Download Determining Lat Using Tide Modeling Tpxo Io

International Conference Data Mining, Civil and Mechanical Engineering (ICDMCME’2014), Feb 4-5, 2014 Bali (Indonesia)
Determining Lat Using Tide Modeling Tpxo Io
(A Case Study: Fani Island)
Muhammad Taufik, and Dika Ayu Safitri
II. GEOGRAPHYCAL OF FANI ISLAND
Abstract— One of outer-lying islands that belong to NKRI is
Fani Island. Fani island has important role to determining maritime
boundaries because the location opposite to Republic Palau. To
determining maritime boundaries, based on UNCLOS 1982, Lowest
Astronomical Tide (LAT) was used to reference in base line
delineation which is used to determine maritime boundaries.
Unfortunately, there is not available permanent tide gauge in Fani
island, so that there is no tide data in that island. To resolve that
problem, using tide modeling is the best way.
Currently tide modeling has evolved, one of them is TPXO tide
modeling by Egbert. The method used to compute the model is
assimilation data between altimetry satellite data and tide gauge data.
In this research using TPXO with Indian Ocean (IO) region and the
result is tidal constituents which are M2, S2, N2, K2, K1, O1, P1,
and Q1. Tidal constituents showed that the highest amplitude is M2
with 0,5 meters and the lowest is Q1 with 0,025 meters. Based on
tidal constituents, LAT in Fani island is -1,282 meters.
Fani Island is one of outer-lying that belongs to Indonesia.
Fani Island is located at 1°3'38"N ; 131°15'54"E,. In addition,
Fani Island is one of Raja Ampat archipelagic series which is
opposite with one of island that belongs to Republic of Palau
(Helen Island). Indonesia’s government already built base
points (in Indonesia called Titik Dasar (TD)) and in Fani
Island, they are TD no. 66 (1°05'20"N ; 131°15'35"E) and TD
no. 66A (1°04'28"N ; 131°16'49"E). This is the best way for
outer-lying island security for Indonesia [3]
Keywords— Fani Island, Tide modeling TPXO IO, Lowest
Astronomical Tide (LAT).
I. INTRODUCTION
NDONESIA is an archipelagic country which has a lot of
islands. It consists of small and big islands. Those islands
have an important role for Indonesia’s sovereignty, especially
for maritime boundary issue. UNCLOS 1982 said that Lowest
Astronomical Tide (LAT) is reference for maritime boundary.
Therefore, the aim in this research is determining Lowest
Astronomical Tide (LAT) in outer-lying islands belong to
Indonesia which is Fani Island. LAT is a calculation from tidal
constituent.
Fani Island did not have permanent tide gauge because there
is unavailable tide data in that island. To resolve that problem,
the best way is using global tide modeling. The global tide
modeling that is used in this research is Generalized Inversion
(GI) schema by Egbert [4] , which called TPXO. The TPXO
method is using assimilating data from altimetry satellite and
tide gauge. Furthermore, The data type for this research is
TPXO Indian Ocean (TPXO IO) due to Fani island’s location.
I
Fig. 1 Fani Island Nautical Chart by DISHIDROS
Picture 1 shows that Fani Island belongs to Asia’s island (
Pulau – Pulau Asia) which consists of two other island, they
are Igi island and Miarin island. Fani island is the biggest in
those series islands. Fani Island is located in Pasifik Ocean
which has some threatens for Fani Island such as big wave and
it makes changing of coast line. If that condition is not
anticipate earlier, it will make significant effect. One of real
anticipate from Indonesia’s government is making a law
according to government regulation number 38 year 2002 (PP
no. 38 / 2002) which consists of base point coordinate list
around Indonesia.
Muhammad Taufik is Head of Geodynamics and Environmental
Laboratory – Sepuluh Nopember Institute of Technology, Surabaya, 60111,
East Java, Indonesia. (Phone: +628563381574, e-mail: taufik_srmd@
yahoo.com).
Dika Ayu Safitri, was master student program for Geomatics Engineering
in Sepuluh Nopember Institute of Technology, Surabaya, 60111, East Java,
Indonesia. (e-mail : [email protected]).
http://dx.doi.org/10.15242/IIE.E0214052
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International Conference Data Mining, Civil and Mechanical Engineering (ICDMCME’2014), Feb 4-5, 2014 Bali (Indonesia)
Based on DISHIDROS’s report [2], base point in Fani
island was used to determine tide in that island. Unfortunately,
the result cannot be used because of limited data of surveying.
