共查询到17条相似文献，搜索用时 0 毫秒
1.
北斗系统短基线解算数据处理方法 总被引：5，自引：1，他引：4
北斗卫星导航系统基线解算和高精度定位中的关键问题是整周模糊度解算。针对北斗系统的相对定位问题,该文利用B1、B2载波相位观测值组成宽巷双差观测值,利用搜索算法固定宽巷双差整周模糊度,建立宽巷及B1、B2的双差观测方程,并利用搜索算法固定B1的整周模糊度,进而固定B2的整周模糊度。以武汉大学PANDA软件处理结果作为参考值处理16km以下的四段基线进行算法的试验检验,结果表明,四段基线在E方向、N方向、U方向的精度分别为1.5cm、2.0cm、5.0cm,验证了利用宽巷组合观测值进行北斗系统基线解算是可行的,其精度和GPS系统相当。 相似文献
2.
综述GPS定位中整周糊度求解问题 总被引：1，自引：0，他引：1
GPS定位中确定整周模糊度是关键问题,而在进行短时段的短基线向量的解算时,由于观测值较少以及卫星星座几何形状变化不大等因素,会出现整周模糊度不能固定为整数的现象,本文综述了当前求解整周模糊度的主要方法,并对GPS精密快速定位中整周模糊度定位问题提出了一定看法,可供GPS研究及定位工作者参考。 相似文献
3.
龚涛 《测绘科学技术学报》2000,17(2):86-90
如何在线精确地求解整周模糊度,是GPS高精度动态相对定位的关键问题.在线解算取决于很多因素:基线长度、数据处理方法、接收机的性能(如双频还是单频)以及抗AS和SA的能力等.现代双频GPS接收机能获得载波相位和L1、L2频道上的精密伪距观测值,组合这4个观测值可进行单历元整周模糊度解算.文中对组合码和相位观测值在线解整周模糊度的算法进行了试验和分析,得出了很有实用意义的结论. 相似文献
4.
顾及基线先验信息的GPS模糊度快速解算 总被引：1，自引：0，他引：1
采用GPS相位观测值进行快速定位时,其解算模型严重病态,最小二乘解得的浮点模糊度精度差且相关性大,导致整周模糊度搜索空间过大,难以正确固定。本文提出一种顾及基线先验信息和模糊度线性约束的整数条件的GPS模糊度快速解算方法,先用顾及基线先验信息的正则化算法解得精度较高且相关性较小的浮点模糊度,以减小整周模糊度的搜索空间;再综合利用整周模糊度间的线性约束的整数条件和基线先验信息,进一步有效地减小模糊度搜索空间,提高搜索效率。算例表明:顾及基线先验信息的正则化算法有效地改善了模糊度浮点解,模糊度线性约束的整数条件有效地提高搜索效率和成功率。 相似文献
5.
虚拟参考站(VRS)技术是目前GPS网络RTK系统研究领域的热点之一,而参考站间整周模糊度的在线解算则是VRS/RTK的关键技术。本文针对中长基线的整周模糊度解算,采用两步法求解:一是提出了采用消电离层伪距组合和双频相位组合法求解宽巷模糊度,该方法既不需要高精度的P码,也不需要顾及电离层的影响;二是对于解算L1双差模糊度,探讨了采用序贯最小二乘法解算模糊度,提出一种改进的序贯最小二乘方法,本方法既能削弱模糊度解算过程中法方程的病态性,又不影响模糊度固定时间,并结合算例进行了分析。 相似文献
6.
GPS双天线定向系统及优化模糊度搜索算法 总被引：2，自引：0，他引：2
研究了GPS载波相位双差测量方向的原理和应用最小二乘法解算基线矢量的方法;提出了快速解算整周模糊度的优化算法.实验表明,采用基线长度作为约束条件,应用GPS双天线测量方向的原理和搜索模糊度优化算法正确,其定向精度达0.12°,解算时间小于0.3s. 相似文献
7.
