Skybrightness (Precalculated)

The rubin_scheduler.skybrightness_pre module accesses pre-calculated skybrightness values over the sky in each bandpass during the expected on-sky period for LSST. The values calculated by the rubin_sim.skybrightness module are packaged into data files which are then read and passed to the scheduler by rubin_scheduler.skybrightness_pre.

Downloading Skybrightness Data

The standard rubin_sim_data download for skybrightness_pre contains a small quantity of skybrightness data, limited to a period around the survey start date. For full simulations, additional skybrightness data will be needed. This can be downloaded to the $RUBIN_SIM_DATA_DIR/skybrightness_pre directory using

rs_download_sky

which will download a series of files from https://s3df.slac.stanford.edu/data/rubin/sim-data/sims_skybrightness_pre/h5_2023_09_12/. These files are identified by the MJD range of data contained within each file (i.e. 60841_61054.h5 contains pre-calculated skybrightness data covering MJD = 60841 to 61054). Downloading individual files by hand, when only a limiting range of skybrightness files are of interest, also works – place the resulting files in the $RUBIN_SIM_DATA_DIR/skybrightness_pre directory.

A full download of the skybrightness data files requires approximately 75GB of disk space.