To find out tide value in Fani Island, government should build
permanent tide gauge which can detect the tide.
108 cycles (all available data for depth<2000m); 11 Antarctic
tide gauges. 1184 representers; 84220 data sites. [7]
IV. LOWEST ASTRONOMICAL TIDE (LAT)
Tides is the vertical movement of ocean water that occurs
periodically caused by the attraction of celestial objects
(especially the moon and the sun) to the earth, as well as other
forces, such as gravity and centripetal force [5].
Three basic tidal patterns occur along the Earth’s major
shorelines. In general, most areas have two high tides and two
low tides each day. When the two highs and the two lows are
about the same height, the pattern is called a semi-daily or
semidiurnal tide. If the high and low tides differ in height, the
pattern is called a mixed semidiurnal tide. Some areas, such as
the Gulf of Mexico, have only one high and one low tide each
day. This is called a diurnal tide. The U.S. West Coast tends to
have mixed semidiurnal tides, whereas a semidiurnal pattern is
more typical of the East Coast (Sumich, J.L., 1996; Thurman,
H.V., 1994; Ross, D.A., 1995). [6]
Based on Arcticle 5 of United Nations Convention on the
Law of the Sea (UNCLOS) 1982, the normal baseline for
measuring the breadth of the territorial sea is the low-water
line along the coast as marked on large-scale charts officially
recognized by the coastal state. By Arsana [1], as a general
definition, the normal baseline can be considered the lowwater line along the continental shore and around islands. This
includes the outer limits of permanent harbour works, the lowwater line along certain low-tide elevations, and the seaward
low-water line of atoll reefs and fringing reefs around islands
(IHO Special Publication No 51, 1993: 74). [1]
The low-water line was description called Lowest
Astronomical Tide (LAT). LAT was calculated some tidal
constituents. [8]
III. GLOBAL TIDE MODELING TPXO IO
Global tide modeling used to find out tide value in area
which do not have permanent tide gauge. Global tide
modeling commonly uses FES, NAO, GOT and many more.
In this research, global tide modeling used TPXO.
TPXO is a current version of a global model of ocean tides,
which best-fits, in a least-squares sense, the Laplace Tidal
Equations and along track averaged data from
TOPEX/Poseidon and Jason (on TOPEX/POSEIDON tracks
since 2002) obtained with OTIS. The methods used to
compute the model are described in details by Egbert, Bennett,
and Foreman(1994) and further by Egbert and Erofeeva
(2002). [11]
The tides are provided as complex amplitudes of earthrelative sea-surface elevation for eight primary (M2, S2, N2,
K2, K1, O1, P1, Q1), two long period (Mf , Mm) and 3 nonlinear (M4, MS4, MN4) harmonic constituents, on a
1440x721, 1/4 degree resolution full global grid (for versions
6.* and later). [11]
In this research, tidal constituent used M2, S2, N2, K2, K1,
O1, P1, and Q1 because all of the constantans have important
values. TPXO global tidal modeling has many regional data
type. It is based on the area to be modeled. Fani Island located
in the Pacific Ocean which is the frame of regional data type
covered some area in Indonesia and this frame is called India
Ocean (IO) in TPXO regional data type.
Zo – All Constituents (AC) ……………..
Zo = Mean Sea Level (MSL)
AC = M2, S2, N2, K2, K1, O1, P1, and Q1.
Formula 1
Determining of tidal constituents to calculate LAT depends
on regional area. Some area are not use formula 1, tidal
constituents for LAT are not that number, sometimes more
than that number or less. [There are a few regions which use
constantans that are not appropriate with this research because
of the shoreline geography.]
V. DATA AND PROCESSING
A. Validation data
Validation data is an important step to identify TPXO
global tide modeling for providing accurate tide for Fani
Island. Validation area for this research is Manokwari, Raja
Ampat, and Ambon. They have permanent tide gauge built by
Badan Informasi Geospasial (BIG) or Geospatial Information
Agency. Moreover, those locations are close to Fani Island.
Tide data from those areas will be compared with TPXO
global tide modeling. After that step, tidal constituents from
TPXO global tide modeling considerably have accurate value
to determine LAT.
