Parabolic Focus Screen

Calculate the focal distance of a parabolic section from aperture width and depth and screen an occupied location against an explicit focus-zone radius.

Description

A parabolic section has a geometry-defined focus.

A parabolic section has a geometry-defined focus. A one-dimensional occupied position can be screened against a selected focus zone.^[1]

Calculate the focal distance of a parabolic section from aperture width and depth and screen an occupied location against an explicit focus-zone radius.

When to use Parabolic Focus Screen

Use this tool to calculate the focal distance of a parabolic section from aperture width and depth and screen an occupied location against an explicit focus-zone radius.

Choose a supported reference topic, run an input-free reference with an empty object, or prepare the measured values and caller-supplied test records requested. Keep acoustic metrics, frequency, units and test conditions consistent.

How to use Parabolic Focus Screen and understand its results

Choose a supported reference topic, run an input-free reference with an empty object, or prepare the measured values and caller-supplied test records requested. Keep acoustic metrics, frequency, units and test conditions consistent.
Enter apertureWidthMeters, depthMeters, occupiedDistanceFromVertexMeters, focusZoneRadiusMeters using the field table and calculation rules, then run the tool.
Read focalDistanceFromVertexMeters, distanceFromFocusMeters, occupiedLocationInFocusZone. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
apertureWidthMeters	Parabolic aperture width (m)	number; minimum: 0	Required
depthMeters	Parabolic depth (m)	number; minimum: 0	Required
occupiedDistanceFromVertexMeters	Occupied distance from vertex (m)	number; minimum: 0	Required
focusZoneRadiusMeters	Focus-zone radius (m)	number; minimum: 0	Required

Enter positive width/depth and nonnegative occupied distance/radius. Compute focus directly or with log fallback; return focus/distance and inclusive distance≤radius gate.

focus=width²/(16depth); distance=abs(occupied−focus)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
focalDistanceFromVertexMeters	Focal distance from vertex (m)	number; minimum: 0
distanceFromFocusMeters	Distance from focus (m)	number; minimum: 0
occupiedLocationInFocusZone	Occupied location in focus zone	boolean

json

{
  "input": {
    "apertureWidthMeters": 8,
    "depthMeters": 2,
    "occupiedDistanceFromVertexMeters": 2.1,
    "focusZoneRadiusMeters": 0.2
  },
  "output": {
    "focalDistanceFromVertexMeters": 2,
    "distanceFromFocusMeters": 0.10000000000000009,
    "occupiedLocationInFocusZone": true
  }
}

Limitations and assumptions

The screen assumes position along the modeled axis. No three-dimensional ray field, pressure gain, wavelength or safety outcome is calculated.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Whispering Gallery Reference: Return the geometric-acoustics mechanism and limitations of whispering-gallery propagation. For a complementary task, use Orchestra Reflector Reference: Return design controls for orchestra shells and overhead reflectors without inventing universal height or angle settings.

References

Parabolic Focus Screen — tool.io

Similar or alternative tools

Whispering Gallery Reference
Return the geometric-acoustics mechanism and limitations of whispering-gallery propagation.
Orchestra Reflector Reference
Return design controls for orchestra shells and overhead reflectors without inventing universal height or angle settings.