NOTES¶

Cross-Validation Workflow — Multi-Method Consensus

No single method's modal results are fully trustworthy. Always cross-validate with complementary methods and vote for consensus.

Global Parameter Reference¶

Method	Parameter	Default	Effect	ESP32 time (5ch×3000)
PP	seg_len	min(n/3,512) pwr2	Resolution vs segments	< 10 ms
	overlap	50%	PSD variance	—
	SNR threshold	4× noise_floor	Peak sensitivity	—
	peak min dist	5 bins	Deduplication	—
FDD	seg_len	1024	Frequency resolution	~50 ms
	pow-iter tol	1e-6	SVD accuracy	—
EFDD	IFFT bandwidth	±3 bins	Damping quality	~2 s/mode
	min δ	0.001	Minimum detectable damping	—
ITD	sn (AR order)	4	Candidates per pair	2-5 s
	n_lags	100	Cross-corr length	—
	cluster tol	10%	Voting strictness	—
ERA	p (block rows)	15	Hankel time span	1-3 s
	q (block cols)	10	Hankel columns	—
	SVD threshold	0.5%·S₀	Order selection	—
SSI	block_rows	12	Toeplitz size	3-8 s
	order range	2,4,...,16	Voting orders	—
	cluster tol	10%	Voting strictness	—
## Recommended Workflow

Goal: get a quick overview of frequency content.

PP → list all prominent frequency peaks

Note: PP may miss weak modes or merge close ones. Reference only.

Goal: confirm frequencies, get reliable mode shapes.

FDD → cleaner SV1 spectrum, SVD-derived shapes
More noise-robust than PP

Goal: most accurate freq/damping/shapes.

ERA → highest overall accuracy
NExT + Hankel SVD + balanced realization

Goal: independent verification of ERA results.

ITD → catches weak modes ERA might miss (short data)
SSI-PW → damping verification (sufficient data)