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论DI2002激光测距仪的气象改正 总被引：1，自引：0，他引：1
针对ＤＩ２００２激光测距仪气象改正公式,结合目前我国在精密测距中实测的气象元素及地震监测特点,在讨论了光电测距基本气象改正的基础上,推导了ＤＩ２００２激光测距仪的精密气象改正公式。结果表明,在仪器说明书所给公式相比,导出的公式不仅提高了气象改正计算精度,而且适合于不同气象元素的测定,具有普遍的实用意义。 相似文献
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WILD厂生产的DI3000脉冲式红外测距仪,是目前精度较高的一种中长程测距仪,其主要技术规格见文献。这种仪器不仅可用作高精度大地测量,而且亦可用作地震形变测量。 一、测距仪测距精度的估计分析 我队于1988年9—10月间用DI3000测距仪施测了乌鲁木齐地区三个独立测距网共29条边,进行了两次仪器加乘常数的鉴定测量。各边不仅进行了早,晚光段的观测,而且也进行了对向观测,光段限差、组间限差均按国家地震局《大地形变测量规范》严格要求。 相似文献
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威特DI2002测距仪性能及其与ME—3000反射镜匹配研究 总被引：1，自引：0，他引：1
本文通过对威特ＤＩ２００２测距仪性能的测试，发现影响测距精度的主要因素是ＧＲＴ１０－ＧＰＨ１Ａ的反射镜系统。威特ＤＩ２００２测距仪匹配ＭＥ－３０００反射镜后，需加两项改正，但观测精度显著提高，实测表明达到与ＭＥ－３０００测距仪相同的精度。 相似文献
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JCY-型激光测距仪研制组 《地震》1982,(4)
激光技术的应用和电子学的进展为研制高精度、远测程和自动化的测距仪创造了条件。近十年来,自动测相和数字显示已成为光电测距仪的发展趋向。激光测距仪的出现,使大地测量和地震水平形变测量发生了重大的变革,目前激光测距网已基本上取代了三角测量网,同时使测距精度相应有了很大提高。 相似文献
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瑞士克恩厂(Kernswiss)生产的 ME—3000测距仪,适用于观测活动断层的水平位移。其标称精度为土(0.3 10~(-6)D)。在施测时要求对中误差在0.1毫米范围以内,否则将影响测距的精度。如果将测距仪和反射器安装在脚架上观测,可使用光学对中器对中。而在 相似文献
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DZR—Ⅲ型厘米级卫星激光测距仪 总被引：4，自引：0，他引：4
本文叙述了由国家地震局地震研究所与中国科学院测量与地球物理研究所协作研制成功的ＤＺＲ－Ⅲ型厘米级卫星激光测距仪的测距原理及主要性能。该设备已装备于武汉人卫激光测距站并已投入日常观测。经国外数据处理中心美国戈达德激光跟踪网（ＧＬＴＮ）和荷兰Ｄｃｌｆｔ大学航空工程系对观测资料进行预处理，单次测距精度已达到±２～３ｃｍ，测程为２万多公里。已能观测到目前国际上统一联测的所有带激光发射镜的卫星，观察资料已用 相似文献
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日本建设省国土地理院将从1987年3月起着手进行应用 GPS(全球定位系统)测量技术的实验。这种利用人造卫星进行测量的技术每公里的误差只有1毫米,即它是一种以 PPM(百万分之一)单位的超高精度为自豪的划时代的测距技术。由于它是利用来自人造卫星的 相似文献
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K. Gronvold G. Larsen P. Einarsson S. Thorarinsson K. Saemundsson 《Bulletin of Volcanology》1983,46(4):349-363
The sixteenth eruption of Hekla since 1104 began on August 17th, 1980, after the shortest repose period on record, only ten years. The eruption started with a plinian phase and simultaneously lava issued at high rate from a fissure that runs along the Hekla volcanic ridge. The production rate declined rapidly after the first day and the eruption stopped on August 20th. A total of 120 million m3 of lava and about 60 million m3 of airborne tephra were produced during this phase of the activity. In the following seven months steam emissions were observed on the volcano. Activity was renewed on April 9th 1981, and during the following week additional 30 million m3 of lava flowed from a summit crater and crater rows on the north slope. The lavas and tephra are of uniform intermediate chemical composition similar to that of earlier Hekla lavas. Although the repose time was short the eruptions fit well into the behaviour pattern of earlier eruptions. Distance changes in a geodimeter network established after the eruptions are interpreted as due to inflation of magma reservoirs at 7–8 kilometers depth. 相似文献
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Tsuneji Rikitake 《Surveys in Geophysics》1972,1(1):4-26
A long-term research program on earthquake prediction in Japan, officially launched in 1965, has made progress. Many of the developments achieved in recent years in various disciplines are outlined. Some of the important findings include: detection of land-deformation by intensified levelling and geodimeter surveys, empirical relations between the extent of a premonitory land-deformation and the magnitude and occurrence-time, and the growth and decay of earthquake swarms accompanied by occurrences of large-scale earthquakes. Operations research on selection of survey areas for levelling and the location of crustal deformation observatories has been made.To process data for earthquake predictions, three centers for different disciplines were set up: in the Geographical Survey Institute, the Japan Meteorological Agency, and the Earthquake Research Institute (University of Tokyo). A newly established committee, called the Coordinating Committee for Earthquake Prediction, which consists of about 30 specialists, analyzes the data flowing into these three channels. The committee issues a warning of earthquake danger, whenever possible.A tentative strategy for achieving earthquake prediction is proposed. An attempt is made to evaluate ratings of earthquake threats on the basis of probability theory.An anomalous land-deformation was found in the South Kanto district, an area south of Tokyo, in 1969. following the strategy, an intensive effort, called Operation South Kanto, aiming at a possible prediction of large earthquakes is now under way. Judging from the results of various earthquake prediction elements, the probability of having an earthquake of magnitude 7 or there-abouts within a period of about 10 yr can not be low if anomalous land-deformation is related to the probability of earthquake occurrence. 相似文献
