Presence Of Spatial Aliasing Research Articles

High-frequency source localization based on steered frequency-wavenumber analysis using sparse array

In this study, we address the problem of estimating the position of a nearby target emitting a high-frequency signal using sparse array. One of the representative localization techniques, Matched Field Processing (MFP), is known to demonstrate reliable performance below 1 kHz. However, at frequencies higher than the design frequency of the array sensor, the localization becomes challenging due to spatial aliasing. Nevertheless, Frequency-Difference Matched Field Processing (FDMFP) is a technique that successfully estimates the position of the target even in the presence of spatial aliasing. It performs signal processing in the low-frequency band using low-frequency components obtained from two high-frequency components. To ensure reliability, we compared and validated the results of this study with the results of FDMFP. In this research, we completed the algorithm by controlling the phenomenon of striation shifting caused by spatial aliasing in the conventional frequency-wavenumber(f-k) analysis through beam steering. We steered the received signal to the location of signal reception and identified the target's position using the f-k spectrum of the steered signal. The data used in the study is the sound of snapping shrimp from SAVEX15, with a frequency range of 5–24 kHz wideband impulse signals.

Source Separation for Arbitrary Array Configuration in the Presence of Spatial Aliasing

Source Separation for Arbitrary Array Configuration in the Presence of Spatial Aliasing

Multichannel trace interpolation in the presence of spatial aliasing

Steep seismic events are often aliased due to spatial undersampling of wave fields creating different kinds of coherent noises and corrupting the migration process, O. Yilmaz (1987). To avoid the expensive costs of high-resolution spatial sampling, seismic traces are interpolated. A novel spatial interpolation algorithm, based on a narrowband multichannel model, is considered.