Uncertainties

Every uncertainty FLITS reports carries a short label saying what kind of number it is, a sentence on what it includes, and a note on how it was computed. When a known term is missing, such as the SEFD calibration uncertainty, the explanation says how to add it.

Kinds of uncertainty

Label in the interface	classification	What the number is
1σ	formal_1sigma	A 1σ uncertainty including every term FLITS knows about, for example a fluence's radiometer noise and SEFD calibration uncertainty combined in quadrature.
1σ statistical	statistical_only	A 1σ statistical uncertainty: radiometer noise, or the scatter of Monte Carlo trials. A known systematic, such as the SEFD calibration uncertainty, was not supplied and is not included.
1σ fit	model_hessian	A 1σ uncertainty from a model fit's covariance: burst-model parameters and the PSD power law. It assumes the model describes the data.
resolution	resolution_limit	Half a time or frequency bin, for quantities read off the sampling grid such as the peak-bin arrival time and the ACF widths. It bounds the error; it is not a standard deviation.
fit width	heuristic_local_fit	The width of the fitted peak of a DM sweep's score (integrated S/N or DMphase): how sharply the metric peaks.
range	conservative_bound	The smoothed-structure DM range: the DMs the noise cannot distinguish from the best one. It is wide, several times the scatter of the best DM.
approximate	diagnostic_only	An approximate interval, such as the PSD crossover frequency's 3σ range, or a value from an older session that did not record how it was computed.

The three 1σ kinds also fill the plain uncertainty fields, such as results.uncertainties.fluence_jyms and the *_err fields of the PSD fit. The others appear in the uncertainty details and the export columns below.

Quoting a statistical uncertainty

A statistical uncertainty is a real 1σ error. In the guided workflow the fluence is 4.032 ± 0.058 Jy ms from radiometer noise, because the example has no SEFD uncertainty. You can quote it as a statistical error and state the calibration uncertainty separately, or supply the SEFD uncertainty so FLITS combines the two. The SEFD term usually dominates.

Adding a missing term

Quantity	Term	Interface	Python	flits measure
Peak flux, fluence	SEFD calibration	SEFD Frac. Uncertainty under Acquisition Overrides	sefd_fractional_uncertainty= in BurstSession.from_file	--sefd-uncertainty
Isotropic energy	SEFD and distance	Both fractional uncertainties; distance is under Source Context	sefd_fractional_uncertainty=, distance_fractional_uncertainty=	–
Drift rate	DM	DM uncertainty in the Drift tab	run_drift_analysis(dm_uncertainty_pc_cm3=...)	–

Values are fractional: 0.1 means a 10% SEFD uncertainty.

Where to find them

• Interface: the label sits next to each value. Hover over it to see what the uncertainty includes and how it was computed. A "Check" line lists problems with the data that affect it, such as low S/N or heavy masking.
• Python: results.uncertainty_details[name] holds the value, units, classification, basis (how it was computed), tooltip (what it means), and warning_flags. The 1σ kinds also fill results.uncertainties.<name>.
• CSV export: each quantity has <name>_uncertainty_value, <name>_uncertainty_class and <name>_uncertainty_basis columns.
• JSON export and session snapshots: the full details.

Older fields

Uncertainty details still contain is_formal_1sigma and publishable so that older sessions and scripts keep working. Both are deprecated: the classification and warning_flags carry the same information.