{
  "waveform_index": "data/index/waveform_index.sqlite",
  "index_audit": {
    "scope": "all waveform_segments rows",
    "segment_rows": 22908,
    "missing_required_field_counts": {},
    "invalid_sampling_rows": 0,
    "end_time_formula_mismatch_rows": 0,
    "duplicate_segment_key_rows_beyond_first": 0,
    "exact_nslc_gap_count_within_selected_periods": 0,
    "exact_nslc_gap_count_by_network": {},
    "exact_nslc_gap_count_by_channel_family": {},
    "exact_nslc_gap_duration_s": {
      "median": null,
      "p90": null,
      "p99": null,
      "maximum": null
    },
    "exact_nslc_overlap_count_within_selected_periods": 0,
    "exact_nslc_overlap_count_by_network": {},
    "exact_nslc_overlap_count_by_channel_family": {},
    "exact_nslc_overlap_duration_s": {
      "median": null,
      "p90": null,
      "p99": null,
      "maximum": null
    },
    "missing_coordinate_rows": 0
  },
  "hdf5_sample_audit": {
    "scope": "deterministic SHA-256-ordered sample stratified by period, network, and HH/BH/EH/HN channel family",
    "sample_per_stratum": 2,
    "selected_segments": 40,
    "sample_window_seconds": 30.0,
    "counters": {
      "datasets_opened": 40,
      "sample_windows_read": 120
    },
    "metadata_mismatch_examples": [],
    "sample_values_examined": 334800,
    "zero_value_fraction": 0.0005465949820788531,
    "longest_zero_run_s_in_sample_windows": 0.025,
    "dtype_extreme_value_count": 0,
    "nonfinite_value_count": 18000,
    "large_first_difference_count_20mad": 9,
    "large_first_difference_note": "Diagnostic flag only; large first differences can be genuine seismic signals."
  },
  "interpretation": "Index checks cover every segment row. Sample-value diagnostics do not replace a full-array scan or comparison with upstream MiniSEED samples."
}