Seabed Mapping with LiDAR

Size: px

Start display at page:

Download "Seabed Mapping with LiDAR"

Belinda Watkins
6 years ago
Views:

1 Seabed Mapping with LiDAR 2011 Jakarta David Jonas Lt Cdr Rupert Forester-Bennett RN (ret( ret d) October 18 th 2011

2 Mapping in South East Asia Field Survey Aerial Photography LiDAR Pleased to Introduce the Next Advance

3 Mapping and Hydrography International Trade and Economy Nautical Charts Ecological Protection Land use / Sea use planning Disaster mitigation & management International Boundaries United Nations Conventions (Laws of the Sea)

4 Data Collection Techniques 4

6 Aircraft Small Local 12

The depth of water and height of land is measured by laser pulses of two wavelengths; Green (532nm) and Infra Red (IR) (1064nm) The green beam penetrates the water,

7 The depth of water and height of land is measured by laser pulses of two wavelengths; Green (532nm) and Infra Red (IR) (1064nm) The green beam penetrates the water, whereas the IR laser is reflected at the surface. The time difference between the green (bottom) and the IR (water surface) laser reflections is used to calculate the depth. 13

Scan Pattern Both lasers are scanned in a pattern on the water surface. The scanning mirror of the LiDAR allows the effects of motion in the platform to be compensated for directly.

8 Scan Pattern Both lasers are scanned in a pattern on the water surface. The scanning mirror of the LiDAR allows the effects of motion in the platform to be compensated for directly. The scanning mirror compensates for pitch and roll by adjusting the direction in which the laser beams are transmitted, ensuring that they are transmitted ahead of the aircraft at an off nadir angle of 20 and scan left and right either side of the line of advance of the aircraft. The result is a generally evenly spaced pattern of transmissions and returns covering the seabed. 14

9 Advantages/Disadvantages Boat operations suffer from: reduced swathe width slow progress dangerous waters dependence on Mother ship high cost/km 2 White Ribbon (Unsurveyed) * 15

Advantages/Disadvantages Bathy LiDAR suffers from: Water Clarity Secchi Disc

11 Speed and Cost Figures are for guidance, and vary MBES ALB according to local factors Average cost per 1 km 2 of survey 3 1 Average cost of a 350 km 2 survey 3 1 Average time for a 350 km 2 (days) 35 2 C Copyright 2011 Pelydryn Limited; All rights reserved 17

at 400m altitude Imagery will also observe ambient sea conditions and phenomena (eddies and

12 Digital Aerial Photography The HawkEye II B is fitted with a ueye IU 2250 C / M camera Imagery is used to assist in data cleaning Orthophotos are available at a resolution of 25cm when flown at 400m altitude Imagery will also observe ambient sea conditions and phenomena (eddies and over falls) Areas of vegetation and vegetation type Extent of Rocks and Reefs Brittany: IFREMER 22

Reflectance Bathymetric data can be processed to produce images of reflectance to

14 Topographic Pulse Land topography is measured by the infrared laser only, scanned in a linear pattern. The land topography and the water surface are scanned with a much denser pattern than the seabed as the pulse frequency is much higher at 8000 Hz giving 64,000 returns/second. Recent trials of System 003 revealed the accuracies in the table when flown over a number of preselected topographic features at 400m: Dimension X Y Z Accuracy m m m for individual flight lines m for combined flight lines 24

khz topographic sounding frequency is multiplied by 8) The use of multi pixel technology allows improvements

15 Bathymetric Pulse The HawkEye IIB system is unique in its use of pixelated discrimination. The receivers are divided into : 4 sections for the Hydro receivers (8 sections for the Topo receivers The 4 khz topographic sounding frequency is multiplied by 8) The use of multi pixel technology allows improvements on: data density Contrast object detection object discrimination Bathy Topo C Copyright 2011 Pelydryn Limited; All rights reserved 25

Object detection 2m Cube at 18m depth HEIIb meets the object detection requirement

18 Current uses of combined Topo/bathy data Maine to New England Survey Area 1500 SqKm US ACE National Coastal Mapping Programme 29

19 Current uses of combined Topo/bathy data New England, USA Data shown courtesy of the USACE National Coastal Mapping Program. 30

20 Current uses of combined Topo/bathy data Maldives: Ministry of Transport, Housing and the Environment Climate Change / Sea Level Rise / Tsunami / Storm Surge Mitigation 31

21 Current uses of combined Topo/bathy data Storm Surge Modeling NOAA Ideal foundation dataset on which to base: Storm Surge/Climate Change modeling Infrastructure design 32

Current uses of combined Topo/bathy data French Hydrographic Office

Current uses of combined Topo/bathy data Irish Government EEZ

25 Points of Contact AAM David Jonas Spatial Solutions Consultant 152 Wharf Street Brisbane Queensland 4000 Australia Tel: +61 (0) E Mail: D.Jonas@aamgroup.com Mobile: +61 (0) Pelydryn David Lye OBE Deputy MD and Head Business Development Pelydryn Limited Scott 1 Tamar Science Park 1 Davy Road Derriford PLYMOUTH, Devon United Kingdom PL6 8BX Tel: +44(0) E mail: david@pelydryn.co.uk Mobile: +44(0) C Copyright 2011 Pelydryn Limited; All rights reserved 44

HawkEye III - A new deep penetrating bathymetric LIDAR system

HawkEye III - A new deep penetrating bathymetric LIDAR system Please insert a picture (Insert, Picture, from file). Size according to grey field (10 cm x 25.4 cm). Scale picture: highlight, pull corner point Cut picture: highlight, choose the cutting icon from the