长距离网络RTK是实现GPS/BDS高精度实时定位的主要手段之一,其核心是长距离参考站网GPS/BDS整周模糊度的快速准确确定。本文提出了一种长距离GPS/BDS参考站网载波相位整周模糊度解算方法,首先利用GPS双频观测数据计算和确定宽巷整周模糊度,同时利用BDS的B2、B3频率观测值确定超宽巷整周模糊度。然后建立GPS载波相位整周模糊度和大气延迟误差的参数估计模型,附加双差宽巷整周模糊度的约束,解算双差载波相位整周模糊度,并建立参考站网大气延迟误差的空间相关模型。根据B2、B3频率的超宽巷整周模糊度建立包含大气误差参数的载波相位整周模糊度解算模型,利用大气延迟误差空间相关模型约束BDS双差载波相位整周模糊度的解算。克服了传统的使用无电离层组合值解算整周模糊度的不利影响。采用实测长距离CORS网GPS、BDS多频观测数据进行算法验证,试验结果证明该方法可实现长距离参考站网GPS/BDS载波相位整周模糊度的准确固定。 相似文献
8.
用遗传算法搜索GPS单频单历元整周模糊度 总被引：10，自引：2，他引：10
介绍了短基线利用单频单历元双差载波相位定位时模糊度固定的基本理论，探讨了利用遗传算法快速搜索GPS单频单历元整周模糊度的一些理论和实现的方法．提出了用改进的正则化方法改善浮动解来提高搜索成功率的新思路。算例分析表明，在一定的条件下．应用遗传算法搜索整周模糊度成功率高、稳键性较好。 相似文献
9.
主要研究了等权法和基于卫星高度角的GPS观测量随机模型确定方法,由此确定权矩阵应用于GPS基线解算中以检验其效果,并通过对模型试验结果的比较,分析说明了采用卫星高度角定权对整周模糊度搜索和基线解算结果的影响。 相似文献
10.
11.
一般卫星导航接收机的伪距测量误差大于宽巷波长。根据宽巷引导模型,直接使用双差伪距取整固定双差宽巷整周模糊度有很大概率会产生一周固定错误。基于此,提出了一种改进的宽巷引导整周模糊度固定算法,针对宽巷整周模糊度一周固定错误进行探测和修复。利用整周模糊度为整数的特质构造理论探测量,并将该探测量与载噪比所确定的门限相比较,判断是否出现宽巷整周模糊度一周固定错误;利用双差整周模糊度自由度为3的特点,修复错误宽巷整周模糊度。对该算法在高斯噪声条件下的可行性进行了理论分析,结果表明正常载噪比的观测数据均可分辨出一周宽巷整周模糊度的估计错误。同时,分析了考虑多径等误差后该算法所能接受的载波相位最大误差。计算了不同伪距误差下宽巷整周模糊度一周固定错误出现的概率。使用GPS实测短基线数据对算法进行验证,该算法可将基于宽巷引导的整周模糊度固定算法的固定率从原来的只有不到1/3提升至接近100%。 相似文献
12.
This paper presents a new strategy for GPS carrier phase data processing. The classic approach generally consists of three steps: a float solution, a search for integer ambiguities, and a fixed solution. The new approach is based on certain properties of ambiguity function method and ensures the condition of integer ambiguities without the necessity of the additional step of the integer search. The ambiguities are not computed explicitly, although the condition of “integerness” of the ambiguities is ensured in the results through the least squares adjustment with condition equations in the functional model. An appropriate function for the condition equations is proposed and presented. The presented methodology, modified ambiguity function approach, currently uses a cascade adjustment with successive linear combinations of L1 and L2 carrier phase observations to ensure a correct solution. This paper presents the new methodology and compares it to the three-stage classic approach which includes ambiguity search. A numerical example is provided for 25 km baseline surveyed with dual-frequency receivers. All tests were performed using an in-house developed GINPOS software and it has been shown that the positioning results from both approaches are equivalent. It has also been proved that the new approach is robust to adverse effects of cycle slips. In our opinion, the proposed approach may be successfully used for carrier phase GPS data processing in geodetic applications. 相似文献
13.
Christian Tiberius Thomas Pany Bernd Eissfeller Peter Joosten Sandra Verhagen 《GPS Solutions》2002,6(1-2):96-99
In this short contribution it is demonstrated how integer carrier phase cycle ambiguity resolution will perform in near future,
when the US GPS gets modernized and the European Galileo becomes operational. The capability of ambiguity resolution is analyzed
in the context of precise differential positioning over short, medium and long distances. Starting from dual-frequency operation
with GPS at present, particularly augmenting the number of satellites turns out to have beneficial consequences on the capability
of correctly resolving the ambiguities. With a 'double' constellation, on short baselines, the confidence of the integer ambiguity
solution increases to a level of 0.99999999 or beyond.
