The WISE Home Page

Explanatory Supplement to the WISE
All-Sky Data Release Products

R. M. Cutri (IPAC/Caltech), E. L. Wright (UCLA), T. Conrow (IPAC/Caltech), J. Bauer (IPAC/Caltech), D. Benford (NASA/GSFC), H. Brandenburg (IPAC/Caltech), J. Dailey (IPAC/Caltech), P. R. M. Eisenhardt (JPL), T. Evans (IPAC/Caltech), S. Fajardo-Acosta (IPAC/Caltech), J. Fowler (IPAC/Caltech), C. Gelino (IPAC/Caltech), C. Grillmair (IPAC/Caltech), M. Harbut (IPAC/Caltech), D. Hoffman (IPAC/Caltech), T. Jarrett (IPAC/Caltech), J. D. Kirkpatrick (IPAC/Caltech), D. Leisawitz (NASA/GSFC), W. Liu (IPAC/Caltech), A. Mainzer (JPL), K. Marsh (IPAC/Caltech), F. Masci (IPAC/Caltech), H. McCallon (IPAC/Caltech), D. Padgett (NASA/GSFC), M. E. Ressler (JPL), D. Royer (JPL), M. F. Skrutskie (U. Virgina), S. A. Stanford (UC Davis), P. L. Wyatt (IPAC/Caltech), D. Tholen (U. Hawaii), C.-W. Tsai (IPAC/Caltech), S. Wachter (IPAC/Caltech), S. L. Wheelock (IPAC/Caltech), L. Yan (IPAC/Caltech), R. Alles (IPAC/Caltech), R. Beck (IPAC/Caltech), T. Grav (JHU), J. Masiero (JPL), B. McCollum (IPAC/Caltech), P. McGehee (IPAC/Caltech), M. Papin (IPAC/Caltech), M. Wittman (IPAC/Caltech)

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Table of Contents


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I. Introduction

  1. Mission Overview
    1. WISE
    2. NEOWISE
    3. WISE At-a-Glance
    4. Data Releases
      1. The All-Sky Data Release
      2. The WISE 3-Band Cryo Data Release
      3. The NEOWISE Post-Cryo Data Release
      4. The ALLWISE Data Release
      5. The WISE Preliminary Data Release
      6. The NEOWISE Post-Cryo Preliminary Data Release
    5. About this Document
  2. Executive Summary of WISE All-Sky Release Data Products
    1. Image Atlas
    2. Source Catalog
    3. Ancillary Products
      1. Reject Table
      2. Single-exposure Images
      3. Single-exposure Source Database
      4. Moving Object Tracklets
      5. Known Solar System Object Possible Association List
      6. Full-Depth Ecliptic Polar Atlas Images
  3. How to Access WISE Data Products
    1. Online Access
    2. Application Programming Interface
    3. Electronic Access to the Full Source Catalog
  4. Cautionary Notes
    1. Top 10 (or so) Things You Should Know About the WISE All-Sky Release Data Products
    2. Source Catalog
    3. Image Atlas
    4. Ancillary Products
  5. Acknowledgments
    1. WISE Personnel
  6. Referencing WISE and NEOWISE
    1. WISE Source Naming Convention
    2. Acknowledging WISE and NEOWISE in Publications
  7. Acronym List
  8. Document Change History

