THz Time-of-Flight Depth
Convert a THz reflection delay into subsurface layer depth.
Description
Reflection time of flight doubles propagation distance through a layer.
Reflection time of flight doubles propagation distance through a layer. Refractive index converts vacuum speed to the assumed material speed.1
Convert a THz reflection delay into subsurface layer depth.
When to use THz Time-of-Flight Depth
Use this tool to convert a THz reflection delay into subsurface layer depth.
Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
How to use THz Time-of-Flight Depth and understand its results
- Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
- Enter roundTripDelaySeconds, refractiveIndex using the field table and calculation rules, then run the tool.
- Read layerDepthMeters, layerDepthMillimeters. 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 |
|---|---|---|---|
| roundTripDelaySeconds | Layer round-trip delay (s) | number; minimum: 0 | Required |
| refractiveIndex | Layer refractive index | number; minimum: 0 | Required |
Enter nonnegative delay in seconds and positive refractive index. Return depth in meters and mm.
depth=c×roundTripDelay/(2n), c=299792458 m/s Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| layerDepthMeters | Layer depth (m) | number; minimum: 0 |
| layerDepthMillimeters | Layer depth (mm) | number; minimum: 0 |
{
"input": {
"roundTripDelaySeconds": 2e-11,
"refractiveIndex": 2
},
"output": {
"layerDepthMeters": 0.0014989622899999999,
"layerDepthMillimeters": 1.49896229
}
}Limitations and assumptions
No echo picking, dispersion, oblique incidence or layered-medium fit is supplied.
Numeric inputs 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.
Alternative or Complementary methods
Use Tablet-Coating Thickness: Convert THz round-trip delay into tablet-coating thickness. For a complementary task, use THz Waveform Spectrum: Compute a direct discrete magnitude spectrum from a THz time-domain waveform.
References
-
THz Time-of-Flight Depth — tool.io
Similar or alternative tools
- Tablet-Coating Thickness
Convert THz round-trip delay into tablet-coating thickness.
- THz Waveform Spectrum
Compute a direct discrete magnitude spectrum from a THz time-domain waveform.