PHASE

PHASE is a specific DESI observational phase, which can include “mainX” for iterations of the DESI Main Science Survey, “svX” for iterations of Survey Validation and “cmx” for commissioning, where X is an integer.

Under each survey phase, secondary targeting information is distributed across 3 directories:

  • indata contains a .txt or .fits file that includes the targets submitted by each researcher who proposed secondary targets for DESI observations.

  • docs contains a .ipynb (Jupyter Notebook) or .txt file provided by the proposer describing how each secondary target class was constructed.

  • outdata contains files from the indata directory with the added targeting information (i.e. IDs and bits) needed by the DESI pipeline.

The filename for a given secondary program is consistent across each of the indata, docs and outdata directories, and corresponds to the name of the secondary targeting bit used by the desitarget pipeline for a given survey phase (see the desitarget GitHub repository for, e.g. sv1 or main). The file extension can differ, though (i.e. some files in docs would have the extension .ipynb whereas the corresponding file in outdata would have the extension .fits).

A special filename case is the veto file (i.e. veto.txt or veto.fits). The veto file was designed as a mechanism to flag targets that should never be observed rather than new secondary targets to additionally observe. The form and contents of the veto files are consistent with the rest of the data model, described in the previous two paragraphs, except:

  • The veto mechanism was never used by DESI — but the desitarget code expected the veto file to exist. Therefore all veto files contain a single “dummy” object at a location well outside of the DESI footprint.

  • To reflect the singular, peculiar nature of the veto file, the filename is lower-case.

The PHASE directory may also contain a notes file, which includes working notes compiled by the run manager for secondary targets (Adam D. Myers, University of Wyoming) while sifting through the various files submitted as part of the DESI secondary proposal process.

Subdirectories: