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.
Forward scattering is a special phenomenon for bi-static sonars, and it has received much attention in recent years because it can provide a lot of useful information for estimations. In this paper, two kinds of speed estimation method are proposed for forward scattering. Very simple geometrical principles are used in the two methods, and the complex acoustic field is not needed to be calculated when...
Compressive holography is applied to characterize the oil droplet in oil spill experiment. The compressive reconstruction method demonstrates good performance in the real experimental data compared with traditional back-propagation based method. The phase transition curve in simulation illustrates the effects of sparsity of object function on the compressive reconstruction success rate, which indicates...
In situ marine algae detection is very important for many global issues. Even though polarized-light scattering has the promising application in the biomedical characterization, its potential to detect marine algae is still not clear. The movements of the suspended marine algae due to their own migrations, arise challenges for the polarization measurement and information acquisition. In this paper,...
T waves excited by earthquakes propagate along the SOFAR channel with low transmission loss, and therefore can be recorded on land-based seismic stations and hydrophones located thousands of kilometers away from earthquake epicenters. Early T-wave observations are mostly based on recordings by land-based stations due to the mechanics of the energy conversion of acoustic waves into seismic phases....
In the shallow water environment, detecting and classifying buried objects is a challenging problem with high operational importance. Acoustical wave becomes an important tool in the detection of objects in underwater systems due to its effectiveness of propagation in the water. Later on, the acoustic scattered field modal for fluid-loaded and thin spherical shell have been determined by the shell's...
Considering the scattering and absorption caused by seawater molecules and suspended particles, the characteristics of blue-green laser in seawater are described. Then a transmission model of blue-green laser in shallow seawater is established and the relations of the attenuation of received power and the requisite transmission power to the transmission distance are summed up. Results of the simulation...
When an object crosses the source-receiver line, a weak acoustic field aberration would be generated. However, it is often overwhelmed by strong direct blast. A lake experiment with a vertical receiver array spanning along water column was designed and conducted, with a 10 kHz pulse. The interested signal was the aberration caused by the forward scattering of a submerged object. The acoustic field...
The polarization dependent and independent scattering contributions of the sea surface could be separated using complex scattering matrix better than using the NRCS (Normalized Radar Cross Section) [1]. By achieving this separation, a polarimetric generalized K distribution (Pol-K) motivated by ENL analysis had been established. It is different from traditional speckle models which consider only the...
Acoustic Doppler current profiler (ADCP) is designed to measure the velocity profile within the water column, whilst the ability of ADCP to measure the suspended sediment concentration has been investigated for a long time. The key of the measurement is to analyze multi-frequency backscattering intensity, and to extract suspended sediment information using acoustic inversion algorithms. To investigate...
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.