The global magazine for hydrography www.hydro-international.com
January/February 2020 | Volume 25 number 1
How to Simplify Survey Reporting Slow Recovery of Remote, frozen, Coral Reef shows Impact critical and changing: the Weddell Sea of Bottom Trawling
01_cover.indd 1 30-01-20 09:21 Duration at depth Magellan, 175:56 hours continuous operational ROV dive at 5,100m.
cNode mini beacon Sonardyne SPRINT-Nav 0m 500 system
1000m
2000m
Reson T-50 dual Edgetech 2205 frequency MBES side scan sonar 3000m
4000m
5000m 8 km 8 km 6000m
Magellan, performance where it counts. Operating the MBES and SSS from an ROV mounted skid allows real-time display of acquired data, excellent terrain follow capabilities and permitting rapid response to target acquisition.
SUBSEA MINERALS | EMERGENCY RESPONSE | INTERVENTION & RECOVERY
WWW.DEEPWATER-SPECIALISTS.COM CONTENTS
P. 14 Research Expedition to Map the Scottisch Seabed Newly developed 3D imaging technology has allowed scientists to map Darwin Mounds, a unique area of cold-water coral reefs off the coast of Scotland, to see whether it has recovered since being declared a Marine Protected Area sixteen years ago.
Hydro International is an independent international magazine published 6 times a year P. 18 Analysing Mean Sea Level Variations by Geomares. The magazine and related e-newsletter inform worldwide professional, across the Strait of Hormuz industrial and governmental readers of the latest news and developments in the hydrographic, surveying, marine cartographic and geomatics world. Hydro International Emirates Defence Industries Company (EDIC) and Fugro recently embarked encompasses all aspects, activities and equipment related to the acquisition, processing, presentation, control and management of hydrographic and surveying- on modernizing the geodetic and hydrographic infrastructure of the Emirate related activities. of Sharjah in the United Arab Emirates (UAE) using GNSS, levelling and gravimetry to develop an accurate local geoid model. This allowed analysis of the fi ne mean sea level (MSL) variations in the Arabo-Persian Gulf and the Oman Sea on both sides of the Strait of Hormuz.
Geomares P. 23 How a Treasure Map Led Her to the Bottom of the Sea P.O. Box 112, 8530 AC Lemmer, The Netherlands Phone: +31 (0) 514 56 18 54 “It wasn’t always easy being a black woman in my early days as an E-mail: [email protected] oceanographer,” says Dawn Wright, chief scientist at a worldwide operating Website: www.geomares-marketing.com company specialized in mapping and spatial analytics software. But a No material may be reproduced in whole or in part without written permission from fi ctional pirate and a pioneering ocean explorer helped her chart her course. Geomares. Copyright © 2020, Geomares, The Netherlands All rights reserved. ISSN 1385-4569 P. 27 Remote, Frozen, Critical and Changing: the Weddell Sea Director Strategy & Business Development: Durk Haarsma Located in the Atlantic sector of the Southern Ocean, the Weddell Sea Financial Director: Meine van der Bijl Editorial Board: RADM Giuseppe Angrisano (retd) of the Italian Navy, MSc, generates extremely dense bottom water that spreads into all the world’s Huibert-Jan Lekkerkerk, Duncan Mallace, Mark Pronk, BSc, Marck Smit, ocean basins, transporting oxygen, CO and other solutes. Everything that is Auke van der Werf 2 Content Manager: Cees van Dijk added here is transferred into the abyssal oceans, including anthropogenic Production Manager: Myrthe van der Schuit Copy Editor: Serena Lyon, www.secondsoul.nl CO2. However, changes are taking place in the Weddell region that will have Marketing Advisors: Feline van Hettema Circulation Manager: Adrian Holland an impact on other oceans and on the global climate. Design: ZeeDesign, Witmarsum, www.zeedesign.nl
Advertisements Sponsored article by Magellan Information about advertising and deadlines are available in the Media Planner. For more information please contact our marketing advisor ([email protected]) or go to www.geomares-marketing.com. P. 30 Duration at Depth
Subscription Hydro International is available bi-monthly on a subscription basis. You can subscribe at any time via https://www.hydro-international.com/subscribe. Subscriptions will be P. 32 Digital Tool to Streamline Hydrographic automatically renewed upon expiry, unless Geomares receives written notification of Information and Make Reporting Easy cancellation at least 60 days before the expiry date. Wouldn’t it be great to work on a hydrographic project without spending a Editorial Contributions lot of time looking for all the elements needed for a professional report? This All material submitted to the publisher (Geomares) and relating to Hydro International was what Sanyal Sunil had in mind when he developed SURge, a digital will be treated as unconditionally assigned for publication under copyright subject to the Editor’s unrestricted right to edit and offer editorial comment. Geomares assumes tool to simplify survey reporting. no responsibility for unsolicited material or for the accuracy of information thus received. In addtion, Geomares assumes no obligation for return postage of material if not explicitly requested. Contributions must be sent to the content manager [email protected].
P. 05 Editorial P. 12 Designing the Future Expedition P. 07 Column GEBCO P. 17 Highlighted Products P. 08 Headlines
The global magazine for hydrography www.hydro-international.com Front Cover January/February 2020 | Volume 25 number 1 On this cover you can see a picture of the Weddell Sea in Antartica. Onboard the research icebreaker the Polarstern, scientists are deploying a CTD Rosette System to measure oceanographic parameters.
How to Simplify Survey Reporting Slow Recovery of Remote, frozen, Coral Reef shows Impact critical and changing: the Weddell Sea of Bottom Trawling
01_cover.indd 1 30-01-20 09:21
Hydro INTERNATIONAL | JANUARY/FEBRUARY 2020 | 3
03_contents.indd 3 30-01-20 11:53 Making Hydrographers’ Tasks Easier
Stand #D300 Courtesy of Cadden Courtesy
Navsight Marine Solution Qinertia
State-of-the-art Motion The Next Generation INS/GNSS & Navigation Solution Post-processing Software
www.sbg-systems.com
SWiFTplus Profiling just got more powerful
Multi-parameter profiler measuring CTD, SVP, Turbidity, Salinity & Density
SWiFTplus has been designed, engineered and manufactured in the UK to exceed your profiling needs. From combining sensors for multiple profiles in a single drop, to seamless data transfer for instant use, and all within our signature titanium casing for durability. Technology and precision are combined in an easy to use compact, robust and portable handheld profiler.
t: +44 (0)1803 869292 e: [email protected] w: www.valeport.eo.uk/swiftplus
_04_Hydro_1-2020.indd 6 28-01-20 11:12 EDITORIAL NOTES
Inspiration Are Multifunctional Robots
I’ve always known, from when I was a in Control? young boy, what I wanted to be: a journalist. It has never been anything I recently received a press else, at least not for longer than a few release from a company that days. I am not sure if the television develops robots. Nothing show Lou Grant triggered my wish to special, I thought, because report on whatever happens in the there are more companies world for a newspaper or a radio doing that, but this time my station, but the series about a grumpy attention was drawn to a editor at the fi ctional newspaper Los special element as the robot Angeles Tribune certainly fuelled my in question turned out to be ambition. I must have been around able to put another robot to Durk Haarsma ten or eleven years old and probably work. This makes it possible, didn’t understand a thing of the show, but I felt that the rush of the for example, to send a UAV to Cees van Dijk newsroom, the variety in topics that need to be covered and the absolute sea with a glider on board that can be essential curiosity would fi t me like a glove. launched remotely.
So far, my choice for a career in media, although not based in an LA Is that special? According to a robotic expert who was interviewed in a newsroom, has never disappointed me. I realize that it is quite special and Dutch radio programme, it is. Although we are perfectly capable of useful for youngsters to know what they want professionally, as it makes developing robots that can focus on one specifi c task, multifunctional choices of study and college easier. However, my experience is not half as robots hardly exist. For example, it is possible to make a programmable inspirational or adventurous as Dawn Wright’s. Now chief scientist with Esri, machine that delivers packages, but it is more diffi cult to have the she describes how she, as a little black girl growing up near the ocean on same device also collect the returns from the web shop, said the the Hawaiian Islands, was inspired by Robert Louis Stevenson’s Treasure specialist interviewed. Island and especially by the treasure map, which played a central role in the book. I do not doubt the authoritative knowledge of the person I heard, but he had probably not yet looked at the developments taking place in the The fascination for this map shaped her choices for a career that already world of hydrography and oceanography. There are already several spans decades of mapping the seabed. It is also inspiring because Wright experiments with autonomous vessels that can be used for various never let go of her aspiration, even when at some points she was one of the tasks. Mayfl ower Autonomous Ship (MAS), an autonomous vessel that only women on an expedition, and often the only black woman. Supporting follows the course of the voyage of the ship that transported the her persistence were role models such as cartographers Tharp and Heezen, Pilgrims to the New World, will soon depart. In one of the previous which kept her going. Read the story of Dawn Wright on page 23 of this editions of Hydro International, we described the trip of an autonomous issue of Hydro International. vessel that ‘sailed’ through severe storms and, although badly damaged, successfully completed a heavy trip through Arctic waters. At the beginning of 2020, I wish a television show, a book, a map or – even Last year, an unmanned vessel crossed Dover Strait, one of the busiest better – a role model like Dawn Wright for every child, to shape their choice sea straits in the world. After leaving England, it passed the shipping for a future career. In hydrography, we need plenty of new, ambitious lanes and arrived safely in Ostend, Belgium. surveying and mapping professionals to help meet the challenges of the future, so anyone who feels he or she can serve as a role model for children When asked whether we will ever see robots that can be used in a in their own environment should at least try. Plant the seed early on, and the multifunctional way, the aforementioned expert answered that this will industry can be sure of a lifelong dedicated infl ux of new hydrographers! take at least another decade. When I look at the developments in the maritime sector, I think he is too pessimistic. By using artifi cial Durk Haarsma, intelligence, self-learning robots are making a rapid and unstoppable director strategy & business development advance. [email protected] As a result, hydrographers and oceanographers can not only do their work better, but also more safely. Regarding this development, let us remember that a robot, no matter how advanced, must always be at the service of humans. Let us bear in mind that the word ‘robot’, ADVERTISERS coined by the Czech writer Karel Cˇ apek, is derived from the Czech word for ‘slave’. Magellan 2 Riegl 10 SBG Systems 4 Klein Maruine Systems 22 Valeport 4 Canadian Hydrographic Conference 25 Cees van Dijk, content manager [email protected] Blueprint Subsea 8 Teledyne Caris 35 Bathy Logger 9 Evologics 36
Hydro INTERNATIONAL | JANUARY/FEBRUARY 2020 | 5
05_editorial.indd 5 30-01-20 11:53 Your Product Platform for Surveying, Positioning and Machine Guidance
Search and compare Get insights Connect column | By GEBCO
Seabed 2030: The Data Centres
The Nippon Foundation-GEBCO Seabed 2030 Project is tackling one of the world’s most exciting challenges: to map the entire ocean floor to the highest resolution possible in less than a decade. The only way they will accomplish this ambitious goal is through coordinated international effort.
