Satellite bathymetry and other satellite derived data - IHO · Satellite bathymetry and other...
Transcript of Satellite bathymetry and other satellite derived data - IHO · Satellite bathymetry and other...
Satellite bathymetry and
other satellite derived data
Per Knudsen, Ole Andersen, Rene Forsberg,
Roberto Saldo, & Henning Skriver
Space and the Arctic
Two major meetings were held in March 2012:
• Space for the Arctic '12
• IAP Applications for the Arctic Workshop
to discuss the contribution of space technologies to one of
the regions most affected by climate change. Co-
organised by Arctic nations, ESA and EC.
“Space systems offer opportunities for monitoring
the environment, facilitating navigation and
communications, enhancing marine safety and
supporting sustainable exploitation of national
resources. Jean-Jacques Dordain, ESA Director
General.”
Space and the Arctic
Both meetings focused on the objectives:
1. To identify operational user needs in the Arctic region.
2. To help to establish operational services in the Arctic
in areas where integrated applications are relevant:
a) Oil and Gas.
b) Shipping
c) Fishing.
d) Search and Rescue.
e) Telemedicine.
f) Tourism
3. ..
Space and the Arctic
Several specific recommendations that should be taken up
by the Arctic stakeholders came out of ‘Space for the
Arctic 2012’, including
• higher bandwidth satellite telecommunication channels,
• improved satellite-based navigation systems, and
• trans-Arctic monitoring of sea ice and icebergs
to increase safety of navigation.
Space and the Arctic
Gaps have been identified that have to be addressed to
support the policies and commitments of European and
Canadian states and the EU in the Arctic:
• Secure the implementation of the GMES programme
• Act to ensure High bandwidth communications
• Investigate means such as Galileo Arctic test-bed to
ensure High reliability navigation above 75ºN
• Ensure continuity and development of Arctic
meteorology and space weather
Collaboration and partnership are fundamental with the
development or improvements of networks
Developing satellite based
infrastructures for the Arctic
Galileo – a GNSS including a ground system to
ensure:
• Positioning with integrity information
• Search & Rescue
GMES - Actual, reliable, standardised
information about the environment based on
Earth observation and in-situ data:
• MyOcean – the marine GMES service
• Safer – emergency management
Galileo - components
• 30 satellites at 23,200 km altitude
• A series of control stations on
ground (RIMS)
• 5 frequencies, 10 navigations
signals, and Search-and-Rescue
• EC / European GNSS Agency +
operators
• Service providers
• Users
Galileo – services
Galileo is designed for 5 different services, targeting different user segments:
• Open Service – freely available for all
• Safety of Life – higher quality and integrity, increased security
• Commercial Service - for professional users, high quality and service guaranty
• Public Regulated Service - Encrypted og robust to jamming
• Search and Rescue (SAR) – Emergency signals and supporting rescue operations.
Galileo – implementation
• On 21.October 2011 the first two
Galileo IOV satellites were launched.
• The next two will follow on 12/10 2012.
• 18 satellites and FOC-1 in 2015.
• 24+ satellitter and FOC in 2019.
Galileo – Arctic Testbed
Project in the European GNSS Evolutions Programme:
• The objective is to develop and deploy an Arctic
TestBed to support Galileo services over ARCTIC
regions.
• Lead: Kongsberg Seatex
• Supported by Kartverket, U Calgary, and DTU (develop
net of ground stations, improve iono models, and
testing)
• 2012-2014
Earth observation
Develop GMES:
• Explore missions, such as GOCE and
Cryosat-2
• Develop applications and products
• Establish services, such as MyOcean
• Operate observation networks
• Sentinels
• In-situ
Operational – soon..
Satellite bathymetry
Information about the bathymetry may be
derived from:
• High resolution images,
• Lasers (air borne demos),
• Radars:
• SAR (wave studies),
• Altimeters (gravity inversion).
Coastlines
E.g. GRASS (a small Danish company) offer analyses of
coastline changes.
• Recently declassified US spy satellite images combined
with modern high resolution satellite images, provides long
time series of coastal development.
• This will allow an analysis of coastline changes in the
period 1960-2005 and an accuracy of app. 15 metres.
• Higher accuracies can be obtained with SPOT which is
available in the period 1986 to present. In this way
accuracies can be within 5 metres.
