Use of a semi-submersible vessel to supplement satellite data in mapping the sub-tidal environment of Lonsdale Bight, Australia

1998 ◽  
Vol 49 (8) ◽  
pp. 875
Author(s):  
Michael McGoldrick ◽  
Joseph Leach
Keyword(s):  
Marine Environment ◽  
Satellite Data ◽  
Satellite Image ◽  
Sea Surface ◽  
Shallow Waters ◽  
Atmospheric Effects ◽  
Accurate Data ◽  
Sea Floor ◽  
Ideal Tool

The study was designed to identify the connection between features on the satellite image and the sea floor in Lonsdale Bight, Victoria, Australia, and to produce a map based on the findings. It used a semi-submersible vessel with an observation pod that can be lowered 1 m below the sea surface; this provides a stable platform from which spatially accurate data can be collected in the sub-marine environment, free from atmospheric effects. The results indicated a link between the depth and composition of the seabed and the spectral values found in the associated satellite image. Hence, the semi-submersible vessel is an ideal tool for seafloor imaging in shallow waters, without the disadvantages associated with diving.

scholarly journals Correction of Atmospheric Haze of IRS-1C LISS-III Multispectral Satellite Imagery: An Empirical and Semi-Empirical Based Approach

2016 ◽  
Vol 10 (2) ◽  
pp. 63-74 ◽  
Author(s):  
Sheikh Mustak ◽  
Naresh Baghmar ◽  
Sudhir Singh2
Keyword(s):  
Satellite Data ◽  
Satellite Image ◽  
Atmospheric Correction ◽  
Urban Land Use ◽  
Atmospheric Effects ◽  
Atmospheric Conditions ◽  
Subtraction Method ◽  
Atmospheric Effect ◽  
Dark Object ◽  
Liss Iii

The atmospheric effect greatly affects the quality of satellite data and mostly found in the polluted urban area in the great extent. In this paper, the atmospheric correction has been carried out on IRS-1C LISS-III multispectral satellite image for efficient results for the Raipur city, India. The atmospheric conditions during satellite data acquisition was very clear hence very clear relative scattering model of improved dark object subtraction method for the correction of atmospheric effects in the data has been carried out to produce the realistic results. The haze values (HV) for green band (band 2), red band (band 3), NIR band (band 4) and SWIR (band 5) are 79, 53, 54 and 124, respectively; were used for the corrections of haze effects using simple dark object subtraction method (SDOS). But the final predicted haze value (FPHV) for these bands are 79, 49.85, 21.31 and 0.13 that were used for the corrections of haze effects applying improved dark object subtraction method (IDOS). We found that IDOS method produces very realistic results when compared with SDOS method for urban land use mapping and change detection analysis. Consequently, ATCOR2 model provides better results when compared with SDOS and IDOS in the study.

SATELLITE DATA FOR INVESTIGATION OF RECENT STATE AND PROCESSES IN THE SIVASH BAY

2017 ◽  
Author(s):  
Ekaterina Shchurova ◽  
Ekaterina Shchurova ◽  
Rimma Stanichnaya ◽  
Rimma Stanichnaya ◽  
Sergey Stanichny ◽  
...  
Keyword(s):  
Satellite Data ◽  
Water Exchange ◽  
High Salinity ◽  
Meteorological Data ◽  
Sea Surface ◽  
Azov Sea ◽  
Seasonal Wind ◽  
Ice Regime ◽  
Very High

Sivash bay is the shallow-water lagoon of the Azov Sea. Restricted water exchange and high evaporation form Sivash as the basin with very high salinity. This factor leads to different from the Azov Sea thermal and ice regimes of Sivash. Maine aim of the study presented to investigate recent state and changes of the characteristics and processes in the basin using satellite data. Landsat scanners TM, ETM+, OLI, TIRS together with MODIS and AVHRR were used. Additionally NOMADS NOAA and MERRA meteorological data were analyzed. The next topics are discussed in the work: 1. Changes of the sea surface temperature, ice regime and relation with salinity. 2. Coastal line transformation – long term and seasonal, wind impact. 3. Manifestation of the Azov waters intrusions through the Arabat spit, preferable wind conditions.

scholarly journals Installation of submarine cables and pipes in shallow waters and connecting them to the shore by the method of horizontal directional drilling

2021 ◽  
Vol 286 ◽  
pp. 04007
Author(s):  
Valeriu-Florian Vasilescu ◽  
Dumitru Dinu
Keyword(s):  
Marine Environment ◽  
Offshore Wind ◽  
Shallow Waters ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Negative Effects ◽  
Subsea Tunnel ◽  
Submarine Cables ◽  
Wind Energy Systems ◽  
The Impact

This article presents the horizontal directional drilling (HDD) as one of the most suitable technique used to reduce the impact on the environment during the submarine pipe and cable installation process, especially in the coastal area and shallow waters. HDD is a technique used to drill a subsea tunnel or under other designated area with the goal to pull a pipe or other facility through the drilled underground tunnel. With the development of the offshore natural gas and wind industry, the demand for the construction of transfer pipeline and cables has also increased. The installation of submarine pipelines and cables can have negative effects on the marine environment. This is one of the main reasons that construction and operation of offshore wind energy systems has been and continues to be regarded with scepticism by environmental activists, despite the undeniable benefits of this renewable energy source. The main objectives of this article are to emphasize the importance of using this technique but also to highlight the benefits, in particular by significantly reducing the impact on the marine environment.

