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Tide Gauge Details - Tonga Island - Nukualofa_TO

Device description

Name
Tonga Island - Nukualofa_TO
Country
Tonga Island
Group
TD UNESCO
Lat/Lon
-21.136801 / -175.180695

Last measured values

Time(UTC)
27 Jul 2024 00:59:00
Latency
1600
Level
1.48

Harmonics

Points count
5939926
First date
29 Apr 2011 19:11
Last date
27 Jul 2024 00:59

Click on following link to see data:

Harmonics Constatns
Comp # Period (day) Cos factor (m) Sin factor (m)
0 0.00000 1.13365E+0 0E+0
1 0.12877 8.0973E-5 -1.64976E-5
2 0.12886 2.07803E-4 1.95423E-4
3 0.12938 1.48086E-4 -1.02532E-4
4 0.14707 -1.17978E-4 4.59626E-5
5 0.16841 3.04109E-4 3.27472E-4
6 0.16857 -1.44719E-4 -1.15175E-3
7 0.17036 7.24045E-4 1.43657E-4
8 0.17052 -2.84375E-3 -1.35142E-3
9 0.17251 -1.0359E-3 1.14242E-3
10 0.17470 4.45358E-4 -2.476E-4
11 0.19989 3.3884E-4 3.74845E-4
12 0.20545 8.14805E-4 -1.25512E-4
13 0.24966 -5.69873E-4 1.16431E-5
14 0.25000 3.77829E-4 3.41061E-4
15 0.25395 -6.62675E-4 -4.09842E-4
16 0.25431 -4.13979E-6 1.14447E-3
17 0.25631 8.78649E-5 -9.12581E-5
18 0.25667 -2.24709E-4 4.93312E-5
19 0.25876 4.85082E-4 -4.87483E-4
20 0.26122 -2.77343E-4 8.55153E-4
21 0.33303 3.22189E-4 1.55082E-3
22 0.34071 1.03219E-3 -1.03767E-4
23 0.34135 6.52241E-4 -4.40908E-4
24 0.34502 -3.24735E-3 3.16346E-3
25 0.34943 -3.7336E-5 3.82583E-4
26 0.48977 -1.44715E-4 9.89226E-4
27 0.49109 9.83062E-4 -1.42443E-4
28 0.49863 1.10038E-2 4.92128E-3
29 0.49932 -1.05167E-3 1.20981E-4
30 0.50000 -3.87291E-2 -4.06553E-2
31 0.50798 2.10554E-3 1.02468E-2
32 0.50924 2.21529E-3 -9.97419E-4
33 0.51606 -4.81361E-3 5.04405E-3
34 0.51679 2.75391E-3 4.96966E-3
35 0.51753 -4.05236E-1 3.07475E-1
36 0.51826 1.05073E-3 -7.2125E-3
37 0.52608 -2.08367E-2 1.54808E-2
38 0.52743 1.02235E-1 6.78346E-2
39 0.53632 1.57627E-2 1.2596E-2
40 0.53772 5.25876E-3 -1.5564E-2
41 0.54697 2.03151E-3 -4.38626E-3
42 0.54843 -1.75496E-3 -4.52959E-4
43 0.89909 6.71632E-5 2.47331E-4
44 0.92942 1.45137E-3 -1.44967E-3
45 0.93417 8.39718E-4 1.71215E-3
46 0.96244 -3.92268E-3 2.81544E-3
47 0.96696 2.6198E-4 -1.86377E-5
48 0.99185 -5.14649E-4 4.57385E-4
49 0.99455 1.85458E-3 6.34193E-4
50 0.99727 4.54164E-2 4.52849E-2
51 1.00000 6.79847E-4 1.8777E-3
52 1.00275 1.09594E-2 1.62702E-2
53 1.00551 -6.14203E-4 9.15696E-4
54 1.02954 -1.03379E-4 2.07413E-3
55 1.03472 1.70132E-3 -2.03045E-3
56 1.04061 4.10236E-4 1.38743E-5
57 1.06951 -6.28733E-4 -1.45144E-3
58 1.07581 3.22803E-2 -7.66422E-3
59 1.11346 3.01642E-4 1.40264E-3
60 1.11951 -2.3109E-3 -5.08503E-3
61 1.16035 5.62651E-4 -7.8311E-4
62 1.16693 8.36723E-5 -5.15913E-4
63 1.21136 1.16723E-4 -1.98294E-4
64 13.66079 2.27091E-3 -8.65119E-3
65 14.76529 1.29087E-3 2.00064E-3
66 27.55455 4.36254E-3 1.41711E-2
67 31.81193 -1.89321E-2 2.62035E-3
68 182.62118 -4.55739E-2 5.38983E-2
69 365.25998 6.35393E-2 1.05033E-1
Mathematical Formula
Tide calculation mathematical formula
Visual Basic Syntax
Function EstimateTideValues() As [Function]
                        Dim Pi As [Double] = Math.PI
                        Dim sum As [Double] = harmonics(0, 1)
                        For k As Int16 = 1 To harmonics.GetUpperBound(0)
                        Dim period As [Double] = 2 * Pi / harmonics(k, 0)
                        Dim coefCos As [Double] = harmonics(k, 1)
                        Dim coefSin As [Double] = harmonics(k, 2) 
                        sum = sum + coefCos * Math.Cos(time * period)
                        sum = sum + coefSin * Math.Sin(time * period)
                        Next
                        Return sum
                        End Function
C# Syntax
double EstimateTideValues()
                        {
                        double Pi = Math.PI;
                        double sum = harmonics[0, 1];
                        for (int k=1; k <= harmonics.GetUpperBound(0); k++)
                        {
                        double period = 2 * Pi / harmonics[k, 0];
                        double coefCos = harmonics[k, 1];
                        double coefSin = harmonics[k, 2];
                        sum += coefCos * Math.Cos(time * period);
                        sum += coefSin * Math.Sin(time * period);
                        }
                        return sum;
                        }

Axis ranges

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