International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
6.2 SPAC Demonstrated Experiment in Japan 
SPAC(Satellite Positioning Research and Application 
Center) activities according to description of the homepage are 
expand the utilization of geospatial information within 
industrial and economic sectors including linkage with 
companies and associations related to satellite positioning, the 
promotion of research and study related to the use of 
next-generation satellite positioning, such as the United State's 
GPS, Europe's Galileo project and Japan's Quasi-Zenith 
Satellite System, as well as diffusing the results of such 
activities, and contributing to the activation and 
commercialization of business activities related to geospatial 
information. Especially, Quasi-Zenith Satellite System(QZSS) 
called "MICHIBIKI" launched in 9th September 2010 by 
JAXA has been demonstrating by many companies and 
universities. KIT and many surveying companies in Hokuriku 
District participated SPAC demonstration experiments since 
early 2010. 
QZSS has 2 types signal. One is similar to GPS and another is 
original signal of QZSS. QZSS has two kinds of original 
signals, one is L1-SAIF called sub-meter signal and another is 
LEX signal called centimeters signal. Our laboratory received 
LEX signal which is able to use corrected information using an 
electronic reference station in Japan. 
Figure 8 is LEX signal receiving apparatus on the automobile 
for move experiments. 
  
Figure 8. LEX signal receiving apparatus 
6.3 Demonstrated Experiments Results 
6.3.1 Moving Observation 
Figure 9 shows a photograph under experiment using LEX 
signal receiving apparatus on the automobile with GPS receiver, 
right side antenna is receiving GPS signal and left side antenna 
is receiving LEX signal. On the experiments, received signal 
was GPS satellite only. QZSS has similar signal of GPS , 
however, the experiment receiving apparatus did not have the 
system to receive QZSS's GPS signal. 
Automobile ran in the campus, Kanazawa City, Nonoichi 
City and Hokuriku highway, the velocity of the car was 30 
km/h to 60 km/h in the city, and it was 80 km/h to 100 km/h on 
the highway. Run course of automobile has variety area which 
is tunnels , mountain area , flat area, city area and local area. 
Figure 9 shows automobile went into a tunnel and Figurel0 
shows locus of a car in the experimental areas including 
highway. Background map is fundamental spatial data of 
Geospatial Information Authority of Japan(GSI) and accuracy 
of fundamental spatial data is 1/2500. 
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Figure 9. Moving observation 
Symbol of a green dot shows GPS and LEX signal at every 
seconds, and red symbol is shown that was not able to receive a 
LEX signal. LEX signal is SHz(five data in every seconds). 
GPS signal has been received through almost all courses , 
however , LEX signal was not able to be received in some 
places. Especially, over 80km/h run on the highway, LEX was 
not able to receive(Graph in Figure 10). Other researcher in the 
Japan reported that more than 30km/h LEX signal not received , 
however, our experiments on the highway can receive at 
80km/h some places. It is new knowledge of MICHIBIKI 
LEX signal's activity. 
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Figure 10. Observation result on the fundamental geospatial 
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6.3.2 Fixed-Point Observation 
Figure 11 shows the condition of fixed-point observation of 
LEX signal. The fixed-point used the triangulation station in 
the Naoe area of Higashi of Kanazawa. Purpose of the 
  
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