Asian Journal of Engineering and Technology (ISSN: 2321 – 2462) Volume 8 – Issue 3, October 2020 Asian Online Journals (www.ajouronline.com) 63 Performance Evaluation of Low-Cost and Real-Time Multi- GNSS Advanced Demonstration Tool for Orbit and Clock Analysis-Precise Point Positioning (MADOCA-PPP) Receiver Systems Ellarizza Fredeluces 1* , Arthur Rey Fabian Lagura 1 , Rosalie Reyes 1 , Nobuaki Kubo 2 1 Department of Geodetic Engineering, University of the Philipines Diliman, Quezon City, Philippines 2 Tokyo University Marine Science and Technology Tokyo, Japan * Corresponding author’s email: etfredeluces [AT] up.edu.ph ______________________________________________________________________________ ABSTRACT— With Multi-GNSS Advanced Demonstration Tool for Orbit and Clock Analysis (MADOCA), a software estimator of precise satellite information, by JAXA, u-blox C099 ZED-F9P and MSJ-3008-GM4-QZS using MADOCA-PPP can be exploited in GNSS applications that require sub-decimeter accuracy without being costly. To evaluate their performance, convergence time and accuracy of solutions are compared to Trimble NetR9, a survey-grade receiver. Post-processed PPP solutions of ZED-F9P were computed using RTKLIB and real-time PPP was provided by the MSJ-3008-GM4-QZS. Results showed ZED-F9P achieved an RMS of 5.28 cm, 2.89 cm, and 9.55 cm in East, North, and Up directions. This means ZED-F9P can be used in applications requiring below 10 cm accuracy even without base station. MSJ-3008-GM4-QZS obtained an RMS of 10.45 cm, 6.27 cm, and 27.56 cm in the same directions. Unlike ZED-F9P, it achieved above 10 cm accuracy in North and Up directions which is due to large errors from cycle slips and jumps in observations. Interestingly, no fixed solutions were achieved between the 20:00 to 21:00 UTC period, although said receiver was able to receive corrections. However, if the observations after 20:00 UTC were removed, the MSJ-3008-GM4-QZS improved to 7.17 cm, 3.58 cm, and 22.32 cm in the same directions. Keywords— MADOCA-PPP, GNSS, RTKLIB ______________________________________________________________________________ 1. INTRODUCTION The Quasi-Zenith Satellite System (QZSS) is a regional satellite positioning and timing system that mainly focuses on Japan and covers neighboring countries in Asia. QZSS navigation signals are designed to be similar with GPS; thus, their compatibility and interoperability with each other. These are L1-C/A, L1C, L2C, and L5 signals. It also has an augmentation signal, namely, L1-SAIF (Sub-meter class Augmentation with Integrity Function), that operates with satellite-based augmentation system (SBAS) through wide-area differential GPS (WDGPS) [1-3]. By providing GNSS interoperable and augmentation signals from its satellites placed in an inclined geostationary and quasi-zenith orbit, QZSS enables users in the region to have fair and consistent positioning even in urban and mountainous areas where signals are most likely to be hampered [4-7]. QZSS also broadcasts L-Band Experimental (LEX) signal. It has the same frequency as that of the Galileo E6 signal and delivers correction which includes precise satellite orbit and clock information, user-range accuracy (URA), and GNSS code and phase biases [2,8]. The LEX signal also includes a satellite message calculated by Multi-GNSS Advanced Demonstration Tool for Orbit and Clock Analysis (MADOCA). It is a software, developed by JAXA, that calculates precise satellite orbit and clock bias of present GNSS systems by utilizing the observation from GNSS monitoring stations distributed around the world [9]. MADOCA-LEX’s precise point positioning (PPP) performance has been evaluated in different countries such as Australia [10], New Zealand [11], Philippines [12], and Vietnam [13], and tested in different precise point positioning application such as robotic [14], transportation [12], and precise farming [15], In these studies, utilization of said technology had been exploited. The demand for low-cost receivers that can achieve high precision and accuracy continues to rise. The achieved accuracy of said receivers are now comparable with survey-grade receivers albeit with limitations. Some PPP and GNSS studies have already tested single-frequency [12, 16-17], dual-frequency [18], and triple-frequency [19] low-cost receivers that usually utilizes the GPS system and their results showed encouraging results. In this study, MADOCA-LEX was tested in a low-cost receiver, u-blox C099 ZED-F9P, and compared to the