A global map showing the shape and depth of trained 90 scholars from 40 countries. Last year, Helmholtz Association (HGF), the centre the world’s ocean floor has “essential real-world an alumni team of the programme won the focuses on polar and marine research. With its applications” according to Seabed 2030 director US$4m Shell Ocean Discovery XPRIZE for ice-covered seas, the remote Southern Ocean Jamie McMichael-Phillips. Such detailed technological innovation in ocean mapping. poses harsh working conditions but despite this, bathymetry will empower the world to use the Responsible for covering an area greater than the launch of Seabed 2030 has seen the oceans sustainably, make informed policy 140 million km², and spanning the Americas in introduction of numerous new bathymetric data decisions, and better understand ocean the west to Australia in the east is the Atlantic sets, which have greatly aided access to deep circulation patterns and how they affect climate and Indian Oceans Regional Center. Based at sea in this region. and weather patterns. But how is this the Lamont-Doherty Earth Observatory (LDEO), The four regional centres feed their findings into monumental task achieved? Seabed 2030 the centre is overseen by Dr Vicki Ferrini, the global centre, hosted at the British divides the world into four regions – each research scientist and affiliate associate Oceanographic Data Centre (BODC) in overseen by a regional centre – and data is professor at CCOM. The centre has several Southampton, UK. Headed by Dr Helen Snaith, gathered from countless worldwide notable national and international mapping a senior data scientist at the BODC, the centre organizations via the regional centres and a initiatives within the region, including the is responsible for creating the centralized global centre, which then collates this vital Atlantic Ocean Research Alliance and the GEBCO products, including the bathymetric information. European Union’s EMODNet. grids. Established in 1989, the BODC’s mission The Arctic and North Pacific Oceans are The South and West Pacific Regional Center is is to operate as a world-class data centre in covered by the regional centre based at the based at the National Institute of Water and support of marine science. It has been Center for Coastal and Ocean Mapping (CCOM) Atmospheric Research (NIWA) in New Zealand, responsible for updating GEBCO’s global at the University of New Hampshire, USA. It is and is headed by its Marine Data Manager bathymetric products since 1990. co-headed by Professor Larry Mayer, director of Kevin Mackay. For over 50 years, NIWA has The latest GEBCO grid, published last year, the School of Marine Science and Ocean been a pioneer in seafloor landmark discovery comprises around 32,000,000 km² of new Engineering and CCOM at the University of New around Aotearoa-New Zealand, including active bathymetric data, with new figures expected to Hampshire, and Professor Martin Jakobsson, faults and volcanoes. In just the first 18 months be published later this year. professor of Marine Geology and Geophysics at of activity, the centre participated in over 30 For more information, Stockholm University. To help build the map of conferences, stakeholder meetings and media please visit https://seabed2030.gebco.net/ the Arctic and North Pacific, teams from this interviews, to promote the Seabed 2030 project centre go on regular mapping expeditions and its significant aims. carried out by Stockholm University’s own The remaining division, the southern tip of Chile About GEBCO research vessel, RV Electra. This centre is also and Argentina through to the coast of The General Bathymetric Chart of the Oceans (GEBCO) home to The Nippon Foundation/GEBCO Antarctica, falls into the remit of the Southern partners with The Nippon Foundation in the Seabed 2030 Postgraduate Certificate in Ocean Bathymetry Ocean Regional Center, based at the Alfred Project. GEBCO is a joint project of the International – an educational programme that has, to date, Wegener Institute (AWI). A member of the Hydrographic Organization (IHO) and the Intergovernmental Oceanographic Commission (IOC) of UNESCO – the United Nations Educational Scientific and Cultural Organization. It is the only intergovernmental organization with a mandate to map the entire ocean floor.
About The Nippon Foundation The Nippon Foundation (founded in 1962) is a private, non-profit foundation that is jointly spearheading international efforts to map the entirety of the world’s ocean floor by the end of the next decade. More than 100 organizations are now contributing to the goal of producing a complete map, which is vital to exploration.
Hydro international | january/february 2020 | 7
07_columngebco.indd 7 30-01-20 12:06 HEADLINES
Peter Sparkes Appointed UK National www.blueprintsubsea.com Hydrographer
sound by design The UK Hydrographic Offi ce (UKHO) has announced the appointment of Rear Admiral Peter Sparkes to the position of national hydrographer and deputy chief executive: a role that helps to improve the sharing, standardization and collection Multibeam Imaging Sonars of marine geospatial data through international collaboration. Single and Dual Frequency Operation As national hydrographer, Peter is the UK government’s 300m and 4000m Depth Rated representative at the International Hydrographic Organization (IHO), where he works with partners to set and maintain standards that protect the safety of mariners around the world.
Peter joins the UKHO as a rear admiral in the Royal Navy. He has served previously in a wide variety of appointments, both at sea and ashore. Notably, he commanded the frigate HMS Cumberland on counter-piracy patrol off Somalia and the UK’s Ice Patrol Ship HMS Protector in Antarctica. In addition to this, he commanded the 44 units (aircraft carriers, destroyers, frigates, minehunters, patrol vessels and the maritime explosive ordnance disposal teams) of the Portsmouth fl otilla.
Ashore, Peter Sparkes has served in Ministry of Defence acquisition appointments and was responsible for the development and introduction into RN service of the Warship Electronic Charting Display Information Micro-USBL Tracking Beacons System. Prior to joining UKHO, he served as the Chief of Defence Staff’s liaison offi cer in the Pentagon, Bidirectional Acoustic Data Modems Washington DC.
Jamie McMichael-Phillips Appointed Director of the Seabed 2030 Project
Jamie McMichael-Phillips has been appointed the new director of The Nippon Foundation-GEBCO Seabed 2030 Project, which aims to map the entire ocean fl oor by the year 2030. McMichael-Phillips has been Portable Sidescan Sonars described as “a leader and hydrographer Towed, OEM, Hull and Pole Mounted who successfully made the transition from the rank of captain in Britain’s Royal Navy to head of partnering and engagement for the UK Hydrographic Offi ce”. As a chartered surveyor, hydrographer and mariner, he has extensive experience in strategy and policy formulation, as well as in international engagement, negotiation, leadership and mentoring – skills gained during his Royal Navy career and in civilian life.
Jamie McMichael-Phillips has managed government-to-government relationships for the exchange of geospatial data for navigational safety and for the benefi t of the wider Blue Economy. He has also led outreach and capacity building for fl edgeling organizations in marine data collection, assessment and cartography. Prior to his Seabed 2030 appointment, McMichael-Phillips chaired – for over nine years – the find out more International Hydrographic Organization’s Worldwide Electronic Navigational Charts (ENC) Database www.blueprintsubsea.com working group, responsible for monitoring the global footprint of electronic charts needed for safe navigation by commercial shipping.
8 | January/February 2020 | Hydro international
BlueprintSubsea HydroInternational ThirdPage-Vert Advert 2018-03 (CMYK, 300dpi) 21 March 2018 15:56:53 08-09-10-11_headlines.indd 8 30-01-20 12:19 More headlines www.hydro-international.com
How Scientists Use “I Wanna See a Kid Satellite-mounted Laser to with a NOAA Shirt”
Map Global Ocean Migration President Trump recently declared that the United States would “act boldly” on a gigantic task: mapping a chunk of the ocean floor that is larger than the A recent study reports on the use of satellite-borne Lidar to map the daily vertical combined land area of all 50 US states. Armed with this strong backing from migration of zooplankton across the world’s seas over the course of a decade. the White House, the National Oceanic and Atmospheric Administration “Lidar allowed us to sample these migrating animals on a global scale every 16 (NOAA) is ready to go where no man has gone before. days for 10 years. We’ve never had anywhere near that kind of global coverage, which enables us to look at their behaviour, distribution and abundance”, said The agency this year plans to accelerate exploration of the entire US Exclusive lead author Michael Behrenfeld of Oregon State University. Economic Zone (EEZ), with the goal of completing the job by 2030. An official described the exploration project as challenging, but the work is already During World War II, naval oceanographers discovered a reflective layer that rose underway, with roughly 40% of the EEZ mapped in recent years. The whole and fell across their sonar screens once each day. Further research revealed that zone covers more than 13,000 miles of coastline and 3.4 million square it comprised swarms of fish and tiny sea creatures called zooplankton migrating nautical miles of ocean. towards the ocean surface as the sun set to feed under cover of darkness, then swimming back to the inky depths at dawn to escape their own predators during Timothy Gallaudet, NOAA deputy administrator, figures there is no reason why daylight hours. This was initially valued as a way for submarines to hide their ocean exploration cannot do for his organization what space exploration did movements. for NASA a half-century ago. “Every time I’m on the mall I see a kid in a NASA shirt,” Gallaudet said. “I wanna see a kid with a NOAA shirt, and “Combining data from ships and satellites helps to increase our quantitative maybe with an ROV and an AUV on it.” understanding of the role of zooplankton in the global carbon cycle, particularly in terms of its variability in time and space. That knowledge is critically important for refining global climate models”, says professor and co-author Deborah Steinberg of the Virginia Institute of Marine Science.
