Improvement of the feature tracking and patter matching algorithm for sea ice motion retrieval from SAR and optical imagery

• Published in: International Journal of Applied Earth Observation and Geoinformation
• Main Authors: Mingci Li, Chunxia Zhou, Xiaoli Chen, Yong Liu, Bing Li, Tingting Liu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2022
• Subjects: Sea ice motion; Feature tracking; Maximum cross-correlation; Q-ORB; Geographic grid-based matching; Locally consistent filtering; geo; envir; Asar; The Sentinel; Sea ice
• Online Access: https://doi.org/10.1016/j.jag.2022.102908; https://doaj.org/article/270d6e12279c423186491e0465e3f233

This study presents an improved, versatile, and efficient algorithm based on the Oriented FAST and Rotated BRIEF (ORB) combined with the maximum cross-correlation (MCC) (ORB-MCC) for extracting sea ice motion (SIM) vectors. Quadtree ORB (Q-ORB) extracts more uniform feature points than ORB (uniformity is 3 times higher) and eliminates the concentration of ORB-extracted feature points on ice ridges, leads and coastlines, thereby providing excellent initial conditions for MCC calculations. In addition, a geographic grid-based matching (GGM) algorithm is developed to replace the brute-force matching algorithm (BFM). GGM is 8–10 times more efficient for matching feature points than BFM, thereby increasing the computational efficiency of extracting SIM vectors. Moreover, a locally consistent (LC) flow field filtering process is incorporated to facilitate the filtering of the SIM field. Combining cross-correlation-coefficient-threshold (CCCT)-based and LC filtering processes eliminates erroneous vectors more efficiently than using a CCCT-based filtering process alone. The improved algorithm, named Q-ORB-MCC, is used to extract SIM vectors from imagery acquired by the Sentinel-1 Synthetic-Aperture Radar (SAR), Envisat Advanced SAR (ASAR), Phased Array type L-band SAR-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 (ALOS-2), and Moderate Resolution Imaging Spectroradiometer (MODIS). An analysis of the accuracy and effectiveness of the extracted SIM vectors shows that Q-ORB-MCC extracted SIM vectors from Sentinel-1, ASAR, and MODIS images with 4%, 253%, and 62% higher accuracy than ORB-MCC, respectively. Meanwhile Q-ORB-MCC could obtain more SIM vectors from Sentinel-1 and ASAR images.