II. The WISE All-Sky Data Products

  1. General Properties of the All-Sky Data Release
  2. Source Catalog
    1. Column Descriptions
    2. Source Selection Criteria
    3. General Properties
    4. Photometric Properties
    5. Astrometric Properties
  3. Atlas Images
    1. Description and Format
    2. Atlas Image Header Description
    3. Image Anomalies and Features
    4. Depth-of-Coverage Maps
    5. Uncertainty Maps
      1. Checking the Plausibility of Uncertainty Map Values
    6. Aperture Photometry using the Atlas Images
      1. Correlated Pixel Noise
      2. Confusion Noise
    7. Astrometry of Image-derived Source Positions
      1. Methods to Correct Image-derived Coordinates and WCS
      2. Source Position Biases in Single-exposure Images
    8. Full-Depth Ecliptic Polar Atlas Images
  4. Ancillary Products
    1. Reject Table
    2. Single-Exposure Images, Bit Masks, Uncertainty Maps
      1. Single-Exposure Image Header Descriptions
      2. Single-Exposure Image Anomalies
    3. Single-Exposure Source Working Database
      1. Column Descriptions
    4. Atlas Image Frame Cross-Reference Table
    5. WISE Moving Object Pipeline Tracklets
      1. Introduction
      2. Retrieving WMOPS Objects
      3. Tracklet Description
    6. Atlas Metadata Table Column Descriptions
    7. Single-Exposure Frame Metadata Table Column Descriptions
    8. Atlas Image Inventory Table Format
    9. Single-Exposure Image Inventory Table
    10. Known Solar System Object Possible Association List Column Descriptions

III. WISE Flight System and Operations

  1. Spacecraft
  2. Payload
    1. Focal Planes
    2. Optics
    3. Cryostat
  3. Mission Operations
    1. Operations Concept
    2. GDS Hardware and Software Architecture
    3. End-to-end Data Flow
  4. Survey Design and Data Acquisition
    1. Scanning Strategy
    2. Survey Strategy
    3. Sky Coverage

