Spectral comparison
TPW Periods in year
ObsPer  DiffPer
28.2    26.5
24.4    24.4
21.2    21.2
18      18
11.3    11.3
 8.9     8.9
 8       8
 7.6     7.6
 7       7
 6.3     6.3
 4.6     4.5
 3.9     3.9
 (3.6)   3.6
 2.98    2.98
 2.25    2.2
() not in plots