wiki:DC3bDataProducts

Version 2 (modified by ktl, 10 years ago) (diff)

Added image products.

DC3b Data Products

The DC3b Data Release Production will generate a number of outputs. This page attempts to describe these outputs in more detail. Provisional class names, typically based on prior usage in DC3a, are given in brackets.

Source-like measurements

S1. Measurements of (quite) bright stars on single CCDs for PSF and WCS determination. [WcsSource]

  • These are only stars.
  • These are produced internal to the Image Characterization Pipeline.

S2. Measurements of astronomical objects over a given S/N threshold on single CCDs. [Source]

  • These are produced by Single Frame Measurement.
  • Do we need to associate these before passing them to Astrometric Calibration?
  • These are used by Astrometric Calibration.
  • These will be associated with Objects by Object Merge/Association?.

S3. Forced photometry measurements on single CCDs using the shapes from Multifit Measurement. [Source and/or FaintSource]

  • These include both stars and galaxies.
  • These may include measurements above and below the S/N threshold. The ones below the S/N threshold could perhaps have less information stored, or all of these could have less information stored. The ones above the S/N threshold might need to be associated with and combined with the measurements in S2, but it is more likely that this association will be indirect through their corresponding Object.
  • These are produced by Forced Photometry.

S4. Measurements on single-CCD difference images using the positions from Difference Detection. [DiaSource]

  • These are only above a detection S/N threshold.
  • These are produced by Difference Measurement.
  • These are used by MOPS.
  • These will be associated with Objects or used to create new Objects by Object Merge/Association?.

S5. Forced photometry measurements on single-CCD difference images using the positions/shapes from Deep Detection (O1). [DiaSource and/or FaintDiaSource]

  • These may include measurements above and below the S/N threshold. The ones below the S/N threshold could perhaps have less information stored, or all of these could have less information stored. The ones above the S/N threshold might need to be associated with and combined with the measurements in S4, but it is more likely that this association will be indirect through their corresponding Object or MovingObject.
  • Will all positions/shapes from Deep Detection be used or only a subset, and if a subset, how will that be determined?
  • Won't we also need to do forced photometry at orbit positions calculated by MOPS for MovingObjects?

S6. S1-5 with additional per-Source photometric calibration information.

  • Will the DiaSources (S4-5) also have photo-cal information?
  • These are produced by Photometric Calibration.

Object-like measurements

O1. Measurements of detections on the panchromatic deep chi-square co-add. [Detection]

  • These are only above a detection S/N threshold.
  • These are produced by Deep Detection.
  • These are used by Multifit Measurement as the initial conditions for fitting.

O2. Model parameters based on stacks of postage stamps for all detections in O1.

  • These are produced by Multifit Measurement.
  • These are used by Forced Photometry.

O3. Astrometric models for all astronomical objects measured sufficient numbers of times in Single Frame Measurement (S2).

  • These are produced by Astrometric Calibration.
  • These are used by Multifit Measurement.

O4. Moving object models (i.e. orbits). [MovingObject]

  • These are produced by MOPS.

O5. Combinations of O1-4 with averages or other summaries of measurements from S1-5. [Object]

O6) O5 with additional per-Object photometric calibration information.

  • These are produced by Photometric Calibration.

CCD-level images

I1. Pre-ISR images in standard format with standard metadata.

I2. Post-ISR images.

I3. Summed visit images.

I4. Calibrated Science Exposures with PSF and WCS.

I5. Difference images.

I6. PSF-matched, warped images for template co-addition.

I7. Calibrated Science Exposures with moving objects masked out.

Co-adds

C1. Template co-adds, one per filter, using "good seeing" exposures.

C2. Deep co-adds, one per filter, using all "reasonable" exposures.

C3. Panchromatic deep chi-square co-add for deep detection and measurement.