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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)
07 Sep 2024 18:59:00
Latency
5060
Level
1.09

Harmonics

Points count
6000346
First date
29 Apr 2011 19:11
Last date
07 Sep 2024 18:59

Click on following link to see data:

Harmonics Constatns
Comp # Period (day) Cos factor (m) Sin factor (m)
0 0.00000 1.13374E+0 0E+0
1 0.12877 8.32741E-5 -1.69485E-5
2 0.12886 2.05676E-4 1.92551E-4
3 0.12938 1.49157E-4 -1.05022E-4
4 0.14707 -1.19316E-4 4.27245E-5
5 0.16841 3.01362E-4 3.22033E-4
6 0.16857 -1.49809E-4 -1.14796E-3
7 0.17036 7.20237E-4 1.43029E-4
8 0.17052 -2.84204E-3 -1.34915E-3
9 0.17251 -1.03839E-3 1.14048E-3
10 0.17470 4.41383E-4 -2.53304E-4
11 0.19989 3.31388E-4 3.84873E-4
12 0.20545 8.21426E-4 -1.19182E-4
13 0.24966 -5.664E-4 6.6038E-6
14 0.25000 3.73024E-4 3.35758E-4
15 0.25395 -6.56343E-4 -4.0653E-4
16 0.25431 -2.95632E-6 1.1384E-3
17 0.25631 8.32873E-5 -7.8446E-5
18 0.25667 -2.10782E-4 4.76076E-5
19 0.25876 4.73699E-4 -4.90718E-4
20 0.26122 -2.76057E-4 8.45433E-4
21 0.33303 3.15076E-4 1.55916E-3
22 0.34071 1.03813E-3 -1.06879E-4
23 0.34135 6.47351E-4 -4.47388E-4
24 0.34502 -3.25312E-3 3.16315E-3
25 0.34943 -1.78919E-5 3.7345E-4
26 0.48977 -1.36185E-4 9.73095E-4
27 0.49109 9.73696E-4 -1.52559E-4
28 0.49863 1.10334E-2 4.90206E-3
29 0.49932 -1.05682E-3 1.56171E-4
30 0.50000 -3.87459E-2 -4.06849E-2
31 0.50798 2.12518E-3 1.02823E-2
32 0.50924 2.24772E-3 -9.81312E-4
33 0.51606 -4.64761E-3 5.1685E-3
34 0.51679 2.5366E-3 5.02444E-3
35 0.51753 -4.05118E-1 3.07273E-1
36 0.51826 1.11207E-3 -6.9818E-3
37 0.52608 -2.08372E-2 1.54658E-2
38 0.52743 1.02226E-1 6.78406E-2
39 0.53632 1.5759E-2 1.25943E-2
40 0.53772 5.24755E-3 -1.5554E-2
41 0.54697 2.05604E-3 -4.38837E-3
42 0.54843 -1.73892E-3 -4.67472E-4
43 0.89909 6.39081E-5 2.60851E-4
44 0.92942 1.45385E-3 -1.4843E-3
45 0.93417 8.10761E-4 1.70731E-3
46 0.96244 -3.93188E-3 2.81784E-3
47 0.96696 2.47388E-4 -4.91009E-6
48 0.99185 -5.75245E-4 5.3475E-4
49 0.99455 1.82879E-3 5.28178E-4
50 0.99727 4.55179E-2 4.5347E-2
51 1.00000 5.61438E-4 1.91029E-3
52 1.00275 1.10124E-2 1.6161E-2
53 1.00551 -5.73556E-4 1.02294E-3
54 1.02954 -9.72918E-5 2.01183E-3
55 1.03472 1.67222E-3 -2.09448E-3
56 1.04061 3.51685E-4 2.97751E-5
57 1.06951 -6.26453E-4 -1.3411E-3
58 1.07581 3.23805E-2 -7.65887E-3
59 1.11346 3.2292E-4 1.35221E-3
60 1.11951 -2.31052E-3 -5.13509E-3
61 1.16035 5.3445E-4 -7.65114E-4
62 1.16693 7.07527E-5 -5.01494E-4
63 1.21136 1.26323E-4 -1.81893E-4
64 13.66079 2.13777E-3 -8.64431E-3
65 14.76529 1.23514E-3 2.13738E-3
66 27.55455 4.2173E-3 1.419E-2
67 31.81193 -1.89842E-2 2.72184E-3
68 182.62118 -4.56482E-2 5.40599E-2
69 365.25998 6.34375E-2 1.04886E-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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