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)
  
  
  
    Table of Contents
  
  
  Search the All-Sky Explanatory Supplement
  
  
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    To read a specific section, click on the section name.
  I. Introduction
  
    - Mission Overview
      
 
        - WISE
 
        - NEOWISE
 
        - WISE At-a-Glance
 
        - Data Releases
          
            - The All-Sky Data Release
 
            - The WISE 3-Band Cryo Data Release
 
            - The NEOWISE Post-Cryo Data Release
 
            - The ALLWISE Data Release
 
 			- The WISE Preliminary Data Release
 
            - The NEOWISE Post-Cryo Preliminary Data Release
 
          
         
        - About this Document
 
      
        -  Executive Summary of WISE All-Sky Release Data Products
      
        - Image Atlas
 
        - Source Catalog
 
        - Ancillary Products
          
            - Reject Table
 
            - Single-exposure Images
 
            - Single-exposure Source Database
 
            - Moving Object Tracklets
 
            - Known Solar System Object Possible Association List
 
            - Full-Depth Ecliptic Polar Atlas Images
 
          
         
      
     
    - How to Access WISE Data Products
      
        - Online Access
 
        - Application Programming Interface
 
        - Electronic Access to the Full Source Catalog
 
      
     
    - Cautionary Notes
      
        - Top 10 (or so) Things You Should Know About the WISE All-Sky Release Data Products
 
        - Source Catalog
 
        - Image Atlas
 
        - Ancillary Products
 
      
     
    -  Acknowledgments
      
        - WISE Personnel
 
      
     
    -  Referencing WISE and NEOWISE
      
        - WISE Source Naming Convention
 
        - Acknowledging WISE and NEOWISE in Publications
 
      
     
    - Acronym List
 
    - Document Change History
 
  
  II. The WISE All-Sky Data Products
  
    - General Properties of the All-Sky Data Release
 
    -  Source Catalog
      
        - Column Descriptions
 
        - Source Selection Criteria
 
        - General Properties
 
        - Photometric Properties
 
        - Astrometric Properties
 
      
     
    -  Atlas Images
      
        - Description and Format
 
        - Atlas Image Header Description
 
        - Image Anomalies and Features
 
        - Depth-of-Coverage Maps
 
        - Uncertainty Maps
          
            - Checking the Plausibility of Uncertainty Map Values
 
          
         
        - Aperture Photometry using the Atlas Images
          
            - Correlated Pixel Noise
 
            - Confusion Noise
 
          
         
        - Astrometry of Image-derived Source Positions
          
            - Methods to Correct Image-derived Coordinates and WCS
 
            - Source Position Biases in Single-exposure Images
 
          
         
        - Full-Depth Ecliptic Polar Atlas Images
 
      
     
    -  Ancillary Products
      
        - Reject Table
 
        - Single-Exposure Images, Bit Masks, Uncertainty Maps
          
            - Single-Exposure Image Header Descriptions
 
            - Single-Exposure Image Anomalies
 
          
         
        - Single-Exposure Source Working Database
          
            - Column Descriptions
 
          
         
        - Atlas Image Frame Cross-Reference Table
 
        - WISE Moving Object Pipeline Tracklets
          
            - Introduction
 
            - Retrieving WMOPS Objects
 
            - Tracklet Description
 
          
         
        - Atlas Metadata Table Column Descriptions
 
        - Single-Exposure Frame Metadata Table Column Descriptions
 
        - Atlas Image Inventory Table Format
 
        - Single-Exposure Image Inventory Table
 
        - Known Solar System Object Possible Association List Column Descriptions
 
        
      
     
  
  
  III. WISE Flight System and Operations
  
    - Spacecraft
 
    - Payload
      
        - Focal Planes
 
        - Optics
 
        - Cryostat
 
      
     
    - Mission Operations
      
        - Operations Concept
 
        - GDS Hardware and Software Architecture
 
        - End-to-end Data Flow
 
      
     
    - Survey Design and Data Acquisition
      
        - Scanning Strategy
 
        - Survey Strategy
 
        - Sky Coverage
 
      
     
  
  
  IV. WISE Data Processing
  
    - Processing Overview - The WISE Science Data System (WSDS)
      
