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Record W2110810381 · doi:10.1190/1.1598118

Deconvolution and spatial resolution of airborne gamma-ray surveys

2003· article· en· W2110810381 on OpenAlex
Stephen Billings, Brian Minty, Garry N. Newsam

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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueGeophysics · 2003
Typearticle
Languageen
FieldHealth Professions
TopicRadioactivity and Radon Measurements
Canadian institutionsUniversity of British Columbia
Fundersnot available
KeywordsDeconvolutionNoise (video)SIGNAL (programming language)AutocorrelationSignal-to-noise ratio (imaging)PhysicsOpticsMathematicsComputer scienceStatistics

Abstract

fetched live from OpenAlex

Abstract The first part of the paper presents a method for frequency domain deconvolution of airborne gamma-ray surveys using a Wiener filter. A geometrical detector model is used to model gamma-ray detection, with aircraft movement simply incorporated by a multiplicative term. The method requires estimation of the autocorrelation functions governing both signal and noise. The former is estimated through the radially averaged power spectrum of the survey data, whereas an error propagation analysis is used to estimate the latter, which is assumed white. Slight manual adjustments to the noise level are used to tune the reconstruction. The technique is applied to a low-altitude radiometric survey collected along closely spaced transects. Results are good for thorium, but are poor for both potassium and uranium. This can be attributed to the high noise levels in the potassium and uranium estimates, principally due to scattered gamma-rays from high thorium concentration. Much better results are obtained when the method is applied to a survey with more typical radioelement concentrations. The reconstructions are improved significantly if an adaptive 2D Lee filter is applied prior to deconvolution. The second part of the paper addresses how noise in the data and attenuation of signal due to the flying height limit the spatial resolution. The autocorrelation functions of signal and noise, along with the gamma-ray model, can be used to determine how signal-to-noise ratio degrades with increasing height. The frequency where signal and noise are present in equal quantity can be used as an estimate of the spatial resolution. Predicted critical sampling rates range from 30 m at 20 m elevation to 60 m at 60 m elevation and 90 m at 120 m elevation.

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)0.001
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: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.234
Threshold uncertainty score0.378

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
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 head0.056
GPT teacher head0.339
Teacher spread0.283 · 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