Hydro international | January/February 2020 | 9
08-09-10-11_headlines.indd 9 30-01-20 12:19 HEADLINES
Volcano F is the RIEGL VQ-840-G Origin of the TOPO-BATHYMETRIC UAV LASER SCANNER Floating Stones
Since August last year, a large accumulation of pumice has been drifting in the south-west Pacifi c towards Australia. Researchers at the GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany), together with colleagues from Canada and Australia, have now identifi ed the origin of this pumice raft: a so-far nameless underwater volcano in Tongan waters. The study has been published online in the international Journal of Volcanology and Geothermal Research. Some volcanic eruptions produce a very porous type of rock with a density so low that it fl oats – pumice. An unusually large amount of it is currently drifting in the south-west Pacifi c towards Australia. When it was fi rst sighted in the waters of the island state of Tonga at the beginning of August, it formed an almost coherent layer on the ocean’s surface. Various underwater volcanoes were discussed at that time as the potential source, but direct proof of the exact origin of the pumice was missing up until now. Researchers are now publishing evidence that clearly identifi es the culprit: the underwater volcano just 50 kilometres north-west of the Tongan island of Vava’u. “In international scientifi c literature, it appears only under the number 243091, or as Volcano F”, says Dr Philipp EFFICIENT HIGH RESOLUTION UAV COASTLINE Brandl of GEOMAR, fi rst author of the study. OR SHALLOW WATER SURVEYING The team found what they were looking for on a freely accessible satellite image of the ESA satellite Copernicus Sentinel-2 taken on 6 August 2019. It • compact and lightweight design, operating altitude 75 to 150 m – shows clear traces of an active underwater eruption ideally suited for integration on UAVs and helicopters on the water surface. As the images were exactly georeferenced, they could be compared with • green laser providing more than 2 Secchi depths water penetration – corresponding bathymetric maps of the seafl oor. highly accurate and feature-rich underwater topography “The eruption traces fi t exactly to Volcano F”, says Dr Brandl. The researchers also compared this • circular scan, measurement rate up to 200 kHz and position with information from global seismic network scanning speed up to 100 scans/sec – high spatial resolution stations. • integrated inertial navigation system – turnkey solution for straight forward integration
• high-resolution digital camera or infrared laser rangefinder optional – additional data for even more precise mission results
newsroom.riegl.international Scan this QR code to watch the RIEGL videos on our YouTube Channel. www.riegl.com ?? RIEGL LMS GmbH, Austria | RIEGL USA Inc. | RIEGL Japan Ltd. | RIEGL China Ltd. | RIEGL Australia Pty Ltd.
10 | January/February 2020 | Hydro international
08-09-10-11_headlines.indd 10 30-01-20 12:19 More headlines www.hydro-international.com
EuroSea Aims to Improve the Ocean Observation
The UK-based National Oceanography Centre (NOC) has joined an international consortium of 55 partners for the new €12.6 million, EU-funded EuroSea project. “The aim of the project is to better combine existing capacities in the European marine observing system, to fill existing gaps and to make the resulting data and information available to users more easily,” says coordinator Dr Toste Tanhua from the GEOMAR Helmholtz Centre for Ocean Research Kiel. NOC’s Prof. Kevin Horsburgh, Chief Scientist for International Development, is leading Work Package 5 (WP5) within the Coastal Resilience & Operational Services Demonstrator project. Prof. Horsburgh commented, “This project will boost the use of oceanographic data in decision-making and over all timescales.” WP5 will provide a demonstration of the end-to-end connection from observations (including a new generation of tide gauge technologies) to their wider use, by combining observations, model data and satellite products into novel decision- making tools. The partners in the EuroSea consortium are scientific institutions and non-public partners from 13 European countries, as well as Brazil and Canada. Other partners include international institutions and networks such as the World Meteorological Organization (WMO), the Intergovernmental Oceanographic Commission of UNESCO (IOC-UNESCO), the European Marine Board and the European part of the Global Ocean Observing System (EuroGOOS).
Mapping the Mariana South Korean Satellite Will Seas Will Start This Spring Focus on Oceanography
In April, a team of 60 scientists and crew from the US National Oceanic and With a focus on oceanography Atmospheric Administration (NOAA) will come to the Mariana Islands aboard and the monitoring of air the NOAA ship Rainier to map the seafloor of the Marianas and conduct coral pollution, the 3.4-ton South reef research. NOAA’s Office of Coast Survey and the Office of Marine and Korean Chollian-2B satellite will Aviation Operations will work together to perform the ocean surveys to be launched on 18 February measure the water depths. The Mariana Islands are a crescent-shaped from the Guiana Space archipelago comprising the summits of 15 mostly dormant volcanic Center using an Arianespace mountains in the western North Pacific Ocean, between the 12th and 21st Ariane-5 launch vehicle. The parallels north and along the 145th meridian east. They lie south-south-east Korean Aerospace Research of Japan, west-south-west of Hawaii, north of New Guinea and east of the Institute (KARI) has stated that this is the first time that a GEMS (Geostationary Philippines, demarcating the Philippine Sea’s eastern limit. Detailed Environmental Monitoring Spectrometer) has been installed on a geostationary information on how deep the water is and the many characteristics of the satellite. An additional GOCI-2 sensor to monitor the ocean environment is also seafloor would also be useful for determining fish habitats and for aboard the satellite. The satellite will be able to capture data for more accurate understanding coral reef health as well as marine geological processes. The weather forecasts as well as provide information to assist the nation’s agencies 2020 operations will comprise two missions: coastal and habitat mapping, in reducing pollution in the region. The operational lifetime expectancy of the and the Mariana Archipelago Reef Assessment and Monitoring Program, or Chollian-2B is approximately 10 years, and it was funded by the government to MARAMP. the tune of US$324 million.
In December 2018, South Korea launched the sister satellite, Chollian-1, for EO and oceanography monitoring, which is equipped with AMI (Advanced Meteorological Imager) and KSEM (Korean Space Environment Monitor) payloads. The Cholian-2B will offer 4x sharper resolutions than the sensors already in orbit and will examine an area of 2,500 kilometres (1,553 miles) over a 10-day period.
Hydro international | January/February 2020 | 11
08-09-10-11_headlines.indd 11 30-01-20 12:19 Designing the Future Expedition
Sampling in the ocean today is mostly that their work will set a new benchmark for team also hopes to develop a technological performed the same way it was 30 years ago, future mid-water expeditions and pave the way workfl ow for species descriptions using 3D and can sometimes be ineffi cient and for a device that combines all of their imaging and genomic sequencing. A DeepPIV destructive to fragile organisms. Many deep-sea technologies into a singular solution for (particle image velocimeter), developed by species remain undescribed simply because specimen characterization. MBARI, will be integrated into SuBastian to they cannot be returned to the surface in good visualize the liquid fl owing through animals such condition for taxonomic inspection. On this During their time on Falkor, the teams outfi tted as jellyfi sh. This instrument consists of a laser expedition, teams of interdisciplinary ROV SuBastian with a novel robotic and optics that illuminate a sheet of fl uid, researchers tested new technology that allows encapsulation device and a near-real-time allowing the fl uid motion to be quantifi ed using them to study species in situ, something that reality capture system to enable rapid imaging from the ROV’s high-defi nition science has never been done before. They anticipate characterization of deep-sea organisms. The camera.
Photo: Crew recovers ROV SuBastian at the end of the second day of the expedition off Oahu, Hawaii. (Image Courtesy: Logan Mock-Bunting / Schmidt Ocean Institute)
12-13_spread.indd 12 30-01-20 12:20 12-13_spread.indd 13 30-01-20 12:20 Feature | By NOC and Hydro International, UK and The Netherlands
Slow Recovery of Coral Reef shows Impact of Bottom Trawling Research Expedition to Map the Scottisch Seabed
Newly developed 3D imaging technology has allowed scientists to map Darwin Mounds, a unique area of cold-water coral reefs off the coast of Scotland, to see whether it has recovered since being declared a Marine Protected Area sixteen years ago.
The images show that in areas of the Darwin settlement experiments deployed in 2011 and This expedition saw the first deployment of a Mounds that had been heavily trawled, coral recovered on this expedition indicate that new newly developed 3D imaging system called growth is still very sparse, and there has been coral larvae can indeed settle in the area.” BioCam, a combined stereo camera and laser no real recolonization. However, healthy coral scanner built by the University of Southampton growth was found in parts that had only been HIGH-DEFINITION VIDEO DATA under NERC’s Oceanids Programme, which minimally damaged by bottom trawling, These findings are the result of a three-week was used to create multi-hectare 3D visual indicating that marine conservation measures research expedition in the North-East Atlantic reconstructions of the seabed. Mounted on are most effective when they are put in place on board the Royal Research Ship Discovery, Autosub6000, a robot sub developed and before damage occurs. The team also home port Southampton, UK. This expedition operated by the NOC, the system successfully discovered a large amount of plastic waste was a collaboration between the NOC, the mapped more than 50 hectares of seabed in snagged on the coral. University of Southampton, the Joint Nature less than 48 hours at photographic resolution. Conservation Committee, the University of Dr Veerle Huvenne from the National Edinburgh, University College Cork and the Together with an extensive series of samples, Oceanography Centre (NOC), and chief scientist Scottish Association for Marine Science. Using and more than 75 hours of high-definition video the expedition that made these discoveries, the latest in marine and robotic technology, the data collected by the HyBIS Robotic Underwater said, “of This proves once again that ecosystem team collected data to evaluate the status of the Vehicle, the BioCam images provided evidence recovery in the deep sea is very slow, and that it Darwin Mounds, a series of cold-water coral of healthy coral growth in locations that is better to put protective measures in place reefs lying at water depths of 1,000 metres, previously had seen only a minimal impact from before damage occurs. However, encouragingly, once heavily impacted by bottom trawling. bottom trawling.
COLD-WATER REEFS Cold-water corals are coral species that can live without light, and the reefs they build are important habitats for a wide variety of deep-sea life, including commercially important fish. The Darwin Mounds have been protected from bottom contact fisheries since 2003, and were last studied in 2011, at which point they had not yet recovered from the fishing impacts.
Dr Veerle Huvenne continued, “It was very encouraging to see the recruitment of new coral polyps on the settlement experiments, although this has not yet translated into widespread new coral growth in the heavily impacted areas. We will continue to monitor the site over the coming years to learn more about how deep-sea ecosystems recover after disturbance.
