quality_control.qc_flags.level2

QC checks for KPF Level 2 (extracted spectra) data products.

class kpfpipe.quality_control.qc_flags.level2.QCL2(kpf_obj)

Bases: QC

QC checks for KPF Level 2 extracted spectra products.

LEVEL = 'L2'

extraction_present()

All expected {CHIP}_{FIBER}_FLUX extensions exist and are non-empty.

flux_finite_fraction()

NaN count from headers <= 1% of total L2 flux pixels.

nonzero_flux()

ZEROFRAC < 0.5.

required_keywords_present()

Every registry-required PRIMARY keyword for L2 is present (presence only).

science_snr()

Science SNR is finite and above a minimum floor.

Reads the GSNRSCI/RSNRSCI metrics written by DiagL2.snr (run DiagL2 before QCL2, mirroring the flux_finite_fraction -> nan_counts dependency). Guards against a silently failed extraction.

variance_positive()

No strictly-negative variance where the flux is finite.

A negative extracted variance is unphysical (box/optimal variance is a sum of non-negative terms) and would corrupt downstream RV weighting. Zero variance at off-detector / fully-masked columns is tolerated.