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WASSP WMB 3250 AND QINSY

BATHYMETRIC SURVEY AND CAPABILITY ASSESSMENT

PENANG WATERS

JANUARY 2015

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BATHYMETRIC SURVEY AND CAPABILITY ASSESSMENT – WASSP WMB 3250 AND QINSY – JANUARY 2015

1.0 INTRODUCTION

GeoSamudra Sdn Bhd In conjunction with THS Geoscience Sdn Bhd conducted a trial of the

WASSP WMNB 3250 Survey Grade Multibeam Sonar System at Penang Waters (Figure 1)

from 24 January 2015 until 27 January 2015. The trial sought to see on how this Multibeam

Survey Sonar System works, assess the characteristics and capabilities of the WASSP WMB

3250 in different scenarios, and how to interface this system with QINSy software navigation

system. The area selected for the survey had a variable depth range (2 - 35 m depth) with

prominent seafloor features. The area included the area that contains coral features,

shipwreck and bridge’s pile. It represents a typical environment where bathymetric data for

various applications would conceivably be required. A brief synopsis of the methods and

results of the survey are presented in this document.

Figure 1: Survey Area at Penang Waters


2.0 PROJECT INFORMATION

2.1 Coordinates

The project coordinates are WGS 84 – UTM Zone 47 North

The vertical datum is derived from Mean Sea Level value.

2.2 Survey Dates

The survey was conducted from 24th January 2015 to 27th January 2015

2.3 Personnel

The personnel involved with this project included:

1. Mr. Mirza Hamza - Project Manager

2. Mr. Mohd Rafy Bin Abd Rajab - Surveyor

3. Mr. Naqiuddin Bin Nadzrin - Survey Engineer

4. Mr. Mohd Shahmy Bin Mohd Said - Data Processor

2.4 Survey Condition

1. Around Penang Bridge I and Penang Bridge II – Slight (Beaufort Scale Number 1

to 3)

2. At Shipwreck Area – Rough Sea (Beaufort Scale Number 5 – 6)


2.5 Survey Vessel

A fishing boat (Figure 3 and Figure 4) was utilized for the survey. The vessel was made

from the fiber glass material and she has the length of 5.7 m. The boat is equipped with

AC Power, fresh water supply and customize work station partition.

Figure 2: Front view of the survey vessel

Figure 3: Back view of the survey vessel


2.6 Survey Equipment

The equipment used in this trial are as follows:

2.6.1 Multibeam Sonar system : WASSP WMB 3250

Figure 4: WMB 3250 Sensor, topside and PC

2.6.2 GNSS and Gyro : Hemisphere Vector V 103

Figure 5: Hemisphere Vector V 103


2.6.3 Motion – Ship Motion Control IMU 108

Figure 6: SMC IMU 108

2.6.4 Sound Velocity Profiler – AML Minos-X SVTP

Figure 7: AML Minos-X SVTP


3.0 BATHYMETRIC SURVEY

The bathymetric survey of this survey project being done in three different areas that

contains three distinguished features around the Penang Water Area. This three

different areas provide the best way to test the full capabilities of the WASSP WMB

3250 system. The three different areas contain features as follow.

1. Coral Feature area (near Jerejak Island, Penang Waters)

2. Bridge Piles Area (Penang Bridge 1)

3. Shipwreck Area (near Rimau Island, Penang Waters)

This bathymetric survey was accomplished using both a “straight” transducer head

configuration (Figure 5), for coral features and shipwreck area, and a “rotated” head

configuration (approximate 30 degrees) for the bridge pile areas (Figure 6). For each

of these head configuration, a patch test was conducted. To investigate the capabilities

of the WASSP WMB 3250 to survey the bridge pile structure, two main piles of Penang

Bridge was scanned. At this survey area, the transducer head configuration is in the

rotated mode (approximately 30 degrees), as mention above. On approaching the

bridge piles, the scan range was reduces in order to increase the ping rate of WASSP

WMB 3250 and maximize the data density.

Figure 8: WMB 3250 Transducer in “straight” head configuration

Figure 9: WMB 3250 Transducer in “rotated” head configuration

FIGURE 5 FIGURE 6


As for the shipwreck area, the survey and scan of the wreck began at the position

indicated by the vessel’s Skipper. According to the skipper, the wreck was the remain

of Chosa Maru, a Japanese warship during World War 2. The Chosa Maru is an

auxiliary gun boat (converted from passenger steamer) and was built on year 1921.

Chosa Maru was sunk on 20th August 1943 by a torpedo from O 24, an O-21 class

submarine from Royal Netherlands Navy. She is assigned to the 10th Special Base

Force (Singapore) at the time of her sinking. The skipper told us that we may not get

a good visual of this wreck since they were a lot of case of thieves involving illegal

salvagers that plundered scrap metal from this shipwreck. We manage to detect the

wreck and acquire the data in that area.

