WAVEFORM IDENTIFICATION OF ALTIMETRY SATELLITE DATA OF SHALLOW AND DEEP WATERS IN SOUTHERN JAVA WATERS

ABSTRACT Waveform patterns of satellite altimetry affect the accuracy of sea surface height estimation from the satellite. The waveform patterns found in the coastal waters are generally not in the ideal form (Brown-waveform), resulting inaccurate in sea surface height estimation. The objec-tives of this research were to identify patterns of the waveform and determine their variability. Satellite altimetry Jason-2 SGDR (Sensor Geophysical Data Record) type D data located in the southern Java island waters of the year of 2013 were used and downloaded from “NOAA's Comprehensive Large Array-data Stewardship System” (www.class.ncdc.noaa.gov) . Waveform identification and analyses were conducted along the satellite pass within the distance of 0-10 km, 10-50 km, and 50-100 km form the coastline. Results showed that the highest number of non-Brown-waveform was found within 0-10 km of the coastline (69%). Meanwhile, within the distance of 10-50 km and 50-100 km from the coastline, the number of non-Brown waveform was 5% and 3%, respectively. Brown waveform patterns could be found generally starting at 7.58 km from the coastline. Factors such as land near coastal waters, the depth and shape of the surface waters, aerosols in the atmosphere, building (example: lighthouse or ship) found in coastal areas suspected to be the cause of the noise in waveforms. Keywords: Borwn and non-Brown waveform, sea level height, altimetry satellite, identification

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WAVEFORM IDENTIFICATION OF ALTIMETRY SATELLITE DATA OF SHALLOW AND DEEP WATERS IN SOUTHERN JAVA WATERS

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v6i2.9021 ◽

2015 ◽

Vol 6 (2) ◽

Author(s):

Bisman Nababan ◽

Romdonul Hakim ◽

Danu Adrian ◽

Jonson L Gaol

Keyword(s):

Coastal Waters ◽

Satellite Altimetry ◽

Sea Surface Height ◽

Sea Surface ◽

Height Estimation ◽

Type D ◽

Deep Waters ◽

Data Stewardship ◽

Geophysical Data Record ◽

The Ideal

ABSTRACT Waveform patterns of satellite altimetry affect the accuracy of sea surface height estimation from the satellite. The waveform patterns found in the coastal waters are generally not in the ideal form (Brown-waveform), resulting inaccurate in sea surface height estimation. The objec-tives of this research were to identify patterns of the waveform and determine their variability. Satellite altimetry Jason-2 SGDR (Sensor Geophysical Data Record) type D data located in the southern Java island waters of the year of 2013 were used and downloaded from “NOAA's Comprehensive Large Array-data Stewardship System” (www.class.ncdc.noaa.gov) <a href="http://www.class.ncdc.noaa.gov"></a>. Waveform identification and analyses were conducted along the satellite pass within the distance of 0-10 km, 10-50 km, and 50-100 km form the coastline. Results showed that the highest number of non-Brown-waveform was found within 0-10 km of the coastline (69%). Meanwhile, within the distance of 10-50 km and 50-100 km from the coastline, the number of non-Brown waveform was 5% and 3%, respectively. Brown waveform patterns could be found generally starting at 7.58 km from the coastline. Factors such as land near coastal waters, the depth and shape of the surface waters, aerosols in the atmosphere, building (example: lighthouse or ship) found in coastal areas suspected to be the cause of the noise in waveforms. Keywords: Borwn and non-Brown waveform, sea level height, altimetry satellite, identification

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Adjusting altimetric sea surface height observations in coastal regions. Case study in the Greek Seas

Journal of Geodetic Science ◽

10.2478/jogs-2014-0012 ◽

2014 ◽

Vol 4 (1) ◽

Cited By ~ 2

Author(s):

Ioannis Mintourakis

Keyword(s):

Satellite Altimetry ◽

Sea Surface Height ◽

Sea Surface ◽

Altimetry Data ◽

Geoid Model ◽

Sea Surface Topography ◽

Marine Gravity ◽

Mean Sea Surface ◽

Process Strategy ◽

Satellite Altimetry Data

AbstractWhen processing satellite altimetry data for Mean Sea Surface (MSS) modelling in coastal environments many problems arise. The degradation of the accuracy of the Sea Surface Height (SSH) observations close to the coastline and the usually irregular pattern and variability of the sea surface topography are the two dominant factors which have to be addressed. In the present paper, we study the statistical behavior of the SSH observations in relation to the range from the coastline for many satellite altimetry missions and we make an effort to minimize the effects of the ocean variability. Based on the above concepts we present a process strategy for the homogenization of multi satellite altimetry data that takes advantage ofweighted SSH observations and applies high degree polynomials for the adjustment and their uniffcation at a common epoch. At each step we present the contribution of each concept to MSS modelling and then we develop a MSS, a marine geoid model and a grid of gravity Free Air Anomalies (FAA) for the area under study. Finally, we evaluate the accuracy of the resulting models by comparisons to state of the art global models and other available data such as GPS/leveling points, marine GPS SSH’s and marine gravity FAA’s, in order to investigate any progress achieved by the presented strategy