        - WSDS Overview
          
            - Ingest
 
            - Pipelines
 
            - Final Product Generation (FPG)
 
            - Quality Assurance (QA)
 
            - Archive
 
          
         - Basic Terminology
 
        - Data Processing Levels
 
        - Data Processing Stages
          
            - Provisional Processing 
 
            - First-Pass Processing
 
            - Second-Pass Processing
 
          
         
        - Selected WSDS Improvements for Second-Pass Processing
          
            - Software Bug Fixes
 
            - Added Functionality
 
            - Improved Calibrations
 
            - Improved Reduction Algorithms
 
          
         
      
   
     - Data Ingest
      
        - Data Transfer
 
        - MOS Ingest
 
        - HRP Ingest
 
        - Quicklook Processing
 
      
     
    - Pipelines
      
        - The Scan/Frame Pipeline
 
        - The Moving Object Pipeline
 
        - The Multiframe Pipeline
 
      
     
    - Pipeline Science Modules
      
        - Single Frame Exposure Instrumental Image Calibration (ICAL)
          
            - Overview
 
            
              - Input Calibration Summary
 
              - Bit-Mask Definitions
 
            
            - Pixel Error Model
 
            
              - Electronic Gain and Read-Noise Calibration
 
            
            - Frame-mask Initialization and Bad-pixel Masking
 
            
              - Prior Masking of Bad Hardware Pixels
 
            
            - Band 3 and 4 Droop Correction
 
            
              - Intra-Quadrant Split-Droop
 
              - Global Inter-Quadrant Droop
 
              - Final Droop Refinement
 
              - Droop Correction Anomalies and Liens
 
            
            - Dark Calibration
 
            - Non-linearity Calibration
 
            
              - Validation
 
            
            - Relative Responsivity (Flat-field) Calibration
 
            
              - Methodologies
 
              - Flat-fielding Accuracy
 
            
            - Dynamic Calibration
 
            
              - Sky-offset Correction
 
              - Band 3 and 4 Delta-flat Correction
 
              - Transient Bad-pixel Masking
 
            
            - Spatial-outlier (Glitch) Masking
 
            - Band 1 and 2 Channel-noise and Bias Corrections
 
            - Instrumental Calibration Performance
 
            
              - Analysis of  Spatial-Bias Residuals
 
              - Analysis of Spatial-Responsivity Residuals 
 
            
          
         - Source Detection (MDET)
          
            - Overview
 
            - Theoretical Basis
 
            
              - Measurement Model
 
              - Detection Algorithm
 
              - Allowance for Cross-band Source Blending
 
            
            - Implementation
 
            
              - Procedure
 
              - Effects of Confusion
 
              - Dealing with Bright Saturated Stars
 
            
          
         
        - WISE Photometry System (WPHOT) 
          
            - Overview
 
            - WPHOT Executive
 
            
              - Memory Optimization
 
              - Coordinate Translation
 
              - Local Background Estimation
 
              - Bright Stars
 
            
            - Profile-Fitting Photometry (WPRO)
 
            
              - The Point Spread Function
 
              - WPRO Output Parameters
 
              - WPRO Magnitude Upper Limits
 
              - Saturation and Transient Fractions
 
              - Frame Detection and Flux Repeatability Statistics
 
              - Variability and Flagging
 
            
            - System (WAPPco)
 
            
              - Special Inputs
 
              - Circular Apertures
 
              - Output
 
              - Confusion and Warning Flags
 
              - Magnitude Upper Limits
 
            
            - 2MASS Galaxies and Elliptical Apertures
 
            - Resolved Sources and the Extended Source Flag
 
            - Aperture Corrections for Large-Aperture Atlas Image Photometry
 
            - PSFs and Curves-of-Growth for WISE Atlas Images
 
          
         
        - Position Reconstruction (PRex)
          
