Calibration Maps for KMTNet Synoptic Survey (KS4 DR1)

This dataset contains calibration maps used in the KMTNet Synoptic Survey of the Southern Sky (KS4) Data Release 1 (DR1). The calibration maps include both photometric and astrometric correction arrays generated through the KS4 DR1 reduction pipeline.

Each map corresponds to a specific KS4 field and filter, and is provided in NumPy .npy format.
These data support reproducibility of photometric zero-point calibration and astrometric solution refinement used in KS4 transient analysis.

Included files (six compressed archives):
 • KS4_DR1_AstroCalibNumStars_Maps.tar.gz – number of stars used for astrometric calibration.
 • KS4_DR1_Astrometry_Maps.tar.gz – astrometric offset correction maps.
 • KS4_DR1_AstrometryError_Maps.tar.gz – 1-σ error maps for astrometric calibration.
 • KS4_DR1_PhotCalibNumStars_Maps.tar.gz – number of stars used for photometric zero-point calibration.
 • KS4_DR1_ZeroPoint_Maps.tar.gz – photometric zero-point correction maps.
 • KS4_DR1_ZeroPointError_Maps.tar.gz – 1-σ error maps for zero-point calibration.

Among these, KS4_DR1_ZeroPoint_Maps.tar.gz and KS4_DR1_Astrometry_Maps.tar.gz are the primary datasets for image calibration in KS4 DR1.
To apply these calibration maps to the KS4 DR1 images, users should employ the corresponding functions provided in the KMTNet_ToO GitHub repository.

These maps are designed to be applied directly to the KS4 DR1 image data, which are not yet publicly available.
Researchers who require access to the original images may contact the authors for data requests.

The KS4 DR1 catalog, already calibrated with these maps, is available through the Astro Data Lab and CDS VizieR services.
No further calibration or modification is required when using the released catalog data.

File structure: compressed archives (tar.gz) containing per-unit subdirectories.

Reference: Jeong et al., KMTNet Synoptic Survey of Southern Sky II: Data Reduction Pipeline for Reference Imaging and Real-time Transient Detection (in preparation).