Enabling catalog simulations of transient and variable sources based on
  LSST cadence strategies
  The Large Synoptic Survey Telescope (LSST) project will conduct a ten year
multi-band survey starting in 2022. Observing strategies for this survey are
being actively investigated, and the science capabilities can be best
forecasted on the basis of simulated strategies from the LSST Operations
Simulator (OpSim). OpSim simulates a stochastic realization of the sequence of
LSST pointings over the survey duration, and is based on a model of the
observatory (including telescope) and historical data of observational
conditions. OpSim outputs contain a record of each simulated pointing of the
survey along with a complete characterization of the pointing in terms of
observing conditions, and some useful quantities derived from the
characteristics of the pointing. Thus, each record can be efficiently used to
derive the properties of observations of all astrophysical sources found in
that pointing. However, in order to obtain the time series of observations
(light curves) of a set of sources, it is often more convenient to compute all
observations of an astrophysical source, and iterate over sources. In this
document, we describe the open source python package OpSimSummary which allows
for a convenient reordering. The objectives of this package are to provide
users with an Application Programming Interface (API) for accessing all such
observations and summarizing this information in the form intermediate data
products usable by third party software such as SNANA, thereby also bridging
the gap between official LSST products and pre-existing simulation codes.