Electronic Publication 相似文献
14.
15.
附有约束条件的GPS模糊度快速解算 总被引：2，自引：1，他引：1
采用GPS相位观测值进行快速定位时,由于坐标与模糊度参数间的强共线性,造成浮点模糊度最小二乘解的精度很差,整周模糊度难以正确固定。在GPS的实际应用中,可以利用坐标参数与模糊度参数的约束条件,改善浮点模糊度的解算精度,减小整数模糊度的搜索空间。首先给出了这两类约束的通用模型,然后给出了不同情况下约束条件的具体形式,并导出了相应的GPS模糊度快速解算公式。用实例验证了算法的有效性。结果表明,采用约束条件,可排除大量错误的模糊度备选组合,从而提高模糊度的解算效率和成功率。因此,在GPS定位时,应尽可能利用各种约束条件。 相似文献
16.
Precise GPS Positioning by Applying Ionospheric Corrections from an Active Control Network 总被引：2，自引：1，他引：1
In this article, initial results are presented of a method to improve fast carrier phase ambiguity resolution over longer
baselines (with lengths up to about 200 km). The ionospheric delays in the global positioning system (GPS) data of these long
baselines mainly hamper successful integer ambiguity resolution, a prerequisite to obtain precise positions within very short
observation time spans.
A way to correct the data for significant ionospheric effects is to have a GPS user operate within an active or permanently
operating network use ionospheric estimates from this network. A simple way to do so is to interpolate these ionospheric estimates
based on the expected spatial behaviour of the ionospheric delays. In this article such a technique is demonstrated for the
Dutch Active Control Network (AGRS.NL). One hour of data is used from 4 of the 5 reference stations to obtain very precise
ionospheric corrections after fixing of the integer ambiguities within this network. This is no problem because of the relatively
long observation time span and known positions of the stations of the AGRS.NL. Next these interpolated corrections are used
to correct the GPS data from the fifth station for its ionospheric effects. Initial conclusions about the performance of this
technique are drawn in terms of improvement of integer ambiguity resolution for this baseline. ? 1999 John Wiley & Sons, Inc. 相似文献
17.
Performance analysis of triple-frequency ambiguity resolution with BeiDou observations 总被引：5，自引：1，他引：4
We investigate triple-frequency ambiguity resolution performance using real BeiDou data. We test four ambiguity resolution (AR) methods which are applicable to triple-frequency observations. These are least squares ambiguity decorrelation adjustment (LAMBDA), GF-TCAR (geometry-free three-carrier ambiguity resolution), GB-TCAR (geometry-based three-carrier ambiguity resolution) and GIF-TCAR (three-carrier ambiguity resolution based on the geometry-free and ionospheric-free combination). A comparison between LAMBDA, GF-TCAR and GB-TCAR was conducted over three short baselines and two medium baselines. The results indicated that LAMBDA is optimal in both short baseline and medium baseline cases. However, the performances of GB-TCAR and LAMBDA differ slightly for short baselines. Compared with GF-TCAR, which uses the geometry-free model, the GB-TCAR using the geometry-based model improves the AR performance significantly. Compared with dual-frequency observations, the LAMBDA AR results show a significant improvement when using triple-frequency observations over short baselines. The performance of GIF-TCAR is evaluated using multi-epoch observations. The results indicated that multi-path errors on carrier phases will have a significant influence on GIF-TCAR AR results, which leads to different GIF-TCAR AR performance for different type of satellites. For GEO (Geostationary Orbit) satellites, the ambiguities can barely be correctly fixed because the multi-path errors on carrier phases are very systematic. For IGSO (Inclined Geosynchronous Orbit) and MEO (Medium Earth Orbit) satellites, when the elevation cutoff angle is set as 30°, several tens to several hundreds of epochs are needed for correctly fixing the narrow lane ambiguities. The comparison of positioning performance between dual-frequency observations and triple-frequency observations was also conducted. The results indicated that a minor improvement can be achieved by using triple-frequency observations compared with using dual-frequency observations. 相似文献