Lidar Polarization Ratio
Calculate lidar depolarization ratio and cross-polarized return fraction.
Description
Lidar depolarization compares cross-polarized return with parallel return.
Lidar depolarization compares cross-polarized return with parallel return. The cross share uses their total as a separate denominator.1
Calculate lidar depolarization ratio and cross-polarized return fraction.
When to use Lidar Polarization Ratio
Use this tool to calculate lidar depolarization ratio and cross-polarized return fraction.
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 Lidar Polarization Ratio 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 parallelReturn, crossReturn using the field table and calculation rules, then run the tool.
- Read depolarizationRatio, crossPolarizedFraction. 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 |
|---|---|---|---|
| parallelReturn | Parallel-polarized return | number; minimum: 0 | Required |
| crossReturn | Cross-polarized return | number; minimum: 0 | Required |
Enter positive parallel and nonnegative cross signals. Return depolarization ratio and cross fraction.
ratio=cross/parallel; fraction=cross/(parallel+cross) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| depolarizationRatio | Cross-to-parallel depolarization ratio | number; minimum: 0 |
| crossPolarizedFraction | Cross-polarized fraction | number; minimum: 0; maximum: 1 |
{
"input": {
"parallelReturn": 90,
"crossReturn": 10
},
"output": {
"depolarizationRatio": 0.1111111111111111,
"crossPolarizedFraction": 0.1
}
}Limitations and assumptions
No instrument polarization calibration, background correction or aerosol classification is provided.
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 Lidar Photon Return: Estimate monostatic lidar received photons from pulse energy and geometric spreading. For a complementary task, use SHG Polarization Anisotropy: Calculate parallel/perpendicular SHG ratio and polarization anisotropy.
References
-
Lidar Polarization Ratio — tool.io
Similar or alternative tools
- Lidar Photon Return
Estimate monostatic lidar received photons from pulse energy and geometric spreading.
- SHG Polarization Anisotropy
Calculate parallel/perpendicular SHG ratio and polarization anisotropy.