almanac

Everything we've got.

Installation

almanac needs local disk access to the raw SDSS data frames.

If you want to use this at Utah, you can install it with:

module load almanac

Tip

If you don't already have a Python environment set up at Utah that uses sdssdb, then you may want to run module load miniconda as well so that you have all the requisite dependencies.

Usage

Use almanac to see details on data taken today from both observatories, or specify the observatory:

almanac
almanac --apo # Apache Point Observatory
almanac --lco # Las Campanas Observatory

Specifying a date

If you want a particular day, either use the --mjd or --date (UTC) flags:

almanac --mjd 59300
almanac --date 2021-01-01

You can use negative MJD values to indicate days relative to today:

almanac --mjd -1 # Yesterday
almanac --mjd -7 # Last week

You can also specify a range of days:

almanac --mjd-start 59300 --mjd-end 59310 # Give me these 10 days
almanac --date-start 2021-01-01 --date-end 2021-01-31 # Give me all of January 2021

Fiber mappings

You can also use almanac to see the fiber mappings for a given plate (SDSS-IV) or FPS pointing (SDSS-V) by specifing the --fibers (or --fibres) flag. This will give you the mapping of fibers to targets, and the target properties.

almanac --mjd 60000 --fibres

The fiber mapping tables are cross-matched to the SDSS database to include the SDSS identifiers for each target. If you don't want to do this cross-match, you can use the --no-x-match flag. The --no-x-match flag is ignored if --fibers is not used.

Output behaviour

By default there is minimal output to the terminal. You can adjust the verbosity level using -v:

• -v: show progress bar only
• -vv: show progress bar and exposure metadata
• -vvv: show progress bar, exposure metadata, and fiber mapping metadata

You can also write the outputs to a structured HDF5 file by specifying an output path with the --output (or -O) flag. If the output path already exists, the default behaviour is to overwrite existing entries only. So if you run almanac once for MJD 60000 and output to a file, and then run it again for MJD 60001 and output to the same file, your file will have data for both MJDs.

almanac --output /path/to/file.h5 # Append today's data to existing file

An example structure of the HDF5 file is below:

    apo/59300/exposures         # a data table of exposures
    apo/59300/sequences         # a Nx2 array of exposure numbers (inclusive) that form a sequence
    apo/59300/fibers/fps/1      # a data table of fiber mappings for FPS configuration id 1
    apo/59300/fibers/plates/2   # a data table of fiber mappings for plate id 2