Polar Axis Alignment Drift Arcminutes per Month Tracker
Signed linear polar-alignment drift tracker using caller measured monthly rate; no mount geometry or sky drift inference.
Description
Polar Axis Alignment Drift Arcminutes per Month Tracker: return projected signed error arcminutes.
An alignment drift rate relates a signed angular error to elapsed time. A linear projection extends a measured rate rather than remeasuring the alignment.
This tool returns projected signed error arcminutes. Use the stated units and model convention when interpreting these fields.
When to use this tool
Use this tool when the supplied inputs match the specific operation described above and you need a repeatable result under its stated convention.
- Check the supported input and output contract against an existing calculation or observation.
- Use the complete example to confirm units, selector spelling and result interpretation.
How to use the tool and how it works
- Enter every field in the input table using the stated units and the exact supported selector spelling where applicable.
- Run the tool. Correct input errors before interpreting an output.
- Read the result fields below; use accompanying flags and the stated sign, boundary or model convention when interpreting a number.
Add initialErrorArcminutes to observedMonthlyDriftArcminutes times nonnegative elapsedMonths.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| initialErrorArcminutes | Initial error arcminutes. Arcminutes. | Finite number |
| observedMonthlyDriftArcminutes | Observed monthly drift arcminutes. Arcminutes. | Finite number |
| elapsedMonths | Elapsed months. | Finite number; zero or greater |
| Output field | Interpretation |
|---|---|
| result | Object containing the following named result fields. |
| result.projectedSignedErrorArcminutes | Projected signed error arcminutes; use the stated units and sign convention. |
{
"input": {
"initialErrorArcminutes": 2,
"observedMonthlyDriftArcminutes": -0.5,
"elapsedMonths": 4
},
"output": {
"result": {
"projectedSignedErrorArcminutes": 0
}
}
}Limitations and assumptions
- The calculation assumes constant signed drift and does not model seasonal changes or diagnose a mount.
- Every declared field is required and unexpected fields are rejected. Numeric inputs must be finite; input errors are distinct from a valid false result or an explicitly qualified output.
- Extremely large inputs and nonfinite or excessively large outputs are rejected. List positions reported by the tool use zero-based indices unless stated otherwise.
Alternative or Complementary methods
Check the underlying observations, units and conventions independently before using the result in a larger workflow. The tools listed below address nearby tasks; compare their inputs and scope before substituting one for this operation.
References
Similar or alternative tools
- convergent point motion alignment
A convergent-point screen compares a star's proper-motion direction with the great-circle bearing toward a supplied cluster apex.
- Secular Aberration Drift Term Note Generator
Qualified caller-reference registry: actual Galactic acceleration vector, reference-frame convention and independently established secular-aberration drift; not a catalog proper-motion correction. Requires independently applicable source/context/date evidence; not an authoritative table, omitted predictive model, diagnosis, permission, safety or compliance determination.