钟差

Instead of it, the thesis develops a method that relative clock error is used to replace the above absolute clock error.

最后分析了采用不同数据计算的卫星钟差结果。

The theory and algorithm of time synchronization about LEO are discussed with the key technique in many ways. On the basis of Bernese 5.0 GPS Software, onboard GPS receivers clock error about GRACE is processed, and the results-specific analysis is computed.

研究了利用星载GPS接收机进行低轨卫星与卫星时间同步，探讨了其中的关键技术，以Bernese 5.0软件为基础，对GRACE卫星的星载GPS接收机钟差进行了解算，具体分析了解算结果。

The satellite position and clock offset at any time can be gained through interpolating precise ephemeredes using CHEBYSHEV polynomial coefficients.

在计算中，通过对精密星历采用切比雪夫多项拟合的方法可计算卫星任意时刻的卫星位置和钟差。

The results show that GPS ground tracking data can be used for estimation of high rate satellite clock errors.

结果表明，利用地面跟踪站的GPS观测数据，可高精度、高密度地估计GPS卫星钟差，估计精度可达0.1～0.5ns。

But for GLONASS, the double difference equation contains the receiver clock parameter. This made the solving of integer ambiguity of double difference more complex.

对于GLONASS卫星，由于站星双差中含有接收机钟差项，使得双差模糊度的求解变得复杂。

The mathematical models of the delay of the GPS signal in the circumstance are put forward respectively. The computation of orbital arc of the two satellite constellations is based on two body problem and perturbations models. An algorithm based on the IRI model and thin layer model is used to simulate the ionospheric delay of the GPS signal. The error models of observation, multipath, relativity and antenna phase center bias are also researched. Under the consideration of the autocorrelation of the electronical measurements, the autoregressive model of time series is introduced into the noise models.

在信号仿真中，研究了利用二体运动和摄动法计算LEO卫星至GPS卫星星座的几何距离的问题；在信号的误差模型中，研究了电离层时延的IRI2001模型和单层投影模型；讨论了观测误差、多径效应、相对论效应和天线相位中心偏移的误差模型；结合电子测量噪声的具有自相关特性的经验，研究了观测误差的AR模型；结合实测数据分析，讨论了接收机钟差和卫星钟差的误差建模问题。

And in the future, more IGS products with increased precision and timeliness will be provide by IGS.

而在卫星钟差估计或精密单点定位中，钟差是作为未知参数处理，这时必须顾及钟差的随机模型。

This paper compares the position and clock offset of the satellites insight obtained from the broadcast ephemerides file five days prior and posterior to the cancel of SA policy on WUHN station with that provided by final IGS precise ephemerides.

利用全球GPS永久性跟踪站WUHN站在SA取消前后五天的广播星历文件计算得到在视卫星的位置和钟差，与事后IGS精密星历提供的卫星位置和钟差进行比较分析，说明SA取消对广播星历的影响。

The precise satellites clock error estimation algorithm of navigation satellites is studied in this paper. The computation of precise satellites clock error based on the non-difference phase is realized and the results are compared with the products provided by IGS analysis centers.

研究了导航卫星精密钟差的估计算法，编程实现了基于非差载波相位的精密卫星钟差的解算，并同IGS若干分析中心提供的精密钟差产品进行了比较。

The accuracy of receiver clock parameter got from point positioning is not high enough to be introduced into the double difference equation. In order to get the accurate receiver clock error, high quality cymometer will be needed, while this is not applicable for the real work.

由于用伪距求得的接收机钟差不能满足精度要求，要想精确求得接收机钟差，需要高精度的频率计，这在实际应用中难以做到，而求解参考卫星站间单差模糊度的方法则是可行的。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。