previous page   back to table of contents   next page

VIII. Post-Cryo Data Release

3. Data Processing

The 2013 NEOWISE Post-Cryo Release products were generated from complete second-pass data processing using version 5.0 of the WISE Science Data System (WSDS). WSDS v5.0 was adapted from WSDS v4.5 that was used to process WISE 3-Band Cryo data. Development of WSDS v5.0 was supported by a grant from the NASA ROSES Near Earth Object Observation Program. WSDS v5 includes all pipeline updates and improvements implemented for the second-pass reductions of the cryogenic missions data, and it corrects known deficiencies in the first-pass Post-Cryo processing, and employs calibrations and reduction algorithms that are optimized specifically for the post-cryogenic survey data. The reprocessed Post-Cryo products provide the best individual flux measurements for solar system objects that were identified by the WISE Moving Object Pipeline during the Post-Cryo survey, and they enable consistent follow-up of inertial sources found in the WISE All-Sky Release Catalog to investigate time-dependent properties such as flux variability and proper motion.

The NEOWISE Post-Cryo Preliminary Data Release (July 21, 2012) is superseded by the 2013 Post-Cryo Release. Post-Cryo Preliminary Release products were generated during first-pass data processing using WSDS v3.5 that utilized calibrations that were not yet optimized for the changing characteristics of the warming telescope and detectors. You should always defer to the newer 2013 Post-Cryo Release products. Please review the limitations and known features that are present in the both the 2013 Post-Cryo and Post-Cryo Preliminary Releases described in the Cautionary Notes section of this Explanatory Supplement.

Because the WISE Post-Cryo operations were intended primarily to support investigation of moving solar system objects, the Post-Cryo data were only run through the Scan/Frame and WISE Moving Object Pipelines. The Post-Cryo data did not undergo Multiframe Pipeline processing. Therefore, the Post-Cryo Release products do not include coadded Atlas Images and deep source detection Database/Catalog like those in the All-Sky and 3-Band Cryo Releases.

The basic design, functionality and algorithms in each WSDS pipeline module are described in section IV of this Explanatory Supplement. Sections VIII.3.a.i and VIII.3.a.ii contain summaries of the pipeline and calibration changes that were made for second-pass and first-pass Post-Cryo processing, respectively. These modifications deal primarily with eliminating W3 and W4 from all aspects of the processing and accommodating the changes to and time-dependence of the performance of the W1 and W2 detectors during the Post-Cryo survey phase. Changes to the individual modules, as well as known limitations in the processing and features of the Post-Cryo Release data products are described in more detail in sections VIII.3.b-d. Modules that are not highlighted in the following subsections are largely unchanged from WSDS v4.

a. Summary of Pipeline Modifications for Post-Cryo Processing

i. WSDS v5.0 Updates for Second-Pass Post-Cryo Processing

ii. WSDS v3.5 Updates for First-Pass Post-Cryo Processing

Last Update: 2013 June 5

previous page   back to table of contents   next page