Performance analysis of a double-beam FTIR spectrometer used for passive standoff detection
Bibliographic record
Abstract
Since 1997, Defence Research and Development Canada - Valcartier (DRDC Valcartier) has been developing a Fourier-transform infrared (FTIR) spectrometer for the passive standoff detection of chemical clouds. This instrument, referred to as the Compact ATtmospheric Sounding Interferometer (CATSI), is a double-beam optically balanced FTIR spectrometer operating in the thermal infrared. The double-beam operation mode capability of the instrument is used to suppress the unwanted clutter radiance from the target's background. A methodology for determining the noise equivalent spectral radiance (NESR) of the CATSI instrument in laboratory conditions is presented, along with results using both the double-beam configuration, and a single-beam configuration in which the reference input port is blocked by a liquid Nitrogen-cooled patch, in order to simulate a standard FTIR spectrometer. NESR is found to be depart from the theoretical diminution with integration time due to measurement drifts, which persist even using frequent calibrations of the instrument. NESR evaluation is performed on the real and imaginary part of calibrated measurements after drift correction.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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.
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 source (direct Gemma or distilled Codex), 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".