﻿ 针对北斗系统的降维快速高精度定向算法
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1. 中国科学院光电研究院， 北京 100094
2. 中国科学院大学，北京 100094

A Fast and High-precision Orientation Algorithm for BeiDou Based on Dimensionality Reduction
ZHAO Jiaojiao1,2, QU Jianghua1, YUAN Hong1
1. Institute of Opto-electronics, Chinese academy of sciences, Beijing 100094, China;
2. University of Chinese Academy of Sciences, Beijing 100094, China
First author: ZHAO Jiaojiao(1989—),female,master,majors in GNSS high-precision positioning.E-mail：zhaojj@aoe.cn
Abstract: A fast and high-precision orientation algorithm for BeiDou is proposed by deeply analyzing the constellation characteristics of BeiDou and GEO satellites features.With the advantage of good east-west geometry, the baseline vector candidate values were solved by the GEO satellites observations combined with the dimensionality reduction theory at first.Then, we use the ambiguity function to judge the values in order to obtain the optical baseline vector and get the wide lane integer ambiguities. On this basis, the B1 ambiguities were solved. Finally, the high-precision orientation was estimated by the determinating B1 ambiguities. This new algorithm not only can improve the ill-condition of traditional algorithm, but also can reduce the ambiguity search region to a great extent, thus calculating the integer ambiguities in a single-epoch.The algorithm is simulated by the actual BeiDou ephemeris and the result shows that the method is efficient and fast for orientation. It is capable of very high single-epoch success rate(99.31%) and accurate attitude angle (the standard deviation of pitch and heading is respectively 0.07°and 0.13°)in a real time and dynamic environment.
Key words: BeiDou     orientation     dimensionality reduction     ambiguity function

1 引 言

2 常规载体定向解算方法

3 针对北斗系统的降维定向算法 3.1 北斗系统星座特性分析

 图 1 50°N地区(效果最差地区)GEO双差方向余弦系数分析结果 Fig. 1 Coefficient value analysis results at 50°N (the least effective area)
3.2 降维双差模型

3.3 模糊度解算方法

 图 2 采用组合观测值带来的搜索量的减小 Fig. 2 The reduction of the amount of search using combined observations
4 算法实施步骤

 图 3 定向解算算法流程 Fig. 3 Flow chart of the new orientation algorithm

5 仿真和结果

 图 4 卫星可见情况 Fig. 4 Visible satellites

 图 5 宽巷求解后所得的基线误差 Fig. 5 Baseline error after solving the wide lane

 图 6 窄巷求解后所得的基线误差 Fig. 6 Baseline error after solving the narrow lane

 图 7 定向解算误差 Fig. 7 Orientation result error
6 结 论

(1) GEO卫星的特殊轨道特性可以使得三维解算转化为二维解算，减小模糊度搜索空间。

(2) 候选值的判断准则采用模糊度函数法，是一种简便高效的判决准则。

(3) 定向解算为短基线下的接收机天线相对位置问题，本文方法采用双差观测量，可以忽略空间误差影响，其模糊度解算成功率高(99.31%)。

(4) 采用双频观测量组成宽巷虚拟观测值，解算时先求宽巷模糊度，再求B1频点模糊度，可以提高解算效率。

(5) 本方法采用单历元数据解算，能够满足实时动态定向解算的需求。定向解算结果精度高(俯仰角的标准差为0.07°，航向角的标准差为0.13°)。

http://dx.doi.org/10.11947/j.AGCS.2015.20140055

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#### 文章信息

ZHAO Jiaojiao, QU Jianghua, YUAN Hong

A Fast and High-precision Orientation Algorithm for BeiDou Based on Dimensionality Reduction

Acta Geodaeticaet Cartographica Sinica, 2015, 44(5): 488-494.
http://dx.doi.org/10.11947/j.AGCS.2015.20140055