Analysis of Ship Detection Performance with Full-, Compact- and Dual-Polarimetric SAR

Abstract

Polarimetric synthetic aperture radar (SAR) is currently drawing more attention due to its advantage in Earth observations, especially in ship detection. In order to establish a reliable feature selection method for marine vessel monitoring purposes, forty features are extracted via polarimetric decomposition in the full-polarimetric (FP), compact-polarimetric (CP), and dual-polarimetric (DP) modes. These features were comprehensively quantified and evaluated using the Euclidean distance and mutual information, and the result indicated that the features in CP SAR are better than those of FP or DP SAR in general. The CP SAR features are thus further studied, and a new feature, named phase factor, in CP SAR mode is presented that can distinguish ships and the sea surface by the constant 0 without complex calculation. Furthermore, the phase factor is independent of the sea surface roughness, and hence it performs stably for ship detection even in high sea states. Experiments demonstrated that the ship detection performance of the phase factor detector is better than that of roundness, delta, HESA and CFAR detectors in low, medium and high sea states.2 of 23 much better. Qin et al. [3] proposed a novel CFAR detection algorithm for high-resolution SAR images using the generalized Gamma distribution (GΓD), and the performance of the proposed algorithm is better than the Weibull distribution. However, with the higher resolution of the SAR image, the sea clutter becomes complex in the time and spatial domains, and then the existing models are not suitable, resulting in the severe degradation of the CFAR detection performance and many false alarms [4]. Additionally, the parameter estimation is complex, and the threshold cannot be acquired easily [5].To overcome the drawbacks of the CFAR method, ship detection methods based on new features have been studied by researchers, and many results has been achieved [6][7][8]. For example, based on Cloude decomposition, Wang et al. [9] used the local uniformity of the third eigenvalue of a polarization coherence matrix (T) to detect ships. Sugimoto et al. [10] combined Yamaguchi decomposition theory and the CFAR method to detect ships by analyzing the differences between the scattering mechanisms of the sea surface and ships. Shirvany et al. [11] indicated the effectiveness of the degree of polarization (DoP) in ship detection. Then, this work was further studied by Touzi et al. [12], who defined an extension of the DoP to enhance significant ship-sea contrasts. In contrast to using a single feature, Yin et al. [13] investigated the capability of m-α and m-χ decompositions in coastal ship detection. Then, three features extracted from compact-polarimetric (CP) SAR were proven to have a good performance in ship detection in [14]. Furthermore, Paes et al. [15] provided a more detailed analysis of the detection capability and sensitivity of δ together with m, µ c ,|µ xy |, and the entropy H ω . Gui et al. [16] extracted a new feature from the proposed power-entropy decomposition, call...

Performance Analysis of Internal Solitary Wave Detection and Identification Based on Compact Polarimetric SAR

“…It can be seen from the figure that the incidence angle increases, the distance value increases in the different polarization feature images, that is, the distinguishability between ISWs and the sea surface increases. This finding is consistent with the ship detection results by CP features indicated in [27]. However, for images with the same incidence angle, the distance value does not change much, and the overall trend is relatively stable, as shown by the solid line in the figure.…”

“…Preliminary studies, such as that of Shirvany et al, who detected ships on the sea surface based on the polarization degree extracted from CP SAR, have been conducted in the field of target detection [18]. In [19], Cao et al constructed CP SAR data based on FP RADARSAT-2 data and compared the ship detection capabilities of FP, CP and DP SAR systems. In [20], Salberg et al introduced some CP features for the detection of oil spills; additionally, the polarization degree and ellipticity, which were obtained from m  − decomposition, were used for oil spill detection.…”

Validating GEV Model for Reflection Symmetry-Based Ocean Ship Detection with Gaofen-3 Dual-Polarimetric Data

“…Herein, the extensive use of TerraSAR-X dual-polarimetric SAR data has been explored for ocean surveillance, including ocean target investigation, coastline/shoreline extraction, sea ice analysis and other marine surveillance activities [3,[13][14][15][16][17][18][19]. Meanwhile, dual-polarimetric data from Radarsat-2 are also widely utilized for oil spill observation, ocean wind retrieval, and ocean target detection, as well as dual-polarimetric data from other satellite SAR systems [4,[20][21][22][23][24]. In these ocean surveillance researches, more information contained in the dual-polarization data are utilized.…”

“…As the co-and cross-polarization HH/HV or VH/VV is the overused dual-polarization state in the satellite SAR systems, exploring HH/HV or VH/VV data attracts intensive attentions on ocean targets, especially for the man-made target observation or detection at sea [1][2][3][19][20][21][22]. Among these researches, many polarimetric scattering characteristic parameters are considered for ship detection, including the polarimetric entropy [1,2,19], phase difference [21] and reflection symmetry [1,3,20,22]. Herein, reflection symmetry, as an important symmetry property characterizing the natural background scenarios, was first exploited for metallic target observation at sea by Migliaccio [3].…”

Editorial on Special Issue “Applications of Remote Sensing in Coastal Areas”

“…Cao et al [13] analyzed 40 features extracted via polarimetric decomposition in the full-polarimetric (FP), simulated compact-polarimetric (CP), and dual-polarimetric (DP) SAR modes for ship detection using the Euclidean distance and mutual information. Authors found that that the features in CP SAR were better than those of FP or DP SAR in general.…”