Near-Ground Propagation Channel Modeling and Analysis in Underground Mining Environment at 2.4 GHz
Bibliographic record
Abstract
This paper presents a detailed measurement and performance analysis of near-ground propagation channels in an underground mine for both Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) scenarios. The analysis is derived from channel measurements conducted at a frequency of 2.4 GHz with a bandwidth of 200 MHz, utilizing four different combinations of transmitter-receiver (Tx-Rx) antenna heights ranging from 10 cm to 120 cm. Key channel characteristics such as large-scale path loss, time dispersion, and coherence bandwidth are reported and evaluated. The study suggests that a multi-slope (four-slope) path loss model is more effective in predicting path loss across various propagation segments in the mining environment. The path loss coefficient (n) and shadowing variance (σ) show significant sensitivity to both the Tx-Rx distance and the heights of the Tx-Rx antennas, while the root mean square delay spread (τ rms) and coherence bandwidth (BC) are less affected by these variables. Moreover, distinct path loss patterns are observed for each combination of Tx-Rx antenna heights, resulting in varying signal attenuation levels. The identification of an optimal height for minimizing signal loss is thus required. These observations provide valuable and crucial insights into the near-ground propagation characteristics within the intricate and scattering-rich conditions of underground mines.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
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".