Measurement of copolar attenuation through the bright band at 4 & 7 GHz
Bibliographic record
Abstract
This thesis describes an experiment designed to measure microwave propagation through the bright band at 4 and 7 GHz. The path is located approximately 100 kilometers east of Vancouver, British Columbia, Canada, forming part of the Trans Canada Telephone System microwave network. The path is coastal and mountainous in nature, 41.3 kilometers in length and experiences an average annual rainfall of 1600 mm/year. Due to these factors and an elevation differential of 1227 m between transmitting and receiving sites, the 0°C isotherm and hence bright band effect normally exist along the path from November to April. A measurement system based on remote telemetry is used to obtain high resolution and accurately time-correlated data. Received signal levels are taken from five selected 4 and 7 GHz microwave channels which are sampled at a rate of 10 Hz. Meteorological information is obtained from five locations along the path and sampled at a rate of 1 Hz. The data thus collected are then time-correlated as it arrives at the University of British Columbia (Vancouver) recording site where it is analyzed using high-level language routines developed as part of a propagation data base management system. A detailed description of both the measurement system and the data management system are provided in the thesis. Results from several precipitation systems indicate that bright band attenuation can be many times (in dB per kilometer) greater than attenuation due to equivalent amounts of rain. This is described by an Excess Attenuation Ratio (EAR) defined as the ratio of the excess attenuation in dB/km calculated using the Laws and Parson distribution at 0°C. The experimental results compare favourably with those predicted by the theoretical model of Matsumoto and Nishitsuji. A scintillation type fading phenomenon superimposed on the broad-band fade has also been observed during bright band propagation conditions. From the preliminary results this phenomenon appears to be correlated with sudden changes in differential temperature between transmitter and receiver sites and thus a corresponding change in the thickness of the bright band.
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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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".