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| ENVISAT: Opportunities and Applications |
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Canadian Users
State-of-the-Art Research
As part of ESA’s data policy to maximize the beneficial use of data from ENVISAT and to stimulate a balanced development of scientific, public and commercial use of data, ESA launched an Announcement of Opportunity (AO) for the use of ENVISAT data. Canada is well represented in the group of chosen projects within the ESA AO. Canadian universities, government departments and industries submitted a wide range of project subjects that were accepted. These diverse projects range from coastal zones and oceans, ice monitoring, geology and disaster management to calibration and validation.
Canadian Ice Service
Title:
OPERATIONAL EVALUATION OF ENVISAT ASAR DATA IN THE CANADIAN ICE SERVICE (CIS)
The overall objective of this project is to assess the utility of and determine the optimum ASAR modes and products for use in operational sea ice monitoring. Wide Swath, Alternating Polarization, and Global Monitoring Mode data will be used. Analysis methods will include: near real-time operational use and analysis of ASAR products; detailed analysis of image quality, information content, and utility for ice analysis and forecasting; and, image mosaicing. Project deliverables will include: identification of optimal ASAR products and the methods required to usefully integrate them into the CIS's operational data stream; creation of an image map of winter ice conditions for the Canadian Arctic and evaluation of the utility of the Global Monitoring product for this purpose; and an assessment of and recommendations on the utility of multi-channel, multi-polarization SAR data for enhancing ice information extraction.
Principal Investigator:
Dean FLETT
Remote Sensing Manager
Canadian Ice Service
E-mail:
Université Laval
Title:
DETERMINATION OF ICE FREEZE-UP AND BREAK-UP DATES OF LARGE LAKES USING ENVISAT ASAR AND AATSR: A CONTRIBUTION TO LAKE ICE MONITORING AND MODELLING ACTIVITIES OF THE CANADIAN CRYSYS PROGRAM
General Circulation Models predict that the magnitude of temperature increases due to enhanced greenhouse warming should be greatest at high latitudes and in winter and early spring. Lake ice is unique in this context in that freeze-up/break-up dates represent an integration of local-regional weather conditions, especially air temperature, leading up to the specified events. In this research we propose to develop a method for determining ice freeze-up and break-up dates, and ice cover duration of large lakes using ASAR and AATSR data in a synergistic manner. In a two- to three-day revisit mode, we will cover lakes along two south-north gradients in Canada. The ultimate goal of this study is to deliver an operational method that could be used to produce maps of freeze-up and break-up dates over large areas in Canada and elsewhere. A second objective is to use the ENVISAT-derived information to validate and improve predictions of a numerical lake ice model currently being developed by our research team.
Principal Investigator:
Claude Duguay
Professor
Université Laval
E-mail:
Title:
BIO-OPTICAL CHARACTERIZATION OF NORTHERN LAKES WITH MERIS: A CONTRIBUTION TOWARDS UNDERSTANDING THE IMPACT OF CLIMATE CHANGE ON FRESHWATER ECOSYSTEMS IN CANADA
The aim of this research will be to validate MERIS data for the analysis of bio-optical properties of lakes, and to extend the application of ENVISAT to provide novel optical indices that can be used in the long term monitoring of global change from space. The work will focus on a south-north transect of lakes in eastern North America from latitudes 44 to 82oN, providing a wide range of limnological and reflectance characteristics. Special emphasis will be placed on measuring chromophoric dissolved organic matter (CDOM) in the surface waters as an integrative measure of climate-related changes in their surrounding lake catchments. The MERIS data will be validated from radiometric profiling of the lakes and in situ measurements of upwelling radiance with instruments currently being deployed by the investigation team. The project will generate maps of optical properties, specifically seasonal CDOM an Chlorophyll a across this broad span of latitudes.
