Description
Return one observed clearness index.
Atmospheric optical and radiation quantities distinguish spectral density, integrated flux, solid-angle response and reporting codes. A local attenuation factor, bin contribution or coverage bound requires compatible geometry and definitions rather than establishing a complete radiative transfer or observed cloud state.
Return one observed clearness index.
When to use this tool
Use Shortwave Clearness Index One Observation when checking the stated optical, radiometric, cloud-code or coverage convention.
How to use the tool and how it works
- Enter surfaceIrradiance, extraterrestrialHorizontal. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read index. Use the output convention below.
Return one observed clearness index. Require surfaceIrradiance >= 0 and extraterrestrialHorizontal > 0; index = surface/extraterrestrial.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| surfaceIrradiance | Surface Irradiance | Required. Finite number; minimum 0. |
| extraterrestrialHorizontal | Extraterrestrial Horizontal | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| index | Position under the explicit zero-/one-based convention, including any stated missing-position sentinel. | Required. Finite number. |
{
"input": {
"surfaceIrradiance": 600,
"extraterrestrialHorizontal": 1000
},
"output": {
"index": 0.6
}
}Limitations and assumptions
- Values above one are retained; compatible time/geometry bases are supplied and no cloud condition, quality control or forecast is inferred.
- 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 source-specific observation code table and an appropriate calibrated spectral/atmospheric model for actual cloud or radiative interpretation.
References
Similar or alternative tools
- Radiometer Field Of View Share
Return accepted solid-angle share and throughput-weighted share.
- Radiometer Bandwidth Normalization
Return mean signal per bandwidth and a reference-bandwidth equivalent.