World sea levels

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)
20 May 2024 20:59:00
Latency
2038
Level
0.96

Harmonics

Points count
5845769
First date
29 Apr 2011 19:11
Last date
20 May 2024 20:59

Click on following link to see data:

Harmonics Constatns
Comp # Period (day) Cos factor (m) Sin factor (m)
0 0.00000 1.13224E+0 0E+0
1 0.12877 8.37428E-5 -1.44655E-5
2 0.12886 2.09947E-4 1.97974E-4
3 0.12938 1.45308E-4 -1.04625E-4
4 0.14707 -1.12693E-4 4.66509E-5
5 0.16841 3.06897E-4 3.16902E-4
6 0.16857 -1.36582E-4 -1.16184E-3
7 0.17036 7.1327E-4 1.41443E-4
8 0.17052 -2.84787E-3 -1.35871E-3
9 0.17251 -1.02733E-3 1.13835E-3
10 0.17470 4.39675E-4 -2.40339E-4
11 0.19989 3.23294E-4 3.72112E-4
12 0.20545 8.05646E-4 -1.17572E-4
13 0.24966 -5.90684E-4 1.41852E-5
14 0.25000 3.53375E-4 3.43605E-4
15 0.25395 -6.61563E-4 -3.96357E-4
16 0.25431 -8.2873E-6 1.15863E-3
17 0.25631 1.04541E-4 -9.36345E-5
18 0.25667 -2.14884E-4 4.44741E-5
19 0.25876 4.73831E-4 -4.84115E-4
20 0.26122 -2.82265E-4 8.70249E-4
21 0.33303 3.24419E-4 1.53005E-3
22 0.34071 1.03145E-3 -1.16527E-4
23 0.34135 6.49738E-4 -4.43527E-4
24 0.34502 -3.2603E-3 3.17425E-3
25 0.34943 -3.99259E-5 3.99341E-4
26 0.48977 -1.54932E-4 1.00131E-3
27 0.49109 9.85407E-4 -1.44175E-4
28 0.49863 1.09168E-2 4.84032E-3
29 0.49932 -9.77875E-4 2.21433E-4
30 0.50000 -3.8754E-2 -4.07646E-2
31 0.50798 1.979E-3 1.02666E-2
32 0.50924 2.19366E-3 -1.06557E-3
33 0.51606 -5.0609E-3 5.39738E-3
34 0.51679 3.07837E-3 4.62954E-3
35 0.51753 -4.05614E-1 3.07741E-1
36 0.51826 1.43118E-3 -7.35835E-3
37 0.52608 -2.08333E-2 1.55599E-2
38 0.52743 1.02153E-1 6.78582E-2
39 0.53632 1.58239E-2 1.26504E-2
40 0.53772 5.24884E-3 -1.5519E-2
41 0.54697 2.01743E-3 -4.39811E-3
42 0.54843 -1.74495E-3 -4.76504E-4
43 0.89909 4.98428E-5 2.41092E-4
44 0.92942 1.40799E-3 -1.44998E-3
45 0.93417 8.2416E-4 1.72606E-3
46 0.96244 -3.96521E-3 2.79296E-3
47 0.96696 2.54132E-4 -3.53061E-5
48 0.99185 -6.7738E-4 3.91007E-4
49 0.99455 2.04183E-3 7.45742E-4
50 0.99727 4.52395E-2 4.51284E-2
51 1.00000 8.20164E-4 2.06174E-3
52 1.00275 1.08601E-2 1.60998E-2
53 1.00551 -5.61884E-4 1.0593E-3
54 1.02954 -1.42537E-4 2.13742E-3
55 1.03472 1.60707E-3 -2.03704E-3
56 1.04061 3.28504E-4 2.57531E-6
57 1.06951 -7.46457E-4 -1.40062E-3
58 1.07581 3.21425E-2 -7.62715E-3
59 1.11346 3.24155E-4 1.4225E-3
60 1.11951 -2.32709E-3 -5.04018E-3
61 1.16035 5.56518E-4 -7.61389E-4
62 1.16693 4.94759E-5 -5.25481E-4
63 1.21136 1.02408E-4 -1.81284E-4
64 13.66079 2.2272E-3 -8.66364E-3
65 14.76529 1.37214E-3 1.8461E-3
66 27.55455 4.11601E-3 1.47309E-2
67 31.81193 -1.9608E-2 2.56624E-3
68 182.62118 -4.78609E-2 5.45623E-2
69 365.25998 6.61931E-2 1.04562E-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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