Principal Investigator:
Warwick Vincent
Professor
Université Laval
E-mail:
Canada Centre for Remote Sensing
Title:
EVALUATION OF SHIP DETECTION AND CLASSIFICATION BY THE ENVISAT ADVANCED SYNTHETIC APERTURE RADAR ALTERNATING POLARIZATION MODE
The performance and capability of the ENVISAT ASAR for ship detection and classification will be assessed and validated using ship validation information from a coastal marine vessel traffic station, together with wind speed data, collected off the West Coast of Canada where ship traffic density and fishing activity levels are high. The analysis will involve a comparison of ocean clutter level and radar cross section of ships for the ENVISAT co- and cross-polarization modes. As part of this study, a demonstration to monitor illegal fishing activity will be conducted off the East Coast of North America over Georges Bank. The demonstration will involve the acquisition and automated processing of ENVISAT ASAR data, and the delivery of ship information products to end-users. The enhanced capability of cross-polarization data for ship detection will be emphasized. It is expected that the demonstration will not be made in near real-time.
Principal Investigator:
Paris W. Vachon
Research Scientist
Canada Centre for Remote Sensing
E-mail:
Title:
USE OF ENVISAT ADVANCED SYNTHETIC APERTURE RADAR ALTERNATING POLARIZATION MODE DATA FOR OCEAN WIND VECTOR AND WAVE FIELD ESTIMATION
Over the past 7 years, ERS-1/2 and RADARSAT SAR validation field programs have involved acquisitions over ship or wind/wave buoy sites. We will extend this measurement time series to include Envisat in its alternating polarization mode. The data will be processed to extract wind vector and image cross spectra. The data will allow validation of VV scatterometer models and improvement of HH hybrid models. The image cross spectra will be used to estimate the degree of azimuth cut-off and to look for any polarization dependence the cut-off might have. The estimated wind vector and cut-off will be analysed as for ERS and RADARSAT data to improve and tune semi-empirical models that relate the azimuth cut-off to the wind and wave conditions. The simultaneously acquired VV and HH data sets will be used to provide insight to the real aperture radar (RAR) modulation transfer function (MTF), which may be estimated as a free term in a SAR wave inversion algorithm.
Principal Investigator:
Paris W. Vachon
Research Scientist
Canada Centre for Remote Sensing
E-mail:
Title:
DETECTION, MONITORING, AND CHARACTERIZATION OF HIGH LATITUDE MESOSCALE CYCLONES USING THE ENVISAT ADVANCED SYNTHETIC APERTURE RADAR GLOBAL MONITORING MODE
Atmospheric mesoscale cyclonic vortices, or polar lows, often develop at high latitudes during cold air outbreaks. With small spatial scales (< 500-km) and short life times (24 to 48 hours), it is difficult for numerical weather prediction models to accurately simulate their initiation, temporal evolution, and spatial structure. Polar lows usually occur in data sparse regions. Satellite data has been an important tool for polar low detection and characterization. The Envisat ASAR Global Monitoring Mode (swath width 405km, spatial resolution 1km) has the capability to provide synoptic scale views of the imprint of polar lows on the ocean's surface. We propose to use this Envisat mode to obtain daily observations over the Labrador Sea and Davis Strait regions, where examples of polar lows have already been detected in RADARSAT ScanSAR data, to detect, monitor, and characterize polar low evolution.
Principal Investigator:
Paris W. Vachon
Research Scientist
Canada Centre for Remote Sensing
E-mail:
Title:
HIGH LATITUDE APPLICATIONS OF ASAR DATA
Objectives:
- To study the use of the ASAR AP mode for improved mapping in high latitudes, particularly the Canadian Arctic (e.g. improved coastline delineation, and to improve ice/water/land discrimination).
- To further explore the capability of repeat-pass InSAR for those areas for which we know that the 35 day repeat orbit will still yield useful coherence. This would include ice motion work in Antarctica, and work in the Canadian Arctic.
