Data Products
Below you will find information of the pixel data products that will be produced by the LSST software stack. As well, you will find information on the potential added value user-generared products the SSSC is planning as well as the data products to be provided by the LSST project calculated via the LSST stack.
How LSST Approaches Solar System/Moving Object Data Products
The goal is to provide products to the community that enable science in four guiding science themes; making a census of the Solar System is one of the four. LSST project therefore design products that are:
- Broadly useful for delivering unique LSST-enabled science
- Capture aspects that the LSST team is uniquely position to deliver
Key LSST Project Deliverables for Solar System Science
- Within 60 seconds of each observation: A real-time stream of observation reports (alerts) with information about astrometry, photometry, and shape including trailing, direction of motion.
- Every day: A stream of linked tracks reported to the Minor Planet Center.
- Every day: A catalog of orbits for LSST-discovered objects.
- Annually: Precisely calibrated photometric catalog (ugrizy bands) accurate to 5mmag (systematics limited), with every data release.
- trailed model PSF
- image cutouts
The Data Products Definition Document (DPDD) defines the outline of what the nightly and yearly catalogs will contain, but adding more detail via discussions with the SSSC is on-going. You can find a handy outline of the proposed database schema for the LSST SSObject table here . More information on the LSST Moving Object Pipeline System (MOPS) can be found here .
LSST Project Data Product Levels
The LSST stack will produce data products at three levels, which are broadly defined below.Prompt data products produced on nightly or shorter timescales which will consist of basic images, source catalogs, transient identifications, moving object identifications, and event alerts.
Data Release annual data release products including refinements to calibrations and photometry, calibration images, image co-adds and catalogs.
User Contributed are user-generated added value products.
Exactly what parameters will be automatically provided within Prompt and Data Release products are still being discussed. You can learn more about the current status on planned Solar System Data Products from LSST in this recorded presentation by Mario Jurić. More information on all LSST data products can be found here.
Annual release will have all LSST observations run through one version of the LSST data pipelines. The version of software run on the nightly observations can change, and old observations won't be rerun through the updated pipelines until the annual release.
Image Credit: LSST Data Management
Additional information on LSST data processing pipelines and data products can be found on the LSST Information for Scientists page.
The LSST Alert Stream
After an LSST image is taken, the image subtraction pipeline will identify transient sources (stuff that moves or varies in brightness). These Difference Image Analysis Sources (DIASources) will be sent out in the public LSST Alert Stream within 60s of the observation's end.
Image Credit: LSST Data Management/Leanne Guy
Image Credit: LSST Data Management/Leanne Guy
Image Credit: LSST Data Management/Leanne Guy
Image Credit: LSST Data Management/Leanne Guy
More about the alert stream can be found in this talk by Eric Bellm, this talk by Leanne Guy at the 2018 LSST Solar System Readiness Sprint, and the LSST Data Management Science Pipelines Design Document .
Proposed SSSC Generated Solar System-Specific Data Products
The following lists are incomplete. Eventually they will be complete, and listed in order of importance based on the cumulative needs of all science cases.