IV. WISE Data Processing

  1. Processing Overview - The WISE Science Data System (WSDS)
    1. WSDS Overview
      1. Ingest
      2. Pipelines
      3. Final Product Generation (FPG)
      4. Quality Assurance (QA)
      5. Archive
    2. Basic Terminology
    3. Data Processing Levels
    4. Data Processing Stages
      1. Provisional Processing
      2. First-Pass Processing
      3. Second-Pass Processing
    5. Selected WSDS Improvements for Second-Pass Processing
      1. Software Bug Fixes
      2. Added Functionality
      3. Improved Calibrations
      4. Improved Reduction Algorithms
  2. Data Ingest
    1. Data Transfer
    2. MOS Ingest
    3. HRP Ingest
    4. Quicklook Processing
  3. Pipelines
    1. The Scan/Frame Pipeline
    2. The Moving Object Pipeline
    3. The Multiframe Pipeline
  4. Pipeline Science Modules
    1. Single Frame Exposure Instrumental Image Calibration (ICAL)
      1. Overview
        1. Input Calibration Summary
        2. Bit-Mask Definitions
      2. Pixel Error Model
        1. Electronic Gain and Read-Noise Calibration
      3. Frame-mask Initialization and Bad-pixel Masking
        1. Prior Masking of Bad Hardware Pixels
      4. Band 3 and 4 Droop Correction
        1. Intra-Quadrant Split-Droop
        2. Global Inter-Quadrant Droop
        3. Final Droop Refinement
        4. Droop Correction Anomalies and Liens
      5. Dark Calibration
      6. Non-linearity Calibration
        1. Validation
      7. Relative Responsivity (Flat-field) Calibration
        1. Methodologies
        2. Flat-fielding Accuracy
      8. Dynamic Calibration
        1. Sky-offset Correction
        2. Band 3 and 4 Delta-flat Correction
        3. Transient Bad-pixel Masking
      9. Spatial-outlier (Glitch) Masking
      10. Band 1 and 2 Channel-noise and Bias Corrections
      11. Instrumental Calibration Performance
        1. Analysis of Spatial-Bias Residuals
        2. Analysis of Spatial-Responsivity Residuals
    2. Source Detection (MDET)
      1. Overview
      2. Theoretical Basis
        1. Measurement Model
        2. Detection Algorithm
        3. Allowance for Cross-band Source Blending
      3. Implementation
        1. Procedure
        2. Effects of Confusion
        3. Dealing with Bright Saturated Stars
    3. WISE Photometry System (WPHOT)
      1. Overview
      2. WPHOT Executive
        1. Memory Optimization
        2. Coordinate Translation
        3. Local Background Estimation
        4. Bright Stars
      3. Profile-Fitting Photometry (WPRO)
        1. The Point Spread Function
        2. WPRO Output Parameters
        3. WPRO Magnitude Upper Limits
        4. Saturation and Transient Fractions
        5. Frame Detection and Flux Repeatability Statistics
        6. Variability and Flagging
      4. System (WAPPco)
        1. Special Inputs
        2. Circular Apertures
        3. Output
        4. Confusion and Warning Flags
        5. Magnitude Upper Limits
      5. 2MASS Galaxies and Elliptical Apertures
      6. Resolved Sources and the Extended Source Flag
      7. Aperture Corrections for Large-Aperture Atlas Image Photometry
      8. PSFs and Curves-of-Growth for WISE Atlas Images
    4. Position Reconstruction (PRex)
      1. SFPRex Input
      2. SFPRex Processing: Initialization
      3. SFPRex Processing: Group Merging
      4. SFPRex Processing: Pattern Matching
        1. Bar-Separation Algorithm
        2. Bar-Match Parameter Uncertainties
        3. Bar-Match Solution Averaging
      5. SFPRex Processing: Parameter Fitting
      6. Constrained Solutions and Reduced Systems of Equations
        1. Fixed Parameters
        2. Scale Changes Equal on Both Axes
      7. Distortion Calibration
      8. Differential Aberration
      9. Tile Position Refinement
      10. Cautionary Notes
        1. Error in W4 Band-Frame Positions
        2. Proper Motions
    5. Known Solar System Object Association
      1. Orbit Data
      2. Orbit Computation
      3. SSO/WISE Assocation
      4. Observation Frequency Distribution
      5. Cautionary Notes
        1. Background Contamination
    6. Atlas Image Generation
      1. Overview
        1. Sky Tiling and Footprint Definition
      2. Throughput (Gain) Matching
      3. Frame Overlap/Background-Level Matching
      4. Flagging Moon-affected Frames Using Prior Mask
        1. Prior Moon-masks
        2. Moon-contamination Processing
      5. Pixel Outlier Detection and Masking
        1. First-Pass Computations
        2. Second-Pass Computations
        3. Outlier Expansion
      6. Frame-Based Rejection
      7. Frame Coaddition Using PRF Interpolation
    7. Artifact Identification (ARTID)
      1. Diffraction Spikes
      2. Scattered-Light Halos
      3. Optical Ghosts
      4. Latents (Persistence)
        1. Short-term Latents: HgCdTe and Si:As arrays
        2. Long-term Latents (Si:As arrays only)
        3. Treatment of Latents by Single-frame WISE Pipeline
        4. Changes in the All-Sky Data Release
        5. Multiframe Flagging
      5. Glints
      6. The Bright Source List (BSL)
      7. Cautionary Notes
    8. Photometric Calibration
      1. Summary and Useful Formulas
        1. Vega Magnitudes to Flux Density
        2. Additional W4 Correction for "Red" Sources
        3. Vega to AB Magnitudes
        4. Examples for Converting WISE Magnitudes to Flux Densities
      2. The WISE Calibration Source Network
      3. Calibrated Magnitudes
      4. Photometric Zero Point Evaluation
      5. WISE Filter Bandpasses and Zero Magnitude Attributes
      6. Flux Corrections and Colors for Power Laws and Blackbodies
      7. Calibration Uncertainties
  5. WISE Moving Object Pipeline
    1. Introduction
    2. Subsystem Overview
      1. Operational Description
      2. Caveats
      3. Finding WMOPS Objects
    3. Summary
  6. Quality Assurance
    1. Steps in the QA Process
      1. Quicklook QA
      2. ScanFrame QA
      3. Multiframe QA
    2. QA Scores in the All-Sky Release Data
    3. Ancillary Notes
      1. Noise Pixels
      2. PSF Moments
  7. Archive Preparation and Loading
    1. Source Data and Metadata
    2. Image Data and Metadata
    3. Data Output
    4. Data and Metadata Transfer to IRSA

