Common Dataset Survey Instructions
1. Introduction
This document details the Shallow Survey 2015 Common Dataset (CDS) Survey areas and
criteria. The aim of the common dataset activity is to provide the international
hydrographic community with a range of datasets, collected using the latest shallow
water survey techniques, so that comparisons can be made and the merits of the
different approaches judged. To this end, areas have been chosen that offer a good
variety of depth, bottom type and sub-sea structures. In addition, a new target detection
test has been devised to ensure that fair comparisons can be made between the object
detection capabilities of the systems.
The areas have been split up into Survey Tasks, which are specific to the type of
equipment being used. For example, those who are taking part in the Multibeam data
collection have three survey tasks (Target Detection, Survey Area 1 and Survey Area 2),
whilst remote sensing techniques (including LiDAR) have their own separate area. The
specifics of these tasks are detailed in the following section.
2. Survey Tasks
2.1. MBES
2.1.1. Target Detection Task
The target detection task is designed to ensure that data that is collected over
known features, in such a way that allows direct comparisons to be made
between the capabilities of each system. In order to do this, set line plans have
been produced, and participants are asked to adhere to a set speed and swath
angle. These parameters are detailed in table 1.
Table 1. Target Detection Task Parameters
Parameter
Swath Angle
Speed Over Ground
Value
70° either side of Nadir
6 Knts
All of the targets are located in the Barn Pool area of Plymouth Sound, and are
with the first priority Survey Area 1 limits (Figure 1).
The line plans consist of three parallel lines. All lines are to be run in the north
to south orientation. The maximum off-line tolerance is 5m. Participants are
requested to collect bathymetry and water column data (if capable) for the
entirety of each line.
ESRI Shapefiles in WGS84 Geographic Coordinates are available at Annex A.
Figure 1 Target detection line plans
2.1.2. Survey area 1
Survey Area 1 (Figure 2) is approximately 2km2 in size and covers Barn Pool in
the west through to the Northern entrance to Drake Channel in the East. It has
a depth range of 0 – approx 35metres. At peak Flood and Ebb, significant tidal
currents are experienced making surveying challenging, especially at the
entrance to The Narrows opposite Devils Point. The area also includes the
narrow passage through The Bridge to the east Drakes Island. An ESRI shapefile
of the survey area can be found at Annex A.
Participants are asked to survey the entire area as completely as they can,
heading inshore to the 5m contour, or as near to this as is safe and practical to
go. There are no restrictions on survey speed or sonar settings, but participants
should aim to deliver a dataset that meets S-44 Order 1a. As a guide, the object
detection and data density requirements for S-44 Order 1a are described
below:
Object Detection - For all parts of the survey area, the minimum size of object
detected shall be:
- Cube with sides of 2m in depths < 40m
- Cube with sides of 10% of depth in depths >40m
Sounding Density - Each object (see above) is to be detected by at least 3 valid
data points in the along-track direction and 3 valid data points in the acrosstrack direction, forming a minimum 3x3 grid of 9 data points.
To monitor compliance with the Target Detection requirements for a given
area, a minimum sounding density of 9 accepted soundings will be achieved in
the following bin sizes:
- Bin with sides of 2m in depths < 40m
- Bin with sides of 10% of depth in depths >40m
Figure 2 Overview of Survey Area 1
2.1.3. Survey area 2
Survey Area 2 (Figure 3) is the second priority area. Ideally, this area is only to
be surveyed once Survey Area 1 is complete. Survey Area 2 is split into two
further priority areas; Block A (priority 1) is approximately 2km2 and covers the
entrance to Wembury Bay and Block B (priority 2) is approximately 1km2 and
covers part of the inner Wembury Bay. The areas have a depth range of
approximately 0 – 35m. An ESRI shapefile of the survey area can be found at
Annex A. Block A should be completed before surveying Block B.
Participants are asked to survey as much of the area as completely as they can,
heading inshore to the 5m contour, or as near this as is safe and practical to go.
There are no restrictions on survey speed or sonar settings, but participants
should aim to deliver a dataset that meets S-44 Order 1a. As a guide, the object
detection and data density requirements for S-44 Order 1a are described
below:
Object Detection - For all parts of the survey area, the minimum size of object
detected shall be:
- Cube with sides of 2m in depths < 40m
- Cube with sides of 10% of depth in depths >40m
Sounding Density - Each object (see above) is to be detected by at least 3 valid
data points in the along-track direction and 3 valid data points in the acrosstrack direction, forming a minimum 3x3 grid of 9 data points.
