Canada’s coastline presents challenges for navigational charting. Within Arctic regions, in situ surveying presents risks to surveyors, is time consuming and costly. To better meet its mandate, the Canadian Hydrographic Service (CHS) has...
moreCanada’s coastline presents challenges for navigational charting. Within Arctic regions, in situ surveying presents risks to surveyors, is time consuming and costly. To better meet its mandate, the Canadian Hydrographic Service (CHS) has been investigating the potential of remote sensing to compliment traditional charting techniques. This paper focuses on an evaluation of sensors and techniques for operational Satellite Derived Bathymetry (SDB) implementation. Analysis focused on Cambridge Bay, Nunavut using Pléiades, SPOT, WorldView and PlanetScope imagery. Multiple SDB techniques were applied to evaluate their agreement with in-situ bathymetric measurements: • An empirical logarithm band ratio approach. • A multiple band modeling technique. • A multi-dimensional Look-Up-Table approach. Through this analysis, CHS attempted to answer critical questions for operational SDB implementation: • Do specific optical sensors offer advantages for SDB? • Are there advantages/disadvantages with the application of SDB techniques within the examined environment? • Can multiple SDB techniques improve CHS’s understanding of the confidence it can place in remotely sensed bathymetry estimates? Early results have achieved overall root mean square errors of 0.56 to 0.99 m relative to in situ survey depths for all sensors and techniques. These similarities suggest that CHS can be confident in the accuracies observed from various SDB approaches. Results do not indicate significant advantages or disadvantages of particular optical sensors, suggesting other factors contain greater importance for SDB image selection (e.g. sea floor visibility). While this analysis provides excellent information for operational empirical SDB implementation within Arctic environments, further work is required within other Canadian coastal regions to support national SDB application.
Abstract A method to estimate nearshore bathymetry using SAR imagery is presented in this paper. A Fast-Fourier Transform (FFT) and Wavelet hybrid method is proposed to analyze the wave spectra and calculate the wavelength of the long...
moreAbstract A method to estimate nearshore bathymetry using SAR imagery is presented in this paper. A Fast-Fourier Transform (FFT) and Wavelet hybrid method is proposed to analyze the wave spectra and calculate the wavelength of the long swell waves from SAR acquisitions. The water depth can be retrieved using the linear dispersion relation for shallow water, which requires wavelength and wave period as input parameters. The retrieved bathymetric method are validated with the SAR image over Western Africa and Haida Gwaii. The retrieved results are compared with the ground truth data and have an over 0.9 correlation coefficient. It is found that this method is more feasible to the swell waves with larger significant wave height.
Canada’s coastline presents challenges for charting. Within Arctic regions, in situ surveying presents risks to surveyors, is time consuming and costly. To better meet its mandate, the Canadian Hydrographic Service (CHS) has been...
moreCanada’s coastline presents challenges for charting. Within Arctic regions, in situ surveying presents risks to surveyors, is time consuming and costly. To better meet its mandate, the Canadian Hydrographic Service (CHS) has been investigating the potential of remote sensing to complement traditional charting techniques. Much of this work has focused on evaluating the effectiveness of empirical satellite derived bathymetry (SDB) techniques within the Canadian context. With greater knowledge of applying SDB techniques within Canadian waters, CHS is now interested in understanding how characteristics of optical sensors can impact SDB results. For example, how does the availability of different optical bands improve or hinder SDB estimates? What is the impact of spatial resolution on SDB accuracy? Do commercial satellites offer advantages over freely available data? Through application of a multiple band modelling technique to WorldView-2, Pléiades, PlanetScope, SPOT, Sentinel-2, and L...
Peatlands provide vital ecosystem and carbon services, and Canada is home to a significant peatland carbon stock. Global climate warming trends are expected to lead to increased carbon release from peatlands, as a consequence of drought...
morePeatlands provide vital ecosystem and carbon services, and Canada is home to a significant peatland carbon stock. Global climate warming trends are expected to lead to increased carbon release from peatlands, as a consequence of drought and wildfire. Monitoring hydrologic regimes is a key in understanding the impacts of warming, including monitoring changes in small and temporally variable water bodies in peatlands. Global surface water mapping has been implemented, but the spatial and temporal scales of the resulting data products prevent the effective monitoring of peatland water bodies, which are small and prone to rapid hydrologic changes. One hurdle in the quest to improve remote-sensing-derived global surface water map quality is the omission of small and temporally variable water bodies. This research investigated the reasons for small peatland water body omission as a preparatory step for surface water mapping, using Sentinel-1 SAR data and image classification methods. It w...
