Duplicate Source Priority Selection

Resolve explicitly grouped duplicate sources by lowest priority rank, then position error, then original order; identity grouping must be supplied.

Description

Catalog duplicate groups may contain records with different priorities and errors.

Catalog duplicate groups may contain records with different priorities and errors. Selecting one record per explicitly supplied identity group is separate from discovering those identities on the sky.^[1]

Resolve explicitly grouped duplicate sources by lowest priority rank, then position error, then original order; identity grouping must be supplied.

When to use Duplicate Source Priority Selection

Use this tool to resolve explicitly grouped duplicate sources by lowest priority rank, then position error, then original order; identity grouping must be supplied.

Prepare the source, detector or coordinate measurements. Confirm frame, epoch, angular units, axis directions and the stated RA proper-motion convention before entering values.

How to use Duplicate Source Priority Selection and understand its results

Prepare the source, detector or coordinate measurements. Confirm frame, epoch, angular units, axis directions and the stated RA proper-motion convention before entering values.
Enter sourceIds, priorityRanks, positionErrors using the field table and calculation rules, then run the tool.
Read selectedIndexes, discardedIndexes. 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
sourceIds	Source ids	list of string	Required
priorityRanks	Priority ranks	list of number	Required
positionErrors	Position errors	list of number	Required

Enter aligned nonempty nonblank source-group IDs, nonnegative integer ranks and positive position errors. Lower rank wins; ties use lower error, then first original occurrence. The tool returns selected indices sorted in original order and every other index as discarded. IDs are compared exactly rather than trimmed for equality.

Paired lists must be nonempty and have equal lengths.

winner=min(priorityRank, positionError, originalIndex) within each exact group ID

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
selectedIndexes	Selected indexes	list of number
discardedIndexes	Discarded indexes	list of number

json

{
  "input": {
    "sourceIds": [
      "A",
      "A",
      "B"
    ],
    "priorityRanks": [
      2,
      1,
      1
    ],
    "positionErrors": [
      1,
      2,
      1
    ]
  },
  "output": {
    "selectedIndexes": [
      1,
      2
    ],
    "discardedIndexes": [
      0
    ]
  }
}

Limitations and assumptions

It does not perform crossmatching or infer duplicate groups. Error values must be comparable, and selection does not merge measurements or verify the priority policy.

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 Spherical Pair Separation Angle: Compute robust great-circle separation and first-to-second position angle east of north, rejecting directionally undefined coincident/antipodal pairs. For a complementary task, use Iterative Astrometric Sigma Clip: Iteratively clip residuals using recalculated sample standard deviation, retaining original indices and a bounded iteration count.

References

Duplicate Source Priority Selection — tool.io

Similar or alternative tools

Spherical Pair Separation Angle
Compute robust great-circle separation and first-to-second position angle east of north, rejecting directionally undefined coincident/antipodal pairs.
Iterative Astrometric Sigma Clip
Iteratively clip residuals using recalculated sample standard deviation, retaining original indices and a bounded iteration count.