Description
Calculate a supplied absorption optical depth and path transmission.
Atmospheric scalar terms require explicit averaging, spectral, geometric and propagation conventions. One fluctuation product is not a time-averaged flux, a squared deviation is not a full scintillation index, and a Nyquist interval does not de-alias radar velocity. Layer terms require compatible units and model assumptions.
Calculate a supplied absorption optical depth and path transmission.
When to use this tool
Use Radiative Absorption Path Transmission when you already have absorptionCoefficient, pathLength and need to calculate a supplied absorption optical depth and path transmission.
How to use the tool and how it works
- Enter absorptionCoefficient, pathLength. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read opticalDepth, transmission. Use the output convention below.
Require absorptionCoefficient and pathLength nonnegative; optical depth=coefficient*length and transmission=exp(-optical depth).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| absorptionCoefficient | Nonnegative Napierian absorption coefficient per input length unit, not a base-ten absorbance coefficient. | Required. Finite number; minimum 0. |
| pathLength | Path Length | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| opticalDepth | Optical Depth | Required. Finite number. |
| transmission | exp(-opticalDepth), for the specified absorption-only path model. | Required. Finite number. |
{
"input": {
"absorptionCoefficient": 0.2,
"pathLength": 5
},
"output": {
"opticalDepth": 1,
"transmission": 0.36787944117144233
}
}Limitations and assumptions
- Use a Napierian coefficient in inverse length. The homogeneous absorption-only model excludes source emission, scattering and spectral variation; nonfinite exported optical depth is rejected.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use the complete measurement and physical retrieval model. Include calibration, averaging, source geometry, spectral response and relevant transfer or flow effects when local weights and signal factors cannot establish the desired atmospheric quantity.
References
Similar or alternative tools
- Cloud Layer Optical Depth Step
Add supplied extinction across one layer to optical depth.
- Cloud Path Liquid Water Contribution
Calculate a supplied cloud liquid-water-path contribution.