14 | january/february 2020 | Hydro international
14-15-16_scottishseabed.indd 14 30-01-20 12:20 “Working with the new BioCam system gave us Discovery. We are looking forward to its next really support marine monitoring and an unprecedented insight into the spatial deployment.” Unfortunately, the imagery also conservation efforts in the future”, pattern of the coral growth. It also showed us demonstrated the presence of a large amount of Hinchen adds. how the marine animals are living with and man-made litter. The area is characterized by around the coral, and it even provided us with strong tidal currents, and coral colonies form In their final blog post, two members of the unexpected discoveries, such as a complete natural obstacles on which plastic debris can expedition, Loic Van Audenhaege and Larissa whale skeleton that we had no idea was on the easily snag. Macedo, wrote, “Reef-forming cold-water corals seabed in the area.” Hayley Hinchen from the Joint Nature Dr Blair Thornton, co-chief scientist and leader Conservation Committee said, “It has been of the BioCam team said, “The multi-hectare fascinating to see first-hand the coral mounds in ABOUT THE NOC scale maps generated by BioCam highlight a the area, some of which are thriving and others The NOC is the UK’s primary centre for providing national wide range of patterns in the spatial distribution which are struggling to recover. This survey has capability for oceanographic sciences. Our vision is to be of coral and the ecology at this site. These range confirmed that, even after more than 15 years one of the world’s top three oceanographic research from the fine, metre-scale patterns seen in video of fisheries closures, the impacts of bottom institutions, leading the way in the advancement of surveys, to much larger patterns in the trawling are still evident, and some newer knowledge and understanding of our oceans. distribution of live coral over several hundreds of pressures seem to be growing. The level of litter metres. The data will help scientists to identify that we observed across the site is quite The institute provides the UK with the national capability these and to measure the distribution of live shocking, and we still don’t know how this is needed to be a top global player and to lead and participate coral in this area.” affecting the seabed communities we’ve seen in international cooperation. The NOC undertakes research over the last three weeks. in large-scale oceanography and ocean measurement LARGE AMOUNT technology innovation. It works with government and OF MAN-MADE LITTER “The wealth of data collected on this expedition business to turn great science and technology into advice “The fact that BioCam was able to collect data will allow us to assess the current status of the and applications. The NOC supports the UK science that is useful for scientific monitoring on its first habitats and species in the Darwin Mounds community, based in universities and smaller research deployment is a tribute to the hard work that both at the small and large scale, and to define institutes, with scientific facilities, research infrastructure went into preparations for this expedition from how it has changed over time. The amazing and irreplaceable data assets – enabling the UK to harness the teams at the University of Southampton, 3D imagery from the BioCam system allows the full power and diversity of its scientific talent in ocean the MARS team at the NOC, local industry us to investigate huge areas of the seabed science. partners and the captain and crew of the RRS at millimetre-scale resolution – a tool that could
Hydro international | january/february 2020 | 15
14-15-16_scottishseabed.indd 15 30-01-20 12:21 and many sponges require specific organisms can sustain themselves in a changes in biodiversity and communities of environmental conditions for settlement, such soft-substrate environment, the apparent marine animals in the area since 2011. This as the presence of a hard substrate, which biodiversity remains low, compared to what we work is part of the CLASS programme (Climate remains a rare feature of the seabed. In the can see from the pictures of the coral reefs. Linked Atlantic Sector Science), which aims to Darwin Mounds area, our dives allowed us to However, it would be foolish to state that this type increase our understanding of how the ocean observe that sand and mud make up the of habitat is not biologically interesting. will evolve under a changing climate and primary substrate of the seafloor, except on the Photographs have limitations in terms of showing increased human exploitation, with the objective mounds themselves.” the full variety of forms in which life can occur. For of supporting sustainable marine management. instance, as revealed by the box core operations, The BioCam project is funded by the NERC’s They continued, “Reef-forming cold-water corals many tiny organisms thrive in the sediment and Oceanids Programme. cannot grow on a soft substrate. This was they may encompass an equally important part of well-observed in our previous blog post as new the life at the Darwin Mounds site.” ACKNOWLEDGEMENT cold-water corals were growing on an eight- This article has been produced in collaboration year-old buoy, but none were observed growing Further detailed analysis of the imagery and with the NOC (UK). on the surrounding seabed. While many samples will be necessary to fully evaluate the
16 | january/february 2020 | Hydro international
14-15-16_scottishseabed.indd 16 30-01-20 12:21 highlighted products
Highlighted Products In each edition of Hydro International, we make an editorial selection of innovative An Ocean Robot Deployed products worth highlighting. Don’t miss out on this unique opportunity, and send us your press releases. If you want to be sure that your new products or services on an Ocean Robot are selected, please contact Feline van Hettema, our account manager. The Caravela AutoNaut, manufactured by UK-based firm AutoNaut, is part of an international experiment to track the formation of clouds and their role in the climate system in the Atlantic Ocean, off the coast of Barbados. The Integrated Sub-bottom Profiler researchers will use combined AutoNaut and glider measurements to understand how the ocean temperatures affect the layer of air above, and how The Innomar SES-2000 the winds and sunshine affect the top tens of metres of the ocean. One of the autonomous model is an AutoNauts has been specially adapted in conjunction with the UK’s University unmanned surface vehicle of East Anglia (UEA) to carry and release an underwater Seaglider in remote (USV) with an integrated and inaccessible ocean locations.The 5m-long AutoNaut is propelled by the Innomar smart sub-bottom motion of the waves and carries a range of sensors for meteorology and/or profiler (SBP). It acquires oceanography, including atmospheric pressure, air temperature and humidity, full-waveform data in water wind speed and sea surface temperature. Furthermore, its systems and depths of less than 1 metre sensors are powered by solar panels and it is designed to withstand heavy seas, down to 100 metres. The layer is self-righting and piloted using satellite communication. resolution is better than 10cm and seabed penetration is up to 20 metres, depending on sediment type and noise level. The main applications are in inshore waters and coastal areas. Innomar’s parametric SBPs are often used in shallow and extremely shallow waters with limited access for vessels. To support such surveys, German-based Innomar offers a remotely operated surface vehicle pre-configured with the Innomar SES-2000 smart SBP.
UAV Smoothly Launched From Another UAV Autonomous Mayflower Voyage Two Silicon Sensing The smooth launch and recovery of a Hugin Autonomous Underwater Vehicle Systems ultra-precise (AUV) has been demonstrated using a new system from the Norwegian AMU30 inertial manufacturer H. Henriksen. Capable of being used by a wide range of small measurement units manned or unmanned auxiliary craft, the Henriksen Launch and Recovery (IMUs) will provide System introduces a versatile new option for the operators of AUVs and critical navigation UUVs. The lightweight Henriksen launch system can be deployed by any data to the autopilot craft capable of supporting its weight and that of the AUV. The Hugin AUV capability for the used to test the system was 5.5-metres long and weighed 780kg, yet with the Mayflower Autonomous Henriksen launch system it was well within the capabilities of the RIB chosen Ship (MAS) throughout to carry it. her milestone transatlantic voyage this autumn. Setting sail this September, the 15-metre long, 5-ton MAS400 will repeat the Mayflower’s original epic voyage made 400 years ago. Led by marine research organization ProMare and powered by IBM, she will sail from Plymouth, England to Plymouth Massachusetts, USA. Instead of a captain and crew, she will use computer vision, machine learning, cutting- edge technologies and sensors to navigate and detect hazards. Travelling at a maximum speed of 12 knots, MAS is expected to take just 12 days to reach the coast of Massachusetts – a fraction of the 66 days of the voyage four centuries ago. Throughout the voyage, the ship will also function as a scientific laboratory. On-board sensors will transmit data for critical research programmes in areas such as maritime cybersecurity, marine mammal monitoring, ocean microplastic analysis and sea-level mapping.
Hydro international | january/february 2020 | 17
17_highlightedproducts.indd 17 30-01-20 12:21 Feature | by Jean-Louis Carme, Benjamin Weyer, Moaz Alakhdar and Mansour Sarooj
Introducing State-of-the-art Geoid Modelling and Related Heights Analysing Mean Sea Level Variations across the Strait of Hormuz
When using GNSS as a geodetic and topographic height survey technique, the GNSS-based ellipsoidal heights must be transformed into orthometric (‘levelling’) heights using the geoid-ellipsoid separation (‘geoid heights’), but these are not accurately known in all countries. Emirates Defence Industries Company (EDIC) and Fugro recently embarked on modernizing the geodetic and hydrographic infrastructure of the Emirate of Sharjah in the United Arab Emirates (UAE). Using GNSS, levelling and gravimetry, an accurate local geoid model was developed. This allowed analysis of the fine mean sea level (MSL) variations along and between the Arabo-Persian Gulf and the Oman Sea on both sides of the Strait of Hormuz.
For demanding applications, global gravitational of the sea surface (TSS) is computed using tide referenced to the ellipsoid and the geoid. models (GGMs) do not suffice; hybrid gauge observations referenced to the geoid. However, the MDT/TSS is reputedly unreliable gravimetric geoids, based on gravimetric geoids Offshore (in the open sea), its equivalent is the nearshore. This project in the UAE researched and GNSS-levelling benchmarks with mean dynamic ocean topography (MDT), which the possible range of its inaccuracy across the (theoretically) known rigorous orthometric is computed using the mean sea surface (MSS), Strait of Hormuz. EDIC and Fugro set up the heights, are required. Nearshore, the topography measured primarily from satellite altimetry, geodetic and hydrographic baseline for the Emirate of Sharjah, including a continuously operating reference station (CORS) network, first-order geodetic control points and levelling benchmarks, radar tide gauges and associated tidal benchmarks, absolute gravity marks and a relative gravity grid, all to determine a hybrid gravimetric geoid.
GNSS-derived ellipsoidal heights The geodetic infrastructure consists of 31 first-order reference points, with 23 first-order geodetic control points (GCPs) complemented with eight active CORS. The geodetic GNSS survey was extended to 67 first-order levelling benchmarks (LBMs).
The data from the eight CORS was collected for 17 days. The local eight-station CORS network was tied into the International Terrestrial Reference Frame (ITRF) using 30 additional regional IGS CORS. Data processing was then performed using Gamit-Globk software from MIT and crosschecked using Bernese software (University of Bern). This step yielded uncertainties of 2mm in Easting and Northing Figure 1: 15km masked satellite altimetry-derived gravity data in the study area. All values are in mGal. and 5mm in Ellipsoidal height for the CORS.
18 | January/february 2020 | Hydro international
18-19-20-21-22_featurecarme.indd 18 30-01-20 12:21 Figure 2a: CORS network. Figure 2b: First-order and LBM subset geodetic network.
