全文获取类型
收费全文 | 140篇 |
免费 | 3篇 |
专业分类
测绘学 | 101篇 |
地球物理 | 2篇 |
地质学 | 1篇 |
海洋学 | 4篇 |
天文学 | 2篇 |
综合类 | 33篇 |
出版年
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 14篇 |
2016年 | 12篇 |
2015年 | 11篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 13篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1992年 | 1篇 |
排序方式: 共有143条查询结果,搜索用时 21 毫秒
91.
GLONASS伪距频间偏差难以利用经验模型消除。在RTK定位解算中,尤其是需顾及大气延迟的中长距离异质基线,IFCB会降低模糊度收敛速度,甚至导致模糊度固定错误。本文基于双差HMW组合和消电离层组合,提出一种站间IFCB实时估计算法,实时获取各频段的非组合站间单差IFCB。试验结果表明,站间IFCB长期稳定,可达数个纳秒;在GPS/GLONASS观测值先验误差比值为3:5的条件下,未改正的IFCB可能导致基线GPS/GLONASS组合RTK定位性能比单GPS差。将本文提出算法应用于RTK定位,能够有效消除IFCB的影响,RTK模糊度浮点解精度、定位收敛速度和固定率都有明显改善,部分基线的RTK定位首次固定时间从9.2 s提高到2.1 s,固定解比率从84.5%提高到97.9%。 相似文献
92.
93.
94.
95.
An approach to GLONASS ambiguity resolution 总被引:9,自引:2,他引:7
J. Wang 《Journal of Geodesy》2000,74(5):421-430
When processing global navigation satellite system (GLONASS) carrier phases, the standard double-differencing (DD) procedure
cannot cancel receiver clock terms in the DD phase measurement equations due to the multiple frequencies of the carrier phases.
Consequently, a receiver clock parameter has to be set up in the measurement equations in addition to baseline components
and DD ambiguities. The resulting normal matrix unfortunately becomes singular. Methods to deal with this problem have been
proposed in the literature. However, these methods rely on the use of pseudo-ranges. As pseudo-ranges are contaminated by
multi-path and hardware delays, biases in these pseudo-ranges are significant, which may result in unreliable ambiguity resolution.
A new approach is addressed that is not sensitive to the biases in the pseudo-ranges. The proposed approach includes such
steps as converting the carrier phases to their distances to cancel the receiver clock errors, and searching for the most
likely single-differenced (SD) ambiguity. Based on the results from the theoretical investigation, a practical procedure for
GLONASS ambiguity resolution is presented. The initial experimental results demonstrate that the proposed approach is useable
in cases of GLONASS and combined global positioning system (GPS) and GLONASS positioning.
Received: 19 August 1998 / Accepted: 12 November 1999 相似文献
96.
给出了基于卡尔曼滤波的组合GPS/GLONASS伪距单点实时动态定位的原理,并通过模拟实验表明组合GPS/GLONASS可以改进单独GPS车辆导航和监控系统的定位精度和可幸性,为车最GPS在高楼林立的城区或其它可视条件受限制地带的应用提供了保证。 相似文献
97.
随着北斗卫星导航系统(BDS)于2012年底正式提供亚太地区区域性服务,研究BDS与其他卫星导航系统的组合定位尤为重要。本文主要分析BDS与GPS、GLONASS组合精密单点定位(PPP),统一了三类卫星的时间系统和空间系统,给出了PPP非差组合模型,利用九峰站全天观测数据进行实验,得到初步结论:组合定位系统能够减少单系统的收敛时间;组合定位系统的定位精度比单系统的定位精度高。 相似文献
98.
Due to the different signal frequencies for the GLONASS satellites, the commonly-used double-differencing procedure for carrier phase data processing can not be implemented in its straightforward form, as in the case of GPS. In this paper a novel data processing strategy, involving a three-step procedure, for integrated GPS/GLONASS positioning is proposed. The first is pseudo-range-based positioning, that uses double-differenced (DD) GPS pseudo-range and single-differenced (SD) GLONASS pseudo-range measurements to derive the initial position and receiver clock bias. The second is forming DD measurements (expressed in cycles) in order to estimate the ambiguities, by using the receiver clock bias estimated in the above step. The third is to form DD measurements (expressed in metric units) with the unknown SD integer ambiguity for the GLONASS reference satellite as the only parameter (which is constant before a cycle slip occurs for this satellite). A real-time stochastic model estimated by residual series over previous epochs is proposed for integrated GPS/GLONASS carrier phase and pseudo-range data processing. Other associated issues, such as cycle slip detection, validation criteria and adaptive procedure(s) for ambiguity resolution, is also discussed. The performance of this data processing strategy will be demonstrated through case study examples of rapid static positioning and kinematic positioning. From four experiments carried out to date, the results indicate that rapid static positioning requires 1 minute of single frequency GPS/GLONASS data for 100% positioning success rate. The single epoch positioning solution for kinematic positioning can achieve 94.6% success rate over short baselines (<6 km). 相似文献
99.
Zhang Yongjun 《地球空间信息科学学报》2013,16(4):32-36
To obtain the GLONASS satellite position at an epoch other than reference time, the satellite's equation of motion has to be integrated with broadcasting ephemerides. The iterative detecting and repairing method of cycle slips based on triple difference residuals for combined GPS/GLONASS positioning and the iterative ambiguity resolution approach suitable for combined post processing positioning are discussed systematically. Experiments show that millimeter accuracy can be achieved in short baselines with a few hours' dual frequency or even single frequency GPS/GLONASS carrier phase observations, and the precision of dual frequency observations is distinctly higher than that of single frequency observations. 相似文献
100.
????IGS??????????????????????Allan???????????????????????????????????????????????????????????????????????????????о????????????1??GPS???????????GLONASS???????????4??????????????????????????????1??1/2??1/3??1/4???2???????????????GPS????????Allan????????????仯????GLONASS????????Allan????????????????仯??????GPS????????д???????????GLONASS???????????????????????????????仯??????С??3????????ε?????????????????仯??? 相似文献