Paper Info
Title
An Automatic Algorithm for Estimating Tropical Cyclone Centers in Synthetic Aperture Radar Imagery
Abstract
Synthetic aperture radar (SAR) can monitor the sea surface imprints of tropical cyclones (TCs) with high spatial resolution, day and night. Automatically locating TC center positions in SAR images is a challenging task. This article developed a two-stage, fully automatic TC-center estimation algorithm. First, the sea surface wind directions (SSWDs) at SSWD points are retrieved by the improved local gradient (ILG) method. We incrementally deflected the SSWD outward at a 0.5 degrees angle from -50 degrees to 10 degrees (the negative angles represent clockwise deflection). The heat maps are generated for each of the 121 angles, and the values at each heat map are the cumulative numbers of the lines perpendicular to the compensated SSWDs. The site corresponding to the maximum cumulative number in all 121 heat maps is the coarsely estimated center position. This center search is the culmination if it falls outside the SAR image. Otherwise, the second stage is triggered, and the sub-SAR image (150 km x 150 km) centered at the coarsely estimated center position is extracted. Then, the first-stage procedure is repeated with the sub-SAR image to precisely estimate the center position. Optionally, the precisely estimated center position can be further adjusted by considering that normalized radar cross section (NRCS) is normally minimal at the TC center. We applied the algorithm to 87 SAR images. Five of these images do not contain TC centers. The results are in good agreement with the visually located TC center positions and those in the best track (BT) datasets.
Year
DOI
Venue
2022
10.1109/TGRS.2021.3105705
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
Keywords
DocType
Volume
Radar polarimetry, Heating systems, Sea surface, Synthetic aperture radar, Oceanography, Estimation, Satellites, Sea surface wind direction (SSWD), synthetic aperture radar (SAR), tropical cyclone (TC)
Journal
60
ISSN
Citations 
PageRank 
0196-2892
0
0.34
References 
Authors
0
8
Name
Order
Citations
PageRank
Yan Wang118362.13
Gang Zheng201.01
Xiaofeng Li333679.94
Lizhang Zhou400.34
Bin Liu54011.42
Peng Chen603.04
Lin Ren701.69
Xiaohui Li800.68