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The results of calibrating satellite altimetry measurements from the space geodetic system “GEO-IK-2” in the water area of the Rybinsk reservoir

Geodesy and Cartography ◽

10.22389/0016-7126-2021-973-7-43-55 ◽

2021 ◽

Vol 973 (7) ◽

pp. 43-55

Author(s):

I.V. Gusev ◽

E.V. Dargel ◽

I.P. Langeman ◽

S.A. Lebedev

Keyword(s):

Satellite Altimetry ◽

Rybinsk Reservoir ◽

Sea Surface Height ◽

Water Area ◽

Sea Surface ◽

Satellite Orbits ◽

Short Time Interval ◽

Geodetic System ◽

Sea Surface Heights ◽

The Rybinsk Reservoir

The authors present the results of satellite altimetry measurements calibration from the space geodetic system “GEO-IK-2” in the water area of the Rybinsk reservoir, obtained through two independent methods. In the first case, the altimetry measurements were calibrated by comparing the sea surface heights with respect to the reference ellipsoid, which were calculated from radio altimeter measurements, and from the processing of ground GNSS measurements performed at the sub-satellite point at the time of passing the GEO-IK-2 spacecraft. For this, in the summer of 2020, special geodetic measurements were carried out in the water area of the Rybinsk reservoir. The GNSS receiver was mounted on the Sea Buoy, which was towed by boat to the specified sub-satellite points, the coordinates of which were predetermined from the forecast of satellite orbits. At the same time, base stations for GNSS observations were installed on the coast. The largest difference in the sea surface height does not exceed 13,9 cm. The second method is cross-calibration by radio altimeter measurements from other altimetry spacecraft. In this case, the tracks of the first and second satellites within a relatively short time interval cross one common point, at which the sea surface height is determined. For this, the Jason-3 spacecraft was selected, the track of which was crossed by the GEO-IK-2 vehicle track on September 11, 2020 over the water area of the Rybinsk Reservoir. The difference in sea surface heights was 9,6 cm.

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Near-coastal satellite altimetry: Sea surface height variability in the North Sea–Baltic Sea area

Geophysical Research Letters ◽

10.1029/2007gl029965 ◽

2007 ◽

Vol 34 (14) ◽

Cited By ~ 39

Author(s):

K. S. Madsen ◽

J. L. Høyer ◽

C. C. Tscherning

Keyword(s):

Baltic Sea ◽

North Sea ◽

Satellite Altimetry ◽

Sea Surface Height ◽

Sea Surface ◽

The North ◽

The North Sea ◽

Sea Area

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Sea surface height variability in the North East Atlantic from satellite altimetry

Climate Dynamics ◽

10.1007/s00382-015-2901-x ◽

2015 ◽

Vol 47 (3-4) ◽

pp. 1285-1302 ◽

Cited By ~ 7

Author(s):

Paul Sterlini ◽

Hylke de Vries ◽

Caroline Katsman

Keyword(s):

Satellite Altimetry ◽

Sea Surface Height ◽

Sea Surface ◽

East Atlantic ◽

North East ◽

The North

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Sea Surface Height Estimation by Ground-Based BDS GEO Satellite Reflectometry

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing ◽

10.1109/jstars.2020.3024743 ◽

2020 ◽

Vol 13 ◽

pp. 5550-5559

Author(s):

Jianming Wu ◽

Yanling Chen ◽

Fan Gao ◽

Peng Guo ◽

Xiaoya Wang ◽

...

Keyword(s):

Sea Surface Height ◽

Sea Surface ◽

Height Estimation ◽

Geo Satellite

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Deep learning to infer eddy heat fluxes from sea surface height patterns of mesoscale turbulence

Nature Communications ◽

10.1038/s41467-020-20779-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Tom M. George ◽

Georgy E. Manucharyan ◽

Andrew F. Thompson

Keyword(s):

Ocean Circulation ◽

Satellite Altimetry ◽

Sea Surface Height ◽

Heat Fluxes ◽

Sea Surface ◽

Data Driven ◽

Global Ocean ◽

Sufficient Information ◽

Eddy Heat Flux ◽

Global Ocean Circulation

AbstractMesoscale eddies have strong signatures in sea surface height (SSH) anomalies that are measured globally through satellite altimetry. However, monitoring the transport of heat associated with these eddies and its impact on the global ocean circulation remains difficult as it requires simultaneous observations of upper-ocean velocity fields and interior temperature and density properties. Here we demonstrate that for quasigeostrophic baroclinic turbulence the eddy patterns in SSH snapshots alone contain sufficient information to estimate the eddy heat fluxes. We use simulations of baroclinic turbulence for the supervised learning of a deep Convolutional Neural Network (CNN) to predict up to 64% of eddy heat flux variance. CNNs also significantly outperform other conventional data-driven techniques. Our results suggest that deep CNNs could provide an effective pathway towards an operational monitoring of eddy heat fluxes using satellite altimetry and other remote sensing products.

