Abstract
Low-latency high-rate (\(>\)1 Hz) precise real-time kinematic (RTK) can be applied in high-speed scenarios such as aircraft automatic landing, precise agriculture and intelligent vehicle. The classic synchronous RTK (SRTK) precise differential GNSS (DGNSS) positioning technology, however, is not able to obtain a low-latency high-rate output for the rover receiver because of long data link transmission time delays (DLTTD) from the reference receiver. To overcome the long DLTTD, this paper proposes an asynchronous real-time kinematic (ARTK) method using asynchronous observations from two receivers. The asynchronous observation model (AOM) is developed based on undifferenced carrier phase observation equations of the two receivers at different epochs with short baseline. The ephemeris error and atmosphere delay are the possible main error sources on positioning accuracy in this model, and they are analyzed theoretically. In a short DLTTD and during a period of quiet ionosphere activity, the main error sources decreasing positioning accuracy are satellite orbital errors: the “inverted ephemeris error” and the integration of satellite velocity error which increase linearly along with DLTTD. The cycle slip of asynchronous double-differencing carrier phase is detected by TurboEdit method and repaired by the additional ambiguity parameter method. The AOM can deal with synchronous observation model (SOM) and achieve precise positioning solution with synchronous observations as well, since the SOM is only a specific case of AOM. The proposed method not only can reduce the cost of data collection and transmission, but can also support the mobile phone network data link transfer mode for the data of the reference receiver. This method can avoid data synchronizing process besides ambiguity initialization step, which is very convenient for real-time navigation of vehicles. The static and kinematic experiment results show that this method achieves 20 Hz or even higher rate output in real time. The ARTK positioning accuracy is better and more robust than the combination of phase difference over time (PDOT) and SRTK method at a high rate. The ARTK positioning accuracy is equivalent to SRTK solution when the DLTTD is 0.5 s, and centimeter level accuracy can be achieved even when DLTTD is 15 s.
Similar content being viewed by others
References
Blewitt G (1990) An automatic editing algorithm for GPS data. Geophys Res Lett 17(3):199–202
Chen L, Jiao W, Huang X, Geng C, Ai L, Lu L, Hu Z (2013) Study on signal-in-space errors calculation method and statistical characterization of beidou navigation satellite system. In: China satellite navigation conference (CSNC) 2013 Proceedings, vol 243. Springer, Berlin, pp 423–434
Chen X, Han S, Rizos C, Chai Goh P (2000) Improving real time positioning efficiency using the singapore integrated multiple reference station network (SIMRSN). In: Proceedings of ION GPS 2000, Salt Lake City, USA, pp 9–16
Comstock SJ (2006) Development of a low-latency, high data rate, differential GPS relative positioning system for UAV formation flight control. Master’s thesis, Air Force Institute of Technology
Dogra S, Wright J, Hansen J (2001) Sea-based JPALS relative navigation algorithm development. In: Proceedings of ION GNSS 2005, Long Beach, USA, pp 2871–2881
Dow J, Neilan R, Rizos C (2009) The international GNSS service in a changing landscape of global navigation satellite systems. J Geod 83(7):689–689
Edwards S, Cross P, Barnes J, Betaille D (1999) A methodology for benchmarking real time kinematic GPS. Surv Rev 35(273):163–174
Euler HJ, Landau H (1992) Fast GPS ambiguity resolution on-the-fly for real-time applications. In: Proceedings of 6th international geodetic symposium on satellite positioning, pp 650–659
Gao Y, Li Z, McLellan J (1997) Carrier phase based regional area differential GPS for decimeter-level positioning and navigation. In: Proceedings of ION GPS 1997, Kansas City, USA, pp 1305–1313
Gao Y, Liu Z, Liu Z (2002) Internet-based real-time kinematic positioning. GPS Solut 5(3):61–69
Griffiths J, Ray J (2009) On the precision and accuracy of IGS orbits. J Geod 83(3–4):277–287
