Seafloor Slope Estimation and its Theoretical Accuracy in Interferometric Synthetic Aperture Sonar

Ole J. Lorentzen; Torstein O. Saebo; Andreas Austeng; Alan J. Hunter; Roy E. Hansen

doi:10.1109/TGRS.2025.3559213

Seafloor Slope Estimation and its Theoretical Accuracy in Interferometric Synthetic Aperture Sonar

Ole J. Lorentzen
, Torstein O. Saebo
, Andreas Austeng
, Alan J. Hunter
, Roy E. Hansen

University of Oslo
FFI (Norwegian Defence Research Establishment)

Research output: Contribution to journal › Article › peer-review

1 Citation (SciVal)

Abstract

Estimating the seafloor slope from interferometric synthetic aperture sonar (SAS) measurements is useful for many applications. The fundamental approach to estimating the slope in a gridded depth map is straightforward, but its statistical accuracy is also desired. We provide expressions for the slope, incidence angle, and normal vector estimates. Then, we derive the Cramér-Rao lower bounds (CRLBs) of these estimates based on error propagation from the CRLBs of the depth estimates. Simulated SAS data supports our results by approaching the theoretical CRLB, and real data examples demonstrate that our results are applicable in practice.

Original language	English
Article number	0b00006493ceca3c
Pages (from-to)	1-16
Number of pages	16
Journal	IEEE Transactions on Geoscience and Remote Sensing
Volume	63
Early online date	9 Apr 2025
DOIs	https://doi.org/10.1109/TGRS.2025.3559213
Publication status	Published - 31 Dec 2025

Acknowledgements

The authors would like to thank Dr. Stig A. V. Synnes and Dr. Marc Geilhufe at the Norwegian Defense Research Establishment (FFI), as well as Dr. Øyvind Ødegård and Dr. Håvard Snefjellå Løvås at the Norwegian University of Science and Technology (NTNU) for their helpful discussions during work with this study. Furthermore, they would like to mention the crew of FFI’s research vessel H. U. Sverdrup II, and the HUGIN operators involved in the data collection of the example data used in this study.

Keywords

Bathymetry
geoacoustic inversion
geophysical measurement
interferometry
synthetic aperture sonar (SAS)

ASJC Scopus subject areas

Electrical and Electronic Engineering
General Earth and Planetary Sciences

Access to Document

10.1109/TGRS.2025.3559213Licence: CC BY

Cite this

@article{b0a8e0bd10aa49f4afa9698a64dc115e,

title = "Seafloor Slope Estimation and its Theoretical Accuracy in Interferometric Synthetic Aperture Sonar",

abstract = "Estimating the seafloor slope from interferometric synthetic aperture sonar (SAS) measurements is useful for many applications. The fundamental approach to estimating the slope in a gridded depth map is straightforward, but its statistical accuracy is also desired. We provide expressions for the slope, incidence angle, and normal vector estimates. Then, we derive the Cram{\'e}r-Rao lower bounds (CRLBs) of these estimates based on error propagation from the CRLBs of the depth estimates. Simulated SAS data supports our results by approaching the theoretical CRLB, and real data examples demonstrate that our results are applicable in practice.",

keywords = "Bathymetry, geoacoustic inversion, geophysical measurement, interferometry, synthetic aperture sonar (SAS)",

author = "Lorentzen, \{Ole J.\} and Saebo, \{Torstein O.\} and Andreas Austeng and Hunter, \{Alan J.\} and Hansen, \{Roy E.\}",

year = "2025",

month = dec,

day = "31",

doi = "10.1109/TGRS.2025.3559213",

language = "English",

volume = "63",

pages = "1--16",

journal = "IEEE Transactions on Geoscience and Remote Sensing",

issn = "0196-2892",

publisher = "IEEE",

}

TY - JOUR

T1 - Seafloor Slope Estimation and its Theoretical Accuracy in Interferometric Synthetic Aperture Sonar

AU - Lorentzen, Ole J.

AU - Saebo, Torstein O.

AU - Austeng, Andreas

AU - Hunter, Alan J.

AU - Hansen, Roy E.

PY - 2025/12/31

Y1 - 2025/12/31

N2 - Estimating the seafloor slope from interferometric synthetic aperture sonar (SAS) measurements is useful for many applications. The fundamental approach to estimating the slope in a gridded depth map is straightforward, but its statistical accuracy is also desired. We provide expressions for the slope, incidence angle, and normal vector estimates. Then, we derive the Cramér-Rao lower bounds (CRLBs) of these estimates based on error propagation from the CRLBs of the depth estimates. Simulated SAS data supports our results by approaching the theoretical CRLB, and real data examples demonstrate that our results are applicable in practice.

AB - Estimating the seafloor slope from interferometric synthetic aperture sonar (SAS) measurements is useful for many applications. The fundamental approach to estimating the slope in a gridded depth map is straightforward, but its statistical accuracy is also desired. We provide expressions for the slope, incidence angle, and normal vector estimates. Then, we derive the Cramér-Rao lower bounds (CRLBs) of these estimates based on error propagation from the CRLBs of the depth estimates. Simulated SAS data supports our results by approaching the theoretical CRLB, and real data examples demonstrate that our results are applicable in practice.

KW - Bathymetry

KW - geoacoustic inversion

KW - geophysical measurement

KW - interferometry

KW - synthetic aperture sonar (SAS)

UR - https://www.scopus.com/pages/publications/105002665062

U2 - 10.1109/TGRS.2025.3559213

DO - 10.1109/TGRS.2025.3559213

M3 - Article

AN - SCOPUS:105002665062

SN - 0196-2892

VL - 63

SP - 1

EP - 16

JO - IEEE Transactions on Geoscience and Remote Sensing

JF - IEEE Transactions on Geoscience and Remote Sensing

M1 - 0b00006493ceca3c

ER -

Seafloor Slope Estimation and its Theoretical Accuracy in Interferometric Synthetic Aperture Sonar

Abstract

Acknowledgements

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this