To monitor compliance with the Target Detection requirements for a given
area, a minimum sounding density of 9 accepted soundings will be achieved in
the following bin sizes:
- Bin with sides of 2m in depths < 40m
- Bin with sides of 10% of depth in depths >40m
Figure 3 Overview of Survey Area 2 – Blocks A and B
2.2. Remote Sensing
The Remote Sensing Area (Figure 4) is approximately 20km2 a cross section of
Plymouth sound, starting ant Wembury Bay in the South East and extending to Fort
Picklecombe in the North West. It has been designed to incorporate MBES Survey
Area 2 as well as interesting topographical features such as the Mew Stone and
Breakwater. It is indented that the resulting data can be compared with an
independent S-44 Order 1A standard reference dataset which will be supplied
alongside the common datasets.
Participants using remote sensing techniques such as Satellite Derived Bathymetry
(SDB) or Airborne acquisition methods such as LiDAR, are asked to survey as much
of the area as possible, to the highest standard achievable.
Please note that the reference dataset will only be provided once the CDS team
have received all of the final processed datasets from participants. An ESRI shapefile
of the survey area can be found at Annex A.
Figure 4 Overview of Remote Sensing Area
3. Tidal Data
Tidal data will be collected throughout the survey period at two locations:
- Tide station 1 – Millbay Dock
- Tide station 2 – Fort Bovisand Pier
Predicted tides will be supplied to participants at the start of their allotted period, with
real tides supplied at the end of each period. Tides will be referenced to Admiralty Chart
Datum.
4. Deliverables and Data Processing
Participants are requested to supply the following data as a minimum:
- All Raw data in proprietary format (e.g. .all, .xtf etc.) and any ancillary information,
such as vessel configuration files, needed to process the data. This data should
organised into a file structure that indicates which Survey area and task it relates to.
- All sound velocity profiles collected in ascii format
- A short report detailing the system(s) used, personnel involved, daily activities,
prevailing weather conditions, contact details and any issues that arose.
Participants are encouraged to supply:
-
A fully cleaned data set as either a Caris HIPS and SIPS project or in .GSF format
5. Data Delivery
Data should be sent on removable media to the following address to arrive no later than
1st November 2014.
Shallow Survey 2015 CDS
C/O Mr Andy Talbot
D3010
United Kingdom Hydrographic Office
Admiralty Way
Taunton
Somerset
United Kingdom
TA1 2DN
Annexure
A. Survey area Coordinates
B. Line Plan and Survey Area shapefiles
Annex A - Survey area Coordinates
(All coordinates are given in WGS 84 Geographic Decimal Degrees)
Survey Area 1
Point
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Longitude
-4.171770
-4.167444
-4.165852
-4.164200
-4.163599
-4.163239
-4.162458
-4.161046
-4.158343
-4.157291
-4.156570
-4.156540
-4.156030
-4.152785
-4.150622
-4.148670
-4.151524
-4.152336
-4.159934
-4.156811
-4.157352
-4.160685
-4.166962
-4.167473
-4.167112
-4.168134
-4.171228
-4.173301
-4.172040
-4.171649
-4.171770
Latitude
50.358849
50.359867
50.359618
50.358984
50.359541
50.360214
50.361078
50.361424
50.361309
50.361175
50.361655
50.362174
50.362424
50.362539
50.363000
50.362346
50.355313
50.354506
50.351605
50.348703
50.348492
50.351451
50.349164
50.349433
50.351297
50.351969
50.353968
50.355601
50.357849
50.358003
50.358849
Survey Area 2 – Block A (Priority 1)
Point
0
1
2
3
4
Longitude
-4.097518
-4.080508
-4.090206
-4.107077
-4.097518
Latitude
50.308121
50.299336
50.291571
50.300562
50.308121
Survey Area 2 – Block B (Priority 2)
Point
0
1
2
3
4
Longitude
-4.097440
-4.089410
-4.078547
-4.086461
-4.097440
Latitude
50.308081
50.314201
50.308683
50.302411
50.308081
Survey Area Remote Sensing
Point
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Longitude
-4.069102
-4.071259
-4.074076
-4.080571
-4.090206
-4.107077
-4.107073
-4.187311
-4.174082
-4.169412
-4.167078
-4.166926
-4.151945
-4.127135
-4.126437
-4.122421
-4.119098
-4.118504
-4.121181
-4.118326
-4.112374
-4.111038
-4.105363
Latitude
50.308397
50.308173
50.304446
50.299285
50.291571
50.300562
50.300565
50.342541
50.344370
50.345201
50.348189
50.349234
50.354999
50.342672
50.336643
50.336997
50.336050
50.328840
50.328132
50.320213
50.319708
50.316487
50.315687
23
24
25
26
27
28
29
-4.101485
-4.088749
-4.085352
-4.076057
-4.070591
-4.068954
-4.069102
50.317635
50.317185
50.318268
50.316301
50.314826
50.312934
50.308397