Data Set Technical Details
This page contains technical specifications of released data, associated with a variety of different sets of information. In many cases, information contained on this page is not needed to use released data sets for scientific investigations.
Much of the information on this page is primarily of interest to LIGO Scientific Collaboration members.
Many of the links here are to internal wikis and web sites which are password protected - these are indicated by a black diamond (◆).
If you are interested in password protected information, please contact the LOSC team. In many cases, we will be able to provide the requested documentation.
LOSC data downsampling and repackagingLOSC builds files from standard LIGO h(t) frames using this code for S5/S6. We have chosen to repackage our data to make it more accessible to casual users both within the LVC and outside.
Notes about the DATA flagSee the Defining the DATA Flag page.
S6 DQ flagsNote that during S6, the CBC group internally used modified DQ category definitions that were not consistent with the definitions shown on these LOSC pages. In particular, the CBC group internally and temporarily redefined "passing CAT3 checks" to mean "passing CAT2 checks and not a HW injection"; the old "CAT3" was called "CAT4", and the old "CAT4" was called "CAT5".
However, S6 publications used the unmodified definitions, consistent with other LSC publications and consistent with what was used for S5 DQ flag definitions. The categories as applied on the LOSC site and in LOSC data files (described in the S5 and S6 data release pages) reflect the system described in S5 and in publications, not the above-described modified DQ category definitions.
Notes about Instrumental LinesBelow we provide links (mostly internal) that document the provenance of the information summarized in the LOSC S5 Spectral Lines page and S6 Spectral Lines page.
Hardware InjectionsBelow we provide links that document the provenance of the information on Hardware Injections summarized in the LOSC S5 and S6 data release pages.
S5 Hardware Injections
Automatic Log Files (ASCII Text)
Annotated Log Files
S5 Burst PlotsInjections are sorted as "successful" or "failed" based on automatically generated log messages. Cases where the recovered SNR is not as expected are marked in the "Flag" and "Note" columns of the annotated log files.
S6 Hardware Injections
S6 Burst InjectionsThe ASCII lists of injections linked from the S6 Burst HW injection page are derived from the more detailed lists shown here: S6 Burst Injection Parameter File. (◆)
A small number of differences exist between the Burst injection lists provided by Timeline and the injection log files. These are detailed on this Wiki page used for the review of this data set.
S6 CBC Injections
S5 Data Set Review
Publication Policy for LIGO/Virgo membersThe LIGO/Virgo MOU includes a policy regarding the use of open data by LIGO and Virgo collaboration members:
"To encourage fairness to other collaboration members, and to discourage abuse of the privileges of collaboration membership, for at least one year after any public data release, current members of either Collaboration, as well as previous members who are still entitled to authorship rights on papers by the LIGO Scientific Collaboration or the Virgo Collaboration, must follow the publication rules of their respective Collaborations. In particular, dissemination of observational results needs to be reviewed by the two Collaborations, and will carry the authorship of both collaborations."