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I. Introduction

I.3. Executive Summary of NEOWISE Data Products


NEOWISE Data Release Archive Contents
ProductYear 1Year 2Year 3Year 4Year 5Year 6Total
a. Single-Exposure Images2,497,867 image sets2,557,865 image sets2,599,344 image sets2,565,705 image sets2,524,881 image sets2,512,443 image sets15,321,139 image sets
b. Single-Exposure Source Database18,468,575,596 detections19,691,230,571 detections19,631,135,692 detections19,098,199,664 detections18,795,708,783 detections18,717,323,537 detections114,402,173,833 detections
c. Moving Object Tracklets *137,547 detections of 10,308 solar system objects, confirmed by the IAU MPC.157,568 detections of 11,686 solar system objects, confirmed by the IAU MPC.159,345 detections of 12,061 solar system objects, confirmed by the IAU MPC.156,775 detections of 11,833 solar system objects, confirmed by the IAU MPC.154,834 detections of 12,066 solar system objects confirmed by the IAU MPC.154,891 detections of 11,974 solar system objects confirmed by the IAU MPC.920,960 detections of 35,958 solar system objects, confirmed by the IAU MPC.
d. Known Solar System Object Possible Association List14,383,217 entries corresponding to 563,059 asteroids, comets, planets and planetary satellites15,625,395 entries corresponding to 614,606 asteroids, comets, planets and planetary satellites16,465,465 entries corresponding to 648,632 asteroids, comets, planets and planetary satellites16,813,681 entries corresponding to 665,251 asteroids, comets, planets and planetary satellites17,655,613 entries corresponding to 705,674 asteroids, comets, planets and planetary satellites18,171,530 entries corresponding to 734,173 asteroids, comets, planets and planetary satellites99,286,565 entries corresponding to 866,493 asteroids, comets, planets and planetary satellites

I.3.a. Single-Exposure Images

The NEOWISE Single-Exposure images consist of photometrically and astrometrically calibrated 1016x1016 pix at 2.75"/pix FITS image sets for each individual NEOWISE exposure. Each image set consists of:

The NEOWISE Single-exposure Image archive contains 15,321,139 image sets that were acquired during the first six years of survey operations, 13 December 2013 to 13 December 2019.

A general description of the Single-Exposure Image sets is presented in III.1. Directions for accessing the Single-Exposure Image products are given in I.5. The processing method and algorithms used to produce the Single-Exposure images and how they differ from those used for the full cryogenic mission phase images are described in IV.2.a.

All of the Single-exposure Images acquired by NEOWISE are made available regardless of their quality. Users are strongly encouraged to read the Cautionary Notes for the Single-exposure Images, and the Advice on Using the Single-exposure Image Products before using them in your research.

Metadata tables that contain basic image information, including positions, observations times, pixel statistics and measurement quality metadata are also provided. Descriptions for these tables are given in III.1.c and III.1.d.


I.3.b. Single-Exposure Source Database

The Single-exposure Source Database is a compendium of position and flux information for source detections made on the individual NEOWISE 7.7s W1 and W2 Single-exposure images. Because NEOWISE scanned the same region of the sky many times, the Single-exposure Database contains multiple, independent measurements of objects. Positions, magnitudes in the two NEOWISE bands, astrometric and photometric uncertainties, flags indicating measurement quality, the time of observations and associations with the AllWISE Source Catalog and 2MASS Point Source Catalog are presented for entries in the Database.

The NEOWISE Single-exposure Source Database contains 114,402,173,833 source measurements made during the first six years of survey operations, 13 December 2013 to 13 December 2019.

The general characteristics and detailed column descriptions of the Single-Exposure Source Database are presented in II.1. Access instructions for the Single-Exposure Source Database are given in I.5. Descriptions of the source detection and photometry algorithms used to generate the Single-exposure Database and how they differ from those used to generate the Single-exposure Database from the original WISE mission can be found in IV.1.

In addition to detections of solar system, galactic and extragalactic sources, the Single-exposure Database also includes spurious detections of low SNR noise excursions, transient events such as cosmic ray strikes and noisy pixels, and artifacts and scattered light from bright sources including the moon. Therefore, the Database should be used with caution. Users are strongly encouraged to read the Cautionary Notes and Advice for Using the Single-exposure Source Database to understand its features and limitations.


I.3.c. Moving Object Tracklets

NEOWISE Moving Object Tracklets are sets of linked positions and observation times of solar system small bodies, i.e., asteroids, comets, planets, and planetary satellites that are identified by the WISE Moving Object Pipeline system (WMOPS; IV.3) data processing. Candidate tracklets are reported to the IAU Minor Planet Center (MPC) within an average of 3 days following the midpoint of the NEOWISE detections. These candidates are vetted by MPC, so confirmed tracklets retrieved from the MPC constitute a highly reliable collection of detections linked to both previously known solar system objects, and objects discovered by NEOWISE.

By the end of the first six years of survey operations, NEOWISE amassed 920,960 * confirmed infrared detections of 35,958 * different small bodies.

* These totals, and those given in row c of Table 1, include additional confirmed NEOWISE detections of 299 objects that were recovered manually by searching the Single-exposure Source Database near the predicted of positions of known Near Earth asteroids that were not found via the automated WMOPS processing. The search for and confirmation of these additional detections are described in Masiero et al. (2018, AJ, 156, 60) and Masiero et al. (2020, PSJ, in press).

These numbers increase continuously because new tracklet candidates are reported to the MPC three times per week, and the MPC continues to link NEOWISE detections with new observations.

A description of updates to the WMOPS for NEOWISE data processing is given in IV.3. Instruction for accessing NEOWISE Moving Object Tracklet information from the MPC is given in IV.3.c.iii.


I.3.d. Known Solar System Object Possible Association List

The NEOWISE Known Solar System Object Possible Association List (KSSOPAL) contains a listing of asteroids, comets, planets and planetary satellites, with orbits known at the time of NEOWISE data processing, that are predicted to be within the field-of-view at the time of individual NEOWISE Single-exposures. If the predicted position of a solar system object is in close proximity to a detection in the corresponding NEOWISE Single-exposure, the NEOWISE detection position and brightness information are also provided.

The positions of individual objects are usually observed multiple times, so most objects have multiple entries in the List. The KSSOPAL contains 99,286,565 entries that correspond to 866,493 different solar system objects whose positions were observed during the first six years of the NEOWISE survey.

The KSSOPAL is not a vetted list of solar system object detections. Most solar system objects observed by NEOWISE are not detected. Even among the KSSOPAL entries with NEOWISE Source Database detections nearby, the majority are chance associations with background sources or spurious noise or artifact detections. For a reliable, well-vetted list of NEOWISE solar system object detections, please use the Moving Object Tracklets.

The KSSOPAL column descriptions are given in IV.2.e.i. The algorithms used to predict known solar system object positions and updates made for NEOWISE processing are described in IV.2.e. Instructions for accessing the KSSOPAL are given in I.5.



Last update: 24 February 2020


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