## 5 Conclusions  
Improving kinematic PPP positioning accuracy needs further research efforts, given its significance in serving various strategic applications aligned with sustainability goals and the broader vision of KSA and global requirements. GNSS-PPP is a promising cost-effective technique for robot localization. The study proves the effect of the number of working satellites offered by each system over the acquired positioning accuracy. GPS systems currently provide a greater number of working satellites (31) compared with the GLONASS system (22). GPS provides better kinematic PPP accuracy over GLONASS. The study presents ideal kinematic PPP solutions using dual-frequency observations as well as cost-effective kinematic PPP solutions using single-frequency observations. GPS dual frequency offers accuracies of (0.03 m, 0.07 m, and 0.08 m) for latitude, longitude, and height, respectively, with 3D position accuracy of 11 cm, while GPS single frequency offers accuracies of (0.06 m, 0.13 m, and 0.16 m) for latitude, longitude, and height, respectively, with 3D position accuracy of 21 cm. GLONASS dual frequency offers accuracies of (0.04 m, 0.14 m, and 0.12 m) for latitude, longitude, and height, respectively, with 3D position accuracy of 19 cm, while GLONASS single frequency offers accuracies of (0.13 m, 0.31 m, and 0.26 m) for latitude, longitude, and height, respectively, with 3D position accuracy of 43 cm. Mixed (GPS/GLONASS) dual frequency offers accuracies of (0.02 m, 0.07 m, and 0.06 m) for latitude, longitude, and height, respectively, with 3D position accuracy of 9 cm, while mixed single frequency offers accuracies of (0.04 m, 0.07 m, and 0.10 m) for latitude, longitude, and height, respectively, with 3D position accuracy of 13 cm. The paper's findings provide reliable alternative solutions for robot localization, considering the availability of satellites in outdoor environments, the economic aspect of using single or dual frequency, and the required level of position accuracy. Further research is needed to enhance kinematic PPP accuracy by incorporating GALILEO and BeiDou alongside GPS and GLONASS in multi-GNSS observations. Using the four global systems will ensure a greater number of visible satellites, better PDOP, and an increased amount of collected observations which will reflect better achieved kinematic PPP accuracy that meets the desired accuracies for a robot localization system. The achieved kinematic PPP accuracies will empower the advancement of real-time robot localization applications. GNSS technology offers a low-cost alternative for robots operating outdoors.  
All authors contributed to the study's conception and design. Material preparation, data collection, and analysis were performed by [PERSON] The first draft of the manuscript was written by [PERSON] and [PERSON]. All authors discussed and approved the final manuscript. All authors have read and agreed to the published version of the manuscript.  
This Project was funded by King Saud University through Researchers Supporting Project number (RSPD2023R685), King Saud University, Riyadh, Saudi Arabia.  
Not applicable.  
The authors acknowledge \"Researchers Supporting Project number (RSPD2023R685), King Saud University, Riyadh, Saudi Arabia\".