The first-order GCPs were observed using spacing in the surrounding emirates to stations values, providing grid point uncertainties geodetic GNSS. A final least squares adjustment complement the existing gravity database of 32µGal. was constrained to the eight initially computed (terrestrial and coastal airborne gravity data). CORS coordinates, which provided uncertainties Measurements were carried out according to Accurate mean sea levels of 5mm in Easting and Northing and 15mm in state-of-the-art methodologies. Three absolute The nearshore water level was observed for two Ellipsoidal height for the GCPs. Transformation of stations were established for tying-in the relative years using radar level tide gauges installed at the geographical GCP coordinates to the UAE measurements to the International Gravity four coastal tidal stations (Figure 4). Harmonic local coordinate reference system (epoch Standardization Network (IGSN71), scaling the analysis to determine the 37 main tidal 2000.0) was performed using the ITRF2014 and network and limiting the error propagation. constituents was performed using a least square GEODVEL tectonic plate motion models Processing of the absolute measurements adjustment. Statistical analysis of the differences (MORVEL56 was tested but not used). was performed by the University of Montpellier between the observed and the predicted tides with Micro-g Lacoste g9 software with a final validated the computation process. With the Accurate gravity grid 5µGal uncertainty. The relative gravity complete datasets, the differences between the To determine the gravity derived geoid, relative measurements were reduced to second-order yearly harmonic components averaged over two gravity data was measured at a 2km grid free-air anomalies. The final least squares years allowed estimating mean sea level (MSL) spacing in the Sharjah Emirate and at a 5km adjustment was constrained to the absolute and lowest astronomical tide (LAT) uncertainties
Figure 3a: FG5 absolute gravimeter. Figure 3b and c: CG6 measurements of vertical gradient. Figure 3d: Combined GNSS and relative gravimetry.
Hydro international | January/February 2020 | 19
18-19-20-21-22_featurecarme.indd 19 30-01-20 12:21 with an uncertainty of between 2 and 4cm depending on the station.
Accurate rigorous orthometric heights A 400km first-order, first-class levelling network made of three loops with 67 levelling benchmarks was established and observed forward and backward to define the vertical datum (Figure 5). Both loops closed to within 1 to 3mm√Km with the difference between forward and backward runs within 4 to 9mm. Gravity observations were carried out at each levelling benchmark. The levelling network was least squares adjusted in geopotential numbers to account for gravity variations along the levelling paths. Helmert orthometric heights were computed approximating integral mean value of gravity with Poincaré-Prey reduction. The Figure 4a and b: Observed and predicted water level over first year and enlargement – Khor-Fakkan. difference between geometric heights (stand-alone levelling without accounting for local gravity variations) and the gravity-reduced The SRTM-1” DTM was used to compute the Al-Hamriyyah MSL (Gulf), comparisons yielded Helmert orthometric heights was 7.1cm at the topographical effect. The 3-space/ differences of -13.0cm at Khalid (Gulf), and extreme of the network. Finally, rigorous no-topography method was implemented due -0.063cm at Khor-Fakkan and -0.001m at orthometric height corrections (terrain, density to its capability to recover short wavelengths of Kalba, (both in Oman Sea). According to and geoid effects) were applied using the smooth input data when adding condensed literature, the MSS varies significantly in the Gulf method by the University of New Brunswick effect after downward continuation. and the Oman Sea (exceeding 15m, mostly due (UNB). Depending on the benchmarks, these to geoid variations), but the four tide gauges of rigorous corrections ranged up to 1.5cm – which The accuracy of the gravimetric geoid was interest happen to be in areas where TSS should is quite significant, considering the challenging evaluated using the 67 levelling benchmarks. be quite similar in height. level of accuracy required for reliably tying the The residual standard deviation was 3.9cm, four tide gauges with each other and achieving showing a remarkable improvement with respect At local scale, MDT models agree as to the TSS an accurate hybrid gravimetric geoid in the to the global GECO gravity model for which this along the Gulf coastline, very slightly decreasing Al-Hajar mountain range. value was only 11.1cm. The gravimetric geoid westward. This trend is confirmed by the was then fitted onto the benchmarks by least measured variation of the MSL between Accurate gravimetric and hybrid squares collocation. In addition to making the Al-Hamriyyah and Khalid (-13.0cm), whose gravimetric geoid models geoid consistent with the vertical datum uncertainty due to some possible – albeit limited – A gravimetric geoid was computed for the realization, such a fitting is essential whenever local effect was estimated below 2cm. The MSL entire Sharjah Emirate using Stokes-Helmert there are areas with strong gravity anomalies gradient along the Oman Sea coastline looks approach implemented in UNB/Fugro’s SHGeo where gravity data is scarce, inaccurate or just more questionable; the TSS is slightly but clearly package. With this method, the topographic not publicly available (typically beyond the decreasing northward (-0.062cm from Kalba to masses are numerically condensed into a layer borders, in this case in Oman), which prevent Khor-Fakkan, with the uncertainty estimated to of infinitesimal thickness on the geoid prior to capturing some medium to long wavelengths of be below 3cm), but this trend cannot be implementing a Stokes integration. The latest the gravity field in the AOI. The hybrid ascertained by any model due to the variability of release (2019) of the software takes into gravimetric geoid was evaluated implementing the TSS slope magnitude and direction in the account the topographic masses’ lateral density blind tests, giving an accuracy of better than Oman sea. Likewise, between the Gulf and the variations for maximal accuracy. 2.5cm (pessimistic estimation). Oman Sea, whereas the TSS appears in the same range in the AOI (virtually the same MSL The process started with the compilation and Studying MSL differences along at Al-Hamriyyah and Kalba), no model seems assessment of all newly acquired and existing Arabo-Persian Gulf and Oman Sea capable of ascertaining the extent to which they datasets available for the region (UAE and Once the levelling network was shifted onto the are the same. Indeed, when compared to the neighbouring countries), and included land, airborne (including lines flown nearshore), shipborne and satellite altimetry-derived marine Geoid model Mean residual [m] Residual standard Minimum Maximum gravity. A least square downward continuation deviation [m] residual [m] residual [m] was computed on the entire datasets to detect Best fitted GGM (GECO) +0.081 0.111 -0.164 +0.450 outliers. The optimal combined/satellite-only Raw gravimetric geoid +0.981 0.039 -0.095 +0.064 reference fields over the area of interest (AOI) Hybrid gravimetric geoid 0.000 0.010 -0.026 +0.019 were found to be the GECO/GOCO05s models. Table 1: Geoid model evaluation using 67 GNSS-levelling benchmarks.
20 | January/february 2020 | Hydro international
18-19-20-21-22_featurecarme.indd 20 30-01-20 12:21 REFERENCES - Ellmann, A. and Vanícˇek, P., “UNB application of Stokes– Helmert’s approach to geoid computation”. Journal of Geodynamics, 2007, vol. 43, no 2, p. 200-213.
- Farzaneh, S. and Parvazi, K., “Noise Analysis of Satellites Altimetry Observations for Improving chart datum within the Persian Gulf and Oman Sea”, Annals of Geophysics 61, 2018; doi: 10.4401/ag-7610.
- Rio M.-H.,1,2, Mulet, S., Etienne, H., Picot, N., Dibarboure, G., “New CNES-CLS18 Mean Dynamic Topography of the global ocean from altimetry, gravity and in-situ data”, Punta Delgada OSTST 2018 2018, https://meetings.aviso. altimetry.fr/fileadmin/user_upload/GEO_05_Rio.pdf
- Sandwell, D., Harper H., Tozer, B., Smith, W. – “Gravity field Figure 5: First-order levelling network and tide gauge locations (four). recovery from geodetic altimeter missions”, 2019, Advances in Space Research; doi:10.1016/j.asr.2019.09.011.
TSS resulting from the study’s tidal those of marine ship-track gravity (3.5 to - Vignudelli, S., Birol, F., Benveniste, J., Raynal, M., Roinard, measurements and the rigorous orthometric 5mGal). Whereas this choice resulted in typical H., “Satellite Altimetry Measurements of Sea Level in the heights, the latest MDT publicly available errors of between 0.5 and 5mGal, one may Coastal Zone”, Surveys in Geophysics 40., 2019, 1319. (CNES-CLS18 MDT, based on GOCO05s GGM, notice that they reach almost 12mGal offshore 10.1007/s10712-019-09569-1. consistent with this geoid at low degree/order) Khor-Fakkan (and 7mGal offshore Kalba), and showed TSS slope biases of 2 to 7mm/km in much higher nearshore. All studies agree that both seas and virtually no difference in the SST extracting accurate MSL from satellite altimetry shift between the two seas (Figure 7). in coastal areas is hardly feasible due to amongst coastal MSL variations. Although slightly The slope inaccuracy was anticipated while other things corrupted waveforms and errors in underestimating TSS slopes in these coastal analysing estimated errors from satellite most of the corrections. However, this geoid areas, CNES-CLS18 MDT has proved fairly altimetry at the geoid computation stage (Figure study suggests that the resulting inaccuracy accurate in the AOI, certainly due to its related 6). All data within 15km of the shoreline was depends on the area and can be anticipated MSS relying on Jason-1/2 and Cryosat-2 and its masked out. This represented an acceptable using the error model provided with the satellite inclusion of data from the Drifters surface compromise for keeping as much data as data. In any case, a network of tide gauges velocity program (SVP) in the Oman Sea. Once possible while using data with errors similar to remains the only way to accurately measure shifted onto a reference MSL
Figure 6: Emirate of Sharjah’s gravimetric geoid. Values are in m. Figure 7: Comparison between Sharjah hydrographic levels/geoid 2019 TSS (in orange font) and CNES-CLS18MDT interpolated and shifted to minimize the differences to the four tide gauges (in blue font).
Hydro international | January/February 2020 | 21
18-19-20-21-22_featurecarme.indd 21 30-01-20 12:21 at a reference port, the model can be used to About the Authors estimate the MSL in first approximation up to a Jean-Louis Carme is a technical director at Fugro France. He holds an MEng in Geodesy, few dozen kilometres from the reference port. Topography and Survey Engineering from Ecole Spéciale des Travaux Publics, du Bâtiment et Even better, the model can be calibrated using de l’Industrie, Paris, France. He has been in charge of geodetic, geomonitoring, geoid two tide gauges in each sea and the SST modelling and hydrographic survey project for almost 30 years at Fugro Geoid. extrapolated much further if the TSS slope is somewhat regular.