- To combine the dual pol capability of the ASAR with repeat-pass interferometric results at HH, VV, and cross-pol for some test sites.
Method: Information derived from ASAR standard beams will be assessed and compared to results derived from other sensors (spaceborne and aircraft, if possible). Existing data will also be reviewed to provide historical information.
Deliverables: Reports on ice motion and high latitude terrain mapping, presentations at ESA ENVISAT Symposia, and papers published in the open literature.
Principal Investigator:
Dr. Laurence Gray
Research Scientist
Canada Centre for Remote Sensing
E-mail:
Title:
INVESTIGATION OF SYNERGY BETWEEN MEDIUM RESOLUTION IMAGING SPECTROMETER AND ADVANCED SYNTHETIC APERTURE RADAR WIDE SWATH MODE FOR THREE COASTAL ZONE CASE STUDIES: MACKENZIE DELTA; LABRADOR SEA MARGINAL ICE ZONE; AND WEST COAST OF VANCOUVER ISLAND
We consider coastal zone applications of synergistic (i.e. overlapping) Envisat ASAR and MERIS data. The geometry of these sensors permits several hundred kilometers of swath overlap. In this overlap region, we will apply data fusion techniques to map coastal zone features. With more frequent coverage from multiple sensors, such features can be tracked for process studies and model calibration. Furthermore, we will compare the fused results to the two data sources on their own as well as to validation data acquired from operational sensors, both in situ and remote, and to operational products such as ice charts from the Canadian Ice Service.
Principal Investigator:
Cathrin BJERKELUND
Oceans Coordinator
Canada Centre for Remote Sensing
E-mail:
Title:
GEOLOGICAL MAPPING IN BARREN ARCTIC ENVIRONMENTS USING LIKE- AND CROSS-POLARISED ASAR AND OPTICAL MERIS DATA
This project endeavours to examine the differences in like- and cross-polarised C-band SAR data from ASAR in barren polar environments for the purpose of geological mapping and exploration. These data will be used derive backscatter response curves for different geological materials in an effort to better understand their expression in SAR images. The benefits of using multipolarised SAR images for improving discrimination of lithological units will be demonstrated from four test sites.
Land application of MERIS data in frontier regions where existing geological maps are at small scales is of particular interest by the mineral exploration industry. This study will take advantage of several data sets (polarisation modes in ASAR and optical data from MERIS) available from ENVISAT to evaluate the potential of using integrated products for geological and permafrost investigations in Arctic environments.
Principal Investigator:
Marc D'Iorio
Acting Head, Applications Development Section
Canada Centre for Remote Sensing
E-mail:
Atmospheric Environment Service
Title:
ESTIMATION OF SURFACE HEAT FLUXES FROM SEA ICE USING ENVISAT MULTI-SENSOR DATA
The main goal is to estimate spatial and temporal patterns of surface heat fluxes from sea ice, and to link them to geophysical forcing. Data from AATSR, ASAR and MERIS will be used in a synergistic manner. Surface temperature, under cloud-free conditions, will be estimated from AATSR IR channels. This will be followed by applications of ice thermodynamic models to calculate surface heat fluxes, ice growth/decay, and to establish a thermal ice classification. ASAR data will be used to develop ice backscatter signature database and hence classify ice types. Results will be used to verify or adjust heat flux products. Deliverables include spatial and temporal mapping of surface heat fluxes, thickness distribution of thin ice, and assessment of synergistic use of ENVISAT sensors to retrieve ice thermal parameters.
