Global Attitude Heading Reference System (GAHRS) is an avionics subsystem of JF-17 aircraft which provides high performance measurement of aircraft attitude by using highly reliable optical fiber gyroscopes and accelerometers. GAHRS is a backup system of Inertial Navigation System (INS). In case of INS failure, it provides roll, pitch and heading information to Weapon Mission Management Computer (WMMC) using RS 422 interface.