Synthetic Aperture Radar (SAR) has been used in characterizing intertidal zones along northern Canadian coastlines. RADARSAT-2, with its full polarimetric information, has been considered for monitoring these vulnerable ecosystems and...
moreSynthetic Aperture Radar (SAR) has been used in characterizing intertidal zones along northern Canadian coastlines. RADARSAT-2, with its full polarimetric information, has been considered for monitoring these vulnerable ecosystems and helping enhance the navigational safety of these waters. The RADARSAT Constellation Mission (RCM) will ensure data continuity with three identical SAR satellites orbiting together, providing superior revisit capabilities. The three satellites are equipped with multiple configurations, including single-polarization (HH, HV, VV), conventional (HH-HV, VV-VH, and HH-VV), hybrid (i.e., compact) dual polarization, and fully polarimetric (FP) modes. This study investigates the potential of the compact polarimetric (CP) mode for mapping an intertidal zone located at Tasiujaq village on the southwest shore of Ungava Bay, Quebec. Simulated RCM data were generated using FP RADARSAT-2 images collected over the study site in 2016. Commonly used tools for CP analysi...
In 2014, through the World-Class Tanker Safety System (WCTSS) initiative, the Government of Canada launched the Northern Marine Transportation Corridors (NMTC) concept. The corridors were created as a strategic framework to guide Federal...
moreIn 2014, through the World-Class Tanker Safety System (WCTSS) initiative, the Government of Canada launched the Northern Marine Transportation Corridors (NMTC) concept. The corridors were created as a strategic framework to guide Federal investments in marine transportation in the Arctic. With new government investment, under the Oceans Protection Plan (OPP), the corridors initiative, known as the Northern Low-Impact Shipping Corridors, will continue to be developed. Since 2016, the Canadian Hydrographic Service (CHS) has been using the corridors as a key layer in a geographic information system (GIS) model known as the CHS Priority Planning Tool (CPPT). The CPPT helps CHS prioritize its survey and charting efforts in Canada’s key traffic areas. Even with these latest efforts, important gaps in the surveys still need to be filled in order to cover the Canadian waterways. To help further develop the safety to navigation and improve survey mission planning, CHS has also been exploring...
Mariners navigating within Canadian waters rely on Canadian Hydrographic Service (CHS) navigational charts to safely reach their destinations. To fulfil this need, CHS charts must accurately reflect the current state of Canadian coastal...
moreMariners navigating within Canadian waters rely on Canadian Hydrographic Service (CHS) navigational charts to safely reach their destinations. To fulfil this need, CHS charts must accurately reflect the current state of Canadian coastal regions. While many coastal regions are stable, others are dynamic and require frequent updates. In order to ensure that important and potentially dangerous changes are reflected in CHS products, the organization, in partnership with the Canadian Space Agency, is exploring coastal change detection through satellite remote sensing (SRS). In this work, CHS examined a hybrid shoreline extraction approach which uses both Synthetic Aperture Radar (SAR) and optical data. The approach was applied for a section of the Mackenzie River, one of Canada’s most dynamic river systems. The approach used RADARSAT-2 imagery as its primary information source, due to its high positioning accuracy (5 m horizontal accuracy) and ability to allow for low and high water line...
The Canadian Hydrographic Service (CHS) publishes nautical charts covering all Canadian waters. Through projects with the Canadian Space Agency, CHS has been investigating remote sensing techniques to support hydrographic applications....
moreThe Canadian Hydrographic Service (CHS) publishes nautical charts covering all Canadian waters. Through projects with the Canadian Space Agency, CHS has been investigating remote sensing techniques to support hydrographic applications. One challenge CHS has encountered relates to quantifying its confidence in remote sensing products. This is particularly challenging with Satellite-Derived Bathymetry (SDB) where minimal in situ data may be present for validation. This paper proposes a level of confidence approach where a minimum number of SDB techniques are required to agree within a defined level to allow SDB estimates to be retained. The approach was applied to a Canadian Arctic site, incorporating four techniques: empirical, classification and photogrammetric (automatic and manual). Based on International Hydrographic Organization (IHO) guidelines, each individual approach provided results meeting the CATegory of Zones Of Confidence (CATZOC) level C requirement. By applying the le...
Approximately 1000 Canadian Hydrographic Service (CHS) charts cover Canada’s oceans and navigable waters. Many charts use information collected with techniques that predate the more advanced technologies available to Hydrographic Offices...
moreApproximately 1000 Canadian Hydrographic Service (CHS) charts cover Canada’s oceans and navigable waters. Many charts use information collected with techniques that predate the more advanced technologies available to Hydrographic Offices (HOs) today. Furthermore, gaps in survey data, particularly in the Canadian Arctic where only 6% of waters are surveyed to modern standards, are also problematic. Through a Canadian Space Agency (CSA) Government Related Initiatives Program (GRIP) project, CHS is exploring remote sensing techniques to assist with the improvement of Canadian navigational charts. Projects exploring optical/Synthetic Aperture Radar (SAR) shoreline extraction and change detection, as well as optical Satellite-Derived Bathymetry (SDB), are currently underway. This paper focuses on SDB extracted from high-resolution optical imagery, highlighting current results as well as the challenges and opportunities CHS will encounter when implementing SDB within its operational chart...
