Known Issues

For issues relevant to DECaLS imaging, consult the DR5 issues page.

Repeat Sources Due to Check-pointing

The legacypipe code applied a series of check-points in case of failures during processing. Unfortunately, when the code resumed after a check-point failure, it sometimes produced a duplicate of the same source. These duplicates can be identified because they have identical coordinates and fluxes but a different OBJID. An example repeated source is here:

http://legacysurvey.org/viewer-dev?ra=215.8471&dec=0.0805&zoom=16&layer=decals-dr5&sources-dr5&bricks

This source has the following attributes in catalog-level DR5 data:

Attribute Source 1 Source 2
RA 215.84766 215.84766
DEC 0.080533681 0.080533681
BRICKID 331231 331231
OBJID 4938 4941
TYPE DEV DEV
FLUX_G 5.86150 5.86150
FLUX_R 22.1008 22.1008
FLUX_Z 47.8499 47.8499
FLUX_W1 28.0480 28.0480

(i.e. fluxes and coordinates are identical but OBJID is different).

In DR6, we estimate that there are many thousands of duplicates spread across 264 bricks. The full list of DR6 bricks that contain duplicates, and the number of duplicates in each brick, is available here.

One brick was processed with a different pipeline version

Brick 1228p810 was processed with a different stack of codes, as detailed at the bottom of the description page.