            - SFPRex Input
 
            - SFPRex Processing: Initialization
 
            - SFPRex Processing: Group Merging
 
            - SFPRex Processing: Pattern Matching
 
            
              - Bar-Separation Algorithm
 
              - Bar-Match Parameter Uncertainties
 
              -  Bar-Match Solution Averaging
 
            
            - SFPRex Processing: Parameter Fitting
 
            - Constrained Solutions and Reduced Systems of Equations
 
            
              - Fixed Parameters
 
              - Scale Changes Equal on Both Axes
 
            
            - Distortion Calibration
 
            - Differential Aberration
 
            - Tile Position Refinement
 
            - Cautionary Notes
 
            
              - Error in W4 Band-Frame Positions
 
              - Proper Motions
 
            
          
         
        - Known Solar System Object Association
          
            - Orbit Data
 
            - Orbit Computation
 
            - SSO/WISE Assocation
 
            - Observation Frequency Distribution
 
            - Cautionary Notes
 
            
              - Background Contamination
 
            
          
         
        - Atlas Image Generation
          
            - Overview
 
            
              - Sky Tiling and Footprint Definition
 
            
            - Throughput (Gain) Matching
 
            - Frame Overlap/Background-Level Matching
 
            - Flagging Moon-affected Frames Using Prior Mask
 
            
              - Prior Moon-masks
 
              - Moon-contamination Processing
 
            
            - Pixel Outlier Detection and Masking
 
            
              - First-Pass Computations
 
              - Second-Pass Computations
 
              - Outlier Expansion
 
            
            - Frame-Based Rejection
 
            - Frame Coaddition Using PRF Interpolation
 
          
         
        - Artifact Identification (ARTID)
          
            - Diffraction Spikes
 
            - Scattered-Light Halos
 
            - Optical Ghosts
 
            - Latents (Persistence)
 
            
              - Short-term Latents: HgCdTe and Si:As arrays
 
              - Long-term Latents (Si:As arrays only)
 
              - Treatment of Latents by Single-frame WISE Pipeline
 
              - Changes in the All-Sky Data Release
 
              - Multiframe Flagging
 
            
            - Glints
 
            - The Bright Source List (BSL)
 
            - Cautionary Notes
 
          
         - Photometric Calibration
          
            - Summary and Useful Formulas 
 
            
              - Vega Magnitudes to Flux Density
 
              - Additional W4 Correction for "Red" Sources
 
              - Vega to AB Magnitudes
 
              - Examples for Converting WISE Magnitudes to Flux Densities
 
            
            - The WISE Calibration Source Network
 
            - Calibrated Magnitudes
 
            - Photometric Zero Point Evaluation
 
            - WISE Filter Bandpasses and Zero Magnitude Attributes
 
            - Flux Corrections and Colors for Power Laws and Blackbodies
 
            - Calibration Uncertainties
 
          
         
      
     
    - WISE Moving Object Pipeline
      
        - Introduction
 
        - Subsystem Overview
          
            - Operational Description
 
            - Caveats
 
            - Finding WMOPS Objects
 
          
         
        - Summary
 
      
     
    - Quality Assurance
      
        - Steps in the QA Process
          
            - Quicklook QA
 
            - ScanFrame QA
 
            - Multiframe QA
 
          
         
        - QA Scores in the All-Sky Release Data
 
        - Ancillary Notes
          
            - Noise Pixels
 
            - PSF Moments
 
          
         
      
     
    - Archive Preparation and Loading
      
        - Source Data and Metadata
 
        - Image Data and Metadata
 
        - Data Output
 
        - Data and Metadata Transfer to IRSA
 
      
     
  
  
  V. Atlas and Catalog Generation
  
    - Overview
    
 - Scan, Tile and Frameset Selection
      
        - Scan Selection
 
        - Tile Selection
 
        - Frameset and Frame Selection
 
        
          - Polar Tile Coverage Attenuation
        
 
      
     
    - Catalog Source Selection
      
        - Tile Edge Boundaries
 
        - Source Reliability Criteria
          
            - Detection and SNR Limits
 
            - Artifact Flagging
 
            - Frame Depth-of-Coverage
 
            - Planet Contamination
 
          
         
        - Duplicate Source Resolution
          
            - Groups
 
            - Associating Groups of Detections Using WAX
 
            
              - Source Confusion
 
              - Search Radius
 
            
            - Detection Selection
 
            
              - Pre-Filter
 
              - Distance to Edge Selection
 
            
          
         
      
     
    - Atlas and Catalog Test and Verification Regions
 
  
  
