previous page   back to table of contents   next page

I. Introduction

4. Cautionary Notes

The WISE survey data acquisition strategy, data processing and quality assurance measures were all designed to yield data products of high reliability and fidelity. However, the accelerated schedule of the WISE data releases combined with challenge of validating such a large data set in a limited time, resulted in a number of limitations and problems that persist into the All-Sky Release products.

Supplement sections I.4.a through I.4.d contain descriptions of known features and limitations that pertain to WISE All-Sky Data Release products. Section I.4.a below presents the list of the most important things that you should know about the Release products to make the best use of them in your research. Click on any item in the list to see a more detailed discussion.

Sections I.4.b and I.4.c address essential information concerning the Source Catalog and Image Atlas. Section I.4.d contains Cautionary Notes for users who make use of the Release Ancillary Data products, including the Single-Exposure Source Database and Image Archive, and the Known Solar System Object Possible Candidate Association Table.

You are strongly encouraged to read and familiarize yourself with all of these Cautionary Notes before using the WISE All-Sky Release data products.

a. Top 10 (or so) Things You Should Know About the WISE All-Sky Release Data Products

Click on the items below to read more detailed descriptions.

  1. The WISE survey depth-of-coverage, and therefore the Catalog and Atlas depth and sensitivity vary with position on the sky (see also I.4.b.ii.3 and I.4.c.i)
  2. There are regions within the All-Sky Release Atlas and Catalog with very low or no effective coverage (see also I.4.c.ii)
  3. The Catalog contains both point-like and resolved sources
  4. The Catalog may not contain all sources that are visible on Atlas Images (see also
  5. The Catalog contains unreliable entries
  6. Catalog W1 and W2 profile-fit photometry measurements may systematically underestimate fluxes for sources fainter than W1>14.0 mag and W2>13.5 mag
  7. A non-null entry in any of the Catalog magnitude columns does not necessarily mean a detection
  8. Catalog photometry is presented in the natural WISE system
  9. Positions of objects measured on the Atlas Images may differ from Catalog positions
  10. The size of a "point-source" is larger on the Atlas Images than on the Single-exposure Images
  11. The intensity units of Atlas Image pixels are Digital Numbers (DN) not calibrated surface brightness

Last update: 2012 March 15

previous page   back to table of contents   next page