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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)
03 Apr 2025 02:59:00
Latency
2913
Level
0.64

Harmonics

Points count
6290669
First date
29 Apr 2011 19:11
Last date
03 Apr 2025 02:59

Click on following link to see data:

Harmonics Constatns
Comp # Period (day) Cos factor (m) Sin factor (m)
0 0.00000 1.13228E+0 0E+0
1 0.12877 8.52743E-5 -1.21102E-5
2 0.12886 1.983E-4 1.69155E-4
3 0.12938 1.44923E-4 -9.93333E-5
4 0.14707 -1.1559E-4 3.13432E-5
5 0.16841 3.19269E-4 3.28531E-4
6 0.16857 -1.54546E-4 -1.11604E-3
7 0.17036 7.18125E-4 1.31658E-4
8 0.17052 -2.79685E-3 -1.31802E-3
9 0.17251 -1.05042E-3 1.13957E-3
10 0.17470 4.32934E-4 -2.6181E-4
11 0.19989 3.26524E-4 3.54426E-4
12 0.20545 7.96381E-4 -9.66296E-5
13 0.24966 -5.4109E-4 -1.17216E-5
14 0.25000 3.25881E-4 2.95941E-4
15 0.25395 -6.31766E-4 -3.90866E-4
16 0.25431 -1.33584E-5 1.08747E-3
17 0.25631 9.21502E-5 -7.33684E-5
18 0.25667 -2.22693E-4 2.14059E-5
19 0.25876 4.51848E-4 -4.82176E-4
20 0.26122 -2.51928E-4 8.31249E-4
21 0.33303 2.90186E-4 1.54508E-3
22 0.34071 1.04032E-3 -1.1355E-4
23 0.34135 6.28058E-4 -4.35351E-4
24 0.34502 -3.24229E-3 3.16557E-3
25 0.34943 2.76536E-5 2.86504E-4
26 0.48977 -8.87832E-5 9.45343E-4
27 0.49109 9.07714E-4 -1.89604E-4
28 0.49863 1.14508E-2 4.99393E-3
29 0.49932 -8.90581E-4 1.80377E-4
30 0.50000 -3.88508E-2 -4.084E-2
31 0.50798 2.34033E-3 1.02692E-2
32 0.50924 2.22622E-3 -1.03396E-3
33 0.51606 -4.73782E-3 4.83092E-3
34 0.51679 2.74905E-3 4.43645E-3
35 0.51753 -4.04421E-1 3.06914E-1
36 0.51826 1.57908E-3 -6.81731E-3
37 0.52608 -2.06964E-2 1.52715E-2
38 0.52743 1.02382E-1 6.78348E-2
39 0.53632 1.56656E-2 1.26027E-2
40 0.53772 5.27685E-3 -1.55687E-2
41 0.54697 2.07557E-3 -4.34636E-3
42 0.54843 -1.75097E-3 -4.88834E-4
43 0.89909 8.81324E-5 2.64606E-4
44 0.92942 1.49508E-3 -1.57151E-3
45 0.93417 7.52662E-4 1.70067E-3
46 0.96244 -3.88855E-3 2.89178E-3
47 0.96696 3.17391E-4 -7.66952E-6
48 0.99185 -6.40072E-4 5.28032E-4
49 0.99455 2.04486E-3 5.82006E-4
50 0.99727 4.59039E-2 4.55624E-2
51 1.00000 7.39851E-4 2.10866E-3
52 1.00275 1.10312E-2 1.61454E-2
53 1.00551 -5.08634E-4 9.60069E-4
54 1.02954 -7.61161E-5 1.97309E-3
55 1.03472 1.76875E-3 -2.04118E-3
56 1.04061 3.21977E-4 -7.94364E-6
57 1.06951 -6.34241E-4 -1.18202E-3
58 1.07581 3.28002E-2 -7.66826E-3
59 1.11346 3.01652E-4 1.26593E-3
60 1.11951 -2.24306E-3 -5.19032E-3
61 1.16035 5.19747E-4 -6.88946E-4
62 1.16693 1.67308E-5 -4.94025E-4
63 1.21136 9.91838E-5 -2.23586E-4
64 13.66079 2.09444E-3 -8.70505E-3
65 14.76529 1.12844E-3 2.08104E-3
66 27.55455 3.76207E-3 1.35813E-2
67 31.81193 -1.7979E-2 2.66513E-3
68 182.62118 -4.51766E-2 5.051E-2
69 365.25998 6.18334E-2 1.00726E-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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