Rotary-Axis Calibration
Summarize rotary-axis calibration errors in arcseconds.
Description
Rotary-axis calibration errors compare measured and commanded angles.
Rotary-axis calibration errors compare measured and commanded angles. RMS here includes systematic bias because it is computed about zero.1
Summarize rotary-axis calibration errors in arcseconds.
When to use Rotary-Axis Calibration
Use this tool to summarize rotary-axis calibration errors in arcseconds.
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 Rotary-Axis Calibration 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 commandedAnglesDegrees, measuredAnglesDegrees using the field table and calculation rules, then run the tool.
- Read meanErrorArcseconds, rmsErrorArcseconds, maximumAbsoluteErrorArcseconds. 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 |
|---|---|---|---|
| commandedAnglesDegrees | Commanded angles (°) | list of number | Required |
| measuredAnglesDegrees | Measured angles (°) | list of number | Required |
Enter nonempty aligned finite degree lists. Return signed mean error, RMS error and maximum absolute error in arcseconds.
error_i=3600(measured_i−commanded_i) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| meanErrorArcseconds | Mean rotary error (arcsec) | number |
| rmsErrorArcseconds | RMS rotary error (arcsec) | number; minimum: 0 |
| maximumAbsoluteErrorArcseconds | Maximum absolute error (arcsec) | number; minimum: 0 |
{
"input": {
"commandedAnglesDegrees": [
0,
1,
2
],
"measuredAnglesDegrees": [
0,
1.001,
1.999
]
},
"output": {
"meanErrorArcseconds": 0,
"rmsErrorArcseconds": 2.93938769133949,
"maximumAbsoluteErrorArcseconds": 3.5999999999996035
}
}Limitations and assumptions
No angular wrap correction, uncertainty fit or compensation table is generated.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Galvo Grid Error: Summarize radial positioning error from a galvo calibration grid. For a complementary task, use Tracker Error Budget: Combine independent laser-tracker error components by root-sum-square.
References
-
Rotary-Axis Calibration — tool.io
Similar or alternative tools
- Galvo Grid Error
Summarize radial positioning error from a galvo calibration grid.
- Tracker Error Budget
Combine independent laser-tracker error components by root-sum-square.