scholarly journals Ocean State Forecast along Ship Routes: Evaluation Using ESSO-INCOIS Real-Time Ship-Mounted Wave Height Meter and Satellite Observations

2015 ◽  
Vol 32 (11) ◽  
pp. 2211-2222 ◽  
Author(s):  
R. Harikumar ◽  
N. K. Hithin ◽  
T. M. Balakrishnan Nair ◽  
P. Sirisha ◽  
B. Krishna Prasad ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Correlation Coefficient ◽  
Wave Height ◽  
Significant Wave Height ◽  
Satellite Observations ◽  
Southern Indian Ocean ◽  
Significant Wave ◽  
Safe Navigation ◽  
Wave Heights ◽  
The Indian Ocean

AbstractOcean state forecast (OSF) along ship routes (OAS) is an advisory service of the Indian National Centre for Ocean Information Services (INCOIS) of the Earth System Science Organization (ESSO) that helps mariners to ensure safe navigation in the Indian Ocean in all seasons as well as in extreme conditions. As there are many users who solely depend on this service for their decision making, it is very important to ensure the reliability and accuracy of the service using the available in situ and satellite observations. This study evaluates the significant wave height (Hs) along the ship track in the Indian Ocean using the ship-mounted wave height meter (SWHM) on board the Oceanographic Research Vessel Sagar Nidhi, and the Cryosat-2 and Jason altimeters. Reliability of the SWHM is confirmed by comparing with collocated buoy and altimeter observations. The comparison along the ship routes using the SWHM shows very good agreement (correlation coefficient > 0.80) in all three oceanic regimes, [the tropical northern Indian Ocean (TNIO), the tropical southern Indian Ocean (TSIO), and extratropical southern Indian Ocean (ETSI)] with respect to the forecasts with a lead time of 48 h. However, the analysis shows ~10% overestimation of forecasted significant wave height in the low wave heights, especially in the TNIO. The forecast is found very reliable and accurate for the three regions during June–September with a higher correlation coefficient (average = 0.88) and a lower scatter index (average = 15%). During other months, overestimation (bias) of lower Hs is visible in the TNIO.

Regional wise characteristic study of significant wave height for the Indian Ocean

2020 ◽  
Vol 54 (7-8) ◽  
pp. 3405-3423 ◽  
Author(s):  
S. Sreelakshmi ◽  
Prasad K. Bhaskaran
Keyword(s):  
Indian Ocean ◽  
Wave Height ◽  
Significant Wave Height ◽  
Significant Wave ◽  
The Indian Ocean

Advanced Altimeter Interferometry for Modelling the Wave Pattern Impacts of MH370 Flaperon

2020 ◽  
pp. 226-250
Keyword(s):  
Indian Ocean ◽  
Wave Height ◽  
Significant Wave Height ◽  
Wave Pattern ◽  
Wave Power ◽  
The Novel ◽  
M Wave ◽  
Significant Wave ◽  
Novel Approach ◽  
The Indian Ocean

Previous studies investigated the Indian Ocean's currents' impacts on the trajectory movement of MH370 debris. This chapter introduces the novel approach of investigating the wave pattern variations in the Indian Ocean on the MH370 debris. The novel approach based on the altimeter interferometry technique is utilized in this chapter. To this end, dual SIRAL instruments on-board of CryoSat-2 are applied to obtain the annual cycle of significant wave height across the Indian Ocean. In this chapter, in a one-year significant wave height cycle, the swell remains propagating from the Southwest to the Northeast from January to March 2015 with a maximum significant wave height of 5 m in the Northeast Offshore Australian Shelf and 7 m significant wave height Southwest of Australian Shelf. In this circumstance, the Pareto algorithm proves that the flaperon would submerge to a water depth less than 300 m on account of the impact of wave power of 22000 KJ/m/wave. It can be said that the flaperon would be submerged further to a water depth of 1000 m because of the wave power of 30000 KJ/m/wave.

Evaluation of SARAL / AltiKa Measured Significant Wave Height and Wind Speed in the Indian Ocean Region

2015 ◽  
Vol 44 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Chiranjivi Jayaram ◽  
Saurabh Bansal ◽  
A. Sai Krishnaveni ◽  
Neethu Chacko ◽  
V. M. Chowdary ◽  
...  
Keyword(s):  
Wind Speed ◽  
Indian Ocean ◽  
Wave Height ◽  
Significant Wave Height ◽  
Indian Ocean Region ◽  
Significant Wave ◽  
Ocean Region ◽  
The Indian Ocean

Dipole behaviour in maximum significant wave height over the Southern Indian Ocean

2017 ◽  
Vol 37 (14) ◽  
pp. 4925-4937 ◽  
Author(s):  
Nitika Gupta ◽  
Prasad K. Bhaskaran ◽  
Mihir K. Dash
Keyword(s):  
Indian Ocean ◽  
Wave Height ◽  
Significant Wave Height ◽  
Southern Indian Ocean ◽  
Significant Wave

Retrieving significant wave height in the Indian Ocean near Visakhapatnam using Jason-2 altimeter data

2015 ◽  
Vol 6 (4) ◽  
pp. 286-294 ◽  
Author(s):  
Aditya Chaudhary ◽  
Sujit Basu ◽  
Raj Kumar ◽  
K.V.S.R. Prasad ◽  
Rashmi Sharma
Keyword(s):  
Indian Ocean ◽  
Wave Height ◽  
Significant Wave Height ◽  
Altimeter Data ◽  
Significant Wave ◽  
The Indian Ocean

scholarly journals Estimation of Significant Wave Heights from ASCAT Scatterometer Data via Deep Learning Network