Benjamin Weyer is a geodetic engineer at Fugro France. He holds an MEng in Geodesy, Conclusion Topography and Survey Engineering from Institut National des Sciences Appliquées, The combination of state-of-the-art GNSS data Strasbourg, France. He is currently involved in precise GNSS and geoid modelling projects. for 17-day observation sessions, water level data from four tide gauges over a two-year observation period, precise geodetic levelling, and absolute and precise relative gravimetry Moaz Alakhdar is a PMP certified project manager at EDIC – Bayanat. He holds a BEng in allows the computation of rigorous orthometric Electronics from Damascus University, Syria, and an MBA from Strathclyde University, UK. He heights and a high-accuracy hybrid gravimetric is managing projects related to spatial data modelling and systems design. geoid. This has given the Emirate of Sharjah a reliable geodetic and hydrographic infrastructure whose robustness has allowed refining of the TSS slopes nearshore along the Mansour Sarooj is an operations manager at EDIC – Bayanat, with more than 20 years of Gulf and the Oman Sea as well as the TSS experience in geodetic and hydrographic surveying. He holds a Diploma in Avionic Engineering difference between both seas. The latter is hard from UAE College of Technology, a Diploma in Geoinformatics from ITC, the Netherlands, and a to accurately measure from satellite altimetry degree in Management Information Systems from Al Hosn University, UAE. alone. This study also suggests that gravity- estimated errors from satellite altimetry can be an indicator of the need for increased coastal water level measurements.
KLEIN MA-X VIEW 600 RE-DEFINING SIDE SCAN SONAR
INDUSTRY’S FIRST SIDE SCAN SONAR WITH INTEGRATED GAP FILLER
Imagine a survey done in 40% less time. Imagine 40% less fuel cost. Imagine an uprecedented resolution both in side scan and nadir.
Today Klein re-defines seafloor imaging with a revolutionary dual frequency side scan - so different yet so simple to use.
Download the MA-X View 600 brochure from www.KleinMarineSystems.com or call us at (603) 893-6131 to find out how Klein is Making the Oceans Transparent!
KleinMarineSystems.com
22 | January/february 2020 | Hydro international
18-19-20-21-22_featurecarme.indd 22 30-01-20 12:21 Perspectives | By Dawn Wright, US
“Tharp Helped Keep Me Going” How a Treasure Map Led Her to the Bottom of the Sea
“It wasn’t always easy being a black woman in my early days as an oceanographer,” says Dawn Wright, chief scientist at a worldwide operating company specialized in mapping and spatial analytics software. But a fictional pirate and a pioneering ocean explorer helped her chart her course.
“I grew up in the Hawaiian Islands, so the ocean existence, and what it could lead to, that drives colourful rendition of the mysterious map was has always been a sacred place to me. My Long John Silver and others to the point of included on the inside of the back cover. summers included many hours spent in the obsession.” “I had no idea at the time as a child what waves, and ample time for reading. The book cartography was, but that map fascinated me to that captured my imagination above all others MYSTERIOUS MAP no end: the shapes of the landforms, the was Robert Louis Stevenson’s Treasure Island. “I fancied myself one of the characters in the colours, the arrow pointing north. Not only was I One of the central anchors of the story is story, fascinated by the idea of a pirate’s life, set on a permanent heading towards a love of Captain Flint’s treasure map. The irony is that, with liberty, equality and fraternity held high. At pirates and pirate lore, I also wanted to know as you read the book, or watch the Disney the beach, I followed imaginary clues and dug how to better decipher maps, and how to make movie, the details of the map are never for loot in the sands. And I pored over the last them myself. I wondered, why did most maps revealed. It is just the notion of the map’s page of my leather-bound copy, where a only show the top of the ocean? What is beneath
Hydro international | January/February 2020 | 23
23-24-25_treasuremap.indd 23 30-01-20 12:25 which her work was based were sparse and far less accurate than what we work from today, the map is still unmatched in its beauty, elegance, and insight.
“Like Flint’s treasure map, Tharp’s panorama still invites wondering minds to seek further discoveries in the world it depicts. It helped inspire me to specialize in the study of the shape of the ocean floor and the geological processes at play. To write my thesis, I travelled along the Tonga Trench in the Western Pacific Ocean, using a sonar ‘sounding’ system to gather yet more detailed swaths of seafloor data.”
SCIENTIFIC DRILLING VESSEL “And it stayed with me as my career took off. Though I hoped to continue mapping unexplored parts of the seafloor after obtaining my Master’s the surface, and how in the world do you make MARINE CARTOGRAPHY degree, my first post, in 1986, was as a laboratory a map of that? “I fell more deeply in love with this document technician aboard the scientific drilling vessel once I learned the backstory of one of its JOIDES Resolution. This type of vessel does not “Those questions ended up launching my creators. As a researcher at Columbia University have sonar mapping equipment; instead, it can career of making real treasure maps of the working in the 1950s and 1960s, Marie Tharp lower miles of drill pipe through the entire depth of ocean floor. I studied geology at college, then began the world’s first systematic, comprehensive the ocean to the seafloor, recovering cores that oceanography at Texas A&M. It was there attempt to map the entire ocean floor. During the reveal rich paleo-oceanographic history. I sailed on that I would find another map to my future: the process of translating millions of ocean-sounding ten of these expeditions, logging nearly six months 1977 World Ocean Floor Panorama by Marie records into a single drawing, she discovered a per year at sea. Though I loved the work, the Tharp and Bruce Heezen, which adorns the rift valley that informed the theory of plate 12-hour days could be arduous: I was usually one walls of many great institutions of oceanography tectonics. Her contributions were for years left out of a handful of women on a ship of 100 people, around the world. It was the first in history to of historical accounts in favour of her male peers, and always the only black woman. Women were hint at the full scope of what lies beneath the but now Tharp is hailed as the inventor of ‘marine expected to deal with the close quarters and heavy blue.” cartography’. And even though the data upon equipment, just as the men were.
24 | January/february 2020 | Hydro international
23-24-25_treasuremap.indd 24 30-01-20 12:25 “On the toughest days, Tharp helped keep me Island danced somewhere in the back of my triumphs and innovations of the seafl oor going. One of my favourite expeditions was to a mind.” mapping community – Tharp in particular. And, famous place boldly depicted in another of her perhaps, the ocean-braving pirates who fi rst stunning panoramas: the Eastern Indian Ocean. MAPPIng EXPEDITIOnS inspired at least one of us.” In preparation for the expedition, I had “As my career progressed, I went on to lead my discovered her Indian Ocean panorama, own seafl oor mapping expeditions. Now I work produced in 1967 for National Geographic. for Esri, a private mapping, GIS and geospatial What are the attractive aspects of our profession, why did Tharp was with me on board, too, in a way: data science company. One of the joys there you choose employment in this industry, what do you see as because our ship was outfi tted to drill beneath has been teaming up with kindred spirits who the most important challenges? These and many other the seafl oor, not to map the highs and lows of the are just as curious about what’s beneath all the questions often dominate the personal meetings between seafl oor with sonar technology, it was important to blue that most other maps show. Mindful of the colleagues. That’s exactly what we would like to highlight. If have her map on hand to help me understand high visual standards that Tharp established you want to contribute to this new section in the features that we were drilling into. with her panoramas, we’ve built an entire ocean Hydro International, please contact Cees van Dijk, basemap with carefully chosen colours, content manager ([email protected]). “When we crossed the equator, it triggered a saturation and shading, legible labels, and a special ceremony – the line-crossing ritual, clear hierarchy of information and coordinates. which was based on US Navy tradition. During It’s become a platform upon which other these rites, ‘pollywogs’ – those who had never scientists can layer their own discoveries. Dawn Wright joined Esri as chief crossed the equator at sea before – have to be scientist in October 2011. Previously, deemed worthy of entering the ranks of “But unlike the maps of Tharp’s time, we can she spent 17 years at Oregon State ‘shellbacks’, or those who had already crossed instantly add high-resolution bathymetric data, University as a professor of geography the equator on prior expeditions, and who are thanks especially to a global initiative to create a and oceanography, where she given all sorts of fantastical names. I was over super-detailed map of the entire ocean fl oor, maintains an affi liated faculty appointment (her article was the moon when given the role of one such known as Seabed 2030. Despite all the seminal fi rst published on www.citylab.com). shellback, Davey Jones, during the festivities studies and maps in science, the technology [email protected] on one of those trips. Flint’s map in Treasure should not cause us to forget the early struggles,
CONFERENCE CHCCanadian Hydrographic Conference Hydrography 2020: Dynamic Evolution
Québec City February 24 - 27, 2020
chc2020.org
Hydro international | January/February 2020 | 25
23-24-25_treasuremap.indd 25 30-01-20 12:25
Feature | by Mario Hoppema, Walter Geibert and Maria Vernet, Germany and US
Scientific Challenges in a Crucial Region for Planet Earth Remote, Frozen, Critical and Changing: the Weddell Sea
Located in the Atlantic sector of the Southern Ocean, the Weddell Sea generates extremely dense bottom water that
spreads into all the world’s ocean basins, transporting oxygen, CO2 and other solutes. Everything that is added here is
transferred into the abyssal oceans, including anthropogenic CO2. However, changes are taking place in the Weddell region that will have an impact on other oceans and on the global climate.
The Weddell Sea (Figure 1) is a huge remote, relatively inaccessible part of the the east. The vigorous water transport of the embayment between the Antarctic Peninsula Southern Ocean – the huge sea expanse that Weddell Gyre is driven by the strong westerly and the Antarctic continent, situated at the surrounds the continent of Antarctica (Figure 2). winds in the north and easterly winds in the southern edge of the Atlantic Ocean. The The water circulation in the Weddell Sea is south, both of which are due to typically stable boundary of the Weddell Sea to the south is characterized by an elongated gyre (a kind of weather patterns in this region. formed by the Filchner-Ronne Ice Shelf, the huge eddy), the Weddell Gyre, which extends greatest floating ice volume on Earth. It is a beyond the Weddell Sea towards the north and Some of the strongest winds and the highest waves in the world occur here: the roaring forties and furious fifties are well known. In austral winter, almost the whole of the Weddell region is covered by sea ice, while in summer the ice cover almost entirely retreats, except for perennial ice fields in the west. Since sea ice is one of the main factors to influence processes and elemental cycles in the ocean, it is evident that the region is subjected to extremely high seasonality. Tabular icebergs of several hundred metres in thickness occur, following the circulation of the gyre.
