The most up-to-date issues and in-progress fixes are available on the GitHub issues pages for the Legacy Surveys website or the legacypipe pipeline.
Issues with CCDs that may have affected the quality of DECam observations are recorded on the DECam CCDs page.
Headers may be inconsistent with catalog values for about 2% of bricks in the Tractor catalogs. This is due to some files being altered while rsync processes were running.
A very small number of
ref_id values for Gaia sources appear twice in the Tractor catalogs. One of the duplicates corresponds to the
"correct" Gaia source and the second duplicate has all of the correct information for a Gaia source but with an incorrect
ref_id that would be correct for the second duplicate is missing entirely from the Tractor catalogs.
An example from DR9 is
ref_id 303293444934132224, which appears in Tractor catalog
correct information (RA, Dec, etc.) and in Tractor catalog
tractor-0238p305.fits with information that actually
corresponds to the Gaia source with
The cause of this problem has yet to be fully diagnosed, although the discrepant Gaia sources tend to lie very close to the boundaries of a brick.
This issue will also propagate to the sweep files.
Bricks where source-fitting failed
A few dozen bricks were intractable on a reasonable timescale as they overlapped regions of high source density. These
bricks were "bailed out" of before they finished processing. Sources in such bricks can be identified as they have
BAILOUT flag set in the MASKBITS bitmask.
In addition, certain high-density regions are missing completely from the Legacy Surveys. A good example is the Large Magellanic Cloud.
Bricks for which
SUB_BLOB was set
To facilitate rapid processing of sources in high-density regions, some DR10 bricks were split into smaller "sub-blobs."
These bricks can be identified as they have
SUB_BLOB set in the MASKBITS bitmask for some pixels in the
image stacks version of the maskbits product. Due to a bug in processing these sub-blobs, some genuine sources were not
extracted and included in DR10. The locations of these bricks are plotted below
and a full list of the 711 affected bricks is available here. Note that these bricks can't be identified in the source-level
catalogs (rather than the pixel-level products). For example, the problematic bricks can't be recovered by checking if
SUB_BLOB is set in the MASKBITS bitmask in the sweep files. This is because some of the relevant sources are
completely missing from the DR10 catalogs.