Hydrographic Survey of Newlyn Harbour, Cornwall. · DISCOVERY MARINE SURVEY AND SUPPORT Hydrographic Survey of Newlyn Harbour, Cornwall. Imagery ©2017 Infoterra Ltd …

DISCOVERY MARINE SURVEY AND SUPPORT

Hydrographic Survey of Newlyn Harbour,

Cornwall.

Imagery ©2017 Infoterra Ltd & Bluesky, DigitalGlobe, Map data ©2017 Google

Survey Report

Date: 30/05/2017

Project: H2O-615-DMS

Hydrographic Survey of Newlyn

Harbour, Cornwall.

Survey Report

Author: Mark Gray

Checker: Matt King

Approver: Trevor Butler

Report No.: H2O-615-DMS

Revision: V1

Date: 30/05/2017

Discovery Marine Survey & Support

24 Galleon Court Newquay TR72AU

T: 07929330762 www.discoverymarinesurvey.co.uk

Swathe Services (UK) Ltd 1 Calenick House

Truro Technology Park Heron Way, Newham

Truro, TR1 2XN

T: +44 (0) 187 227 5642 www.swathe-services.com

http://www.discoverymarinesurvey.co.uk/

http://www.swathe-services.com/

Executive Summary

A hydrographic survey was undertaken in the Newlyn Harbour, Cornwall, UK

using an Unmanned Survey Vessel (USV) and Single Beam Echo Sounder (SBES)

sonar system combined with Hemisphere AtlasLink L-band corrections to

provide positioning. The purpose was to gain sufficient bathymetric data of the

designated site to allow for pre-dredge assessment.

All onsite operations took place between 22nd May 2017 and 24th May 2017,

with standard operating hours (including travel to site, mobilisation and

demobilisation and equipment maintenance) between 08:00 – 19:00 (UTC).

Survey operations were carried out utilising the Unmanned Survey Solutions

Mark II, Inception class USV and CEE HydroSystems CEESCOPE-USV SBES.

Survey planning, data acquisition and post-processing were all conducted with

the HYPACK Hydrographic software package. All deliverables and data images

provided with this report have been created by or directly taken from the

processing software, unless expressly stated. The attached charts have been

presented in WGS84, UTM North Zone 30 with depths referenced to Chart

Datum via tidal data from the Newlyn Tide Gauge, provided by the British

Oceanographic Data Centre.

No dangerous incidents or near misses occurred during survey operations.

Newlyn Harbour Survey Report

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Table of Contents Executive Summary ................................................................................................................................. 3

1. Scope of Work ............................................................................................................................... 5

2. Survey Overview ........................................................................................................................... 6

2.1. Schedule of Activities .................................................................................................................... 6

2.2. Geodetic Parameters .................................................................................................................... 7

3. Equipment ..................................................................................................................................... 7

4. Personnel ...................................................................................................................................... 8

5. Survey Methodology ..................................................................................................................... 8

5.1. Mobilisation, Deployment, Offsets ............................................................................................... 8

5.2. Survey plan and online operations ............................................................................................... 9

5.3. Equipment and survey methodology .......................................................................................... 12

5.3.1. Tide and vertical referencing ................................................................................................. 12

5.3.2. Echo Sounder ......................................................................................................................... 12

5.3.3. Positioning ............................................................................................................................. 12

5.4. Post-processing Summary .......................................................................................................... 14

6. Deliverables ................................................................................................................................ 15

7. Equipment Specifications ........................................................................................................... 17

7.1 Hemisphere AtlasLink ................................................................................................................. 17

7.2 CEE HYDROSYSTEMS CEESCOPE Echosounder ........................................................................... 19

7.3 CEE HYDROSYSTEMS CEE-LINK.................................................................................................... 20

Table of Figures and Tables

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Figure 1 – Imagery ©2017 Infoterra Ltd & Bluesky, DigitalGlobe, Map data ©2017 Google ________________ 5 Table 1. Schedule of Activities __________________________________________________________________ 6 Figure 2. Geodetic Parameters used for acquiring and post-processing of survey data, as entered in the HYPACK

software. __________________________________________________________________________________ 7 Figure 3. 'Inception' Class USV with CEESCOPE-USV SBES ___________________________________________ 8 Figure 4. CEESCOPE and GNSS offsets in HYPACK __________________________________________________ 9 Figure 5. Planned run lines, further coverage was attained by piloting the USV visually where planned run line

were impractical. ___________________________________________________________________________ 10 Figure 6. Survey Matrix (3m*3m) denoting coverage achieved. ______________________________________ 11 Figure 7. Position check screenshot over OS rivet _________________________________________________ 13 Figure 8. Position check Comparison & location of OS Rivet with Google Maps _________________________ 13 Figure 9. Raw single beam data _______________________________________________________________ 14 Figure 10. Raw single beam data with filter applied (denoted by red X’s). ______________________________ 14 Figure 11. Example Search and filter options, as entered in processing. _______________________________ 15


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1. Scope of Work A hydrographic survey was conducted of the Newlyn Harbour, Cornwall using

an Unmanned Survey Vessel (USV) and Single Beam Echo Sounder (SBES) sonar

system. The purpose of the survey gather bathymetric data for charting

purposes and pre-dredge assessment. Figure 1 shows the area of survey

highlighted in red.

