Abstract: Apparatus for calibrating the magnetic azimuth detector of a gyromagnetic compass system utilizes the system gyro to provide a plurality of heading references to which the corresponding heading outputs of the magnetic azimuth detector are compared to provide cardinal and inter-cardinal error data from which one cycle and two cycle compensation coefficients are derived. The gyro heading references are compensated for gyro drift in accordance with the proportionate drift occurring with respect to a particular heading reference with respect to the total gyro drift occurring during the calibration procedure in accordance with coincident initial and final heading reference points. The calibration is effected by orienting the aircraft in which the gyromagnetic compass system is installed at the plurality of headings to provide the gyro reference and magnetic azimuth detector data.

Abstract: A toroidal accelerometer having a housing containing an electrolytic fluid at least partially immersing a plurality of electrodes disposed within said housing and an amplifier circuit coupled to the electrodes for providing an output signal indicative of the angle of tilt or rotation of the accelerometer about a reference axis. The accelerometer further includes a circuit connected across the amplifier to prevent polarization of the electrolytic fluid by detecting any d.c. voltage developed by the amplifier circuit and, in response thereto, coupling a compensating signal generated thereby to the amplifier until the d.c. voltage is substantially eliminated.

Abstract: A flux valve compass heading repeater system is provided with a compensating system which, when connected to a three-legged flux valve, provides fully compensated, three-wire output signals of the synchro data transmitter type for direct use in apparatus requiring precision three-wire heading data. The compensating system includes control circuits for generating sine and cosine components of magnetic heading and for compensating them for typical compass errors such as those induced by changes in operating latitude and two cycle and index errors. Latitude compensation is accomplished by a novel proportional automatic gain control; two cycle cardinal heading error compensation is accomplished by a compensation circuit having only a single manual control, while index error compensation is similarly accomplished by a compensation circuit requiring only a single manual control.

Abstract: A flux valve compass heading repeater system is provided with a compensating system which, when connected to a three-legged flux valve, provides fully compensated, three-wire output signals of the synchro data transmitter type for direct use in apparatus requiring precision three-wire heading data. The compensating system includes control circuits for generating sine and cosine components of magnetic heading and for compensating them for typical compass errors such as those induced by changes in operating latitude and two cycle and index errors. Latitude compensation is accomplished by a novel proportional automatic gain control; two cycle cardinal heading error compensation is accomplished by a compensation circuit having only a single manual control, while index error compensation is similarly accomplished by a compensation circuit requiring only a single manual control.

Abstract: A flux valve compass heading repeater system is provided with a compensating system which, when connected to a three-legged flux valve, provides fully compensated, three-wire output signals of the synchro data transmitter type for direct use in apparatus requiring precision three-wire heading data. The compensating system includes control circuits for generating sine and cosine components of magnetic heading and for compensating them for typical compass errors such as those induced by changes in operating latitude and two cycle and index errors. Latitude compensation is accomplished by a novel proportional automatic gain control; two cycle cardinal heading error compensation is accomplished by a compensation circuit having only a single manual control, while index error compensation is similarly accomplished by a compensation circuit requiring only a single manual control.

Abstract: A gyroscopic stable reference system for navigable craft is provided that provides heading, pitch, and roll outputs substantially free of errors at all aircraft attitudes.