V. Atlas and Catalog Generation

  1. Overview
  2. Scan, Tile and Frameset Selection
    1. Scan Selection
    2. Tile Selection
    3. Frameset and Frame Selection
      1. Polar Tile Coverage Attenuation
  3. Catalog Source Selection
    1. Tile Edge Boundaries
    2. Source Reliability Criteria
      1. Detection and SNR Limits
      2. Artifact Flagging
      3. Frame Depth-of-Coverage
      4. Planet Contamination
    3. Duplicate Source Resolution
      1. Groups
      2. Associating Groups of Detections Using WAX
        1. Source Confusion
        2. Search Radius
      3. Detection Selection
        1. Pre-Filter
        2. Distance to Edge Selection
  4. Atlas and Catalog Test and Verification Regions

VI. Analysis of Data Products

  1. Comparison of Achieved Performance with Level 1 Science Requirements
  2. Sky Coverage
    1. All-Sky Release Data Area
    2. Sky Coverage Statistics
    3. Caveats About Low Coverage
  3. Photometric Properties
    1. Photometric Sensitivity
      1. External Sensitivity Checks
    2. Photometric Accuracy
    3. Photometric Biases
      1. Measurement Biases
      2. Calibration Biases
    4. Characteristic Source Brightness for the Onset of Saturation
      1. Saturated Source Characterization
      2. Saturation as a Function of Brightness
        1. Source Catalog
        2. Single-Exposure Source Database
        3. Bright Source Photometry Limits
    5. Extended Source Photometry
  4. Position Reconstruction Performance
    1. Overview
    2. WISE Positional Residuals Relative to 2MASS
    3. Astrometric Positions of Faint Sources
    4. Astrometric Quality of W3 and W4-Dominated Sources
    5. Atlas Image Astrometry
    6. All-Sky Performance Relative to the ICRS
    7. Summary
  5. Catalog Completeness
    1. Requirement
    2. Internal Tests
    3. Completeness Estimates
    4. External Tests
  6. Catalog Reliability
    1. Internal Reliability
    2. Comparison with 2MASS
    3. Comparison with Spitzer
    4. Supplemental Reliability Figures

VII. 3-Band Cryo Data Release

  1. Introduction
    1. 3-Band Cryo Operations
    2. Executive Summary of 3-Band Cryo Data Products
      1. Image Atlas
      2. Source Working Database
      3. Single-Exposure Images
      4. Single-Exposure Source Database
      5. Known Solar-System Object Possible Association List
    3. How to Access the 3-Band Cryo Data Products
    4. Cautionary Notes
      1. Top 10 (or so) Things You Should Know About the 3-Band Cryo Release Products
      2. General
      3. Source Working Database
      4. Image Atlas
      5. Single-Exposure Source Working Database
      6. Single-Exposure Images
  2. 3-Band Cryo Data Products
    1. Source Working Database
      1. Format and Column Description
    2. Image Atlas
      1. Image Anomalies
    3. Single-Exposure Source Working Database
      1. Format and Column Descriptions
    4. Single-Exposure Images, Bit Masks, Uncertainty Maps
      1. Single-Exposure Image Anomalies and Features
    5. Atlas Image Frame Cross-Reference Table
    6. Atlas Metadata Column Descriptions
    7. Single-exposure (Level 1) Frame Metadata Column Descriptions
    8. Atlas Image Inventory Table Column Descriptions
    9. Single-Exposure (Level 1) Image Inventory Table Column Descriptions
    10. Known Solar System Object Possible Association List Format
  3. 3-Band Cryo Data Processing
    1. Summary of Pipeline Modifications for 3-Band Cryo Processing
    2. Single Frame Exposure Instrumental Calibration (ICAL)
      1. Calibration Summary
      2. Bit-Mask Definitions
      3. Electronic Gain, Read-Noise, and Pixel Uncertainty Estimation
      4. Bad-pixel Masking and Saturation Tagging
        1. Saturated Pixel Tagging
        2. Caveats
      5. Band 3 Droop Correction
      6. Non-linearity Calibration
      7. Relative Responsivity (Flat-field) Calibration
      8. Dynamic Calibration
        1. Caveats
    3. Source Photometry (WPHOT)
      1. Variability and Flagging"
    4. Position Reconstruction (PRex)
    5. Atlas Image Generation
      1. Overview
      2. Additional Metadata and Corrections
      3. Photometric Zero-Point Corrections
      4. Caveats
    6. Artifact Identification (ARTID)
    7. Photometric Calibration
    8. Quality Assurance
    9. Archive Preparation and Loading
  4. Atlas and Source Working Database Preparation
    1. Scope and Scan Selection
    2. Tile Selection
    3. Frameset and Frame Selection
    4. Duplicate Source Identification
    5. All-Sky Release Catalog Association
  5. Analysis of 3-Band Cryo Data Products
    1. Sky Coverage
    2. Photometric Performance
      1. Photometric Accuracy
      2. Photometric Sensitivity
    3. Position Reconstruction Performance
    4. Completeness
    5. Reliability

