Satellite derived bathymetry for Arctic charting: a review of sensors and techniques for operational implementation within the Canadian Hydrographic Service

Abstract

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 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 Pleiades, 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.