| 摘要 |
PURPOSE:To simplify the construction, by performing a computation based on information on position and time from different artificial satellites received with receiving circuits in the number less by one than the number of unknowns in the position measuring computation and altitude information at observing points with the known altitude memorized in an arithmetic unit. CONSTITUTION:A CPU8 calculates the elevation angle of artificial satellites using orbit data or the like taken in and selects a PN signal PNS alloted to the satellite with the elevation angle of over 5 deg. to assign it to a PN signal generation circuit 7 of channel data receiving circuits DTR1-DTR3 while it calculates a Doppler shift of the satellites and sends a control signal to a Doppler shift locking VCO10 to lock by controlling. Moreover, when it is judged that the receiving circuits DTR are all locked, positional information of the satellites involved is selected from the received data LDA while reception time information N is taken into the CPU8 from a timer 16 to determine the position of the observing points in combination with altitude information from an altitude information memory 8a. |