Fig. 2 TPXO Indian Ocean Data
TPXO global tidal modeling using Bathymetry data is
developed by Smith and Sandwell, v.12.1; with
resolution 1/12º; the calculated tidal constituents are m2, s2,
n2, k2, k1, o1, p1, q1, m4, ms4, mn4. Those data will be
assimilated with Altimetry Satellite Topex Poseidon 531
cycles (each 2nd along track for deep water H>2000m and all
available for shallow water H<2000m); Topex Tandem 114
cycles (all available data in shallow water H<2000m); ERS
http://dx.doi.org/10.15242/IIE.E0214052
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International Conference Data Mining, Civil and Mechanical Engineering (ICDMCME’2014), Feb 4-5, 2014 Bali (Indonesia)
Manokwari is the capital of West Papua and is one of the
largest cities in Indonesia. BIG has built a permanent tide
gauge in Manokwari at 0°52'06"S and 134°04'32"E. In this
research, Manokwari tide data were recorded on January 1,
2011 - January 1, 2012.
TIDAL CONSTITUENTS IN MANOKWARI
Tidal
Amplitude
Fase
Constituents
(meters)
(radian)
0,49268
290,1
S2
0,18237
319,5
N2
0,0974
272,9
K2
0,04817
312,06
K1
0,20888
79,68
O1
0,14206
64,27
P1
0,06712
Q1
0,02702
175,69
0,094462
194,43
Q1
0,061005
167,55
TABLE IV
ACCUMULATE ERROR FOR VALIDATION DATA
Tidal constituents by T_tide –
Area Validation
tidal constituents by TPXO IO (meters)
Manokwari
0,0024375
75,2
Raja Ampat
0,035716
49,58
Ambon
0,022559875
B. LAT in Fani island
Fani Island coordinates was represented by two base points
(TD) on the Island. They are TD no. 66 and TD no. 66A. TD
no. 66 is located in 1°05'20 "N and 131°15'35”E and TD no.
66A in 1°04'28"N and 131°16'49"E. TPXO global tide
modeling showed that tidal constituents in those two base
points have same amplitude because the location was so close.
Table 5 shows the highest amplitude of M2 with 0,5 meters
and the lowest amplitude of Q1 with 0,025 meters.
Raja Ampat is in West Papua. There are 4 large Islands in
Raja Ampat, which are Missol Island, Salawati, Batanta and
Waigeo. BIG has built permanent tide gauge in Raja Ampat at
0°03'24"S and 130°58'50"E. In this research, Raja Ampat tide
data were recorded on 11 Feb 2011 - 31 December 2012.
TABLE II
TIDAL CONSTITUENTS IN RAJA AMPAT
Tidal
Amplitude
Fase
Constituents
(meters)
(radian)
M2
0,499712
139,89
S2
0,196325
207,65
N2
0,098972
121,24
K2
0,051755
230,05
K1
0,16924
187,36
O1
0,102525
175,69
P1
0,05032
194,43
Q1
0,018583
167,55
TABLE V
TIDAL CONSTITUENTS IN FANI ISLAND
USING TPXO IO
Tidal
Amplitude
Fase
Constituents
(meters)
(radian)
Ambon is the capital of the province of Maluku and located
in west of Irian Jaya. BIG has built permanent tide gauge in
Ambon on 3°38'21”S and 128°12'01"E. In this research,
Ambon tide data were recorded on 17 April 2013 - September
10, 2013.
M2
0,459296
139,89
S2
0,143372
207,65
N2
0,113526
121,24
K2
0,039019
230,05
K1
0,285444
187,36
M2
0,5
-71,7
S2
0,21
-43,5
N2
0,093
-90,3
K2
0,058
-45,3
K1
0,197
81,4
O1
0,136
68,7
P1
0,063
79,1
Q1
0,025
64,6
Determining LAT in Fani Island used formula 1, the used
tidal constituents are M2, S2, N2, K2, K1, O1, P1, and Q1. In
table 6 showed some references datum for tide. They are
Highest Astronomical Tide (HAT), Highest High Water Level
(HHWL), Mean High Water Level (MHWL), Mean Sea Level
(MSL), Mean Low Water Level (MLWL), Chart Datum Level
(CDL), Lowest Low Water Level (LLWL), and Lowest
Astronomical Tide (LAT). These references datum uses tidal
constituents from TPXO IO global tide modeling.
TABEL III
TIDAL CONSTITUENTS IN AMBON
Tidal
Amplitude
Fase
Constituents
(meters)
(radian)
http://dx.doi.org/10.15242/IIE.E0214052
0,212729
P1
Tidal constituents in table 1, 2 and 3 were calculated by
T_tide program, after that tidal constituents on those locations
are calculated with TPXO IO global tide modeling. In table 4
shows the lowest accumulate error in Manokwari with
0,0024375 meters and the highest in Raja Ampat with
0,035716 meters.