  VI. Analysis of Data Products
  
    - Comparison of Achieved Performance with Level 1 Science Requirements
 
    - Sky Coverage
      
        - All-Sky Release Data Area
 
        - Sky Coverage Statistics
 
        - Caveats About Low Coverage
 
      
     
    
    - Photometric Properties
      
        - Photometric Sensitivity
          
            - External Sensitivity Checks
 
          
         
        - Photometric Accuracy
 
        - Photometric Biases
          
            - Measurement Biases
 
            - Calibration Biases
 
          
         
        - Characteristic Source Brightness for the Onset of Saturation
          
            - Saturated Source Characterization
 
            -  Saturation as a Function of Brightness
 
            
              - Source Catalog
 
              - Single-Exposure Source Database
 
              - Bright Source Photometry Limits
 
            
          
         
        - Extended Source Photometry
 
      
     
    - Position Reconstruction Performance
      
        - Overview
 
        - WISE Positional Residuals Relative to 2MASS
 
        - Astrometric Positions of Faint Sources
 
        - Astrometric Quality of W3 and W4-Dominated Sources
 
        - Atlas Image Astrometry
 
        - All-Sky Performance Relative to the ICRS
 
        - Summary
 
      
     
    - Catalog Completeness
      
        - Requirement
 
        - Internal Tests
 
        - Completeness Estimates
 
        - External Tests
 
      
     
    - Catalog Reliability
      
        - Internal Reliability
 
        - Comparison with 2MASS
 
        - Comparison with Spitzer
 
        - Supplemental Reliability Figures
 
      
     
  
  
  VII. 3-Band Cryo Data Release
  
    - Introduction
      
        - 3-Band Cryo Operations
 
        - Executive Summary of 3-Band Cryo Data Products
          
            - Image Atlas
 
            - Source Working Database
 
            - Single-Exposure Images
 
            - Single-Exposure Source  Database
 
            - Known Solar-System Object Possible Association List
 
          
         
        - How to Access the 3-Band Cryo Data Products
 
        - Cautionary Notes
          
            - Top 10 (or so) Things You Should Know About the 3-Band Cryo Release Products
 
            - General
 
            - Source Working Database
 
            - Image Atlas
 
            - Single-Exposure Source Working Database
 
            - Single-Exposure Images
 
          
         
      
     
    - 3-Band Cryo Data Products
      
        - Source Working Database
          
            - Format and Column Description
 
          
         
        - Image Atlas
          
            - Image Anomalies
 
          
         
        - Single-Exposure Source Working Database
          
            - Format and Column Descriptions
 
          
         
        - Single-Exposure Images, Bit Masks, Uncertainty Maps
          
            - Single-Exposure Image Anomalies and Features
 
          
         
        - Atlas Image Frame Cross-Reference Table
        
 - Atlas Metadata Column Descriptions
 
        - Single-exposure (Level 1) Frame Metadata Column Descriptions 
 
        - Atlas Image Inventory Table Column Descriptions
 
        - Single-Exposure (Level 1) Image Inventory Table Column Descriptions
 
        - Known Solar System Object Possible Association List Format 
 
      
     
    - 3-Band Cryo Data Processing
      
        - Summary of Pipeline Modifications for 3-Band Cryo Processing
 
        - Single Frame Exposure Instrumental Calibration (ICAL)
          
            - Calibration Summary
 
            - Bit-Mask Definitions
            
 - Electronic Gain, Read-Noise, and Pixel Uncertainty Estimation 
 
            - Bad-pixel Masking and Saturation Tagging
 
            
              - Saturated Pixel Tagging
 
              - Caveats
 
            
            - Band 3 Droop Correction
 
            - Non-linearity Calibration
 
            - Relative Responsivity (Flat-field) Calibration
 
            - Dynamic Calibration
 
            
              - Caveats
 
            
          
         
        - Source Photometry (WPHOT)
          
            - Variability and Flagging"
 
          
         
        - Position Reconstruction (PRex)
 
        - Atlas Image Generation
          
            - Overview
 
            - Additional Metadata and Corrections
 
            - Photometric Zero-Point Corrections
 
            - Caveats
 
          
         