• Using QuickBird data with a spatial resolution of 60 cm,
the results are comparable to aerial photography.
Coastlines
• Contain information about bathymetry, obviously.
Satellite bathymetry
Fugro NPA have extensive experience of
bathymetric mapping using satellite imagery in
shallow water areas.
Satellite bathymetry
WorldView-2 from DigitalGlobe provide 1.84 m resolution multi-spectral
imagery, plus a Coastal Blue detector focused on the 400 – 450
nanometer spectral range.
With the Coastal Blue band included it is be possible to calculate depths
up to 20 m and potentially as deep as 30 m, by measuring relative
absorption of the Coastal Blue, Blue and Green bands.
Laser bathymetry – air-borne
Infrared laser .. surface
Green laser ... Sea bottom .. Down to 2-50 m
Theoretical sea surface: geoid (gravity field
equipotential surface ... If known green ok)
Commercial systems:
Optech-Shoals (Canada)
LADS (Australia)
Hawk-Eye (Sweden/UK)
Commercial systems
New instrument #1:
Photon counting – SigmaSpace ”icemapper”
(prototype for proposed NASA Jupiter moon
mission
10x more effective than present systems (less
power needed)
3 cm accuracy in timing, 2000 m+ flight elev
15 deg scanning
60 kg in rack
Flown in Antarctica Feb 2011
Solution for Arctic bathymetry needs ? Laser tests in Antarctica
(Univ. of Texas / DTU-Space)
Laser bathymetry – air-borne
NOAA's contractors use LIDAR to collect near shore
bathymetry in Alaska, the North Atlantic Coast and the
Caribbean. Future developments include improving object
detection capabilities to better identify near shore hazards
to navigation.
• Depending on water clarity, these systems can reach
depths of 50 meters.
Satellite bathymetry - radars
Using geophysical methods space-borne radars
may be used:
• SAR or other imaging radars to study waves:
• Changes in wavelengths due to shallow
waters
(no examples)
• Altimeters measuring marine geoid undulations:
• Changes in gravity due to changes in
bathymetry such as reefs and sea mounts.
• Principle of using Gravity to predict Bathymetry
(From Sandwell/Smith)
Satellite bathymetry - altimetry
• High Quality MSS/Gravity field can be used to map bathymetry.
• Using Spectral sepration throught filtering (20 and 120 km)
• Adjusting wavelength 20 km – 120 km based on DNSC08 gravity
optimizing coherency (outside these bands GEBCO-1 is used)
• Adjusting depth where GEBCO-1 > 100 meters.
(Figure from Sandwell/Smith)
Satellite bathymetry - altimetry
Comparison with Polar Stern Bathymetry
11.981 obs Std Dev.
(meters)
Max difference
(meters)
ETOPO 5 (5 minute) 531 3014
ETOPO 2 (2 minute)
(Altimetry enhanced)
243 1642
GEBCO – 1 minute 201 1792
DNSC08 – 1 minute 132 1188
Survey example around Antarctica
GEBCO-1 Global Bathymetry
On satellite bathymetry
None of the (space-based) methods described
above may work:
• as stand-alone hydrographic surveying tools,
• in areas covered by sea ice.
Satellite based method may support the
hydrographic mapping by identifying areas of
interest.
Other relevant satellite data
ESA Explore missions:
• GOCE:
• Gravity for ocean circulation
• SMOS:
• Salinity
• Cryosat:
• Sea ice – also thickness
• Ocean topography/geoid
Sea ice thickness from Cryosat
MyOcean services
MyOcean provide products for
• Maritime safety
• Marine resources
• Coastal and marine environment
• Weather, climate and seasonal forecasting
Examples:
• Temperature
• Salinity
• Currents
• Sea level
• Sea ice
Seaice.dk - 5-10-2012
Seaice.dk – 5-4-2012
Seaice.dk – 5-9-2012
Space and the Arctic
Gaps have been identified that have to be addressed to
support the policies and commitments of European and
Canadian states and the EU in the Arctic:
• Secure the implementation of the GMES programme
• Act to ensure High bandwidth communications
• Investigate means such as Galileo Arctic test-bed to
ensure High reliability navigation above 75ºN
• Ensure continuity and development of Arctic
meteorology and space weather
Collaboration and partnership are fundamental with the
development or improvements of networks