Comparison the polarisation-dependent signature and detectability of ships between ENVISAT ASAR AP mode images and ERS-2 SAR image
Haibo YUE(1) and Jie ZHANG(2)
Ocean University of China,
No.5 Yushan Road,
266003 Qingdao ,
(2) First Institute of Oceanography, SOA, No.6 Xianxialing Road, 266061 Qingdao, China
Ship detection with spaceborne SAR (Synthetic Aperture Radar) has been an interesting research topic for maritime and fishing administration. Considerable research has been carried out to establish the actual capabilities of single channel SAR on the European satellites ERS-1 and ERS-2, as well as the RADARSAT-1. The ENVISAT ASAR AP (Alternating Polarisation) mode can acquire polarization information of ships, provides a new opportunity for space borne monitoring of vessel traffic and fishing activities. Several ENVISAT ASAR AP mode images and ERS-2 SAR images covered Qingdao and Dalian are acquired and scatter feature of ships is compared. A campaign of field measurement in anchorage of Qingdao Port is carried out in Oct. 28, 2005. The data of ship’s location, length and width, water line and sea surface wind speed, direction are measured with simultaneous with ENVISAT ASAR image acquirement. SAR imaging ability and polarization-dependent feature are comprised and analyzed between different ships. CFAR (Constant False Alarm Rate) model is used to detect ships. It found that detection error and false alarm can decrease whether the polarisation information is combined. So ENVISAT ASAR AP mode images are more favorable to vessel detection.