WATER MASS FORMATION In this frosty region in the far south, the seawater closest to the sea surface gets as cold as it can in winter, reaching freezing point at about -1.9°C. At the same time, the excess salt left over from extensive sea-ice formation is released into the cold seawater that stays behind. In some areas, dubbed coastal polynyas (open water within the ice coverage), this process occurs at a very high rate, producing extremely dense seawater, among the densest on Earth. The dense water is transformed (by mixing with other local waters) into a water mass called Antarctic Bottom Water, filling the deepest parts of the Weddell Sea that may reach depths of over 5,000 metres. The Figure 1: Map of the Weddell Sea and environs. (Courtesy: AWI, Bremerhaven) formation process involves surface waters and
Hydro international | January/February 2020 | 27
27-28-29_weddellsea.indd 27 30-01-20 12:25 thus all the chemical and biological species deep water into the surface layer, where the ecosystem. As to the biology of the region, the
present, and dissolved gases in this surface water nutrient and CO2 concentrations increase. abundance of Antarctic krill is decreasing, are transferred into the Antarctic Bottom Water. whereas its competitor, salps, is expanding its
This bottom water therefore contains abundant Because of the uptake of man-made CO2, the territory to the south. Finally, changes in the ice
oxygen and CO2 (including anthropogenic CO2). local ocean is becoming more acidic, which coverage have been observed by satellite These processes occur predominantly in winter, may have a detrimental influence on the observations, though quite different from those making it hard to observe them in this inaccessible region (Vernet et al., 2019).
CONNECTIVITY WITH OTHER OCEANS The Weddell Sea is not just a remote corner of the oceanic realm, where nothing worthwhile happens. Instead, it is one of the world’s major drivers of processes and chemical cycles in all oceans, and highly relevant to the global climate. The locally-produced Antarctic Bottom Water leaves the Weddell region towards the north, replenishing the layers of bottom and deep water in all the major oceans. This means that, in many places in the oceans, the water close to the sea floor is derived (at least in part) from this relatively small region, the Weddell Sea. By way of the Antarctic Bottom Water, the Weddell Sea (and some other maritime regions around Antarctica) therefore ventilate the abyssal oceans (i.e. supply oxygen), but also
transfer (anthropogenic) CO2, nutrients and other chemicals. The Weddell Gyre itself is influenced by remote atmospheric conditions and climate modes. For example, the Southern Annular Mode, a belt of westerly winds moving north and south and a major climate driver, appears to enhance upwelling of deeper water into the surface layer. Also, the El Niño phenomenon in the equatorial Pacific seems to Figure 2: Ice coverage in the Southern Ocean. (Courtesy: AWI, Bremerhaven) exert remote control on the Weddell Gyre, with a spin-up of the gyre transport, followed by a weakening of the transport.
CHANGES IN THE WEDDELL REGION Although its relative inaccessibility means that the Weddell Sea is undersampled compared to other oceanic regions, we do have some data that is suitable for analysing decadal trends in physical and chemical variables and parameters. We need to continue these observations of the changing sea before imminent changes accelerate in the near or further future. We know, for example, that the very dense bottom waters of the region are becoming warmer and decreasing in surface area. At the same time, ventilation of the waters formed in the Weddell Sea is decreasing, meaning that less oxygen is transferred into the other oceans. The atmospheric forcing in the southern hemisphere is also changing, partly due to the ozone hole, and this has an impact Figure 3: Moorings with instruments and an AUV used by the Alfred Wegener Institute. (Courtesy: AWI, Bremerhaven/ on the Weddell Gyre, with more upwelling of FRAM/Sabine Lüdeling)
28 | January/february 2020 | Hydro international
27-28-29_weddellsea.indd 28 30-01-20 12:25 taking place in the Arctic. The changes in ice use of Autonomous Underwater Vehicles (AUV) keep track of the effects of climate change in cover will feedback on many other processes has recently become more common. AUVs enable such dynamic regions with an impact far and cycles, such as albedo and heat a suite of measurements to be carried out in sea beyond their own boundaries, continuous exchanges, gas exchange between the ocean areas that are inaccessible to ships, such as under observations must be made a priority. and the atmosphere, and the ecosystem, which the ice shelves of the Weddell Sea. is closely intertwined with the water and the ice. Particularly valuable datasets can be collected Dr Mario Hoppema is a senior chemical OBSERVING AN using stationary moorings that collect data and oceanographer/biogeochemist based at INACCESSIBLE REGION samples for one or two years, overcoming the the Alfred Wegener Institute in Traditional observations from ships are still the limited seasonality of ship-based measurements Bremerhaven, Germany. He received his backbone of our knowledge and should continue. (Figure 3). However, these moorings still need to training in the Netherlands. His working They are arduous and expensive, but necessary. be collected to read out the data, collect samples area has for many years been the Antarctic and Southern However, our lack of knowledge of wintertime and service the equipment. As some of the Ocean, in particular its carbon cycle; he has been on several processes will hardly be addressed in this way as important climate cycles driven by the Southern expeditions with the ice breaking German research vessel ships do not often visit the region in the winter. Ocean are decadal, long-term commitment is Polarstern (Polar Star). New methods for observation are however being essential if we want to obtain reliable observations [email protected] developed, such as biogeochemical Argo floats, of a changing ocean. For the Arctic Ocean, a which float around the gyre at a depth of about network of state-of-the-art observatories called 1,000m and measure vertical profiles of FRAM has been installed by the German temperature, salinity, oxygen, nitrate and other Helmholtz foundation. This type of coordinated Dr Walter Geibert is a geoscientist who parameters every ten days, and transfer the data observations would be particularly helpful for uses natural radioactivity to study the to a satellite. Software is now available that lets the polar systems like the Weddell Sea. timescales of chemical, physical and floats stay under the ice and only send their data biological processes in the ocean. He if there is water above them. Seals are also being CONTINUOUS OBSERVATIONS studied in Trier and Bremen, followed by used as platforms for instruments, and generally ARE A PRIORITY positions as a researcher at the stay in the region all year. Research in the remote Antarctic is University of Edinburgh, the Scottish Association for Marine international, with strong cooperation among Science in Oban, and the Alfred Wegener Institute for Polar Temperature and salinity data are also collected many countries and institutes. Reliable and and Marine Research in Bremerhaven, Germany, where he is and transmitted by satellite to the lab. For whale robust technology is key to the observation of now a senior scientist. and other mammal research in the Weddell Sea, the changing Weddell Sea, an important region [email protected] passive hydro-acoustic instruments are used, for the Earth’s climate. Deploying instruments which provide information on the abundance and and producing regular time series requires a routes of these animals. These instruments can be considerable commitment from universities and moored and therefore present all year. Finally, the research institutions. However, if we want to Prof. Maria Vernet is a senior researcher/phytoplankton ecologist at Scripps Institution of Oceanography. Dr Vernet has conducted research in the Arctic since 1987 and in Antarctica since 1988 and has taken part in many expeditions. She was part of the team to study the effect of ultraviolet radiation on marine phytoplankton after the discovery of the Antarctic ozone hole in 1985. [email protected]
References: Vernet, M., W. Geibert, M. Hoppema, P.J. Brown, C. Haas, H.H. Hellmer, W. Jokat, L. Jullion, M. Mazloff, D.C.E. Bakker, A. Brearley, P. Croot, T. Hattermann, J. Hauck, C.D. Hillenbrand, C.J.M. Hoppe, O. Huhn, B.P. Koch, O.J. Lechtenfeld, M.P. Meredith, A.C. Naveira Garabato, E.-M. Nöthig, I. Peeken, M.M. Rutgers van der Loeff, S. Schmidtko, M. Schröder, V.H. Strass, S. Torres-Valdés and A. Verdy, 2019. The Weddell Gyre, Southern Ocean: present knowledge and future challenges. Reviews of Geophysics 57: 623-708. https://doi.org/10.1029/2018RG000604.
Hydro international | January/February 2020 | 29
27-28-29_weddellsea.indd 29 30-01-20 12:25 sponsored article
Magellan, 175:56 Hours Continuous Operational ROV Dive at 5,100m Duration at Depth
A few operators have developed systems capable of ‘bouncing’ to 6,000m depths, but no one has amassed the experience and technical capability of operating on a continuous basis, day in day out, at these depths. Until now.
The abyssopelagic zone, at 3,000–6,000 The independent ultra-deepwater depth. A programme of continuous metres depth, covers 83% of the ocean company, Magellan Ltd, was formed with improvement and risk mitigation has floor. Until recently, the demanding the goal of developing systems and subsequently culminated in steadily conditions and pressures at these depths techniques capable of conducting routine increasing reliability and extended dive times. have prevented companies from operations at the extreme limits of the conducting routine operations in the abyssopelagic zone. “Magellan’s Argus Worker ROV systems deepest reaches of this zone. The vast have now proven their capability to operate majority of commercial systems have a During the past 30 months, Magellan has at these extreme depths (5,000–6,000m) maximum design depth of 4,000 metres, been quietly developing the systems and reliably, with extended mission times during with almost no operators actually experience to successfully operate dual ROV continuous operations”, says Doug Scott, operating the systems at their design limits. systems at these depths. System reliability has offshore manager onboard the MV Freja. been proven with over 10,800 hours of The discovery of deep ocean mineral operations at depths greater than 5,000 “Building on the experience gained in deposits has created a demand for metres. Paradoxically, it has been found that combined MBES, SSS, Visual ROV surveys companies and systems capable of the majority of system failures occurred for the traditional oil and gas market, performing commercially viable operations during transits through the water column, Magellan has brought together an between 4,000 and 6,000 metres. driving the goal of extended mission time at experienced multidisciplinary team with
30 | January/february 2020 | Hydro international
30-31_sponsoredmagellan.indd 30 30-01-20 13:49 sponsored article
experience in deepwater operations to drive Velocity Log (DVL) and a high accuracy or sister company projects, as well as our push into the ultra-deep regions.” pressure sensor in a single housing. performing on-demand search and survey work scopes for companies requiring ULTRA-DEEPWATER MBES SURVEY A Teledyne RESON SeaBat T50-S Integrated ultra-deepwater operations. This extended mission time has been Dual Head multibeam system (200kHz and exemplifi ed by the recent 200kHz 400kHz capability) typically provides 600m “With dual 6,000m Argus electric ROVs and Multibeam survey of a topographically swath coverage at 125m altitude, with the a 6,000m 50-tonne active heave challenging site at 5,100 metres depth. The real-time PDS display allowing the ROV compensated winch, permanently mobilized site survey was completed in a single pilots to correct altitude and tracking on the Danish-fl agged MV Freja, Magellan operational dive of 175:56 hours with thereby ensuring full coverage through has a cost-effective, versatile platform real-time display of acquired data. topographically challenging areas on the capable of rapid response to ultra- fi rst pass. deepwater search, identifi cation and Blending the real-time data acquisition of recovery projects worldwide”, says Richard deep-tow systems with the ability of AUVs Optional equipment such as an EdgeTech Parkinson, Magellan founder and director. to operate in challenging regions, these 2205 Side Scan Sonar (75–1,600kHz dual systems open up new possibilities in frequency system) can be fully integrated ultra-deepwater search and survey. into the package, bringing deep-tow swath coverage to ROV operations. EQUIPMENT Subsea positioning of the ROV system is “Combining the low frequency, 75kHz achieved using a USBL-aided Sonardyne coverage of the side scan sonar’s Full SPRINT-Nav 500 system. The vessel’s HIPAP Spectrum CHIRP processing with the higher 500 system has been complimented by the resolution 400kHz coverage of the RESON addition of Kongsberg cNode MiniS T-50 Multibeam on the ROV allows rapid transponders providing good tracking to confi rmation of targets as the search area Doug Scott has been involved with full depth. The Sonardyne system combines is covered”, says Richard Parkinson. ROVs from the infancy of the industry in a solid-state dual Attitude Heading the early 80s. He witnessed fi rst-hand Reference System (AHRS) and Inertial PHILOSOPHY the development of the industry as Navigation System (INS), a Syrinx Doppler Applying and building on Magellan’s technology became both more reliable philosophy of providing what is needed and sophisticated with increasing operating depths. rather than what would be nice to have, Building on his involvement with early ROV-mounted MBES each project is analysed and planned to systems and subsequent IRM campaigns, he naturally deliver the needed results with the best evolved into ultra-deepwater (6,000m) with Swire Seabed effi ciencies and lowest costs. during their push into ultra-deepwater. For the past two years, he has been bringing his extensive ultra-deepwater WHERE DO WE GO FROM HERE…? and commercial experience to Magellan operations. Magellan continues to build its experience www.deepwaterspecialists.com. in ultra-deepwater operations on its own
Hydro INTERNATIONAL | JANUARY/FEBRUARY 2020 | 31
30-31_sponsoredmagellan.indd 31 30-01-20 13:49 Feature | by Sanyal Sunil, India
How to Simplify Survey Reporting Digital Tool to Streamline Hydrographic Information and Make Reporting Easy
Wouldn’t it be great to work on a hydrographic project without spending a lot of time looking for all the elements needed for a professional report? This was what Sanyal Sunil had in mind when he developed SURge, a digital tool to simplify survey reporting.
