On-site helicopter-borne high-resolution image acquisition and mosaicking for investigation of drifting Arctic sea ice

摘要

On-site high-resolution sea ice images from the imaging instruments on airplane, helicopter, ship and unmanned aerialvehicle (UAV) platforms have been used as the reference datasets for validation of the sea ice properties. Among the lowaltitude remote sensing platforms, helicopters usually carried onboard icebreakers for scientific research activities andlogistics have been recognized as a reliable remote sensing platform from enhanced endurance and verified stability, andhave flexibility for the attachment of multiple sensors. Although areal reference datasets, e.g., helicopter-borne highresolutionimages, can be used to validate lower resolution sea ice information from the characteristics of enoughcoverage and fine spatial resolution, continuous drift of sea ice causes distorted locations of image acquisition along thedrift; thus, becomes an obstacle for precise image mosaicking and matching with the sea ice information extracted fromlower-resolution remote sensing imagery. This study presents methods for the cost-effective acquisition of helicopterbornehigh-resolution images over drifting Arctic sea ice using a simple configuration of imaging sensor and GPS logger,and for the compensation of the effect from sea ice drift from each imaging location using the drift trajectory of sea ice.After mosaicking the sea ice drift compensated high-resolution helicopter-borne images with structure-from-motiontechnique, the applicability of the mosaicked image was assessed by comparing with lower resolution satellite syntheticaperture radar image. The results suggest that the proposed methods can be applicable to the high-resolution images fromother low altitude remote sensing platforms, e.g., UAVs, and can be used for precise comparison with various sea iceproducts from satellite remote sensing.