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从微震仪标定的基本公式出发，以误差理论为基础，以ＤＤ—１型地震仪为例，导出标定中各因素对标定精度的影响；并用概率统计方法，对标定精度做了比较符合实际的计算，进而提出了提高标定精度的改进措施。 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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In this paper, we derived a high-efficiency formula for calculating the precision of carrier phase relative positioning,analyzed the various factors that affect the positioning accuracy using the carrier phase, and proposed the concept of using a frequency dilution of precision to describe the quantitative effect of different frequency combinations on the positioning precision. To this end, we computed and plotted the global spatial distribution map of the relative positioning dilution of precision for single-day solution, half-hour solution, and single-epoch solution of the global positioning system(GPS), regional Beidou navigation satellite system(BDS2), future global Beidou navigation satellite system(BDS3), and their fusion systems.Using processing software with autonomous intellectual property rights(GCN and VENUS/ARSNet), we solved the measurement data and examined the positioning precision of the single-day solution and single-epoch solution of GPS and BDS2.The analysis demonstrated that the B1/B2 frequency positioning precision of BDS2 was better than that of L1/L2 frequency positioning of GPS, but the positioning precision of the BDS2 is worse than that of GPS over most of the service region of the BDS2. Further, the positioning precision of BDS3 is better than that of GPS in the Asia-Pacific region, while it is the opposite in other regions. Based on these conclusions, we put forth some optimization recommendations regarding the signal frequency of the navigation system and GPS measurement standards to serve as references for optimizing the system performance and formulating standards. 相似文献
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介质物理性质与应力状态的改变是导致地震波速变化的主要因素,通过高精度波速变化测量可推测地下介质发生的变化.然而,高精度波速变化测量对测量仪器提出了较高要求,波速变化的测量精度常常受到仪器的采样率、信噪比以及时间触发精度的影响.为实现高精度测量,设计一套由大功率稀土超磁致可重复震源和高采样率通用数采组成的观测系统,通过叠... 相似文献
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Using the precision of the mean to estimate suitable sample sizes for monitoring total phosphorus in Australian catchments 
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下载免费PDF全文 The effect of the sample size on prediction quality is well understood. Recently, studies have assessed this relationship using near‐continuous water quality samples. However, this is rarely possible because of financial constraints, and therefore, many studies have relied on simulation‐based methods utilizing more affordable surrogates. A limitation of simulation‐based methods is the requirement of a good relationship, which is often not present. Therefore, catchment managers require a direct method to estimate the effect of sample size on the mean using historical water quality data. One measure of prediction quality is the precision with which a mean is estimated; this is the focus of this work. By characterizing the effect of sample size on the precision of the mean, it is possible for catchment managers to adjust the sample size in relation to both the cost and the precision. Historical data are often sparse and generally collected using several different sampling schemes, all without inclusion probabilities. This means that an approach is needed to obtain unbiased estimates of the variance of the mean using a model‐based approach. With the use of total phosphorus data from 17 sub‐catchments in southeastern Australia, the ability of a model‐based approach to estimate the effect of sample size on the precision of event and base‐flow mean concentrations. The results showed that for estimating annual base‐flow mean concentration, little gain in precision was achieved above 12 observations per year. Sample sizes greater than 12 samples per event improved event‐based estimates; however, the inclusion of more than 12 samples per event did not greatly reduce the event mean concentration uncertainties. The precision of the base‐flow estimates was most correlated to percentage urban cover, whereas the precision of the event mean estimates was most correlated with catchment size. The method proposed in this work could be readily applied to other water quality variables and other monitoring sites. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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随着水平井、多分支井等技术的出现,随钻测量技术对磁方位精度的要求越来越高.常规单测点磁方位校正法误差较大,无法满足复杂结构对磁方位精度的需求.近年来,国外围绕Brooks多测点分析法的基本公式,建立了一系列优化后的多测点分析法来提高磁方位的精度.本文以多测点分析法的公式为基础,结合常规单测点磁方位校正法,推导出一套收敛的改进多测点分析法.并通过实验来验证改进后的多测点分析法的效果.用改进后的多测点分析法得到的方位角精度在0.2°以内,达到或接近国际先进水平.通过进一步开展数据处理和分析,该套算法可以应用于水平井、多分支井等大斜度钻井工程中的精确定位和导向. 相似文献