VIII. Post-Cryo Data Release

  1. Introduction
    1. Post-Cryo Operations
    2. Executive Summary of Post-Cryo Data Products
      1. Post-Cryo Release Products
      2. Preliminary Post-Cryo Release Products
    3. How to Access the Post-Cryo Data Products
    4. Cautionary Notes
      1. 2013 Post-Cryo Release
        1. Top 10 (or so) Things You Should Know About the 2013 Post-Cryo Release Products
        2. General
        3. Single-Exposure Source Database
        4. Single-Exposure Images
      2. Post-Cryo Preliminary Release
        1. Top 10 (or so) Things You Should Know About the Post-Cryo Preliminary Release Products
        2. General
        3. Single-Exposure Source Database
        4. Single-Exposure Images
  2. Post-Cryo Release Data Products
    1. Post-Cryo Single-Exposure Source Database Format and Column Descriptions
      1. 2013 Post-Cryo Release
      2. Post-Cryo Preliminary Release
    2. Single-Exposure Images, Bit Masks, Uncertainty Maps
      1. Image Anomalies and Features
    3. Single Exposure (Level 1) Image Metadata Table Column Descriptions
      1. 2013 Post-Cryo Release
      2. Post-Cryo Preliminary Release
    4. Single Exposure (Level 1) Image Inventory Table Column Descriptions
      1. 2013 Post-Cryo Release
      2. Post-Cryo Preliminary Release
    5. Known Solar-System Object Possible Association List Column Descriptions
      1. 2013 Post-Cryo Release
      2. Post-Cryo Preliminary Release
  3. Data Processing
    1. Summary of Pipeline Modifications for Post-Cryo First-Pass Processing
      1. WSDS v5.0 Updates for Second-Pass Post-Cryo Processing
      2. WSDS v3.5 Updates for First-Pass Post-Cryo Processing
    2. Single Frame Exposure Instrumental Image Calibration (ICal)
      1. Overview
      2. Dark Calibration
        1. Preliminary Release
        2. 2013 Release
      3. Relative Responsivity (Flat-field) Calibration
        1. Preliminary Release
        2. 2013 Release
      4. Static Bad-Pixel Masks
        1. Preliminary Release
        2. 2013 Release
      5. Electronic Gain and Read-Noise Calibrations
        1. Preliminary Release
        2. 2013 Release
      6. Channel-Noise and Bias Corrections
        1. Preliminary Release
        2. 2013 Release
      7. Dynamic Calibrations
        1. Preliminary Release
        2. 2013 Release
      8. Performance
        1. Preliminary Release
        2. 2013 Release
    3. Position Reconstruction
      1. Modeling Changes in Distortion with Time
      2. Evaluation of the Time-Dependent Distortion Model
      3. Evaluation of Reconstructed Source Positions
    4. Single-Frame Artifact Identification (ARTID)
    5. Photometric Calibration
      1. Summary
      2. Deriving the Post-Cryo Photometric Instrumental Zero Points
      3. Post-Cryo Calibration Validation
      4. Post-Cryo Preliminary Release Calibration
    6. Quality Assurance (QA)
      1. Judging
      2. QA Scores
      3. Establishing New Thresholds for qi
      4. Assessing Thresholds for qn

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Last update: 2015 February 19

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