The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Locating the head wave of ultrasonic echo accurately is the basis of measuring the thickness of sediment in drilling hole precisely. This paper presents a method to locate the echo head wave by local signal-to-noise ratio (L-SNR). The original signal is filtered by a parameters constrained Gabor filter and transformed into frequency domain by windowed Fourier transform firstly, and then the L-SNR...
The normal method of measuring sediments thickness in drilling hole base on ultrasonic is to measure the sound time and intensity of echo signal. This paper presents a new viewpoint which is to measure the sediments by estimating the ultrasonic echo's time delay, and proposes an echo time delay estimation method based on Wiener filter. Meantime, the Wiener filter is improved to make selecting of k...
A new super-resolution TOA estimation method the in frequency domain for indoor geolocation based on IEEE 802.11 a/g was proposed. WLAN IEEE 802.11 a/g offers the frequency channel response which is necessary for frequency domain TOA estimation, and the Root-MUSIC algorithm was adopted for its super-resolution capability in narrow bandwidth conditions. Experiment results show that this new method...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.