unillustrated built in the telescope a this distance measuring device is the general one built in a camera etc and actualized by making use of a triangle measuring method and a phase difference detection method the memory of the arithmetic control unit 34a is stored with a result of the measurement further the arithmetic control unit 34a detects a bearing of a direction a s direction toward the target object s from the location a by using the bearing sensor 31a the memory of the arithmetic control unit 34a is also stored with this bearing with the processes described above in the arithmetic control unit 34a there are set coordinate axes specifically the y axis coincident with the a s direction and the x axis orthogonal to the y axis and passing through the location a as shown in fig4 and 5 note that the coordinate of the target object s is expressed by s o l on the other hand when the coordinate setting switch 42b of the telescope b is pushed down the same processes are to be performed in the telescope b and the coordinate axes as shown in fig4 and 5 are set in the arithmetic control unit 34b that is the arithmetic control unit 34a and the arithmetic control unit 34b are hereafter to execute the processes based on the same coordinate axes next it is assumed that the observer.