受接收机类型、固件版本和天线的影响，GLONASS IFCB变化规律复杂且难以有效改正，导致GLONASS HMW组合包含系统性偏差，无法用于GLONASS宽巷模糊度固定。本文提出一种基于GLONASS HMW组合观测值残差的站间IFCB估计方法，并对站间IFCB变化特性进行分析。结果表明，站间IFCB长期稳定，少数相同类型硬件（包括接收机类型、固件版本和天线）站间IFCB可达0.5 m。为削弱伪距多路径效应对站间IFCB估值的影响，基于一个轨道重复周期的观测数据求得一组站间IFCB对实时观测值进行补偿，实现HMW组合平滑序列直接用于GLONASS宽巷模糊度实时固定。进行站间IFCB补偿后，基线宽巷模糊度固定正确率均在98%以上。
GLONASS inter-frequency code biases (IFCBs) vary with receiver manufacturers,firmware versions,and antenna types.IFCBs are hardly corrected or modeled precisely,so that Hatch-Melbourne-Wübbena (HMW) combination observation contains a systemic bias and cannot applied into GLONASS wide-lane ambiguity resolution.Utilizing the residuals of GLONASS HMW combination observations,we propose an algorithm to estimate IFCB of different sites (DS-IFCB).The experiment results show that DS-IFCB is long term stability and the sizes of DS-IFCBs in some homogeneous baselines (composed by same type of devices,i.e.receiver type,version and antenna) are larger than 0.5 meters.In order to achieve wide-lane ambiguities in real-time,DS-IFCBs,estimated with previous observations,are used as priors to cancel IFCBs in current observations.After DS-IFCB offset,both the success rate and correct rate of GLONASS wide-lane ambiguity resolutions are improved,regardless of whether baselines are equipped with homogeneous devices.The correct rates of all baselines are higher than 98%.
[1] YAMADA H, TAKASU T, KUBO N, et al. Evaluation and Calibration of Receiver Inter-channel Biases for RTK-GPS/GLONASS[C]//Proceedings of the 23rd International Technical Meeting of the Satellite Division of the Institute of Navigation. Portland, OR:Oregon Convention Center, 2010:1580-1587.
[2] WANNINGER L, WALLSTAB-FREITAG S. Combined Processing of GPS, GLONASS, and SBAS Code Phase and Carrier Phase Measurements[C]//Proceedings of the 20th International Technical Meeting of the Satellite Division of the Institute of Navigation. Fort Worth, TX:Fort Worth Convention Center, 2007:866-875.
[3] WANNINGER L. Carrier-phase Inter-frequency Biases of GLONASS Receivers[J]. Journal of Geodesy, 2012, 86(2):139-148.
[4] 安向东. GLONASS模糊度固定方法研究[D]. 武汉:武汉大学, 2016. AN Xiangdong. The Research of GLONASS Integer Ambiguity Resolution[D]. Wuhan:Wuhan University. 2016.
[5] SHI Chuang, YI Wenting, SONG Weiwei, et al. GLONASS Pseudorange Inter-channel Biases and Their Effects on Combined GPS/GLONASS Precise Point Positioning[J]. GPS Solutions, 2013, 17(4):439-451.
[6] 刘志强, 王解先, 段兵兵. 单站多参数GLONASS码频间偏差估计及其对组合精密单点定位的影响[J]. 测绘学报, 2015, 44(2):150-159. DOI:10.11947/j.AGCS.2015.20130800. LIU Zhiqiang, WANG Jiexian, DUAN Bingbing. Estimation of GLONASS Code Inter-frequency Biases with Multiple Parameters Based on a Single Station and Its Impact on Combined Precise Point Positioning[J]. Acta Geodaetica et Cartographica Sinica, 2015, 44(2):150-159. DOI:10.11947/j.AGCS.2015.20130800.
[7] MERVART L, BEUTLER G, ROTHACHER M, et al. Ambiguity Resolution Strategies Using the Results of the International GPS Geodynamics Service (IGS)[J]. Bulletin Géodésique, 1994, 68(1):29-38.
[8] HATCH R. The Synergism of GPS Code and Carrier Measurements[C]//Proceedings of the 3rd International Geodetic Symposium on Satellite Doppler Positioning.[S.l.]:Bulletin Géodésique, 1983:1213-1231.