Hydrographic survey reporting has always been Being an active surveyor, I came across this calibration, transit fixes, rig positioning reports a headache for surveyors in the field, as they situation a number of times. This made me …. The list of reports we produce is endless and have to spend a lot of time formatting the think about developing a consolidated software the effort we put into preparing them could be reports, finding the correct logos and diagrams, platform for survey reporting, in which you just diverted into the operational part of our job, if we displaying observations schematically, and have to input the parameters in a graphic user had such a utility. carrying out irrelevant calculations, all of which interface and select the observation data files to have to be neatly represented in the report but produce a well-manicured survey report. The IDEA GAINING SHAPE have nothing to do with the operational part of idea seemed unprecedented and novel. A I began to work on this idea during my free the job. Considering the usual cramped and report generator programme to help us with all offshore days and, after almost two years and a hectic working environment on board survey the reporting we have to carry out during the lot of trial and error, I have managed to present vessels, these long and tedious reporting calibration and field phases of survey – a decent product. Input and feedback from my exercises distract and exhaust the surveyor. positioning system calibration, heading sensor colleagues encouraged me to move ahead,
32 | January/february 2020 | Hydro international
32-33-34_surge.indd 32 30-01-20 12:26 Figure 1
finally consolidating all the required reports into positional input is correct and the system is The USBL head mounted in this way may have this single platform, enabling a centralized ‘calibration free’ for all the other freedom of a mounting angle error, which means that the monitoring for the reporting formats and movements? The answer lies in the heading heading sensor that is used by the USBL allowing periodic updating if required. information provided by the USBL system. system to calculate the underwater positions may not be aligned with the heading sensor that ‘SURge’, as I call it, is a single platform solution EQUIPMENT CALIBRATION is used by the survey vessel to calculate the for all the hydrographic survey reports during It is true that if the equipment is used as a relative positions of the various equipment, the calibration and field phases of a survey and stand-alone system with the low-quality GPS including the USBL head. is presently only used by the survey division of receiver provided, placed exactly above the the National Petroleum Construction Company, USBL head, then the equipment does not REFERENTIAL COORDINATES Abu Dhabi, where I am presently employed as a require calibration as it is receiving an absolute The mounting angle error can be easily hydrographic surveyor. position. By making use of its inbuilt heading identified by comparing the vessel heading and and altitude sensors, it then correctly calculates the USBL heading and has to be corrected if WHERE IT REALLY MATTERS the position of the underwater unit. the USBL is using positional input from the Of late, there has been a great deal of vessel’s referential frame. But at this point, I discussion about the ‘calibration free’ (as But sadly, this will not be the case most of the have seen people ignore this factor, simply claimed by the manufacturer) underwater time, when the USBL has to be used with a quoting the ‘calibration free’ tagline provided by positioning Ultra Short Base Line equipment combination of different sensors combined on a the manufacturer and therefore inducing an (USBL). If we inspect their claim in detail, we referential frame of the survey vessel. For this error in the data. They simply measure the X can conclude that their claim is legitimate, but purpose, the USBL head has to be mounted on and Y coordinates of the USBL head with also misleading to some extent. a frame and placed in a suitable location on the respect to the positional sensor and enter these survey vessel’s coordinate frame, and has to be into the USBL system (surprisingly, the Is it really calibration free? Let me illustrate with positioned using this frame. manufacturer has kept the abnormal coordinate an incident that happened in one of the ROV positioning jobs I had. A pipeline inspection was in progress using an observation-class ROV with eventing and CP survey. The ROV was positioned using the above-mentioned ‘calibration free’ USBL. During the course of the survey, the DP vessel on which the ROV was mobilized had to turn around by 180 degrees due to operational constraints, keeping the ROV above the pipeline being inspected. As the vessel turned, the ROV began to shift its position on the survey screen and when the turn had been completed, the ROV was almost 0.4 metres away from where it had been before the turn. Note that, on the ground, the ROV was sitting idle above the pipeline.
This made the survey team on board recalculate the offsets, which were confirmed. So, where was the error? How can a USBL system provide a wrong coordinate for the beacon, when the
Hydro international | January/February 2020 | 33
32-33-34_surge.indd 33 30-01-20 12:26 convention for the lever arms), ignoring the fact Now, we have an underwater object with the unit with respect to the vessel. The utility will that the USBL system has its own referential absolute coordinates (15,10). If we take a fix provide the coordinates to be entered. coordinates and the system may end up using the beacon, the USBL will provide the providing incorrect coordinates for underwater values (14.1079,12.1967), by calculating the The lack of a common performance guideline units if the GPS antenna coordinates have not position in its own coordinate frame. for standard survey reporting has always been of been recalculated according to the USBL lever concern to hydrographic surveyors in the field arm frame. If we have calculated the lever arm corrections and, as a result, the surveyor has to produce exactly, that is we have recalculated the position of reports according to the client’s whims. The The manufacturer has not made any provision RP with respect to the USBL head in its coordinate consolidation of survey reports into a single for entering a correction value for the heading, frame (shown in red), we will get (0.93,6.26) as platform and standardization with a universal probably because it will diminish their claim that the USBL head coordinates instead of (2,6). This identity with a suitable prefix abbreviation for their equipment does not require calibration. It will result in the USBL system correctly calculating each report would bring a seamless survey has tried to get around the problem with a the coordinates of the underwater object in reporting scenario into play. Governing bodies relatively new term – ‘the lever arm correction’ position (15,10). The problem in this scenario is like the International Hydrographic Organization – for which the relative position of the USBL that the values 0.93 and 6.26 are hypothetical and IMCA could effectively implement this. head with respect to the GPS unit has to be values and cannot be physically measured on recalculated, according to the lever arms of the board. The values have to be derived. USBL system. CALIBRATION TIME Sanyal Sunil (1977) joined the Indian SCENARIO EXAMPLE But how? If you have a good command of Navy and specialized in hydrographic Let me illustrate the scenario with an example. In AutoCAD, you can draw the offsets in CAD and surveying. He gained his sea legs in the Figure 1, the GPS positioned at the vessel rotate the whole figure according to the heading Indian Navy’s Hydrographic reference point (the small circle on the lower edge) correction, keeping the USBL head as centre Department, nurtured his interest in has an absolute coordinate value of (0,0). The and aligning it with the referential frame of the geography, and graduated. He has a postgraduate degree in USBL head is measured as two metres to USBL. But that exercise is going to consume a GIS and Remote Sensing. He has worked in the field of starboard and six metres to bow (2,6): if the lever large part of your calibration time (also hydrographic surveying since 1996 and witnessed the shift arm correction is not calculated and applied, the considering the time required to open an in perspective from the analogue era to present-day digital USBL coordinates will remain (2,6). Now consider AutoCAD programme). So, we came up with a technology. He ventured into commercial hydrographic that the angular difference between the vessel’s utility in SURge to calculate the lever arm surveys after retiring from the navy in 2011 and founded gyro and the USBL gyro is 10° (USBL gyro high), coordinates for the USBL, where you just have Team SURge with three other navy colleagues. which can be the result of a mounting angle (10° to enter the measured coordinates of the GPS [email protected] is slightly exaggerated to prove the point). and USBL unit and the angular difference of the
34 | January/february 2020 | Hydro international
32-33-34_surge.indd 34 30-01-20 12:26 PRODUCTS FOR POSSIBILITIES
S-100 in CARIS HPD
The new S-100 Universal Hydrographic Data Model opens up a world of possibilities for data and services that can improve safety of navigation, open the door to economic opportunities and help conserve our marine environment.
CARIS HPD offers concurrent S-57 and S-101 ENC production from a single source database backed by fully customizable mappings. Stepping into the world of S-100 doesn’t mean starting over.
Get ready to explore the possibilities with the partner you trust. Start the process today.
Get more CARIS HPD details www.teledynecaris.com/HPD
Copyright © 2019 Teledyne CARIS. All rights reserved.
DESDESK-2252 - HI Full Pg S-100 HPD (June2019).indd 1 6/20/2019 1:36:20 PM SMART SUBSEA SOLUTIONS
Delivering data in most adverse conditions: underwater acoustic modems with advanced communication techology and networking
Accurate USBL and LBL positioning of underwater assets
Modem emulator and other cost-saving developer tools
Automonous surface vehicle for bathymetry, monitoring and AUV support
Meet us at OCEANOLOGY INTERNATIONAL 2020! 17 - 19 March London, ExCel Stand C251
[email protected] EvoLogics.de