sparc4-pipeline

The sparc4-pipeline is a set of routines that make use of the AstroPoP package and other astronomical packages to reduce the data of photometric and polarimetric observations obtained with the SPARC4 instrument installed at the Pico dos Dias Observatory (OPD/LNA). The pipeline has a main module called sparc4_mini_pipeline.py to run the pipeline from the command line and allow the reduction of data from the four SPARC4 channels automatically. The pipeline also has a file called sparc4_params.yaml with the pipeline execution parameters, where one can configure the reduction parameters according to the science needs.

WARNING: The current version was tested with AstroPoP Version: 0.9.3

Installation

git clone https://github.com/edermartioli/sparc4-pipeline.git

cd sparc4-pipeline

pip install -U .

Execution

Below is an example to run the SPARC4 pipeline :

python -W ignore ~/sparc4-pipeline/scripts/sparc4_mini_pipeline.py --nightdir=20230605 -vp

The pipeline routines are organized in the following 5 main libraries:

• pipeline_lib.py: pipeline execution routines and functions
• db.py: a simple interface to create and manage a database of input raw data
• utils.py: utility routines for reduction
• products.py: I/O routines containing the definition of SPARC4 reduction products
• product_plots.py: routines to get diagnostic plots of reduction products

These libraries can also be used independently to reduce data step by step, as in the examples provided in the Jupyter notebooks.

Download the minidata package containing SPARC4 data to test the pipeline. You may also want to downaload the minilcdata package containing time series data in photometric mode.

See the SPARC4 Quick Tutorial (in Portuguese) to start using the pipeline quickly.

The SPARC4 Pipeline Workshop Guidelines (pdf version) are now available, providing step-by-step instructions to reduce the minidata. Make sure you also check the slides presented in the workshop at the XLVII RASAB 2024 as well as the hands-on SPARC4 Pipeline Workshop Jupyter notebooks with examples for accessing the pipeline products obtained from the reduction of the minidata.

Warnings

Date: 2024-Oct-03

• The current FWHM values provided in the catalogs are incorrect; they appear to be twice the correct value. These values are calculated by the third-party tool photutils, but we are working on a solution soon.
• The sources and sky magnitude values provided in the catalogs are instrumental, meaning they are not calibrated for any photometric system.
• The pipeline does not work for objects with non-sidereal movements.
• The position angle of the linear polarization is not calibrated to the equatorial system. This applies to both half-wave and quarter-wave retarders.
• Polarimetry using a quarter-wave plate requires prior determination of the fast-axis direction. Simultaneously fitting the fast-axis direction and the normalization constant is unreliable and not permitted in the pipeline.

• If a new reduction is to be rerun with updated parameters, it is mandatory to delete any products affected by this new reduction; otherwise, it will have no effect. The current version of the pipeline only checks for the existence of a product by its file path, not whether its contents are consistent with the parameters used for the reduction.

The SPARC4 pipeline is under development in collaboration with the scientific community. If you are interested in collaborating, send an email to the pipeline team at the following address: sparc4-pipeline@googlegroups.com.