Starshade IWA Fresnel Number Geometry Check
Ideal small-angle starshade radius/distance and radius-convention Fresnel numberR²/(λz), not aperture-diameter convention, actual suppression, IWAperformance or flight-design validation.
Description
Starshade geometry relates radius, separation and wavelength to angular scale and Fresnel number.
Starshade geometry relates radius, separation and wavelength to angular scale and Fresnel number.1
Geometric quantities alone do not establish achievable starlight suppression. Use this tool to calculate the stated observation or conditional model from supplied measurements.
When to use Starshade IWA Fresnel Number Geometry Check
Use this tool to calculate the stated observation or conditional model from supplied measurements. Establish the observation or experimental context, reference/calibration source, unit basis and adopted model assumptions.
How to use Starshade IWA Fresnel Number Geometry Check and understand its results
- Establish the observation or experimental context, reference/calibration source, unit basis and adopted model assumptions.
- Enter starshadeRadiusMeters, starshadeDistanceMeters, observedWavelengthMeters, using the field meanings and rules below, then run the tool.
- Read result.conditionalGeometricIwaRadians, result.conditionalRadiusFresnelNumber. Interpret each field using the units, signs and evidence rules below.
- If input validation fails, correct the reported field and run again. Before applying a successful result, check the stated reference scope, units, assumptions and any retained unknown evidence.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| starshadeRadiusMeters | Starshade radius meters | number | Required |
| starshadeDistanceMeters | Starshade distance meters | number | Required |
| observedWavelengthMeters | Observed wavelength meters | number | Required |
Require positive radius, separation and wavelength in meters. Return radius/separation in radians and radius²/(wavelength×separation) as dimensionless radius-based Fresnel number. No petal geometry, suppression curve or instrument resolution test is performed.
geometricIwaRadians=radiusMeters/separationMeters; radiusFresnelNumber=radiusMeters²/(wavelengthMeters×separationMeters) Apply the field units and exact ordering, boundary and evidence rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Structured result containing the calculation or selected reference fields below | object |
| result.conditionalGeometricIwaRadians | Conditional Geometric Iwa Radians; use the units, sign convention and calculation stated above | number |
| result.conditionalRadiusFresnelNumber | Conditional Radius Fresnel Number; use the units, sign convention and calculation stated above | number |
{
"input": {
"starshadeRadiusMeters": 10,
"starshadeDistanceMeters": 100000000,
"observedWavelengthMeters": 5e-7
},
"output": {
"result": {
"conditionalGeometricIwaRadians": 1e-7,
"conditionalRadiusFresnelNumber": 2
}
}
}Limitations and assumptions
Geometric quantities alone do not establish achievable starlight suppression. Results depend on the independently established measurement basis and the exact model assumptions above.
Every listed input requires an explicit value. Unexpected fields, incorrect value types, nonfinite numbers and sparse numeric arrays fail validation; tool-specific bounds and alignment rules apply as described above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful calculation that reports a false comparison or retains unknown evidence.
Alternative or Complementary methods
Use Titan Tholin Haze Optical Depth Column Estimate Calculator to examine a related aspect: Optical depth relates a column mass to a wavelength-matched mass extinction coefficient.
Use Gray-Greenhouse Simple Layered Atmosphere Temp Estimator where its separate inputs and scope apply: An ideal gray atmosphere represents infrared opacity using discrete layers.
References
Similar or alternative tools
- Titan Tholin Haze Optical Depth Column Estimate Calculator
Optical depth relates a column mass to a wavelength-matched mass extinction coefficient.
- Gray-Greenhouse Simple Layered Atmosphere Temp Estimator
An ideal gray atmosphere represents infrared opacity using discrete layers.