查询词典 zenith distance

Astronomy the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day .

从天顶交叉口向西顺着天赤道测量的一个角距离；对在一个特定的地点和特定的时间观测者来说是赤经。

The basic principle is based on spherical astronomy and elementary geometry of the trajectory mapping method based on the observation of a celestial body zenith distance, then the ship is located in order to sing the next point as the center of this satellite zenith distance of the ship's position as the radius of the circle, observing the same two objects, or objects at different times of the two observations, we can get two ship's position round, then the ship must have been a point of intersection of two ship's position on the circle.

其基本原理是建立在球面天文学和初等几何中的轨迹作图法基础上的，观测一个天体的天顶距，则航船就位于以星下点为圆心，此星天顶距为半径的船位圆上，观测两个天体或者不同时间同一天体的两个观测值，就可以得到两个船位圆，则航船一定在两个船位圆的一个交点上。

Error causes are analyzed,and it is recommended that the 2′ could be used as the accuracy standard for civil user at present,when measuring zenith distance based on the direction of gravitational force line.

分析了误差产生的原因，建议以重力线作基准直接测定天体顶距时，近期民用设备可用2′作为标准，理论分析和实验表明，这样可降低仪器造价和对测者的要求，天文定位仍可获得满意的结果。

By the same method we also obtain the distribution of the lunar zenith distance versus the occurring probability of earthquakes.

同样的方法，可得地震的月球天顶距地震频度分布。

The difference between the observation atmospheric refraction and Pulkovo table is about 15 arc second at the zenith distance of 84 degree.

在天顶距84°时，与普尔科沃大气折射表的差值约为15。

To get the observer's Lat.and Long.just by pressing a button without the sea horizon to turn to,we should know clearly the relationship between the accuracy of zenith distance observed and the accuracy of a position fixed,the causes of the errors of zenith distance observed,what accuracy of zenith distance observed could be obtained and what accuracy standard should be used.

要在无水天线测天时一按按钮就可定出较精确的船位经纬度，必须弄清天体顶距测量精度对定位精度的影响，弄清顶距测量误差产生的原因，可达到的精度及选用适当的精度标准。

The method does not depend on strict local parameters and precise instruments, while the observational principle is relatively simple. An experimental observation was carried out with a simple telescope with large field of view at Xinglong station of NAOC at the end of 2007. The atmospheric refraction from the zenith distance of 44.8 degree to 87.5 degree is gotten by the differential method, which proves the feasibility of the method tentatively.

该方法不依赖于严格的地方参数和复杂精密的观测仪器，并且观测原理相对简单。2007年底，利用一台简易的大视场望远镜在兴隆观测站进行了试验观测，根据较差方法实测得到真天顶距44.8°至87.5°的大气折射值，初步证明了大气折射较差测量方法的可行性。

The results indicate that the distribution of the solar zenith distance versus the occurring probability of earthquakes is quite consistent with the lunar case, and the case for small earthquakes is different from the larger earthquakes. The latter is mainly clustered at 0oand l80o of the zenith distance, and consistent with the distribution of the absolute value of the solar tide forces, while the former are clustered at 60o and l2Oo.

统计发现：地震的太阳天顶距地震频度和月球天顶距地震频度分布表现出一致的规律性，且较大地震和小地震的活动规律不同，较大地震丛集发生在太阳天顶距0°和180°附近，与地面引潮力的绝对值分布有较好的一致性；而小地震多丛集在太阳天顶距60°和120°附近。

According to the engineering practice, the theoretical basis and method that survey directly the horizontal distance and height difference by the total station system as fourth grade and below fourth grade control network are put forward instead of surveying slant distance and zenith distance.

摘要根据工程实践，提出了用全站仪直接测量平距、高差来代替测斜距、天顶距作四等及四等以下控制网测量的理论依据和方法，并以张河湾抽水蓄能电站施工控制网为例进行了比较计算。

Based on the ISC earthquake catalogue data, according to the orbit equations of two-body-problem and the perturbation theory of celestial mechanics, we could determine the projection pole of the sun, and thus calculate the zenith distance from the sun to the epicenter. After calculating all the earthquakes on their zenith distances, we could get the distribution of the solar zenith distance versus the occurring probability of earthquakes.

基于ISC地震记录，利用天体动力学中二体问题的轨道方程和摄动理论，确定发震时刻太阳在地面的投影点位置，并进一步计算出太阳相对震中的地心天顶距，将地震按天顶距的大小进行统计，得到地震的太阳天顶距地震频度分布。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。