Deformation composite of the RADARSAT Geophysical Processor System (RGPS) Lagrangian motion data

• Main Authors: Bouchat, Amélie, Hutter, Nils
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2022
• Subjects: sea ice; deformation; RGPS; satellite observations; rheology; Arctic; Sea ice
• Online Access: https://doi.org/10.5281/zenodo.6321327

Deformation composite constructed from the Lagrangian RADARSAT Geophysical Processor System (RGPS) Lagrangian motion data for January-February-March, 1997 to 2008.The nominal temporal and spatial scales for the composite data areT * = 3 days, and L * = 10 km. This data is analyzed and compared with model deformation statistics inBouchat et al., Sea Ice Rheology Experiment (SIREx), Part I: Scaling and statistical properties of sea-ice deformation fields, Journal of Geophysical Research: Oceans (2022). The original RGPS Lagrangian motion data set consists in lists of trajectories (time and positions records) for points that are tracked in sequential synthetic aperture radar (SAR) images. The trajectories are organized in different “streams”, corresponding to different initial satellite passes over which a set of tracked points were initialized. For all streams, the trajectories are initialized on auniform 10 km x 10 km grid at the beginning of the winter in November.Each tracked pointcan therefore be assigned to (i,j) indices corresponding to its initialization location on the grid. As time increases andthe position records are updated, the tracked points are no longer uniformly separated, but their assigned (i,j) indices do not change.The trajectory records are updated when the tracking algorithm detects the tracked points in a new SAR image. The update interval is therefore not always the same for allpoints, nor is it always on the same time/day within a given stream as the tracking algorithm may be unsuccessful for certain images/points. Moreover, the multiple streams can overlap spatially, such that more than one trajectory can be assigned to the same (i,j) indices. Computingstrain rates directlyfrom the original RGPS Lagrangian motion product therefore results in deformation estimates that can span a wide range of spatio-temporal scales, that are not temporally coherent across all streams,and that can also be spatiallyredundant.The goal of constructing a deformation composite from theoriginal RGPS Lagrangian ...