Figure 1 – Imagery ©2017 Infoterra Ltd & Bluesky, DigitalGlobe, Map data ©2017 Google


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2. Survey Overview

2.1. Schedule of Activities

Table 1. Schedule of Activities

Date Time (BST) Activity 21/05/2017 08:00 – 14:00 Bench test equipment and wet test in Mylor

Harbour.

22/05/2017 08:30 Meet at Swathe office

22/05/2017 09:00 Travel to site

22/05/2017 10:00 Arrive at site, & Initial Safety and Survey Plan

assessment

22/05/2017 11:00 Deployment of tide gauge

22/05/2017 11:07 Collection of SVP

22/05/2017 11:30 Position Check

22/05/2017 12:00 Vessel Mobilisation

22/05/2017 12:30 Vessel Deployed

22/05/2017 12:45 Online survey


22/05/2017 15:00 Recovery of Vessel and battery change

22/05/2017 15:30 Resume Online Survey



22/05/2017 19:00 Vessel Recovery

22/05/2017 19:10 Tide gauge Recovery

23/05/2017 09:30 Arrival at site

23/05/2017 10:00 Tide Gauge deployed



23/05/2017 13:30 Vessel Recovery. Survey worked stopped due to

technical issue

24/05/2017 11:00 Arrival at site and deployment of vessel

24/05/2017 11:30 Tide gauge deployment




24/05/2017 18:00 Recovery of all equipment

26-31/05/2017 Post-processing, Report writing and creation of

deliverables.


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2.2. Geodetic Parameters

All data was acquired in WGS84 UTM North Zone 30. The geodetics in the project was set up by the Swathe Services Surveyor, then checked and agreed upon by the Discovery Marine Survey and Support representative. Figure 2 is a screen shot demonstrating the parameters as entered in HYPACK.

Figure 2. Geodetic Parameters used for acquiring and post-processing of survey data, as entered in the HYPACK software.

3. Equipment

USV ‘Inception’ mark II is a 2m long multi-hulled remote control boat made of

aluminium. It is powered by x2 12v DC lead acid batteries driving x2 brushless

thrusters. The payload consists of a CEE-Hydrosystems CEESCOPE-USV which is

a combined SBES, GNSS and telemetry system.

A Valeport miniSVP Sound Velocity Profiler (SVP) was used to determine the

speed of sound within the harbour. This is required for accurate depth

calculations using the sonar system. Tidal data was also collected using a

Valeport WLR recorder, this acted as a redundancy in case a reliable tide file

from the Newlyn tide gauge was unobtainable.


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Figure 3. 'Inception' Class USV with CEESCOPE-USV SBES

4. Personnel

Two personnel were involved in onsite operations.

1. Trevor Butler, Discovery Marine Survey

2. Mark Gray, Swathe Services Surveyor

5. Survey Methodology

5.1. Mobilisation, Deployment, Offsets

Upon arrival of equipment and personnel at Newlyn, an assessment was made

as to the most suitable location to launch the vessel. Following this appraisal,

the equipment was unloaded, made ready for deployment and mobilised.

Full safety and operations tests were carried out on all communications, vessel

control, emergency systems and payload equipment and the system was

confirmed to be operational. Prior to deployment of the vessel, the AtlasLink

corrections were confirmed as to being received and correctly formatted.

A tool box talk was carried out by the surveyor and boat operator Mark Gray,

detailing deployment and recovery procedures and associated risks.


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Once the USV had been successfully deployed, the personnel charged with

deployment then transited the vessel to the specified area of survey for the

given day and commenced hydrographic survey operations.

Prior to commencement of survey activities, the relevant equipment offsets

were measured and input to the HYPACK software, as shown in figure 4, these

offsets remained constant throughout the entirety of the survey.

Figure 4. CEESCOPE and GNSS offsets in HYPACK

5.2. Survey plan and online operations

Once the USV was deployed, the vessel was then remotely piloted visually

from the shoreline with the navigation display in HYPACK used for reference.

The first online surveying operation was to run logging lines of the boundary

points of sections of the survey site, from which survey lines were created at

6m line spacing running the length of the section. Cross-lines were also logged

during the survey, the acquisition of multiple orientations of survey lines aided

quality control of the acquired data. Figures 5 & 6 show the intended line plan

files, and the matrix (3m*3m) denoting actual coverage achieved of the survey

area. In all cases, lines were run as close to the boundary limits as safely

possible. Due to the nature of a working harbour, full coverage to the quay

walls in many instances was not possible due to occupied births/moored

vessels.

