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Record W3110326815

TREX: A small antenna RF spectrometer

2007· article· en· W3110326815 on OpenAlexaboutno aff
Saša Nedeljković

Bibliographic record

VenueTSpace · 2007
Typearticle
Languageen
FieldComputer Science
TopicBluetooth and Wireless Communication Technologies
Canadian institutionsnot available
Fundersnot available
KeywordsSpectrometerAntenna (radio)Remote sensingEnvironmental scienceComputer sciencePhysicsOpticsTelecommunicationsGeology
DOInot available

Abstract

fetched live from OpenAlex

TREX (21 cm Reionization EXperiment/Trail Reflection EXperiment) is a digital spectrometer with a broadband antenna optimized for frequencies of 70–250 MHz. A frequency-independent rectangular approximation of a two arm conical spiral antenna has been designed, built and tested. I have developed a short integer fast Fourier transform which performs faster than any other known algorithm on Intel platforms. There are two primary scientific goals for TREX: detection of the reionization epoch, and observations of forward scattering of meteors at multiple frequencies. A method to detect the reionization signature via the red-shifted 21 cm hydrogen line is discussed in detail. If the spectrum signature due to this line is in the form of a sharp "temperature step" of ∼ 0.02 K, it should be possible to detect it by using two specially designed antennas each rescaled by 1% in the frequency range of 150-250 MHz. I have measured the levels of noise in Algonquin Park, Canada, and concluded that activity in the sporadic E layer of the ionosphere seriously affects observations of the 21 cm reionization signature. Meteor forward-scattering is a well known method of detecting meteors using a radio telescope to receive signals emitted by distant transmitters and scattered from a meteor trail. If the same meteoroid is detected at additional frequencies due to forward scattering of rays coming from spatially separated transmitters, it is possible to estimate where the scattering occurred, and find the meteoroid velocity vector. Previously, there were no known methods to estimate orbital parameters from forward-scattering observations. In this project, a pipeline to find orbital parameters from the observations is developed. I performed a set of meteor observations at the Algonquin Radio Telescope site and used data to demonstrate the method of measuring the speed of a meteoroid. The data gathered show increased activity during the Lyrid meteor shower as expected. Finally, no evidence was found for the Pegasid shower.

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.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.031
Threshold uncertainty score0.105

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0010.001
Science and technology studies0.0010.000
Scholarly communication0.0010.001
Open science0.0020.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0310.011

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 head0.033
GPT teacher head0.297
Teacher spread0.263 · 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

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designNot applicable
Domainnot available
GenreMethods

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2007
Admission routes1
Has abstractyes

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