Figure 10: Chosa Maru – Japanese Warship in World War II

As for the coral feature area, the survey procedures and setting for the bathymetric

survey at this coral feature area was same as the usual bathymetric survey work

procedures. The transducer head configuration for this area was in the straight mode.


QINSy (Quality Integrated Navigation System) software was used as the only software

to acquire, navigate, and process the data throughout the survey project. The primary

philosophy behind QINSy is to save time in processing, and the possible need for re-

survey, by providing tools for real-time qualification of the raw data and on-the-fly

correcting for offsets, motion, sound velocity refraction and height, to produce “final”

xyz soundings as the survey proceeds. The software seamless workflow, - from

acquire, process and export data -, make this survey project a very effective time and

cost management.

At the start of each survey day, the equipment installation was verified, this included

checks of the transducer mount and system communication and integration. Before

the survey, a sound velocity profile (SVP) through the water column in the survey area

would be taken and its time and location logged, survey operations would then

commence. Additional SVPs would be taken based on time interval and/or spatial

variation. Multibeam data was collected in most places with 100 percent overlap.

Figure 11: WASSP PC Application System Program and QINSy software in action during

survey operation.


4.0 POST PROCESSING.

QINSy software was used to post process the multibeam data, from start to finish, and

this involves several step of procedure. The first step is to replay all the data with the

correct pitch, roll and heave calibration value. After that, all the data were applied with

correct tide value. Next step is the process of cleaning and validate the data. All the

process of cleaning and validate the data was done using QINSy Processing Manager

and Qloud. Several automatic filters was being used in this stage together with manual

editing and inspecting techniques. After all the data was clean, the data was export to

several deliverables. All the resulting deliverables that being presented in this

document was exported from QINSy.

The bathymetric data from the multibeam was tide corrected using the Simplified

Admiralty Tide Table value of Kedah Pier station (averaging of 60 minutes per

reading). The tide were applied to all the data in QINSy software.


5.0 RESULTS

The result of the survey are shown in a series of maps and plots. There are three type of area

represented in this result section based on type of survey area that being done. All the data

and maps represent here is based on grid surface with 1m bin size exported from QINSy.

5.1 Coral Features Area

The bathymetric survey done in this coral area was done with transducer in straight head

configuration. The depth range at this area is range from -8m to -15m. All the survey

equipment performed well together with a good weather conditions resulting to this good

bathymetric data representation. The WMB 3250 presented a good coral detection capability.

Figure 12: Color shaded bathymetric map of coral feature area generated from Grid Surface (1m bin

size)


Figure 13 : Close up view of the bathymetric data of the coral features.

Figure 14 : Figure show the another close up view from another side of the bathymetric data of the

coral features.


5.2 BRIDGE PILES

The multibeam survey at the bridge pile area was done with the transducer was in a rotated

head configuration. In the rotated head configuration, the multibeam sonars will have the

ability to scan vertical and steep angled structures even in shallow water. The physical

information of the surveyed structure is shown in the figures below.

Figure 15: Photograph of the Penang Bridge 1 with labels indicating the positions of the surveyed

bridge piles

Figure 16: A full overview of pile 1 and pile 2 on grid surface (1m bin size)

PILE 1 PILE 2

PILE 1 PILE 2


Figure 17, 18, 19: Additional oblique views of the WASSP WMB 3250 rotated head survey of Penang

Bridge 1, showing piles structures, seabed slope and surrounding bathymetry.

FIGURE 17

FIGURE 18

FIGURE 19


5.3 SHIPWRECK FEATURES

One of the better way to test the capabilities of the WASSP WMB 3250 is by scanning

and survey the shipwreck area. The depth range at this area is range from -25m to -

34m. The sea condition during the survey at this shipwreck area was rough (Beaufort

Scale Number 5 – 6), thus affected the quality of acquired data. Nevertheless, based

on the processed data below, the capability of WASSP WMB 3250 in detecting

shipwreck is fully tested. As we mentioned above, the activities of illegal salvagers

were so active in this shipwreck area. The illegal salvagers have plundered tonnes of

scrap metal from this shipwreck resulting the processed data represented as in the

figures below. The survey shows a 90m long and 20m width of shipwreck remains on

the seafloor area. The structure of the shipwreck was clearly deteriorated.

Figure 20: Full overview of shipwreck features area and nearby seafloor area on

grid surface (1m bin size)

Shipwreck


Figure 21 AND 22: The close up view of the shipwreck features in point clouds and

wireframe display

FIGURE 21

FIGURE 22


Figure 23 AND 24: Additional oblique views of the WASSP WMB 3250 Shipwreck feature on

grid surface (1m bin size)

FIGURE 23

FIGURE 24


APPENDIX


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