Description
Divide halfwidth by radius for radians and multiply by 180/π for degrees.
Coordinate uncertainty can be expressed as angular halfwidths, linear components, or variances. A local spherical conversion and a covariance projection use different conventions; neither alone defines a complete confidence region.
Divide halfwidth by radius for radians and multiply by 180/π for degrees.
When to use this tool
Use Coordinate Uncertainty Angular Halfwidth when you need a local uncertainty or rounding term with supplied geometry and statistics.
How to use the tool and how it works
- Enter linearHalfwidth, radius. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read radians, degrees. Use the output convention below.
Require nonnegative linearHalfwidth and positive radius. Divide halfwidth by radius for radians and multiply by 180/π for degrees.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| linearHalfwidth | Linear Halfwidth | Required. Finite number; minimum 0. |
| radius | Radius in the common length unit, with its geometric role defined above. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| radians | Radians | Required. Finite number. |
| degrees | Degrees | Required. Finite number. |
{
"input": {
"linearHalfwidth": 3.141592653589793,
"radius": 180
},
"output": {
"radians": 0.017453292519943295,
"degrees": 1
}
}Limitations and assumptions
- Length units must match. This is a spherical angular halfwidth, not automatically longitude uncertainty at arbitrary latitude or a statistical confidence interval; no half-turn cap is imposed.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete error-propagation model with known coordinate reference and covariance. Distinguish resolution from measurement uncertainty and variance from standard deviation or confidence limits.
References
Similar or alternative tools
- Coordinate Rounding Ground Error Bound
Return radius times angular step divided by two as latitudeHalfwidth and multiply it by cosine latitude for longitudeHalfwidth.
- Geographic Axis Uncertainty Projection
Return eastSigma² cos²(angle) plus northSigma² sin²(angle) plus twice correlation times both sigmas times cosine and sine.