models.     

微火箭电场仪的原理及其应用

介绍一种新型的雷雨云电场探测仪器---微火箭电场仪 ,由直径为 55mm×760mm农用消雹小火箭改装而成 .它利用导体在电场中感应电荷原理 ,由电场传感器、测量线路、1 680MHz遥测发射机及天线组成 .仪器特点是结构简单、高密集、超小型、快速机动、低功耗、低成本 .此仪器于 1 998年年初试飞成功 .电场探测范围 1- 1 0 0kV/m .探测高度为7 5km左右 .主要用于飞行器升空安全保障 ,以及气象部门对雷电、冰雹的探测和预警     

山东省泰安台压容差应变观测排除干扰研究

泰安台压容差应变仪１９９１年投入观测以来，为确保资料正常、连续，对井上仪器，探头引线及井下探头３个环节的干扰因素进行了排除工作。整点值资料已连续４年，缺数不超过４８小时，采用多种方法判定异常，发现改进的多道维纳滤波方法处理的资料，对４００ｋｍ范围内的中旨地震有明显的异常显示。     

表面垂直位移和重力变化引起的大地水准面形变

在涉及表面垂直位移的地球物理正演和反演问题的研究中,表面真垂直位移等于表面视垂直位移和大地水准面高变化的和.本文从广义Bruns公式、广义stokes公式和广义Ve-ning-Meinesz公式出发,导出了用表面垂直位移和重力变化确定大地水准面形变的公式.讨论了表面垂直位移和重力变化对大地水准面高变化的影响.在此基础上,给出了表面荷载源、几种不同充填介质的膨胀源和位错源所引起的大地水准面高变化对视垂直位移影响的数值结果,分析了局部地球物理事件引起的大地水准面高变化的特点.最后给出了使用辽南地区的实际观测资料确定的局部大地水准面高变化以及对视垂直位移影响的计算结果.     

太阳活动高年上电离层中O+-H+离子过渡高度的特征

本文用日本电离层探测卫星ISS-b的资料,假设F₂层峰顶以上电离层中各类离子随高度呈扩散平衡分布,得到了太阳活动高年（1978年8月-1979年8月）确定顶外电离层电子密度剖面形状的一个重要参数,即O⁺-H⁺离子过渡高度h_T的一些变化特征.指出h_T的日变化特性主要受电离层中O⁺离子的产生与复合作用的控制.太阳活动高年在不同纬度和所有经度区域,平均说来日间h_T为大约1500-2500km变化,而夜间位于800-1400km,冬夜甚至接近中性氢、氧原子的化学平衡高度.过渡高度也表现出明显的纬度关系,在接近±20°的磁赤道地区,h_T基本上不随纬度变化;但在大于±30°磁纬区域h_T随纬度很快增加.义中还就h_T随时间和地磁（或地理）纬度变化的机制作了简要讨论.     

Ceilometer observations of the boundary layer over Warsaw,Poland

Jenoptik’s CHM 15k ceilometer was used to monitor the vertical structure of the atmospheric boundary layer (ABL) over Warsaw, from 2008 until 2011, on Mondays and Thursdays, in 24h periods. Hereby, we present an assessment of the signal-to-noise ratio along with a sensitivity study of signal smoothing methods developed in-house. With the proposed averaging, ceilometer attenuated-backscatter signals reached the high troposphere, which makes this sensor competitive to a single-wavelength elastic lidar. The smoothed signals were employed as an input for algorithms developed to automatically detect the ABL height, clouds, fog, and precipitation in the lower troposphere. The classification of weather conditions was validated by the METAR reports from the Warsaw Airport. The obtained ABL heights were compared to those assessed from radio-soundings from a nearby meteorological station WMO12374 in Legionowo. An inter-comparison of the ABL heights, derived by using the Jenoptik’s automated routine against the in-house developed algorithms, is in favor of the latter. The presented four annual cycles of the ABL height, obtained with various derivative-based methods, are the first such long-term results reported using the CHM 15k sensor in Eastern Europe.     