scholarly journals Recovering Marine Gravity Over the Gulf of Guinea From Multi-Satellite Sea Surface Heights

2021 ◽  
Vol 9 ◽  
Author(s):  
Richard Fiifi Annan ◽  
Xiaoyun Wan
Keyword(s):  
Gravity Field ◽  
Gravity Anomalies ◽  
Sea Surface ◽  
Shallow Waters ◽  
Gulf Of Guinea ◽  
Gravity Field Model ◽  
The North ◽  
Marine Gravity ◽  
Sea Surface Heights ◽  
East Component

A regional gravity field product, comprising vertical deflections and gravity anomalies, of the Gulf of Guinea (15°W to 5°E, 4°S to 4°N) has been developed from sea surface heights (SSH) of five altimetry missions. Though the remove-restore technique was adopted, the deflections of the vertical were computed directly from the SSH without the influence of a global geopotential model. The north-component of vertical deflections was more accurate than the east-component by almost three times. Analysis of results showed each satellite can contribute almost equally in resolving the north-component. This is attributable to the nearly northern inclinations of the various satellites. However, Cryosat-2, Jason-1/GM, and SARAL/AltiKa contributed the most in resolving the east-component. We attribute this to the superior spatial resolution of Cryosat-2, the lower inclination of Jason-1/GM, and the high range accuracy of the Ka-band of SARAL/AltiKa. Weights of 0.687 and 0.313 were, respectively, assigned to the north and east components in order to minimize their non-uniform accuracy effect on the resultant gravity anomaly model. Histogram of computed gravity anomalies compared well with those from renowned models: DTU13, SIOv28, and EGM2008. It averagely deviates from the reference models by −0.33 mGal. Further assessment was done by comparing it with a quadratically adjusted shipborne free-air gravity anomalies. After some data cleaning, observations in shallow waters, as well as some ship tracks were still unreliable. By excluding the observations in shallow waters, the derived gravity field model compares well in ocean depths deeper than 2,000 m.

Kerch Strait and Its Technogenic Pollution: Possibilities of Optical and Radar Remote Sensing

2021 ◽  
Vol 25 (8) ◽  
pp. 21-27
Author(s):  
A.Yu. Ivanov ◽  
D.V. Khlebnikov ◽  
B.V. Konovalov ◽  
S.K. Klimenko ◽  
N.V. Terleeva
Keyword(s):  
Remote Sensing ◽  
Satellite Imagery ◽  
Marine Environment ◽  
Satellite Data ◽  
Emergency Situation ◽  
Anthropogenic Pollution ◽  
Complete Information ◽  
Technogenic Pollution ◽  
Radar Remote Sensing ◽  
Kerch Strait

The possibilities of using satellite imagery of modern remote sensing satellites, both optical and radar, to study anthropogenic pollution and the state of the marine environment of the Kerch Strait are discussed. It is shown that satellite data and images allow one to quickly obtain practically complete information about a particular phenomenon and emergency situation in the strait.

Recent Arborescent Dendrophryid Foraminifera Found On Upper Pleistocene Cold-water Corals from the Inner Sea of the Maldives

2018 ◽  
Vol 48 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Matías Reolid ◽  
Jesús Reolid ◽  
Dorothea Bunzel ◽  
Michael A. Kaminski ◽  
Christian Betzler
Keyword(s):  
Cold Water ◽  
Test Construction ◽  
Shallow Waters ◽  
Calcareous Nannoplankton ◽  
Planktic Foraminifera ◽  
Sea Floor ◽  
The Indian Ocean ◽  
The Caribbean ◽  
Wall Growth ◽  
Sponge Spicules

Abstract Recent specimens of Spiculidendron were found on Late Pleistocene (21,400–22,500 BP) cold-water corals from the sea floor at 457 m depth of the inter-atoll Kardiva Channel of the eastern row of the Maldives archipelago. Spiculidendron and other dendrophryid foraminifera (Rhizammina-like forms) exclusively colonized specimens of the genus Enallopsammia, which was characterized by a phosphatic-stain surface. The Spiculidendron wall was composed of sponge spicules, elongated diatom frustules, tests of juvenile benthic and planktic foraminifera, and calcareous nannoplankton, among other materials. Sponge spicules and elongated diatom frustules were arranged longitudinally, with foraminiferal tests and other bioclasts packed in between, indicating that the agglutination process of Spiculidendron is selective with respect to the manner of growth. In the most distal parts of the branches, only sponge spicules and elongated diatom frustules were present, working as guides for the test construction, prior to the agglutination of juvenile foraminiferal tests and other bioclasts. Moreover, in the sediment associated with the coral fragments, 94 species of benthic foraminifera were identified, an assemblage distinct from the taxa incorporated into the agglutinated Spiculidendron tests. The process of wall growth is complex and ordered. This foraminifer, as well as the Rhizammina-like specimens, tolerates dysoxic conditions (0.896 ml/l) and low temperature (12°C). This observation represents a new record of Spiculidendron from the Indian Ocean and from deeper (aphotic) environments than previously reported from the shallow waters of the Caribbean. A cryptobiontic habitat is interpreted for Spiculidendron.

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