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Record W7162067321 · doi:10.82308/2584

Development of proximal sensing systems for crop biomass determination

2017· dissertation· en· W7162067321 on OpenAlexaboutno aff
Yue Su

Bibliographic record

Venuenot available
Typedissertation
Languageen
FieldEnvironmental Science
TopicRemote Sensing in Agriculture
Canadian institutionsnot available
Fundersnot available
KeywordsCanopyCalibrationBiomass (ecology)Sampling (signal processing)Precision agricultureHyperspectral imagingCombine harvesterInverse distance weightingUltrasonic sensor

Abstract

fetched live from OpenAlex

Knowledge of in-field biomass can help optimize crop production efficiency through well-informed farm management decisions and practices. In this project, research was conducted on canopy characterization to estimate the biomass of foliage-based crops, such as vegetables and forage. Emphasis was placed on nondestructive methods, such as canopy reflectance and plant height sensing for in-season resource allocation. Two feasibility studies were described in this thesis.In the first experiment, a portable tripod system with a rotation ultrasonic proximity sensor was used to estimate the in-situ biomass of baby arugula and spinach grown on a high rotation raised plot. A calibration study was conducted in Sherrington, QC by scanning the canopy profile within 50 by 50 cm areas. A correlation model was built by relating the percentile of the measured height, or average maxima within 10o angular displacements, with manually determined biomass. The generated linear regression models produced the coefficient of determination (r2) values of up to 0.80 for arugula and 0.92 for spinach. The second experiment was conducted in the farm fields of Macdonald Campus of McGill University, located in Ste-Anne-de-Bellevue, QC. An integrated sensor system comprised of an ultrasonic proximity sensor and an active canopy sensor were tested individually and in combination to estimate fresh forage biomass. The system was conducted on a variety of alfalfa and grass/legume mixtures through: 1) stationary sensor sampling and 2) on-the-go field mapping. Calibration data were obtained by using stationary samples and the interpolation of mapped data using an inverse distance weighting (IDW) method. The r2 of 0.76 and 0.65 was found when predicting biomass using NDVI and plant height measurements, respectively. However, it was observed that each sensor has advantages and mutually they can compensate for their shortcomings. Thus, plant height was less affected by changes in the field and vegetation, and it predicted biomass at full canopy coverage. NDVI was more sensitive to changes in vegetation density and vegetation type that height measurement would not be able to take into account. As such, the combined sensor regression model explained 78% of the variability using field-specific biomass-predicting calibration models.

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)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.003
Threshold uncertainty score0.012

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0010.001
Open science0.0020.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.002

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 head0.264
Teacher spread0.247 · 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 designBench or experimental
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
Published2017
Admission routes1
Has abstractyes

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