查询词典 ephemeris

The POD algorithm based on pseudo range and carrier phase epoch-wise differency observations is estimated by the simulated data. Based on the calculation results under different weighting and different GPS ephemeris accuracy, the influence of these factors to the POD results and the selection of the weighting are discussed.

按照实现简洁、精度符合要求的优选标准，研究了利用伪距和载波相位历元差快速几何定轨方法，给出了仿真计算结果，分析了等各种因素对于最终结果的影响，讨论了权因子选取问题。

At the bottom of Figure 25, a geocentric ephemeris (using Bretagnon and Simon 1986) gives the apparent positions of the naked-eye planets during the eclipse.

在图25的底部，一个地心历表（使用Bretagnon和Simon 1986）给出了日食期间肉眼可见的行星的视位置。

At the bottom of Figure 25, a geocentric ephemeris (using Bretagnon and Simon 1986) gives the apparent positions of the naked-eye planets during the eclipse.

在图25的底部，星历表显示了在日食期间可以用肉眼观测到的行星的位置。

Provided by the use of IGS precise ephemeris and precision clock bad, you can achieve high-precision positioning and orbit determination, which makes GPS in determining the satellite orbit to monitor the ionosphere and troposphere in the job to play an increasingly important role.

利用IGS提供的精密星历和精密钟差，可以实现高精度定位和定轨，这使得GPS在确定卫星轨道、监测电离层和对流层中的工作中发挥了举足轻重的作用。

In this study, six campaigns around Anping tide gauge, Tainan, were successfully performed and the collected GPS buoy data were processed with four types of precise ephemeris provided by IGS, including final product, rapid product, ultra-rapid product and ultra-rapid product with the use of PPP technique. Comparing the PPP results with DGPS, the differences reach 3~5 cm in the horizontal and 10 cm in the vertical with final product; 6~8 cm in the horizontal and 15 cm in the vertical with rapid product; 15~20 cm in the horizontal and 30~40 cm in the vertical with ultra-rapid product; 2~3 m in the horizontal and 3~4 m in the vertical with ultra-rapid product. In addition, the collected data were also processed by DGPS techniques using different reference stations to analyze the effect of various baselines. The results show that accuracy degrades when the baselines increase.

本研究在台南安平潮位站旁进行6次GPS浮标施测，首先利用与GPS浮标距离不同之GPS参考主站来进行差分定位，分析基线距离对GPS浮标定位成果的影响，由实验结果可得出基线越长则定位准确度越低；再以IGS提供之最终产品、快速产品、超快速产品(Ultra-Rapid product)之观测部分observed half、超快速产品(Ultra-Rapid product)之预估部分四种不同发布延迟时间的精密星历与精密时表改正资料对GPS浮标进行精密单点定位解算，与传统差分相对定位方法定位结果进行比较后，得出使用最终产品之平面方向均方根误差(Root Mean Square Error， RMSE)可达3~5公分，而高程方向均方根误差可达10公分；快速产品之平面方向均方根误差可达6~8公分，而高程方向均方根误差可达15公分；超快速产品观测部分之平面方向均方根误差可达15~20公分，而高程方向均方根误差可达30~40公分；超快速产品预估部分之平面方向均方根误差可达2~3公尺，而高程方向均方根误差可达3~4公尺。

It routinely produced precise GPS ephemeris and other products using observations from IGS tracking station.

在非差数据处理中，主要考虑对流层和钟差这两种时变参数的随机模型。

By using high-resolution reference data to identify accurate GCPs, considering the spacecraft attitude deviations which TBUS can't supply, and adjusting the epoch time and ephemeris data at the criteria of constraint LeastMean-Square-Error, the geolocation accuracy of navigation for AVHRR data can be improved greatly.

由于采用具有足够定位精度的高分辨率参考图象以提取高精度的地面控制点，考虑了TBUS轨道报所不能提供的卫星姿态偏差，对历元时刻和卫星轨道根数进行有约束条件的参数最优调整，可使整条轨道大范围内的AVHRR导航定位精度有较大提高。

With adjusting the epoch time and ephemeris data at the criteria of constraint Least-Mean-Square-Error, the geolocation accuracy can reach 2 pixels in the whole images; and it can be improved to approximately 1 pixel in the whole images and less than 1 pixel at nadir by considering the spacecraft attitude deviations moreover.

如果进行历元时刻和卫星轨道根数的约束最优调整，导航定位精度在整条轨道大范围内可提高到2个像元左右；如果再加入卫星姿态偏差的校正，导航定位精度在整条轨道大范围内可稳定提高到1个像元左右，在星下点附近小于1个像元。

Data in the gamma-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope, while the radio rotational ephemeris used to fold gamma-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank.

伽玛波段的数据来自于Fermi伽玛射线空间望远镜上的大面积望远镜的观测，用于折叠伽玛射线数据的射电旋转周期数据来自于Green Bank望远镜和位于Jodrell Bank的Lovell望远镜的观测。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