Volume 40, Issue 1 (January 2012)
Application of Hilbert-Huang Transform to Inertial Profile Verification: A Laboratory Approach
Past studies have shown that most inertial profiler verification procedures are conducted through repeated profile measurements on test sections with known profiles. This type of an evaluation can erroneously affect inertial profile results because of non-controllable parameters such as profiler equipment, analytical software, and operator variables. In order to improve the accuracy of inertial profiler certifications, a laboratory simulation method for inertial profilers was developed. This method uses an apparatus that combines sinusoidal vertical displacements of various frequencies and amplitude levels. As a result, errors attributed to operator variables are excluded, and errors induced by a profiler and software are further identified. This study utilizes the Hilbert-Huang transform (HHT) to improve the laboratory verification process by reducing measurement noise and creating a more stable signal in different frequency-amplitude combinations. The noise source is also identified by applying the HHT, which can provide guidance on further profiler verification enhancements.