PURPOSE: To prevent lock-off due to an acceleration upon launching and miniaturize a device.

CONSTITUTION: When a sudden acceleration is generated upon launching, the output of an integrator 3, integrating the output of a rate sensor 2, is selected as the commanding value of feedback by a loop switching device 4 and feedback is applied so that the output of the integrator 3 becomes zero. According to this method, a gimbals can be returned to an initial angle even when the oscillation of the gimbals due to mass unbalance thereof upon launching is generated and a target is lost from the field of sight of a target camera unit. When the acceleration of launching is set and flight is shifted to stationary flight, the loop switching device 4 is switched so as to select the output of an error angle sensor 1 as the commanding value of feedback whereby the tracking of the target can be effected.