TABLE I
M2
O1
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International Conference Data Mining, Civil and Mechanical Engineering (ICDMCME’2014), Feb 4-5, 2014 Bali (Indonesia)
TABLE VI
TIDE IN FANI ISLAND
Definisi
Highest
Astronomical Tide
Highest High Water
Level
Mean High Water
Level
Istilah
Perhitungan
HAT
HHWL
Xo+(M2+S2+N2+K2+K1
+O1+P1+Q1)
Xo+(M2+S2+K2+K1+O1
+P1)
Hasil (m)
MSL
Xo
Mean Low Water
Level
MLWL
Xo-(M2+K1+O1)
-0,833
Chart Datum Level
CDL
Xo-(M2+S2+K1+O1)
-1,043
Lowest
Astronomical Tide
LAT
OTIS Regional Tidal Solutions. Indian Ocean : Retrieved on 20 January
2014 at 6 pm from http://volkov.oce.orst.edu/tides/IO.html
[8] Poerbondono dan Durnarsjah. Survei Hidrografi. Bandung. PT. Refika
Aditama. 2005.
[9] Republic of Indonesia. Peraturan Pemerintah Republik Indonesia Nomor
38 Tahun 2002 Tentang Daftar Koordinat Geografis Titik-Titik Garis
Pangkal Kepulauan Indonesia. 2002.
[10] Republic of Indonesia. Peraturan Pemerintah Republik Indonesia Nomor
37 Tahun 2008 Tentang Daftar Koordinat Geografis Titik – Titik Garis
Pangkal Kepulauan Indonesia. 2008.
[11] The OSU/ TOPEX Poseidon Global Inverse Solution TPXO. TPXO :
Retrieved on 20
January 2014
at 6
pm
from:
http://volkov.oce.orst.edu/tides/global.html
[12] United Nations. 1982. United Nations Convention on the Law of the
Sea. Retrieved on 10 January 2014 at 1 pm
from:
http://www.un.org/depts/los/convention_agreements/texts/unclos/unclos
_e.pdf
0,833
0
-1,164
-1,282
According to [9 and 10], TD no. 66 was used as baseline
reference delineation and TD no. 66A was used as straight
archipelagic baselines reference delineation. Table 6 showed
that LAT in Fani Island is -1,282 meters, which assume MSL
is 0 meters.
VI. CONCLUSION
Determining tide in outer-lying islands using global tide
modeling is the best way for that area which did not have
permanent tide gauge. TPXO IO global tide modeling gave
accurate tidal constituents in validation process which
represents in Manokwari, Raja Ampat and Ambon. Tidal
constituents of tide gauge from BIG have similar value with
tidal constituents from global tide modeling TPXO IO. Tidal
constituents have been calculated by TPXO IO showed that
LAT in Fani Island is -1,282 meters. This research needs
accurate tide data to compare with other global tide modeling
for the best result. The LAT in this research can be used as
consideration to maritime boundary delineation between
Indonesia and Republic of Palau.
ACKNOWLEDGMENTS
We would like to thank to Badan Informasi Geospasial
(BIG) to support this research in processing data using TPXO
IO tide modeling, specially Mr. Ibnu Sofian as advisor ;
DISHIDROS to provide the navigation chart (Fani island); and
Geomatics Engineering Master Program – Sepuluh Nopember
Institute of Technology Surabaya.
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[2]
[3]
[4]
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Dishidros. Laporan Survei dan Pemetaan Base Point XVIII Perairan
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D.A.Safitri. Studi Dampak Perubahan Garis Pantai Pulau Kecil Terluar
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Egbert, Gary and Erofeeva, Avetlana. Efficient Inverse Modelling of
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http://dx.doi.org/10.15242/IIE.E0214052
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[7]
Mean Sea Level
LLWL
[6]
1,164
Xo+(M2+K1+O1)
Xo(M2+S2+K2+K1+O1+P1)
Xo(M2+S2+N2+K2+K1+O1
+P1+Q1)
Kelompok Bidang Keahlian Kelautan. Diktat Kuliah ”Pendidikan
Survey Hidrografi ITB – Pertamina”. Bandung: Jurusan Teknik Geodesi
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1,282
MHWL
Lowest Low Water
Level
[5]
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