Draft for review. These pages collect the current understanding of AIMS detection-data provenance. They are intended to be reviewed for technical accuracy before being treated as final public documentation.
What AIMS is
The Asteroid Institute Moving Source Catalog (AIMS) is the Asteroid Institute’s normalized catalog of moving-source and difference-image detections used for precovery, attribution, and related solar-system search workflows.
AIMS is not a replacement for the original survey archives. It is a curated integration layer that keeps source identity and observatory provenance while translating heterogeneous survey outputs into a common observation schema.
AIMS is designed to:
- make large archival and prompt detection streams searchable using one observation model;
- preserve enough source metadata to trace a detection back to the publishing survey or observatory;
- expose consistent time, position, uncertainty, photometry, filter, and observatory-code fields;
- support cross-matching against Minor Planet Center observations and known-object identities;
- publish partitioned runtime products that precovery jobs can consume without scanning each upstream survey directly.
Current source families
| Source | AIMS dataset id | Status in this draft |
|---|---|---|
| NOIRLab Source Catalog DR2 | nsc | Drafted |
| Zwicky Transient Facility alerts | ztf | Drafted |
| ATLAS difference detections | atlas | Drafted |
| SkyMapper Southern Survey DR2 | skymapper | Drafted |
| Vera C. Rubin Observatory / LSST alerts | lsst | Drafted |
| Minor Planet Center observations | mpc | Drafted as reference/attribution source |
Additional datasets can be documented with the same pattern: source publisher, access path, AIMS filtering, AIMS-derived values, known limitations, and links to source documentation.
AIMS observation structure
AIMS normalizes source detections into a common observation schema. The most important public-facing fields are:
| Field | Meaning |
|---|---|
dataset_id | Source family such as nsc, ztf, atlas, skymapper, lsst, or mpc. |
observatory_code | MPC observatory code for the telescope/site where the observation was taken. |
observation_id | Source-specific stable observation identifier when available, otherwise a deterministic AIMS identifier. |
exposure_id | Source exposure, visit, image, or deterministic exposure grouping identifier. |
obstime_mjd_utc, obstime_ts | Observation time in UTC MJD and timestamp form. |
exposure_mjd_mid_utc, exposure_mjd_mid_key_us | Exposure midpoint and an integer microsecond key used for joining to frames. |
ra_deg, dec_deg | ICRS/J2000 right ascension and declination in degrees, as supplied or derived from the source. |
ra_sigma_deg, dec_sigma_deg | Per-axis astrometric uncertainty in degrees when the source provides or AIMS can derive it. |
mag, mag_sigma, filter | Source photometry and filter/band, with source-specific caveats. |
healpixel | NESTED HEALPix at nside=128, derived from RA/Dec for spatial partitioning. |
materialized_at | AIMS materialization timestamp for the normalized row. |
System organization
AIMS has four relevant layers:
- Per-survey ingest. Each survey has its own pipeline and validation rules. These produce source tables such as
aims_ztf,aims_atlas,aims_nsc,aims_skymapper, andaims_lsst. - Unified detections. Per-survey tables and MPC-derived observations are merged into
aims_detections_hot,aims_detections_archive, and the union viewaims_detections_unified. - AIMS/MPC attribution. AIMS observations are cross-matched with MPC observations through
observation_attribution_edges_v2and current MPC identities. Attribution records are separate from the source detections themselves. - Runtime products. Partitioned parquet detections and frame-index products are published with a catalog manifest for precovery and API jobs.
AIMS uses a daily “hot” surface for recent and operational partitions and a monthly archive surface for older partitions. This split is an implementation detail for cost and performance; the consumer-facing surface is the unified observation view and runtime catalog.
Normalization and derived values
AIMS tries to preserve source measurements rather than recalibrate them into a single photometric or astrometric system. Derivations are applied only where needed to make the data queryable and comparable:
- Times are normalized to UTC MJD/timestamp fields. When a source reports another time scale, the dataset-specific page documents the conversion.
- Exposure midpoints are computed when the source provides exposure start time and exposure duration.
- HEALPix values are computed or downsampled to nside=128 NESTED indexing.
- Source filters are carried forward as the source reports them or through a documented source mapping.
- Observation identifiers are source IDs when available; otherwise AIMS uses deterministic IDs built from source columns.
- Duplicate rows are rejected or deterministically collapsed where source-specific duplicate behavior is known.
Quality and confidence model
AIMS confidence rests on three levels of evidence:
- Publisher processing and calibration. Each source survey publishes its own descriptions of extraction, calibration, quality cuts, data products, and known limitations.
- AIMS source filtering. AIMS selects rows relevant to moving-source use cases. This often means AIMS intentionally stores a subset of a much larger source catalog.
- AIMS validation. AIMS validates canonical schema shape, observation-key uniqueness, expected date windows, row counts, and HEALPix range invariants.
AIMS users should interpret rows as source detections normalized for search, not as final object identifications. Object attribution is supplied by a separate AIMS/MPC cross-match layer and can change as MPC identities evolve.
Review checklist
Open items before final publication:
- Fill in production row counts and last-materialized dates from the current production AIMS dataset.
- Decide how much internal access-path detail should be included on public pages.
- Add version history for material changes to filters or derivations.
- Complete final stakeholder review before removing the technical-review notices.