At first, {TAIL ~ a plurality} of road side data exchange devices are provided separately on {HEAD ~ road sides} to exchange satellite calibration data to form a road side data exchange net 
At first , { TAIL ~ a plurality } of road side data exchange devices are provided separately on { HEAD ~ road sides } to exchange satellite calibration data to form a road side data exchange net
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH