Arithmetical Operation
19
Table 4: Numeric values for the four variables In the coordinates of Moon and
Sun In °/Moon day and related periods (cf. Table 5)
Designation
[°/Moon day]
Period [a]
13,638230516
27,321583 days=tropical Month
h
1,020194382
365,242196 days=tropical year
P
0,115308512
8,84752 years=orbital period of mean perigee
N‘
0,054809904
18,6133 years=orbital period of the mean node
f) 8 or, respectively, 96 least square fits for calcula
ting the coefficients
The coefficients c In equation (1) with j = 0...2/7- at respectively retained k
and / - are determined on the basis of a sufficient number of (filtered) observa
tions by k*I=8 least square fits In such a manner that
||Ac — bll —» Minimum\ A e R'"’", b e R" with m > n . (4)
In the event of 1=1, the vector b consists of observed time differences
HWI = HWT° bs - t t or LWI = LWT° bs - t t and in the event of 1=2, it consists
of HWH or LWH. Due to filtering m < N start - N end +1. Thus, a solution c e R" Is
required for the linear root mean square problem (4) and hence a vector c,
which minimises the residuum r(c) := b - Ac of the overdetermined system In
the Euclidean norm. For calculating the vector c a method with singular value
decomposition after Golub and Relnsch (1970) was used.
In the case of 2 with k=96 least square fits for calculating the coefficients c of
the hydrograph (tidal curve), the method Is analogous to case 1, with the differ
ence that the points In time are already predetermined by fixed Intervals of 1/4
Moon hour.