Integration of GNSS-PPP and IMU/SPEED Sensors in Urban Areas

JAXA has developed MADOCA product which is real-time precise orbit and clock information for a long time. The augmentation message of MADOCA has been provided on L6E signal of QZSS since December 6, 2017 freely. Currently, precise orbit and clock information of GPS/QZSS/GLONASS are provided. It is highly good time to use PPP service in Asia and Oceanian region. We have developed and evaluated the integration program using low-cost GNSS/IMU/SPEED sensors for several years and we already achieved 1-2 m level accuracy in horizontal in the normal urban areas. However, some applications require sub-meter level accuracy in the relatively open sky condition. In that case, we need RTK or PPP solutions capable of decimeter level accuracy. Therefore, we tried to couple our previous integration algorithm with PPP solutions. The merit of this service lies on that we don’t have to receive correction data via other radio communication devices. All we need is to just receive signals of QZSS. The motivation of this research is to investigate the integration of PPP and our previous integrated result using low-cost IMU/SPEED sensors. This paper will describe the PPP technology and the current performance. Then loosely coupled integration of PPP and our previous integrated result which means velocity information is discussed. The navigation performance of this integrated system was analyzed using road test dataset in expressway. The horizontal accuracy in the relatively open sky condition including some GNSS outages was stable and within several 10 cm.