{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T15:48:37Z","timestamp":1781020117324,"version":"3.54.1"},"reference-count":34,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,1,17]],"date-time":"2021-01-17T00:00:00Z","timestamp":1610841600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The occlusion of buildings in urban environments leads to the intermittent reception of satellite signals, which limits the utilization of observations. This subsequently results in a decline of the positioning and attitude accuracy of Global Navigation Satellite System (GNSS)\/Inertial Navigation System (INS) integrated system (GNSS\/INS). This study implements a smooth post-processing strategy based on a tightly coupled differential GNSS\/INS. Specifically, this strategy used the INS-estimated position to reinitialize integer ambiguity. The GNSS raw observations were input into the Kalman filter to update the measurement. The Rauch\u2013Tung\u2013Striebel smoothing (RTSS) algorithm was used to process the observations of the entire period. This study analyzed the performance of loosely coupled and tightly coupled systems in an urban environment and the improvement of the RTSS algorithm on the navigation solution from the perspective of fully mining the observations. The experimental results of the simulation data and real data show that, compared with the traditional tightly coupled processing strategy which does not use INS-aided integer ambiguity resolution and RTSS algorithm, the strategy in this study sufficiently utilized INS observations and GNSS observations to effectively improve the accuracy of positioning and attitude and ensure the continuity of navigation results in an obstructed environment.<\/jats:p>","DOI":"10.3390\/s21020620","type":"journal-article","created":{"date-parts":[[2021,1,20]],"date-time":"2021-01-20T03:34:25Z","timestamp":1611113665000},"page":"620","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Effect Analysis of GNSS\/INS Processing Strategy for Sufficient Utilization of Urban Environment Observations"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9592-1002","authenticated-orcid":false,"given":"Bo","family":"Shi","sequence":"first","affiliation":[{"name":"College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266000, China"},{"name":"Key Laboratory of Ocean Geomatics, Ministry of Natural Resources of China, Qingdao 266000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mengke","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunpeng","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuntian","family":"Bai","sequence":"additional","affiliation":[{"name":"College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kang","family":"Lin","sequence":"additional","affiliation":[{"name":"College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7934-5850","authenticated-orcid":false,"given":"Fanlin","family":"Yang","sequence":"additional","affiliation":[{"name":"College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266000, China"},{"name":"Key Laboratory of Ocean Geomatics, Ministry of Natural Resources of China, Qingdao 266000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Sairam, N., Nagarajan, S., and Ornitz, S. (2016). Development of Mobile Mapping System for 3D Road Asset Inventory. Sensors, 16.","DOI":"10.3390\/s16030367"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Wan, G., Yang, X., Cai, R., Li, H., Zhou, Y., Wang, H., and Song, S. (2018, January 21\u201325). Robust and Precise Vehicle Localization Based on Multi-Sensor Fusion in Diverse City Scenes. Proceedings of the 2018 IEEE International Conference on Robotics and Automation (ICRA), Brisbane, Australia.","DOI":"10.1109\/ICRA.2018.8461224"},{"key":"ref_3","first-page":"1207","article-title":"From Geomatics to Geospatial Intelligent Service Science","volume":"46","author":"Deren","year":"2017","journal-title":"Acta Geod. Cartogr. Sin."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"10599","DOI":"10.3390\/s130810599","article-title":"The Performance Analysis of a Real-Time Integrated INS\/GPS Vehicle Navigation System with Abnormal GPS Measurement Elimination","volume":"13","author":"Chiang","year":"2013","journal-title":"Sensors"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"15983","DOI":"10.3390\/s121115983","article-title":"Performance Analysis of Constrained Loosely Coupled GPS\/INS Integration Solutions","volume":"12","author":"Falco","year":"2012","journal-title":"Sensors"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1007\/s10291-018-0725-y","article-title":"Odometer, low-cost inertial sensors, and four-GNSS data to enhance PPP and attitude determination","volume":"22","author":"Gao","year":"2018","journal-title":"GPS Solut."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"23286","DOI":"10.3390\/s150923286","article-title":"INS\/GPS\/LiDAR Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm","volume":"15","author":"Gao","year":"2015","journal-title":"Sensors"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Chang, L., Niu, X., Liu, T., Tang, J., and Qian, C. (2019). GNSS\/INS\/LiDAR-SLAM Integrated Navigation System Based on Graph Optimization. Remote Sens., 11.","DOI":"10.3390\/rs11091009"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1007\/s10291-006-0050-8","article-title":"GPS\/MEMS INS integrated system for navigation in urban areas","volume":"11","author":"Godha","year":"2007","journal-title":"GPS Solut."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"80","DOI":"10.5081\/jgps.11.1.80","article-title":"Observability Analysis of Non-Holonomic Constraints for Land-Vehicle Navigation Systems","volume":"11","author":"Niu","year":"2012","journal-title":"J. Glob. Position. