A method for determining a declination of an object , the method comprising the steps of: pivoting a gyroscope , which gyroscope is mounted to the object , at a pivoting angular velocity (ω car-ousel ) about a swivel axis ; measuring an undetermined pivoting of the object about an axis with the gyroscope , wherein the axis is different from the swivel axis ; determining a component of the rotation of the Earth acting on the gyroscope using the undetermined pivoting, and the pivoting angular velocity (ω carousel ); and determining the declination of the object with respect to true north from the component of the rotation of the Earth acting on the gyroscope ; wherein the object is a vehicle or a part of a vehicle , which vehicle comprises a first vehicle part and a second vehicle part; wherein the first vehicle part is pivotable about the swivel axis relative to the second vehicle part; wherein the gyroscope is mechanically mounted to the first vehicle part; and the method being characterised by further comprising the step of: determining the pivoting angular velocity (ω carousel ) of the gyroscope about the swivel axis with a second sensor, which second sensor is distinct from the gyroscope and capable of providing a measurement of the pivoting angular velocity (ω carousel ) that is not affected by Earth rate, wherein the vehicle comprises a manipulator arm , wherein the first vehicle part is a first arm section of the manipulator arm , and wherein the second vehicle part is a second arm section of the manipulator arm or the second vehicle part is a frame or a body of the vehicle. pivoting a gyroscope , which gyroscope is mounted to the object , at a pivoting angular velocity (ω car-ousel ) about a swivel axis ; measuring an undetermined pivoting of the object about an axis with the gyroscope , wherein the axis is different from the swivel axis ; determining a component of the rotation of the Earth acting on the gyroscope using the undetermined pivoting, and the pivoting angular velocity (ω carousel ); and the undetermined pivoting, and the pivoting angular velocity (ω carousel ); and determining the declination of the object with respect to true north from the component of the rotation of the Earth acting on the gyroscope ; wherein the object is a vehicle or a part of a vehicle , which vehicle comprises a first vehicle part and a second vehicle part; wherein the first vehicle part is pivotable about the swivel axis relative to the second vehicle part; wherein the gyroscope is mechanically mounted to the first vehicle part; and the method being characterised by further comprising the step of: determining the pivoting angular velocity (ω carousel ) of the gyroscope about the swivel axis with a second sensor, which second sensor is distinct from the gyroscope and capable of providing a measurement of the pivoting angular velocity (ω carousel ) that is not affected by Earth rate, wherein the vehicle comprises a manipulator arm , wherein the first vehicle part is a first arm section of the manipulator arm , and wherein the second vehicle part is a second arm section of the manipulator arm or the second vehicle part is a frame or a body of the vehicle. <EOS>