[9] MELBOURNE W G. The Case for Ranging in GPS-based Geodetic Systems[C]//Proceedings of the First International Symposium on Precise Positioning with the Global Positioning System. Maryland:[s.n.], 1985:1519.
[10] WVBBENA G. Software Developments for Geodetic Positioning with GPS Using TI-4100 Code and Carrier Measurements[C]//Proceedings of the First International Symposium on Precise Positioning with the Global Positioning System. Rockville, Maryland:[s.n.], 1985:19.
[11] REUSSNER N, WANNINGER L. GLONASS Inter-frequency Biases and Their Effects on RTK and PPP Carrier-phase Ambiguity Resolution[C]//Proceedings of the 24th International Technical Meeting of the Satellite Division of the Institute of Navigation. Portland, OR:Fort Worth Convention Center, 2011:712-716.
[12] LIU Yang, GE Maorong, SHI Chuang, et al. Improving Integer Ambiguity Resolution for GLONASS Precise Orbit Determination[J]. Journal of Geodesy, 2016, 90(8):715-726.
[13] REUβNER N, WANNINGER L. GLONASS Inter-frequency Code Biases and PPP Carrier-phase Ambiguity Resolution[J]. Journal of Geodesy, 2012, 86(2):139-148.
[14] GENG Jianghui, BOCK Y. GLONASS Fractional-cycle Bias Estimation across Inhomogeneous Receivers for PPP Ambiguity Resolution[J]. Journal of Geodesy, 2016, 90(4):379-396.
[15] 姚宜斌, 胡明贤, 许超钤. 基于DREAMNET的GPS/BDS/GLONASS多系统网络RTK定位性能分析[J]. 测绘学报, 2016, 45(9):1009-1018. DOI:10.11947/j.AGCS.2016.20160133. YAO Yibin, HU Mingxian, XU Chaoqian. Positioning Accuracy Analysis of GPS/BDS/GLONASS Network RTK Based on DREAMNET[J]. Acta Geodaetica et Cartographica Sinica, 2016, 45(9):1009-1018. DOI:10.11947/j.AGCS.2016.20160133.
[16] 张绍成. 基于GPS/GLONASS集成的CORS网络大气建模与RTK算法实现[D]. 武汉:武汉大学, 2010. ZHANG Shaocheng. The GPS/GLONASS Integrated CORS Network Atmosphere Modeling and RTK Algorithm Implementation[D]. Wuhan:Wuhan University, 2010.
[17] ZHANG Xiaohong, HE Xiyang, LIU Wanke. Characteristics of Systematic Errors in the BDS Hatch-Melbourne-Wübbena Combination and Its Influence on Wide-lane Ambiguity Resolution[J]. GPS Solutions, 2017, 21(1):265-277.
[18] AL-SHAERY A, ZHANG S, RIZOS C. An Enhanced Calibration Method of GLONASS Inter-channel Bias for GNSS RTK[J]. GPS Solutions, 2013, 17(2):165-173.
[19] GE Linlin, HAN Shaowei, RIZOS C. Multipath Mitigation of Continuous GPS Measurements Using an Adaptive Filter[J]. GPS Solutions, 2000, 4(2):19-30.
[20] WANG J. An Approach to GLONASS Ambiguity Resolution[J]. Journal of Geodesy, 2013, 74(5):421-430.
[21] 段举举, 沈云中. GPS/GLONASS组合静态相位相对定位算法[J]. 测绘学报, 2012, 41(6):825-830. DUAN Juju, SHEN Yunzhong. An Algorithm of Combined GPS/GLONASS Static Relative Positioning[J]. Acta Geodaetica et Cartographica Sinica, 2012, 41(6):825-830.
[22] SNAY R A, SOLER T. Continuously Operating Reference Station (CORS):History, Applications, and Future Enhancements[J]. Journal of Surveying Engineering, 2013, 134(4):95-104.
[23] BRUYNINX C, BECKER M, STANGL G. Regional Densification of the IGS in Europe Using the EUREF Permanent GPS Network (EPN)[J]. Physics and Chemistry of the Earth, Part A:Solid Earth and Geodesy, 2000, 26(6-8):531-538.
[24] TEUNISSEN P J G. An Optimality Property of the Integer Least-squares Estimator[J]. Journal of Geodesy, 1999, 73(11):587-593.
