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Record W3156418222 · doi:10.14288/1.0396552

Lunar Brightness Temperature Measurement with CHIME

2021· article· en· W3156418222 on OpenAlexaboutno aff
Yuze Zhang

Bibliographic record

VenuecIRcle (University of British Columbia) · 2021
Typearticle
Languageen
FieldEngineering
TopicSpacecraft and Cryogenic Technologies
Canadian institutionsnot available
Fundersnot available
KeywordsAstrobiologyGeologyBrightnessRemote sensingAstronomyPhysics

Abstract

fetched live from OpenAlex

Half a century after measurement of the lunar brightness temperature for preparations of the moon landing, Canadian Hydrogen Intensity Mapping Experiment (CHIME) provides improved instrumentation and a more sophisticated method for the same measurement. Such measurement also helps our understanding of CHIME itself and extends its limit, such as better calibration of antenna beam patterns and understanding of the artifacts within CHIME data. Previous research in 1950s has provided multiple data points with lunar brightness temperatures from 230 to 240 Kelvin between 100MHz and 1000MHz. However, a recent measurement performed by Murchison Widefield Array (MWA) indicates a much lower value of the lunar brightness temperature around 180 Kelvin at 150 MHz. Given that the CHIME band is also in low frequencies, a series of measurements can be performed between 400MHz and 800MHz to test the result from MWA which can potentially reject 1950s’ results and enhance our knowledge about lunar brightness temperature in low frequencies. This research is aimed to measure the lunar brightness temperature within the CHIME band from 400MHz to 800MHz. To measure the lunar brightness temperature from CHIME’s visibility data, Fringestop was performed. Subsequently, an averaged background intensity was measured and subtracted from the intensity obtained after Fringestop. Rayleigh Jeans Law was used to finalize the calculation of the lunar brightness temperature. There is inconsistency in my result. Between the two measured lunar brightness temperature values at different times and frequencies, one agrees with the 1950s measurement while the other agrees with the data measured by MWA in 2017. Nevertheless, this study helps to pave the foundation of lunar brightness temperature measurement with CHIME. More future measurements can be performed and averaged with improved methods.

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)0.000
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: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.004
Threshold uncertainty score0.010

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.002
Science and technology studies0.0000.000
Scholarly communication0.0000.001
Open science0.0000.001
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0030.001

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 head0.005
GPT teacher head0.133
Teacher spread0.127 · 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 designObservational
Domainnot available
GenreEmpirical

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
Published2021
Admission routes1
Has abstractyes

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