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Record W2252825410 · doi:10.11575/prism/27199

On the Use of Hybrid Compact Polarimetric SAR for Ship Detection

2014· dissertation· en· W2252825410 on OpenAlex
Atteia Allah

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenuePRISM (University of Calgary) · 2014
Typedissertation
Languageen
FieldEngineering
TopicSynthetic Aperture Radar (SAR) Applications and Techniques
Canadian institutionsnot available
Fundersnot available
KeywordsRemote sensingPolarimetryComputer scienceGeologyPhysicsOptics

Abstract

fetched live from OpenAlex

Maritime surveillance is an issue of particular interest and importance for countries bordering on the sea. Monitoring and controlling maritime activities are essential for these countries to assert their sovereignty over their waters. Ship detection is one of the most vital elements of maritime control. Traditional surveillance methods suffer from narrow coverage and high cost to achieve comprehensive surveillance. However, Synthetic Aperture Radar (SAR) with its ability to provide images covering wide geographic areas and acquired with a variety of imaging modes, polarization configurations, incidence angles and resolutions may be considered as a promising alternative/complement for existing methods. Quad-polarimetric SAR data has been used successfully for ship detection. However, narrow swath of quad-polarimetric SAR promotes the urgent need to explore ship detectors for dual-polarimetric systems. Compact polarimetric (CP) SAR has high potential of providing more information than linear dual-polarimetric SAR. Even wider swaths will be provided in many of the CP imaging modes of the upcoming Canadian Radarsat Constellation Mission (RCM) SAR to be launched in 2018. In this thesis, the use of CP SAR for ship detection is explored. To fulfill this purpose, two novel contributions are introduced. The first is an investigation study of the possibility and benefits of using pseudo-quad data for improved ship detection. This is achieved by comparing the ship detection performance of dual-polarized CP and pseudo-quad data to linear and circular dual-polarized SAR. The pseudo-quad data is generated by a reconstruction algorithm that aims to reconstruct some elements of the quad-pol covariance matrix from CP data specifically for maritime applications. This study is applied on Radarsat-2 scenes with fine resolution and simulated medium and low resolution RCM data . The effect of spatial resolution, ship orientation and incidence angle on the detection performance has been explored. The second contribution is a new hybrid ship detection algorithm that utilized CP Stokes parameters and some of their derived parameters for ship detection. The pre-screener of the algorithm merges three detection strategies to declare candidate ships and the discriminator uses a CP decomposition technique to discriminate ships from false alarms based on the type of scattering mechanism. The proposed detection algorithm is applied to a number of simulated RCM scenes with medium and low resolutions. The findings of this thesis suggest the usefulness of CP reconstruction for improved ship detection. For the hybrid ship detection algorithm, a detection rate of 100% is obtained for medium resolution data and about 98% for low resolution data.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Other design · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: none
Teacher disagreement score0.984
Threshold uncertainty score0.601

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.016
GPT teacher head0.201
Teacher spread0.185 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it