Some Elements of Operational Modal Analysis

Table 2

Modal identification on dataset 4 of the Heritage Court Tower case.

Modal quantity	Modal identification method
	AR	ITD	ERA	SSI	FDD	FD-PR
Mode 1, 𝑓𝑛, (Hz)	1.246	1.246	1.246	1.215	1.235	1.213
Mode 1, 𝜍𝑛, (%)	1.12	1.05	1.12	1.92	2.72	2.52
Mode 1, 𝜋𝑛, (%)	23.4	26.0	23.4	16.3	35.5	31.8
Mode 2, 𝑓𝑛, (Hz)	1.299	1.300	1.299	1.279	1.293	1.301
Mode 2, 𝜍𝑛, (%)	1.57	1.40	1.57	7.20	2.45	2.62
Mode 2, 𝜋𝑛, (%)	3.4	3.6	3.4	10.0	0.7	0.2
Mode 3, 𝑓𝑛, (Hz)	1.441	1.442	1.441	1.443	1.450	1.446
Mode 3, 𝜍𝑛, (%)	0.33	0.31	0.33	0.89	1.27	1.08
Mode 3, 𝜋𝑛, (%)	58.6	34.1	58.6	69.0	63.8	63.6