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Zhang, C., Li, X., Gao, S., Lin, T., and Wang, L. (2017). Performance Analysis of Global Navigation Satellite System Signal Acquisition Aided by Different Grade Inertial Navigation System under Highly Dynamic Conditions. Sensors, 17.","DOI":"10.3390\/s17050980"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Chen, Z., Lai, J., Liu, J., Li, R., and Ji, G. (2018). A Parameter Self-Calibration Method for GNSS\/INS Deeply Coupled Navigation Systems in Highly Dynamic Environments. Sensors, 18.","DOI":"10.3390\/s18072341"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Xu, R., Ding, M., Qi, Y., Yue, S., and Liu, J. (2018). Performance Analysis of GNSS\/INS Loosely Coupled Integration Systems under Spoofing Attacks. Sensors, 18.","DOI":"10.3390\/s18124108"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"25336","DOI":"10.3390\/s151025336","article-title":"GPS Cycle Slip Detection Considering Satellite Geometry Based on TDCP\/INS Integrated Navigation","volume":"15","author":"Kim","year":"2015","journal-title":"Sensors"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1007\/s00190-018-1222-3","article-title":"The improvement in integer ambiguity resolution with INS aiding for kinematic precise point positioning","volume":"93","author":"Zhang","year":"2019","journal-title":"J. Geod."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Falco, G., Pini, M., and Marucco, G. (2017). Loose and Tight GNSS\/INS Integrations: Comparison of Performance Assessed in Real Urban Scenarios. Sensors, 17.","DOI":"10.3390\/s17020255"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Liu, Y., Liu, F., Gao, Y., and Zhao, L. (2018). Implementation and Analysis of Tightly Coupled Global Navigation Satellite System Precise Point Positioning\/Inertial Navigation System (GNSS PPP\/INS) with Insufficient Satellites for Land Vehicle Navigation. Sensors, 18.","DOI":"10.3390\/s18124305"},{"key":"ref_18","unstructured":"Li, T., Zhang, H.P., Niu, X.J., and Zhang, Q. (2016). Performance analysis of BDS+GPS RTK+INS tightly coupled algorithm in urban environment. Bull. Surv. Mapp., 9\u201312."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"8685","DOI":"10.3390\/s150408685","article-title":"Performance Analysis on Carrier Phase-Based Tightly-Coupled GPS\/BDS\/INS Integration in GNSS Degraded and Denied Environments","volume":"15","author":"Han","year":"2015","journal-title":"Sensors"},{"key":"ref_20","first-page":"478","article-title":"Performance Analysis of Tightly Coupled RTK\/INS Algorithm in Case of Insufficient Number of Satellites","volume":"43","author":"Li","year":"2018","journal-title":"Geomat. Inf. Sci. Wuhan Univ."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Dorn, M., Filwarny, J.O., and Wieser, M. (2017, January 9\u201312). Inertially-aided RTK based on tightly-coupled integration using low-cost GNSS receivers. Proceedings of the 2017 European Navigation Conference (ENC), Lausanne, Switzerland.","DOI":"10.1109\/EURONAV.2017.7954208"},{"key":"ref_22","first-page":"1031","article-title":"Fixed-Interval Smoothing Post-Processing A lgorithms Based on Tightly Coupled Carrier Phase DGNSS\/INS Method","volume":"35","author":"Hao","year":"2015","journal-title":"J. Geod. Geodyn."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Dong, Y., Wang, D., Zhang, L., Li, Q., and Wu, J. (2020). Tightly Coupled GNSS\/INS Integration with Robust Sequential Kalman Filter for Accurate Vehicular Navigation. Sensors, 20.","DOI":"10.3390\/s20020561"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1017\/S0373463313000623","article-title":"Airborne Earth Observation Positioning and Orientation by SINS\/GPS Integration Using CD R-T-S Smoothing","volume":"67","author":"Gong","year":"2013","journal-title":"J. Navig."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1007\/s10291-017-0601-1","article-title":"New optimal smoothing scheme for improving relative and absolute accuracy of tightly coupled GNSS\/SINS integration","volume":"21","author":"Zhang","year":"2017","journal-title":"GPS Solut."},{"key":"ref_26","unstructured":"Hide, C., and Moore, T. (2005, January 13\u201316). GPS and Low Cost INS Integration for Positioning in the Urban Environment. Proceedings of the 18th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2005), Long Beach, CA, USA."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1109\/TAES.1978.308617","article-title":"The Psi-Angle Error Equation in Strapdown Inertial Navigation Systems","volume":"14","author":"Weinred","year":"1978","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Groves, P.D. (2015). Principles of GNSS, Inertial, and Multisensor Integrated Navigation Systems, National Defense Industry Press. [2nd ed.].","DOI":"10.1109\/MAES.2014.14110"},{"key":"ref_29","unstructured":"Qin, Y.Y., Zhang, H.Y., and Wang, S.H. (2015). Kalman Filter and Integrated Navigation Principle, Northwestern Polytechnical University Press. [3nd ed.]."},{"key":"ref_30","unstructured":"(2020, July 12). NOVATEL.SPAN on OEM6 User Manual [EB\/OL] (2017-02-22). Available online: https:\/\/novatel.com\/support\/support-materials\/manual."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Leick, A., Rapoport, L., and Tatarnikov, D. (2015). GPS Satellite Surveying, John Wiley & Sons, Inc.. [4th ed.].","DOI":"10.1002\/9781119018612"},{"key":"ref_32","first-page":"276","article-title":"Analysis of BDS\/GPS Integrated Kinematic Difference Positioning Algorithm in Multi- Occlusion Environment","volume":"38","author":"Wang","year":"2018","journal-title":"J. Geod. Geodyn."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1007\/BF00863419","article-title":"The least-squares ambiguity decorrelation adjustment: A method for fast GPS integer ambiguity estimation","volume":"70","author":"Teunissen","year":"1995","journal-title":"J. Geod."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Titterton, D., and Weston, J. (2004). Strapdown Inertial Navigation Technology, Institution of Engineering and Technology. [2nd ed.].","DOI":"10.1049\/PBRA017E"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/2\/620\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:12:09Z","timestamp":1760159529000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/2\/620"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,17]]},"references-count":34,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["s21020620"],"URL":"https:\/\/doi.org\/10.3390\/s21020620","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,17]]}}}