Calculated Distance Error Performances According to Actual GPS Measurements in Relay Type GPS

In recent years, Global Positioning System (GPS) has been used widely. However, it is very difficult to receive GPS signals directly from GPS satellites in urban areas because many tall buildings block GPS signals. To solve this problem, relay type GPS has been proposed. In the relay type GPS, it is possible to calculate the target GPS receiver's position assisted by the many mobile terminals around it (we call them G-MTs), which transmit their own positions via the same GPS signal format. As far, the performances of the proposed relay type GPS have been evaluated by computer simulations on the conditions of the typical building models simulating urban areas. In this paper, we first measure the calculated distance errors of the G-MTs by using an actual GPS receiver in the Shinjuku area, metropolitan Tokyo. Next, computer simulations obtain the CCDF (Complementary Cumulative Distribution Function) of the calculated distance error of the target GPS receiver by using the measured GPS positioning results with the Shinjuku area models. Compared with the conventional GPS, the calculated distance error of the target GPS receiver is reduced by 95.23 m by using relay type GPS in the Shinjuku area.