An improved imaging algorithm for multi-receiver SAS system with wide-bandwidth signal

X Zhang, P Yang - Remote Sensing, 2021 - mdpi.com
When the multi-receiver synthetic aperture sonar (SAS) works with a wide-bandwidth signal,
the performance of the range-Doppler (RD) algorithm is seriously affected by two …

Quaternion Neural Networks: A physics-incorporated intelligence framework [Hypercomplex Signal and Image Processing]

A Hirose, F Shang, Y Otsuka, R Natsuaki… - IEEE Signal …, 2024 - ieeexplore.ieee.org
Why quaternions in neural networks (NNs)? Are there quaternions in the human brain?“No”
may be an ordinary answer. However, quaternion NNs (QNNs) are a powerful framework …

Biquaternion Fourier domain filter for InSAR noise suppression by enhancing polarimetric-interferometric fringe patterns

Y Otsuka, R Natsuaki, A Hirose - IEEE Transactions on …, 2024 - ieeexplore.ieee.org
The Goldstein-Werner (GW) filter is one of the most widely used methods to suppress noise
in interferometric synthetic aperture radar (InSAR) data. However, the insufficient filtering …

Polarimetric goldstein filter for interferometric phase denoising

Y Otsuka, R Natsuaki, A Hirose - IGARSS 2024-2024 IEEE …, 2024 - ieeexplore.ieee.org
The Goldstein filter is one of the most commonly used methods to reduce noise in
interferometric synthetic aperture radar data. However, the low filtering performance in …

Proposal of biquaternion neural networks for coherent processing of polarization-and-phase information in PolSAR and PolInSAR

Y Otsuka, R Natsuaki, A Hirose - IGARSS 2023-2023 IEEE …, 2023 - ieeexplore.ieee.org
As the resolution of polarimetric synthetic aperture radar (PolSAR) and polarimetric
interferometric SAR (PolInSAR) data increases, coherent processing of polarization and …

Phasor quaternion neural network framework and its significance in Big SAR intelligence

A Hirose - 2021 International Conference on Emerging …, 2021 - ieeexplore.ieee.org
In this paper, first we overview the use of artificial intelligence (AI) in observation and data
processing in synthetic aperture radar (SAR). Then we discuss the function and significance …

Interferometric phase restoration using biquaternion neural networks in PolInSAR

Y Otsuka, R Natsuaki, A Hirose - 2023 8th Asia-Pacific …, 2023 - ieeexplore.ieee.org
Singular points (SPs) in interferometric synthetic aperture radar (InSAR) data hinder the
generation of accurate digital elevation models (DEMs). Since one of the main causes of …

Uniform LFM reconstruction from non-uniform data

X Zhang, X Liu, Z **, Y Liu - 2021 14th International Congress …, 2021 - ieeexplore.ieee.org
The multi-channel sampling technique is often exploited nowadays, as it can largely reduce
the sampling rate. However, it may suffer from non-uniform sampling. If this data was directly …

Adaptive Subsurface Imaging based on Peak Phase-Profile: The Significance in Separation of Scattering Phase from Propagation Phase

A Hirose, S Shimomura - 2021 Asia-Pacific Signal and …, 2021 - ieeexplore.ieee.org
This paper discusses the separation of scattering phase and propagation phase in radar
systems. Recently we proposed a novel radar imaging scheme using complex-valued self …

SAS Doppler Estimation Based on Radon Transformation

X Zhang, Z **, X Feng, Y Liu - 2021 CIE International …, 2021 - ieeexplore.ieee.org
Due to the motion errors, synthetic aperture sonar (SAS) maybe suffers from slight deviation
of Doppler centroid. If the inaccurate Doppler centroid is used for imagery, the SAS image …