lris2-drp

lris2-drp is a data reduction pipeline for LRIS2 flat-field images.
It performs flat-field normalization, correction, slit tracing, and QA visualization using a Prefect-based workflow engine.

Table of Contents

1. Installation
2. Setting Up Your Package
3. Running the DRP
4. Output Files
5. Configuration Tips

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1. Installation

Requirements

• Python 3.10 or higher
• pip
• setuptools >= 42
• FITS images from LRIS2

Clone the Repository

git clone https://github.com/caltech/lris2-drp.git
cd lris2-drp

Create and Activate Virtual Environment

python -m venv .venv
source .venv/bin/activate

Install the Package

pip install --upgrade pip setuptools wheel
pip install -e .[dev]

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2. Setting Up Your Package

This package is built using PEP 517/518 with pyproject.toml.

To install only the core dependencies:

pip install -e .

Optional developer tools (like black, flake8, pytest) can be installed via:

pip install -e .[dev]

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3. Running the DRP

To batch-process a folder of flat-field FITS files:

from lris2_drp.flows import batch_process_all_flats

batch_process_all_flats(
    input_dir="/path/to/flats",
    output_dir="/path/to/results",
)

This will process up to 2 files in parallel (configurable) using Prefect’s ConcurrentTaskRunner.

Each file goes through:

• Normalization
• Flat-field correction
• Slit tracing
• QA plot generation
• FITS header augmentation

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4. Output Files

For each input FITS file, the following will be written to the output directory:

<filename>/
├── flat_corrected.fits     # Flat-field corrected image
├── flat_norm_qa.png        # QA plot of normalized flat
└── slit_trace.txt          # Slit trace positions

The corrected FITS file includes a FLATCOR keyword in the header:

FLATCOR = 'True' / Flat-field correction applied

Additional keywords track reduction steps (optional to expand).

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5. Configuration Tips

Adjust Parallelism

To change the number of files processed in parallel, set max_workers in ConcurrentTaskRunner:

@flow(task_runner=ConcurrentTaskRunner(max_workers=4))
def batch_process_all_flats(...):

Customize Output Paths

Output filenames and directory structure can be customized in:

• save_trace_solution()
• save_corrected_fits()
• generate_qa_plot()

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