O-Jong Kim

The study of error sources for MOSAIC/DME system: A single station based positioning system for APNT

This paper presents a new kind of navigation system, a single station based 3-dimensional positioning system, named MOSAIC/DME. Particularly, its possible error sources, such as tropospheric delay, antenna misalignment and multipath are studied and applied to simulations for understanding and verification of this system. For tropospheric and multipath simulations, WAAS tropospheric model and ray-tracing approach are applied respectively. The results present that MOSAIC/DME system is vulnerable to small errors in signal, because of the bad geometry using only a single station for positioning. But this system also has its own advantage to treat those errors.

Performance Verification of Psudolite-based Augmentation System Using RF signal logger and broadcaster

Wide Area Differential GNSS(WA-DGNSS) was developed in order to improve the accuracy and integrity performance of GNSS. In this paper, overall structure of Pseudolite-Based Augmentation System(PBAS) and experimental methods which enables the post-processing test with commercial receiver will be described. For generating augmenting message, GPS measurement collected from five NDGPS reference stations were processed by reference station S/W and master station S/W. The accuracy of augmenting message was tested by comparing SP3, IONEX data. In the test, RF signal of user was collected and correction data were generated. After that, RF signal was broadcasted with pseudolite signal. Test was conducted using three commercial receiver and the performance was compared with MSAS and standalone user. From the position output of each receiver, it was shown that improved position was obtained by applying augmenting message.