SINS/BDS integrated navigation engineering algorithm under emission system

The invention relates to an SINS/BDS integrated navigation engineering algorithm under a transmitting system, which relates to the technical field of aircraft navigation, and comprises the following steps: calculating an integrated navigation system error equation which comprises a change rate equation of attitude error, a time derivative equation of speed error and a time derivative equation of position error; calculating a state equation of the integrated navigation system, and selecting a position error, a speed error, a platform error, gyroscopic drift and accelerometer drift as state variables; and calculating a measurement equation of the integrated navigation system, and filtering and correcting a calculation result by taking a difference value between the measured positions and speeds of the inertial measurement unit and the satellite as a filtered measurement value. According to the scheme, under the condition that a low-cost combined navigator is used, position and speed combination under a transmit