The survey site was separated into sections. Within sections that were of

regular shape, a line plan of 6m spacing and 25m cross-sections were followed.

Areas with limited space or other restrictions were run visually.


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Figure 5. Planned run lines, further coverage was attained by piloting the USV visually where planned run line were impractical.


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Figure 6. Survey Matrix (3m*3m) denoting coverage achieved.


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5.3. Equipment and survey methodology

5.3.1. Tide and vertical referencing

Without provision of a harbour authority approved tide file, all data has been

applied with a tide file obtained from the British Oceanographic data centre.

The data was collected from the Newlyn tide gauge and is referenced to chart

datum. The data is freely available from https://www.bodc.ac.uk/data. Due to

the project time constraints, the applied tide file is RAW and supplied with the

following disclaimer “Raw data files of sea surface elevation are made available

to provide immediate access for the convenience of interested persons. These

data are raw data and have not been through quality control. While BODC

believes the information to be reliable, human or mechanical error remains a

possibility. Therefore, the NERC does not guarantee the accuracy,

completeness, timeliness, or correct sequencing of the information. Neither

BODC, NERC nor any of the sources of the information shall be responsible for

any errors or omissions, or for the use of or results obtained from the use of

this information”. Prior to application, the tidal data was checked and

compared to predicted tides. However, both Discovery Marine Survey and

Swathe Services emphasize, acknowledge and repeat this disclaimer for all tide

applied data submitted to the client.

Whilst an independent tide gauge was deployed for the entirety of the survey

operation, it has been kept as a redundancy system if no Chart Datum

referenced tidal data was available.

5.3.2. Echo Sounder

A CEE HYDROSYSTEMS CEESCOPE echo sounder was used for the survey. Data

was collected at 20Hz ping rate, utilising a 200kHz frequency transducer with a

9-degree beam width.

5.3.3. Positioning

Positioning was provided by a Hemisphere AtlasLink smart antenna, receiving

L-Band corrections throughout the entirety of the survey. In this setup,

Hemisphere quote the horizontal positioning accuracy as: RMS (67%) ± 0.08 m,

2DRMS (95%) ± 0.16 m


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Figure 7. Position check screenshot over OS rivet

Figure 8. Position check Comparison & location of OS Rivet with Google Maps


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5.4. Post-processing Summary

Raw data files were edited and cleaned using the HYPACK single beam editor,

figure 9 shows an example raw line file and its corresponding digital echogram.

Figure 9. Raw single beam data

Following this, a series of filters and manual editing were applied to the data to

aid in the cleaning process. The effect of these filters can be seen in figures 10

and 11, denoted by the red X’s.

Figure 10. Raw single beam data with filter applied (denoted by red X’s).


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Figure 11. Example Search and filter options, as entered in processing.

Once editing was complete, data was exported in three main forms. 1. Daily

RAW unprocessed XYZs without the application of tide files or SVPs. 2. Daily

RAW unprocessed XYZs with tide files and SVPs applied. 3. Fully processed

XYZs, with tide files and SVPs applied. These are submitted by day, full site,

inside the harbour, outside the harbour and XYZ sorts at a range of XY

intervals.

These fully processed XYZs were then used to create both the TIN

(Triangulated Irregular Network) models and contours that the charts consist

of. These were created using the HYPACK TIN editor. This program creates

surface models from XYZ data files by connecting adjacent data points in

optimised triangles.

6. Deliverables

• All Raw logged single beam files

• All Edited single beam files, with applied tide and SVPs

• XYZs


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o Fully Processed: 1m sort, 2m, 3m, 4m, 5m, 10m, and 20m sorted

XYZs

o Daily XYZs: RAW data with no tide or SVPs applied

o Daily XYZs: With the Newlyn tide gauge data and collected SVPs

applied.

A series of charts has been created and supplied with this survey report, this

series consists of:

• Solid fill 0.1m Tin model with 1m contours tin model, depths relevant to

Chart datum

• Solid fill 0.1m Tin Model with 20m*20m sorted soundings, depths

relevant to Chart datum

• Fair sheet denoting survey lines ran (5m*5m sort), depths relevant to

Chart datum.

All printed charts have been appended to this report.


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7. Equipment Specifications

7.1 Hemisphere AtlasLink


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7.2 CEE HYDROSYSTEMS CEESCOPE Echosounder


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7.3 CEE HYDROSYSTEMS CEE-LINK

Documents

Hydrographic Survey of Newlyn Harbour, Cornwall. · DISCOVERY MARINE SURVEY AND SUPPORT Hydrographic Survey of Newlyn Harbour, Cornwall. Imagery ©2017 Infoterra Ltd …