Han S, Rizos C (1996) GPS network design and error mitigation for real-time continuous array monitoring systems. In: Proceedings of of ION GPS 1996, Kansas City, USA, pp 1827–1836
Hatch R, Sharpe R, Yang Y (2007) GPS navigation using successive differences of carrier-phase measurements. US Patent 7,212,155 B2
Hauschild A, Montenbruck O, Steigenberger P (2013) Short-term analysis of GNSS clocks. GPS solut 17(3):295–307
Hofmann-Wellenhof B, Lichtenegger H, Collins J (2001) Global positioning system: theory and practice, 5th edn. Springer, Berlin
Hu Z, Chen G, Zhang Q, Guo J, Su X, Li X, Zhao Q, Liu J (2013) An initial evaluation about BDS navigation message accuracy. China satellite navigation conference (CSNC) 2013 Proceedings. Springer, Berlin, pp 479–491
Lawrence DG (1999) Reference carrier phase prediction for kinematic GPS. US Patent 5,903,236
Michaud S, Santerre R (2001) Time-relative positioning with a single civil GPS receiver. GPS Solut 5(2):71–77
Mohamed A, Schwarz K (1998) A simple and economical algorithm for GPS ambiguity resolution on the fly using a whitening filter. Navig: J Inst Navig 45:221–250
Montenbruck O, Steigenberger P, Hauschild A (2014) Broadcast versus precise ephemerides: a multi-GNSS perspective. GPS Solut 19(2):321–333. doi:10.1007/s10291-014-0390-8
Newby S, Corcoran W (1995) What’s new from NovAtel. In: Proceedings of ION GPS 1995, Palm Springs, USA, pp 133–140
Raquet J (1998) Development of a method for kinematic GPS carrier-phase ambiguity resolution using multiple reference receivers. Dissertation, University of Calgary
Remondi BW (1985) Performing centimeter-level surveys in seconds with GPS carrier phase: initial results. Navigation 32(4):386–400
Sjöberg LE (1999) Unbiased vs biased estimation of GPS phase ambiguities from dual-frequency code and phase observables. J Geod 73(3):118–124
Steigenberger P, Hugentobler U, Hauschild A, Montenbruck O (2013) Orbit and clock analysis of Compass GEO and IGSO satellites. J Geod 87(6):515–525
Teunissen P (1993) Least-squares estimation of the integer GPS ambiguities. In: Invited lecture, section IV “theory and methodology”, at the general meeting of the International Association of Geodesy, Beijing, China, pp 1–16
Teunissen P (1995) The least-squares ambiguity decorrelation adjustment: a method for fast GPS integer ambiguity estimation. J Geod 70(1–2):65–82
Teunissen P (1997) A canonical theory for short GPS baselines. Part I: the baseline precision. J Geod 71(6):320–336
Teunissen P, Kleusberg A (1998) GPS for geodesy, 2nd edn. Springer, Berlin
Wang H, Ou J, Yuan Y (2011) Strategy of data processing for GPS rover and reference receivers using different sampling rates. Geosci Remote Sens IEEE Trans 49(3):1144–1149
Wanninger L (1999) The performance of virtual reference stations in active geodetic GPS-networks under solar maximum conditions. In: Proceedings of ION GPS 1999, Nashville, USA, pp 1419–1427
Wübbena G, Bagge A, Seeber G, Boeder V, Hankemeier P (1996) Reducing distance dependent errors for real-time precise DGPS applications by establishing reference station networks. In: Proceedings of ION GPS 1996, Kansas City, USA, pp 1845–1852
Xu G (2007) GPS: theory, algorithm and application, 2nd edn. Springer, Berlin
Zhang J, Zhang K, Grenfell R, Deakin R (2006) GPS satellite velocity and acceleration determination using the broadcast ephemeris. J Navig 59(02):293–305
Zhodzishsky M, Vorobiev M, Khvalkov A, Ashjaee J (1998) Real-time kinematic (RTK) processing for dual-frequency GPS/GLONASS. In: Proceedings of ION GPS 1998, Nashville, USA, pp 1325–1331
Acknowledgments
We gratefully acknowledge engineer Meng Liansheng for the experimental data provided. We also thank the other colleagues of our laboratory for supporting this research.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liang, Z., Hanfeng, L., Dingjie, W. et al. Asynchronous RTK precise DGNSS positioning method for deriving a low-latency high-rate output. J Geod 89, 641–653 (2015). https://doi.org/10.1007/s00190-015-0803-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00190-015-0803-7