## 1 Introduction
So, extra research effort is needed to improve the accuracy of kinematic PPP based on factors such as used systems (single or mixed), observation type (single or dual frequency, and satellite geometry. [PERSON] et al. explored the application of PPP solutions in marine applications, reporting a decimeter-level accuracy in ellipsoidal height comparisons [49]. Similarly, the PPP solution for maritime applications was evaluated by [PERSON] et al. [50]. At Halic Bay, Istanbul, Turkey, in August 2009, a test was conducted. Leica Geo-Office 8.0 software was used to acquire the reference differential GNSS (DGNSS) solution, and the Canadian Spatial Reference System (CSRS) PPP online service was used to generate the kinematic PPP solution. The kinematic PPP solution provided a position accuracy of 15 cm and height accuracy of up to 25 cm, compared to the DGNSS solution. [PERSON] et al. investigated the accuracy of the kinematic PPP solution using Bernese GNSS Version 5.2 software for hydrographic applications [51]. Their PPP solutions were compared with the double-difference solution from Bernese software. The research involved two kinematic trajectories along the Rhine River in Duisburg, Germany. In the first kinematic trajectory, the kinematic PPP solution exhibited standard deviations of 6 cm in the east, 2.1 cm in the north, and 6.8 cm in height. The second trajectory, which started with 40 min of quasi-static observation time (non-moving vessel), achieves a more precise solution. The standard deviation values of all measurements are 1.7 cm in the east, 2.6 cm in the north, and 4.9 cm in height. [PERSON] et al. assessed the effectiveness of GNSS kinematic PPP and PPP-Inter Ambiguity Resolution (IAR) techniques in monitoring the structural health of bridges [52]. This investigation utilized regional network stations located in China. The findings indicated that both GNSS kinematic PPP and PPP-IAR approaches can achieve precise structural health monitoring of bridges, while PPP-IAR is anticipated to exhibit quicker convergence and greater real-time monitoring accuracy. [PERSON] et al. presented the possibility of using the PPP-Ambiguity Resolution (AR) method in the precise positioning of the aircraft [53]. GPS data were gathered during two distinct photogrammetric flights conducted within a project aimed at creating a digital photogrammetric map of the Izmir region in Turkey. Accuracies of 2.75 cm, 3.0 cm, and 6.0 cm were achieved for north, east, and height, respectively. Recently, there has been a notable trend towards increased accessibility and affordability of single and dual frequencies, along with the availability of GPS and GLONASS satellites. This development holds great promise for facilitating a more flexible integration of mobile robot localization in industrial applications through online IoT systems. However, to ensure that these advancements align with the precision accuracy required by mobile robots, further investigations and research are necessary. These studies will help determine the suitability of these technologies for meeting the specific requirements of outdoor mobile robots in the context of Industry 4.0 [5; 40]. This paper addresses the accuracy issue of robot localization systems using the GNSS-PPP kinematic technique. A GPS, GLONASS, and multi-GNSS with single- and dual-frequency observations-based kinematic PPP solutions are proposed. The six solutions aim to provide robot designers with balanced alternatives between accuracy and cost. The rest of the paper is organized as follows: In Section 2, the scope of the study is presented. The results of the six studied solutions are shown and evaluated in Section 3, followed by Section 4. The conclusion is presented at the end.