Multi-Domain-Calibrated Causal Cycle-Slip Detection and Direct Repair for Multi-GNSS: Station-Disjoint 1 s/5 s Validation

GNSS cycle-slip diagnostics require thresholds that transfer across receivers and observation conditions. We combine causal dual-frequency phase–Doppler innovations (PDI), current-epoch common-mode subtraction, trailing robust normalization, worst-source quantile calibration, and half-cycle-grid ambiguity-increment repair. Three IGS source stations and an expanded station-disjoint target cohort of five stations supplied four separated 15 min blocks per station at native 1 s and decimated 5 s sampling. Two targets were usable from the original list; three were added after the primary run but before their data were inspected. Threshold calibration is source-only, whereas score normalization uses the causal target-stream history. At 1 s and the 1% source budget, PDI produced a 1.114% unmodified-background alarm rate (UBAR), 98.68% detection, and 98.34% exact dual-frequency repair over 3184 seeded event epochs. A post hoc fixed-score audit reduced UBAR from pooled calibration’s 1.284% without changing event success. A stronger covariance-weighted GF/MW integer-search control repaired 96.86% on the half-cycle grid; PDI’s paired five-station repair-gain interval was 0.19–2.97 percentage points. On integer-only events the control slightly exceeded PDI, and at 5 s it repaired 81.97% versus PDI’s 54.99%. Thus, the large advantage over componentwise GF/MW rounding does not extend to all classical repair estimators. The sampling-rate comparisons use separately generated, identically specified injection ensembles rather than paired physical events. The contribution is source-only threshold calibration with causal target-stream normalization, not universal repair superiority. UBAR includes unlabeled natural events; moving-receiver transfer and downstream positioning benefit remain unvalidated.