Description
Apply a wavelength-to-wavenumber density Jacobian.
Spectral and radiation quantities depend on their denominator coordinates, reference levels and physical definitions. A density per wavelength changes by a Jacobian when expressed per frequency, and photon counts, radiant energy, exposure and absorbed dose remain different quantities.
Apply a wavelength-to-wavenumber density Jacobian.
When to use this tool
Use Spectral Irradiance Wavenumber Jacobian when checking the stated spectral, photon, attenuation or radiometric conversion.
How to use the tool and how it works
- Enter perWavelength, wavenumber. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read perWavenumber. Use the output convention below.
Apply a wavelength-to-wavenumber density Jacobian. Require wavenumber > 0; perWavenumber = perWavelength/wavenumber².1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| perWavelength | Per Wavelength | Required. Finite number. |
| wavenumber | Strictly positive reciprocal wavelength (1/lambda), not angular wavenumber 2*pi/lambda. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| perWavenumber | Per Wavenumber | Required. Finite number. |
{
"input": {
"perWavelength": 8,
"wavenumber": 2
},
"output": {
"perWavenumber": 2
}
}Limitations and assumptions
- Wavenumber here is reciprocal wavelength, not angular wavenumber; wavelength and reciprocal-length units must be mutually consistent.
- 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 a complete spectrum, measurement calibration and appropriate physical interaction model for integration, uncertainty or exposure interpretation.
References
Similar or alternative tools
- Spectral Flux Frequency Wavelength Jacobian
Convert spectral density per frequency to per wavelength.
- Spectral Radiance Solid Angle Basis
Change a radiance value's solid-angle denominator basis.