Vector Angular Continuity in the Fusion of Coseismic Deformations at Multiple Optical Correlation Scales

Area of Science:

• Geophysics
• Remote Sensing
• Earthquake Science

Background:

• Optical image correlation techniques measure coseismic deformations, overcoming limitations of radar interferometry and pixel offset tracking.
• Conventional methods face a trade-off between accuracy and detail preservation due to correlation window size.

Purpose of the Study:

• Develop a post-processing workflow (VACI-OIC) to reduce shift estimation dependence on correlation window size.
• Improve the accuracy and detail of coseismic deformation measurements using optical image correlation.

Main Methods:

• Treat coseismic deformation as a 2D vector, considering both east-west and north-south directions.
• Introduce an angular continuity index for fusing deformation fields from different correlation windows.
• Apply the VACI-OIC workflow to the 2021 Maduo, China earthquake.

Main Results:

• Achieved higher spatial resolution deformation mapping in the surface rupture zone than SAR data.
• Generated more uniform and consistent deformation field results compared to single-scale optical correlation.
• Clearly detected the earthquake's strip fracture zone.

Conclusions:

• The VACI-OIC workflow effectively reduces dependency on correlation window size for shift estimation.
• The angular continuity index provides a more robust constraint for fusing deformation data.
• This method offers superior detail and uniformity in coseismic deformation analysis, particularly in high-deformation areas.