The tables in our database is where the information about individual objects is aggregated. They can be directly explored in read–only mode as shown in some of our use case jupyter notebooks (https://github.com/alercebroker/usecases), although we recommend accessing them using our different APIs.
ZTF alert packets contain associated stamps, metadata and information related to previous detections. As alerts arrive we store the original AVRO files in repository for future analysis and extract a selection of the fields contained in these packets to be added directly to a PostgreSQL database engine. As the data is processed and object alerts aggregated, we add different statistics to different tables in our database.
The most important tables in our database are:
- object: basic object statistics, aggregated in time and band
- magstats: basic object statistics, aggregated in time, dependent on band (g or r)
- detection: detailed object information that is time and band dependent (e.g. light curve)
- reference: properties of the reference images used to build templates
- non-detection: limiting magnitudes
- dataquality: detailed object information regarding the quality of the data
- feature: features computed for machine learning classification (e.g. periods)
- probabilities: classification probabilities associated to a given object, classifier, and class
- ss_ztf: known solar system objects near detected objects
- ps1_ztf: PanSTARRS objects near detected ZTF objects
- gaia_ztf: GAIA objects near detected ZTF objects
For details, see tabs in this Google Sheets link.