| 摘要 |
A measuring device is disclosed for measuring a vectorial physical quantity (x), comprising a first and a second sensor (S1, S2), an actuator (M2), a noise extraction unit (NX) and a low frequency noise estimator (LF). The first and a second sensor (S1, S2) are arranged for measuring a component of the vectorial physical quantity (x), and for generating a respective sense signal (y1, y2). The sensors have an Allan variance curve with a minimum value for a particular integration time Tmin, said Allan variance curve having a first tangent line to a portion of the curve for which the integration time approaches 0, and having a second, horizontal, tangent line of constant standard deviation corresponding to said Allan minimum value, said first and said second tangent line having an intersection point for a second particular integration time. The low frequency noise estimator (LF) estimates a low frequency noise component from the difference signal (r) and from information about the relative rotation ( a) between the sensors and generates an estimated noise signal (n1) indicative for the estimated value of said noise component. The low frequency noise estimator has an effective integration time that is at least two times a sample time with which the sense signals are obtained, which effective integration time is less than the smallest particular integration time of the sensors comprised in the measuring device and which effective integration time is at most two times said second integration time. |