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ACCURACY IMPROVEMENT ON SEA SURFACE HEIGHT ESTIMATION BASED ON WAVEFORM RETRACKING ANALYSES OF JASON-2 SATELLITE IN JAVA SEA

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v7i2.11254 ◽

2016 ◽

Vol 7 (2) ◽

Author(s):

Muhammad R. Hakim ◽

Bisman Nababan ◽

James P. Panjaitan

Keyword(s):

Coastal Region ◽

Geoid Undulation ◽

Sea Surface Height ◽

Sea Surface ◽

North Coast ◽

The North ◽

Type D ◽

Waveform Retracking ◽

Java Sea ◽

Reflected Signal

A waveform created by the reflected signal from altimeter satellite in offshore is generally in ideal shape (Brown-waveform) and produces an accurate sea surface height (SSH) estimation. However, over coastal waters, the waveform shape becomes complex due to a disruption by reflected signal from land, resulting inaccurate SSH estimation. The objective of this research was to improve the accuracy of SSH estimation employing waveform retracking analyses of Jason-2 altimeter satellite data in the Java Sea during the years of 2012-2014. This study used data from the Sensor Geophysical Data Record type D (SGDR-D) from Jason-2 satellite (cycle 129 - 239) and global geoid undulation data of Earth Gravitational Model 2008 (EGM08). Waveform retracking analyses were conducted using several retracker methods. The performance of the all retrackers were examined using a world reference undulation geoid of EGM08. The results showed that the waveform retracking analyses were able to improve the accuracy of SSH estimation approximately 29.7% in the north coast and 56.4% in the south coast of total non-Brown-waveform in each region. Higher improvement percentage (IMP) of SSH estimation found in the southern coastal areas was due to a relatively smooth coastline formation in this region than in northern coastal region. There was no specific retracker that produce dominant IMP of SSH estimation. However, the threshold 10% retracker produced better SSH estimation than the other retrackers with dominant IMP values of 57.1% (pass 051), 48.1% (pass 064), and 25.7% (pass 127). OCOG retracker the worst retracker to estimate SSH in the Java Sea. Keywords: EGM08, waveform retracking, SSH, Jason-2, ocean retracker, threshold retracker

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ACCURACY IMPROVEMENT ON SEA SURFACE HEIGHT ESTIMATION BASED ON WAVEFORM RETRACKING ANALYSES OF JASON-2 SATELLITE IN JAVA SEA

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v7i2.11254 ◽

2016 ◽

Vol 7 (2) ◽

Cited By ~ 2

Author(s):

Muhammad R. Hakim ◽

Bisman Nababan ◽

James P. Panjaitan

Keyword(s):

Coastal Region ◽

Geoid Undulation ◽

Sea Surface Height ◽

Sea Surface ◽

North Coast ◽

The North ◽

Type D ◽

Waveform Retracking ◽

Java Sea ◽

Reflected Signal

A waveform created by the reflected signal from altimeter satellite in offshore is generally in ideal shape (Brown-waveform) and produces an accurate sea surface height (SSH) estimation. However, over coastal waters, the waveform shape becomes complex due to a disruption by reflected signal from land, resulting inaccurate SSH estimation. The objective of this research was to improve the accuracy of SSH estimation employing waveform retracking analyses of Jason-2 altimeter satellite data in the Java Sea during the years of 2012-2014. This study used data from the Sensor Geophysical Data Record type D (SGDR-D) from Jason-2 satellite (cycle 129 - 239) and global geoid undulation data of Earth Gravitational Model 2008 (EGM08). Waveform retracking analyses were conducted using several retracker methods. The performance of the all retrackers were examined using a world reference undulation geoid of EGM08. The results showed that the waveform retracking analyses were able to improve the accuracy of SSH estimation approximately 29.7% in the north coast and 56.4% in the south coast of total non-Brown-waveform in each region. Higher improvement percentage (IMP) of SSH estimation found in the southern coastal areas was due to a relatively smooth coastline formation in this region than in northern coastal region. There was no specific retracker that produce dominant IMP of SSH estimation. However, the threshold 10% retracker produced better SSH estimation than the other retrackers with dominant IMP values of 57.1% (pass 051), 48.1% (pass 064), and 25.7% (pass 127). OCOG retracker the worst retracker to estimate SSH in the Java Sea. Keywords: EGM08, waveform retracking, SSH, Jason-2, ocean retracker, threshold retracker

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