A magnetic sensor system for monitoring a motor, comprising: at least one bias magnet configured to produce a magnetic field; a first magnetic sensor configured to detect changes to the magnetic field induced by a first magnetic target arranged to be rotated by a motor shaft operably connected to the rotor of the motor, the first magnetic target having a first number of features for inducing a change in the magnetic field; a second magnetic sensor configured to detect changes to the magnetic field induced by a second magnetic target arranged to be rotated by the motor shaft, the second magnetic target having a second number of features for inducing a change in the magnetic field, wherein the first and second magnetic targets (3, 4) are configured such that a difference between the first number of features and the second number of features corresponds to a number of pole pairs of the motor to be monitored; and a processing circuit in communication with the first magnetic sensor and the second magnetic sensor, the processing circuit configured to: detect a difference between measurements obtained by the first magnetic sensor and the second magnetic sensor; and generate initial shaft rotation angle information associated with a starting position of the motor shaft based on the detected differences between measurements obtained from the first magnetic sensor and the second magnetic sensor; and generate, from the starting position associated with the initial rotation angle information, subsequent shaft rotation angle information by counting the first number of features of the first magnetic target or the second number of features of the second magnetic target based on further measurements obtained from the first magnetic sensor or the second magnetic sensor respectively. at least one bias magnet configured to produce a magnetic field; a first magnetic sensor configured to detect changes to the magnetic field induced by a first magnetic target arranged to be rotated by a motor shaft operably connected to the rotor of the motor, the first magnetic target having a first number of features for inducing a change in the magnetic field; a second magnetic sensor configured to detect changes to the magnetic field induced by a second magnetic target arranged to be rotated by the motor shaft, the second magnetic target having a second number of features for inducing a change in the magnetic field, wherein the first and second magnetic targets (3, 4) are configured such that a difference between the first number of features and the second number of features corresponds to a number of pole pairs of the motor to be monitored; and a processing circuit in communication with the first magnetic sensor and the second magnetic sensor, the processing circuit configured to: detect a difference between measurements obtained by the first magnetic sensor and the second magnetic sensor; and generate initial shaft rotation angle information associated with a starting position of the motor shaft based on the detected differences between measurements obtained from the first magnetic sensor and the second magnetic sensor; and generate, from the starting position associated with the initial rotation angle information, subsequent shaft rotation angle information by counting the first number of features of the first magnetic target or the second number of features of the second magnetic target based on further measurements obtained from the first magnetic sensor or the second magnetic sensor respectively. detect a difference between measurements obtained by the first magnetic sensor and the second magnetic sensor; and generate initial shaft rotation angle information associated with a starting position of the motor shaft based on the detected differences between measurements obtained from the first magnetic sensor and the second magnetic sensor; and generate, from the starting position associated with the initial rotation angle information, subsequent shaft rotation angle information by counting the first number of features of the first magnetic target or the second number of features of the second magnetic target based on further measurements obtained from the first magnetic sensor or the second magnetic sensor respectively.