## 1 Introduction  
Since 1994, the International Global Positioning System (GPS) Service (IGS) organization has provided precise GPS satellite orbit and clock products, enabling the development of a novel positioning methodology known as precise point positioning (PPP) [1; 2]. Based on the processing of un-differenced pseudo-range and carrier phase observations from a single GPS receiver, positioning solutions with accuracies in the centimetre to decimetre range can be attained globally. Precise point positioning (PPP) is one of the most popular techniques for carrier phase-based precise positioning. PPP sometimes makes use of ionosphere-free linear combination to decrease the effect of ionospheric delay. However, it is not based on integer coefficients, and currently, the state information does not preserve the integer nature of ambiguities. Consequently, PPP cannot adequately resolve ambiguities and access the full range of global navigation satellite system (GNSS) carrier-phase accuracies [3; 4]. Moreover, long observation times are required for convergence [5]. Many researchers have attempted to improve the performance of PPP by improving the precision of the satellite orbit and clock products [2; 6] and speeding up the ambiguity-resolution process [7; 8; 9]. Satellite positioning availability and integrity can be significantly improved by using multiple GNSSs so that more satellites will be available [10; 11; 12]. [PERSON] et al. tested the accuracy of multiple-constellation PPP and discussed the main challenges associated with this process [13; 14]. The use of multiple GNSSs is expected to enhance the capability of PPP by improving the positioning accuracy and reducing the convergence time. Since the International Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) Experiment (IGEX-98) and the follow-on GLONASS Service Pilot Project (IGLOS), the precise GLONASS orbit and clock data have become available. A combined GPS and GLONASS PPP program was developed by [PERSON] and [PERSON] in 2007 [15]. Research on GPS- and GLONASS-based PPP has been conducted continuously since then, and the results have demonstrated that the positioning precision and convergence speed were improved by the dual-constellation signal [16; 17; 18]. The BeiDou Navigation Satellite System (BDS) is a global satellite navigation system that was independently developed, deployed, and operated by China and remains in operation today [19]. The BDS consists of two separate satellite constellations: a limited test system that has been operating since 2000 and a full-scale global navigation system that is currently under construction. Table 1 lists the satellites in the BDS constellation at or before December 2012. In total, 23 satellites have been involved, 3 of which are no longer operational. Twenty BDS satellites are currently in operation: 6 in geostationary orbits (GEOs), 8 in 55-degree inclined geosynchronous orbits (IGSOs) and 6 in medium Earth orbits (MEOs). The full constellation is planned to eventually comprise 35 satellites. According to its overall planning schedule, the BDS will have global coverage by 2020 [17]. Researchers [20; 21; 22] have also developed a model that combines GPS- and BDS-based PPP. The test results revealed that the combined GPS- and BDS-based PPP can decrease the convergence time and improve the positioning precision. Because of improvements in the precision of the BDS and Galileo satellite orbit and clock products, quad-constellation (GPS, BDS, GLONASS and Galileo) PPP has become possible [23]. [PERSON] et al. and [PERSON] et al. [24; 25] improved the performance of quad-constellation PPP. However, most of the research mentioned above addressed PPP for a statistic object. In this work, the performance of PPP for a kinematic user is addressed. In this study, we assessed the performance of multi-constellation kinematic PPP in terms of the positioning accuracy and convergence time using the measurements collected from receivers on a vehicle.