Dither Signal Filtering in Ring Laser Gyroscope Using Modified Stockwell Transform

Ring laser gyroscopes (RLGs) are widely used in many airborne and navigation systems for accurate measurement of the true rotation of the body movement, but the RLGs suffer a serious problem at low frequencies known as lock-in frequency. To avoid the lock-in problem, the RLG is vibrated mechanically to a high frequency, which is known as dithering. In order to get the true rotation of the body, the dither signal has to be removed. Normally, digital filters are used to remove the dither signal. These filters have the disadvantage that either the filter length is too large or the phase characteristics are not linear. The Stockwell transform and the modified Stockwell transform (MST) are widely used for the analysis of signals. In this article, the MST is used as a filter to filter the dither signal, which is attenuated by 114.5 dB.