Satellite tracking method for vehicle-mounted antenna system

A satellite tracking method for a mobile-mounted antenna system, in which a satellite tracking controller receives a signal through a satellite broadcasting receiver and a turning angle of a moving body provided by a gyroscope for the purpose of controlling an antenna orientation control driver and rotating the antenna mounted on the moving body,

• the satellite tracking method comprising:
• an initial mode for rotating the antenna depending on the turning angle of the moving body until a level voltage of a reception signal which is transmitted from a satellite with a system power on is larger than a fourth threshold voltage corresponding to a predetermined rainfall margin;
• a maximum value search mode for rotating the antenna depending on the turning angle of the moving body and a symmetric point of the reception signal level voltage with respect to the maximum reception signal level voltage so as to search for a voltage corresponding to the maximum reception signal level voltage, which is defined as a first threshold voltage, the maximum value search mode being accomplished when the reception signal level voltage is larger than the fourth threshold voltage;
• a normal tracking mode for controlling the orientation of the antenna depending on the turning angle of the moving body so as to maintain the reception signal level voltage to be larger than a second threshold voltage, the normal tracking mode accomplished when the reception signal level voltage is between the first threshold voltage and the second threshold voltage;
• an error correction mode for rotating the antenna in the left and right directions depending on the turning angle of the moving body, the initial mode, the maximum value search mode and the normal tracking mode according to whether the reception signal level voltage is between the second threshold voltage and a third threshold voltage, the error correction mode being performed when the reception signal level voltage is between the second threshold voltage and the third threshold voltage;
• a signal blocking mode for controlling the orientation of the antenna depending on the turning angle of the moving body until a time value in a timer is over a predetermined time, the signal blocking mode accomplished when the reception signal level voltage is smaller than the third threshold voltage, and the time value in the timer is not over a predetermined time
• a rainfall mode for controlling the orientation of the antenna depending on the turning angle of the moving body, until a time value in a timer exceeds a predetermined time the rainfall mode accomplished when the time value in the timer exceeds the predetermined time and the reception signal level voltage is between the fourth threshold voltage and the third threshold voltage even though the reception signal level voltage is in the same range as in the signal blocking mode,
• wherein the first threshold voltage is greater than the second threshold voltage which is greater than the third threshold voltage which is greater than the fourth threshold voltage, the second threshold voltage is a voltage when the reception signal level voltage is smaller than the first threshold voltage by a predetermined voltage level, the third threshold voltage is a voltage when the reception signal level voltage is smaller than the second threshold voltage by a predetermined voltage level.