实验室声发射三维定位及标本波速场各向异性研究

根据慢度离差法的基本原理,给出由遗传算法确定AE空间位置、发生时刻及慢度离差5个参量的具体方法。结合实验条件,通过数值试验对定位误差等问题进行探讨,并对真实AE定位的误差分布给出统计上的圈定。数值试验结果表明,算法具有较高的精度和较好的收敛性及稳健性;探头数量及布设方式对定位结果的优劣有影响, 4个以上探头有记录时,即可得到理想的结果;大的定位误差主要来源于台阵外部少数“ AE”的结果。到时测量的随机误差小于最小测量时间单位的50%时,平均有97%的“AE”定位误差分布在3 mm 范围内,小于物理不可分辨精度(探头直径)。     

Stratospheric and mesospheric cooling trend estimates from u.s. rocketsondes at low latitude stations (8°S–34°N), taking into account instrumental changes and natural variability

Long-term changes of temperature and wind data have been investigated using U.S. rocketsondes at six selected sites at northern tropical and subtropical locations (from 8°S to 34°N). The analysis method used here is based on a multi-function regression analysis that allows for a continuous linear trend, for natural variability, and for sudden changes of the mean due to successive instrumental improvements. Results show that while sensor replacement does not seem to induce major measurement bias, successive correction procedures have produced significant mean temperature shifts, mostly above 55 km. Changes in the local time of measurement may have an impact on trend estimates because of tidal effects. This effect is probably enhanced by the direct solar radiative heating on the sensor. Selecting data according to the time of measurement has sometimes reduced the amplitude of the observed cooling.Using a detailed statistical model and error analysis, significant temperature trends are detected in the upper stratosphere with amplitudes slightly increasing with height. As the trend profiles from the selected sites are very similar in patterns and magnitudes, a mean annual temperature trend profile is composed using these six data sets. A significant cooling of 1.1±0.6 K per decade is estimated for 25 km height, increasing with height up to 1.7±0.7 K per decade in the altitude range of 35 to 50 km, and to 3.3±0.9 K per decade near 60 km. Previous published simulations of stratospheric changes induced by greenhouse gas increases and stratospheric ozone depletion, using numerical models, predict smaller cooling than that estimated here by a factor of around two. A similar analysis for zonal wind data reveals no significant changes larger than 5 m · s⁻¹ per decade.     

VLF RESISTIVITY MAPPING AND VERTICALIZATION OF THE ELECTRIC FIELD1

For over 20 years, powerful VLF transmitters have been used as electromagnetic sources for subsurface investigations in mining exploration. Measurements initially concerned the vertical component of the magnetic field or the inclination of the field and were later extended to measurement of the horizontal electric field in the direction of the transmitter, to determine the resistivity of the terrain. Measurement of the electric field is usually performed with electric lines, grounded or not, with lengths of at least 5 m. This paper presents the concept of a VLF resistivity meter with a very short electric sensor (1 m) and the results obtained with it. This technique improves the measurement of the electric field, which is in principle a point value. It also permits a higher spatial sampling rate and, by closely linking the electric sensor with the magnetic sensor on a lightweight mount, makes it possible for the instrument to be used by a single operator. In addition, transformation of the electric field data, analogous to reduction to the pole in magnetism, is proposed to correct the horizontal deformation of the anomalies created by polarization of the primary field. Comparison with direct current electrical measurements shows highly satisfactory correlations. This transformation, validated for VLF, can be extended to any electrical or electromagnetic method using a uniform primary field, i.e. gradient array in direct current or low-frequency magnetotellurics. We call this verticalization of the electric field. Resistivity measurements and mapping using the VLF frequency range can be applied not only to mining but also to a wide range of shallow geophysical studies (hydrology, civil engineering, etc.) and are not limited to problems concerning the location of conductive targets