Principal Investigator:
Dr. Mohammed Shokr
Atmospheric Environment Service
E-mail:
Title:
IDENTIFICATION OF SEA ICE PROCESSES IN THE ARCTIC USING SAR AND ATSR IMAGE ANIMATION
SAR data archive of ERS-1 and ERS-2 during their tandem operation provides an excellent opportunity to monitor Arctic sea ice processes at fine resolutions and relatively frequent coverage. We propose to apply a novel image animation technique to a large volume of SAR images and to ice surface temperature derived from either ATSR or AVHRR infrared data. This will offer simultaneous monitoring (temporal and spatial) of mechanical processes such as ice formation, deformation, and breakup; and linking them qualitatively, and later quantitatively, with the thermal history of ice. At the technological side, the final product will be a prototype of animated SAR images with surface temperature overlaid in color. This prototype is aimed for operational use in national ice centers. At the scientific side, temporal evolution and regional variability of climate-related ice processess will be identified and linked to meteorological data and climatological hypotheses.
Principal Investigator:
Dr. Mohammed Shokr
Atmospheric Environment Service
E-mail:
Institute of Ocean Sciences
Title:
PLANKTON BLOOM DETECTION ON THE WEST COAST OF CANADA
The objective is to demonstrate MERIS capability to detect plankton blooms in western Canadian coastal waters, and to distinguish between species groups (coccolithophores, diatoms, blue-green algae, etc.). We need to avoid false alarms due to Case 2 water (river plumes, glacial melt-water, resuspended bottom sediment). Both reduced and full resolution MERIS data are requested, to image both offshore waters and the narrow coastal inlets where fish-farms are located. Damage to the aquaculture industry from harmful blooms is assessed at several million dollars per year. We have assembled a time series of bright blooms detected using AVHRR imagery at IOS, and are extending this, including Seawifs data, into the MERIS time period. Sources of surface measurements include the optical sensors that we are starting to deploy on the west coast weather buoy array, and data gathered by local fish farms and our research vessels, which are often directed on the basis of satellite imagery.
Principal Investigator:
Dr. Jim Gower
Institute of Ocean Sciences
E-mail:
Title:
MEASUREMENTS OF BIOMASS, RED TIDES AND BOTTOM VEGETATION IN THE SPECTRAL RANGE 650 TO 720 NM USING A MODIFIED MERIS BAND-SET
The objective is to evaluate and perhaps refine a modified MERIS band set for giving improved information on solar-stimulated chlorophyll a fluorescence, red tide detection and mapping of bottom vegetation. This project is designed to be an important demonstration of the value of MERIS's band flexibility, applied to a problem which was one of the main design-drivers of the instrument. Two short (one to two week) time periods are requested in which five bands in the standard band set will be repositioned to provide contiguous coverage of the wavelength range 650 to 720 nm with a resolution of 7.5 to 10 nm. This should leave sufficient bands to cover most of other on-going the MERIS water and land mapping targets. We propose a time period in late July or early August in each of two years, when red tides are prevalent in the northern temperate waters which include our European and west Canadian test areas.
Principal Investigator:
Dr. Jim Gower
Institute of Ocean Sciences
E-mail:
Université de Montréal
Title:
MULTI-SENSOR AND MULTI-RESOLUTION SPACEBORNE REMOTE SENSING DATA AS INPUTS TO A GEOGRAPHIC INFORMATION SYSTEM FOR THE MANAGEMENT OF INSULAR AND COASTAL ENVIRONNEMENTS
The objective of this research is the establishment of methods and techniques for the extraction of useful and pertinent information from ENVISAT imagery covering coastal and insular zones. Such information could be integrated to a GIS intended for the management and the monitoring of insular and coastal environments. Our approach is based on multi-resolution and multi-sensor space borne image analysis in a GIS context in order to characterize each coastal zone according to criteria based on geomorphologic-geologic, oceanographic, climatologic and biologic principles. The ultimate objective is to use such information together with data provided from other sources in order to build indices which characterize the environmental sensitivity of the coastal zones to natural or anthropogenic impacts. The studied zone is the Aegean Sea (Greece). Two environments have been chosen: the alluvial coastal plain of the Nestos River (Khrisoupolis) and the Cyclades Islands (Southern Aegean Sea).
Principal Investigator:
François Cavayas
Professor
Université de Montréal
E-mail:
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