Estimation and Mitigation of the Main Errors for Centimetre-level Compass RTK Solutions over Medium-Long Baselines

Abstract

Centimetre-level RTK solutions are mainly influenced by satellite orbit errors, ionospheric and tropospheric delays, and measurement noise (including multipath effects). Estimation and mitigation of the main errors for the CM-level Compass RTK solutions over medium-long baselines are investigated. Tests conducted for this research lead to the following conclusions: 1.For 100 km baselines, a 4 cm error in height component will be induced by a 10 m orbit error. For longer baselines, rapid precise ephemeris will be needed for CM-level accuracy RTK solutions.2.The residual ionospheric delay error can be eliminated using the optimal triple-frequency ionosphere-free linear combination with the coefficients of 2·6087, −0·5175 and −1·0912 respectively for observations on f1, f2 and f3 frequencies. This combination is optimal in terms of its noise level, e.g., the noise is only amplified three times. It can be used for high accuracy RTK positioning.3.The residual tropospheric delay can be resolved for the introduced relative zenith tropospheric delay (RZTD) parameters.It is shown that the RTK solutions estimated from the least squares (LS) with the RZTD parameters are worse than that without these parameters. For instance, the errors in the height components are amplified approximately three times, which may be caused by the strong correlation between the introduced RZTD parameters and the height components. However, considering the fact that the residual zenith tropospheric delays vary slowly with time and the variation can be assumed to follow a random walk process, the RTK solutions can be improved using the Kalman filter and a priori information for the RZTD parameters.

First combined COMPASS/BeiDou-2 and GPS positioning results in Australia. Part II: Single- and multiple-frequency single-baseline RTK positioning

“…Some BeiDou results can be found in the literature, where we have simulation results in Grelier et al (2007), Huang and Tsai (2008), Cao et al (2008), Chen et al (2009), Feng and Li (2010), Zhang et al (2010), Guo et al (2011), Yang et al (2011) and Qu et al (2012). Real data results were presented by Shi et al (2013), who evaluated BeiDou-only Single Point Positioning (SPP), relative code positioning and Real-TimeKinematic (RTK).…”

Precise Orbit Determination of BDS MEO Satellites Based on Satellite TT&C Stations

“…On the basis of triplefrequency combination model of BDS above, according to the selection criteria and constraint conditions of combination coefficients [14,17], considering the properties of (7) and ensuring the magnitude of error TC is of cm level, the combination coefficients and their other properties of some wide-lane (WL) and extra-wide-lane (EWL) of BDS triplefrequency combination are listed in Table 2. In order to realize precise orbit determination for BDS MEO satellites, if we choose the EWL of B2-B3 carrier combination in Table 2, (17) can be recovered as follows:…”

Long-range Single Baseline RTK GNSS Positioning for Land Cadastral Survey Mapping

“…It has been found that atmospheric bias affect more error in vertical component rather than in horizontal component which up to several decimeters in RTK GNSS positioning [20,21]. Fig.…”