The Canadian Hydrographic Service (CHS) supports safe navigation within Canadian waters through approximately 1000 navigational charts as well as hundreds of publications. One of the greatest challenges faced by the CHS is removing gaps...
moreThe Canadian Hydrographic Service (CHS) supports safe navigation within Canadian waters through approximately 1000 navigational charts as well as hundreds of publications. One of the greatest challenges faced by the CHS is removing gaps in bathymetric survey data, particularly in the Canadian Arctic where only 6% of navigational water is surveyed to modern standards. Therefore, the CHS has initiated a research project to explore remote sensing methods to improve Canadian navigational charts. The major components of this project explore satellite derived bathymetry (SDB), coastline change detection and coastline extraction. This paper focuses on the potential of two stereo satellite techniques for deriving SDB: (i) automatic digital elevation model (DEM) extraction using a semi-global matching method, and (ii) 3D manual delineation of depth contours using visual stereoscopic interpretation. Analysis focused on quantitative assessment which compared estimated depths from both automati...
The new high-resolution and full polarimetric modes of RADARSAT-2 are evaluated for digital elevation model (DEM) generation using stereo-radargrammetry with Toutin's 3D physical model. The stereo-radargrammetric DEMs were evaluated...
moreThe new high-resolution and full polarimetric modes of RADARSAT-2 are evaluated for digital elevation model (DEM) generation using stereo-radargrammetry with Toutin's 3D physical model. The stereo-radargrammetric DEMs were evaluated with accurate Lidar data. Results on a test site north of Que¿bec City, Canada showed good accuracy: (2 m 1¿ horizontal and vertical) for Ultra-Fine mode (better than the resolution), and 5 m and 11 m (1¿ horizontal and vertical, respectively) for the Fine-Quad polarimetric mode (about the resolution).
ABSTRACT: High-resolution images have to be geometrically and precisely processed with ground information, such as ground control points (GCPs) and digital elevation models (DEM) to generate accurate map products and 3D geospatial...
moreABSTRACT: High-resolution images have to be geometrically and precisely processed with ground information, such as ground control points (GCPs) and digital elevation models (DEM) to generate accurate map products and 3D geospatial information. Consequently, the 3D multi-sensor physical model developed at Canada Centre for Remote Sensing for medium-resolution satellite images was adapted for these new high-resolution data, such as SPOT-5,
... measured radiance with a modelled radiance, the latter calculated using MODTRAN 4.2. Measurements have been made for a number of instruments including Airborne Visible and Infra-Red Imaging Spectrometer (AVIRIS), SWIR Full Spectrum...
more... measured radiance with a modelled radiance, the latter calculated using MODTRAN 4.2. Measurements have been made for a number of instruments including Airborne Visible and Infra-Red Imaging Spectrometer (AVIRIS), SWIR Full Spectrum Imager (SFSI), and Hyperion. ...
A spatio-triangulation process is applied to 15 RADARSAT-SAR fine mode images (5 paths by 3 rows). The paths were acquired over the Rocky Mountains, Canada, from different look angles (F1 and F4), creating a weak 6° intersection geometry....
moreA spatio-triangulation process is applied to 15 RADARSAT-SAR fine mode images (5 paths by 3 rows). The paths were acquired over the Rocky Mountains, Canada, from different look angles (F1 and F4), creating a weak 6° intersection geometry. A precise geometric correction model and algorithms developed at CCRS were used. Results over 3-image paths and 5-path block gave errors of
Spatio-triangulation process, based on a multisensor block adjustment, is applied to 40 different VIR and SAR images: Landsat-7 ETM, panchromatic SPOT-4 HRV, multiband ASTER, RADARSAT (fine, standard, wide modes) and ERS-1. The images...
moreSpatio-triangulation process, based on a multisensor block adjustment, is applied to 40 different VIR and SAR images: Landsat-7 ETM, panchromatic SPOT-4 HRV, multiband ASTER, RADARSAT (fine, standard, wide modes) and ERS-1. The images were acquired over Rocky Mountains, Canada from different view/look angles (nadir, across- and in-track) creating various intersection geometries in the overlap areas. Only 1:50,000 paper maps were