2021 ◽  
Vol 13 (2) ◽  
pp. 195
Author(s):  
He Wang ◽  
Jingsong Yang ◽  
Jianhua Zhu ◽  
Lin Ren ◽  
Yahao Liu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Wave Height ◽  
Significant Wave Height ◽  
Incidence Angle ◽  
Ocean Waves ◽  
Global Scale ◽  
Learning Technology ◽  
Sea State ◽  
Significant Wave ◽  
Wave Heights

Sea state estimation from wide-swath and frequent-revisit scatterometers, which are providing ocean winds in the routine, is an attractive challenge. In this study, state-of-the-art deep learning technology is successfully adopted to develop an algorithm for deriving significant wave height from Advanced Scatterometer (ASCAT) aboard MetOp-A. By collocating three years (2016–2018) of ASCAT measurements and WaveWatch III sea state hindcasts at a global scale, huge amount data points (>8 million) were employed to train the multi-hidden-layer deep learning model, which has been established to map the inputs of thirteen sea state related ASCAT observables into the wave heights. The ASCAT significant wave height estimates were validated against hindcast dataset independent on training, showing good consistency in terms of root mean square error of 0.5 m under moderate sea condition (1.0–5.0 m). Additionally, reasonable agreement is also found between ASCAT derived wave heights and buoy observations from National Data Buoy Center for the proposed algorithm. Results are further discussed with respect to sea state maturity, radar incidence angle along with the limitations of the model. Our work demonstrates the capability of scatterometers for monitoring sea state, thus would advance the use of scatterometers, which were originally designed for winds, in studies of ocean waves.

Development of Operational Limit Diagrams for Offshore Lifting Procedures

2015 ◽  
Author(s):  
Leonardo Roncetti ◽  
Fabrício Nogueira Corrêa ◽  
Carl Horst Albrecht ◽  
Breno Pinheiro Jacob
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Technological Development ◽  
Automatic Generation ◽  
Dynamic Responses ◽  
Offshore Platforms ◽  
Peak Period ◽  
Significant Wave ◽  
Wave Heights ◽  
Offshore Crane

Lifting operations with offshore cranes are fundamental for proper functioning of a platform. Despite the great technological development, offshore cranes load charts only consider the significant wave height as parameter of environmental load, neglecting wave period, which may lead to unsafe or overestimated lifting operations. This paper aims to develop a method to design offshore crane operational limit diagrams for lifting of personnel and usual loads, in function of significant wave height and wave peak period, using time domain dynamic analysis, for a crane installed on a floating unit. The lifting of personnel with crane to transfer between a floating unit and a support vessel is a very used option in offshore operations, and this is in many cases, the only alternative beyond the helicopter. Due to recent fatal accidents with lifting operations in offshore platforms, it is essential the study about this subject, contributing to the increase of safety. The sea states for analysis were chosen covering usual significant wave heights and peak periods limits for lifting operations. The methodology used the SITUA / Prosim software to obtain the dynamic responses of the personnel transfer basket lifting and container loads on a typical FPSO. Through program developed by the author, it was implemented the automatic generation of diagrams as a function of operational limits. It is concluded that using this methodology, it is possible to achieve greater efficiency in the design and execution of personnel and routine load lifting, increasing safety and a wider weather window available.

scholarly journals Significant Wave Height Estimation from Space-Borne Cyclone-GNSS Reflectometry

2019 ◽  
Vol 11 (5) ◽  
pp. 584 ◽  
Author(s):  
Qin Peng ◽  
Shuanggen Jin
Keyword(s):  
Standard Deviation ◽  
Correlation Coefficient ◽  
Wave Height ◽  
Significant Wave Height ◽  
Satellite System ◽  
Measurement Range ◽  
Ocean Dynamics ◽  
Global Ocean ◽  
Physical Parameters ◽  
Significant Wave

The significant wave height (SWH) of the sea is an important parameter and plays an important role in the prediction of waves and ocean dynamics. However, traditional methods, e.g., buoys or traditional remote sensing techniques such as X-band radar image have small measurement range and high cost. Recently, Global Navigation Satellite System-Reflectometry (GNSS-R) has provided a new opportunity to estimate the SWH, especially the space-borne Cyclone-GNSS (CYGNSS) launched on December 15, 2016. The GNSS-R uses the GNSS-reflected signal received by the receiver to invert ground physical parameters with all-weather, global fast coverage, high resolution, high precision, high long-term stability, rich signal sources, passive detection, and strong concealment. In this paper, the global ocean significant wave height is estimated using space-borne CYGNSS GNSS-R data for the first time though the relationship between the square root of the signal-to-noise ratio (SNR) data of CYGNSS delayed Doppler map (DDM) and the SWH. Then, the estimated significant wave height is compared with the satellite altimeter and buoy data. Compared with the AVISO SWH observation, the standard deviation value reaches 0.3080 m and the correlation coefficient reaches 0.9473 m. The correlation coefficient with the buoy SWH observation is 0.9539 m and the standard deviation is 0.2761 m. The SWH estimations from CYGNSS can provide important support in ocean shipping development, marine environmental protection, marine disaster warning and forecasting.

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