        - Artifact Identification (ARTID)
 
        - Photometric Calibration
 
        - Quality Assurance
 
        - Archive Preparation and Loading
 
      
     
    - Atlas and Source Working Database Preparation
      
        - Scope and Scan Selection
 
        - Tile Selection
 
        - Frameset and Frame Selection
 
        - Duplicate Source Identification
 
        - All-Sky Release Catalog Association
 
      
     
    - Analysis of 3-Band Cryo Data Products
      
        - Sky Coverage
 
        - Photometric Performance
 
        
          - Photometric Accuracy
 
          - Photometric Sensitivity
 
        
        - Position Reconstruction Performance
 
        - Completeness
 
        - Reliability
 
      
     
  
  
  VIII. Post-Cryo Data Release
  
    -  Introduction
      
        - Post-Cryo Operations
        
 - Executive Summary of Post-Cryo Data Products
          
            - Post-Cryo Release Products
 
            - Preliminary Post-Cryo Release Products
 
           
          
         
        - How to Access the Post-Cryo Data Products
 
        - Cautionary Notes
          
            - 2013 Post-Cryo Release
              
                - Top 10 (or so) Things You Should Know About the 2013 Post-Cryo Release Products
 
                - General
 
                - Single-Exposure Source Database
 
                - Single-Exposure Images
 
              
             
            - Post-Cryo Preliminary Release
              
                - Top 10 (or so) Things You Should Know About the Post-Cryo Preliminary Release Products
 
                - General
 
                - Single-Exposure Source Database
 
                - Single-Exposure Images
 
              
             
          
         
      
     
    - Post-Cryo Release Data Products
      
        - Post-Cryo Single-Exposure Source Database Format and Column Descriptions
 
        
          - 2013 Post-Cryo Release 
 
          - Post-Cryo Preliminary Release
 
        
        - Single-Exposure Images, Bit Masks, Uncertainty Maps
 
        
          - Image Anomalies and Features 
 
        
        - Single Exposure (Level 1) Image Metadata Table Column Descriptions
 
        
          - 2013 Post-Cryo Release 
 
          - Post-Cryo Preliminary Release
 
        
        - Single Exposure (Level 1) Image Inventory Table Column Descriptions
 
        
          - 2013 Post-Cryo Release 
 
          - Post-Cryo Preliminary Release
 
        
        - Known Solar-System Object Possible Association List Column Descriptions 
 
        
          - 2013 Post-Cryo Release 
 
          - Post-Cryo Preliminary Release
 
        
      
     
    - Data Processing
      
        - Summary of Pipeline Modifications for Post-Cryo First-Pass Processing
          
            - WSDS v5.0 Updates for Second-Pass Post-Cryo Processing
 
            - WSDS v3.5 Updates for First-Pass Post-Cryo Processing
 
          
         
        - Single Frame Exposure Instrumental Image Calibration (ICal) 
          
          
            - Overview
 
            - Dark Calibration
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
            - Relative Responsivity (Flat-field) Calibration
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
            - Static Bad-Pixel Masks
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
            - Electronic Gain and Read-Noise Calibrations
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
            - Channel-Noise and Bias Corrections
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
            - Dynamic Calibrations
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
            - Performance
              
                - Preliminary Release
 
                - 2013 Release
 
              
             
          
         
        
        
        - Position Reconstruction
          
            - Modeling Changes in Distortion with Time
 
            - Evaluation of the Time-Dependent Distortion Model
 
            - Evaluation of Reconstructed Source Positions
 
          
         
        
        
        
        - Single-Frame Artifact Identification (ARTID)
 
        - Photometric Calibration
          
            - Summary
 
            - Deriving the Post-Cryo Photometric Instrumental Zero Points
 
            - Post-Cryo Calibration Validation
 
            - Post-Cryo Preliminary Release Calibration
 
          
         
        - Quality Assurance (QA)
          
            - Judging 
 
            - QA Scores
 
            - Establishing New Thresholds for qi
 
            - Assessing Thresholds for qn
 
          
         
      
     
  
  
  
  
  
  
   
  
  
  
  
  
  
  Last update: 2015 February 19
  For assistance, contact The WISE Helpdesk