GB843411A - Improvements in or relating to radio aids to navigation - Google Patents

Abstract

843,411. Radio navigation. COMPAGNIE GENERAL DE TELEGRAPHIE SANS FIL. Dec. 13, 1957 [Dec. 20, 1956], No. 38795/57. Class 40(7). Relates to means which utilize a hyperbolic radio navigation system as described in Specification 620,479 and a receiver phasemeter as described in Specification 620,480 and which indicate to a navigator that a predetermined course is being held. If the vehicle's speed is known the mean rate of change of phase across a portion of the hyperbolic set produced by two transmitters is calculated and the indicating phasemeter's field is held stationary either by mechanical counter-rotation of its armature, Figs. 2-5 (not shown), or electrically by a counter-rotating field from auxiliary coils on the armature, Fig. 6 (not shown). In another embodiment a rotatable disc with an index segment and coaxial with the phasemeter's dial is driven by an adjustable-speed motor, the navigator checking that the desired course is being followed by reference to a steering compass and adjusting the motor speed until the phasemeter pointer and the disc index rotate in synchronism continuation of which shows correct steering, Fig. 7 (not shown). In a further embodiment two hyperbolic sets are used, Fig. 8 (not shown): disc 83 is rigidly mounted on the shaft of phasemeter 81 and a disc 84, coupled to disc 83 by a transmission ratio calculated from the hyperbolic geometry and desired course, rotates independently of the shaft of second phasemeter 82. Steering is controlled so that pointer 89 remains in line with index 88 after their correspondence has been initiated by running on the desired course ascertained from the steering compass. The transmission between discs 83 and 84 may be effected by a selsyn system, Fig. 10 (not shown).