DOI: 10.5281/zenodo.1145822
title: Simlib_Minion

description: SYNOPSIS<br>
Observing strategies for Large Synoptic Survey Telescope (LSST) (1.) are published in terms of an output from the Operations Simulator (2). The simlib files are derived products that approximately summarize the information in such outputs that can be used with codes like SNANA (3). The Operations Simulator output used here is the `minion_1016_sqlite.db` baseline cadence (4). A description of the data product `minion_1016_sqlite.db` is supplied by the LSST project (5). These simlibs may be used with the SNANA code to simulate LSST observations of transient/variable objects.

The products contained are :<br>
- minion_1016_DDF.simlib : simlib file for the LSST DDF only<br>
- minion_1016_WFD.simlib : simlib file for the LSST WFD fields only<br>
- minion_1016_DDF.simlib.COADD : simlib file for the LSST DDF with nightly coadds<br>
- minion_1016_WFD.simlib.COADD : simlib file for LSST WFD withe nightly coadds

## Code and Inputs

This simlib was generated using code from OpSimSummary : https://github.com/rbiswas4/OpSimSummary<br>
 and SNANA

The input data is the opsim output `minion_1016_sqlite.db` (4).

## Procedure<br>
In generating this simlib:<br>
- duplicate visits in the summary table with different proposal IDs have been removed<br>
- SNR is calculated using the `filtSkyBrightness` and `FWHMeff` columns, and an atmosphere of 1.2 airmass. But the differences in the atmospheric transmission due to airmass differences are neglected.<br>
- This does not treat the overlaps between the fields and the dithers. <br>
- The observations were coadded using SNANA:

```<br>
$SNANA_DIR/bin/simlib_coadd.exe minion_1016_DDF.simlib<br>
$SNANA_DIR/bin/simlib_coadd.exe minion_1016_WFD.simlib<br>
```

## People involved in generating simlibs from the OpSim output:<br>
- R. Biswas<br>
- D. Cinabro<br>
- R. Kessler

## Version Release Notes:<br>
This release uses OpSimSummary version 1.2.0 : https://github.com/rbiswas4/OpSimSummary/releases/tag/v1.2.0<br>
and SNANA version `v10_52j`.

Changes: The changes that were necessary for this release are:<br>
- precision of MJD for each visit in the simlib is increased in output. This uniquely identifies each visit with a visit in the OpSim database.<br>
- A similar issue in `simlib_coadd.exe` for skysigs coadded and then written out with lower precision leading to slightly inaccurate values for coadds. This was fixed in version SNANA `v10_50b`

## Acknowledgements<br>
RB would like to thank Lynne Jones, Peter Yoachim, Scott Daniel, Zeljko Ivezic and Alex Kim for useful discussions.<br>
## References<br>
1. P.~A.~Abell {\it et al.} [LSST Science and LSST Project Collaborations], LSST Science Book, Version 2.0, http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:0912.0201.<br>
2. F. Delgado et. al.,  Proc. SPIE 9910, Observatory Operations: Strategies, Processes, and Systems VI, 991013 (July 15, 2016); doi:10.1117/12.2233630, http://adsabs.harvard.edu/abs/2014SPIE.9150E..15D<br>
3. R. Kessler et. al., Publications of the Astronomical Society of Pacific, Volume 121, Issue 883, pp. 1028 (2009). http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:0908.4280<br>
4. http://ops2.lsst.org/runs/minion_1016/data/minion_1016_sqlite.db.gz , description at https://www.lsst.org/scientists/simulations/opsim/opsim-v335-benchmark-survey