35 results about "Depolarization ratio" patented technology

The invention discloses a sea surface oil spilling detection method of a complete polarization synthetic aperture radar (SAR). The method comprises the following steps of: carrying out adaptive threshold value segmentation on a complete polarization SAR image to obtain complete polarization SAR images getting rid of the sea surface; selecting a training sample and a testing sample from the complete polarization SAR images getting rid of the sea surface; training an SVM (Support Vector Machine) detector, and normalizing polarization characteristic vectors of the detector, which comprise a scattering entropy H, a scattering angle alpha, a negative entropy A, a co-polarization ratio gamma, a cross polarization ratio eta, a depolarization ratio delta, a co-polarization phase difference phi HH-VV and a cross polarization phase difference phi HH-VV; and finally, detecting and identifying spilled oil and suspected objects by using the SVM and outputting a detection result. The method has thecharacteristics of high detection speed and low false alarm rate and is suitable for the sea surface oil spilling detection of the SAR.

The invention provides a non-spherical aerosol particle mixing ratio detecting method and device. The method comprises the steps that the mixing ratio of non-spherical aerosol particles is calculated according to the depolarization ratio of the non-spherical aerosol particles in atmospheric aerosol, the depolarization ratio of spherical aerosol particles and the depolarization ratio of the atmospheric aerosol, accordingly the pollution type of the atmospheric aerosol can be accurately and visually determined according to the proportion, embodied by the non-spherical aerosol particle mixing ratio, of the non-spherical aerosol particles of the atmospheric aerosol in the aerosol particles.

The invention relates to a comprehensive polarization measuring device of argon fluoride (ArF) laser optical thin film elements. An ArF excimer laser, an ArF excimer laser beam expanding and collimating device, an iris diaphragm, a polarizer, a beam splitter and a sample platform of the comprehensive polarization measuring device are placed in sequence along a main optical axis; a reference lightpolarization detecting device is positioned on a reflected light path of the beam splitter; the sample platform is positioned on a transmission light path of the beam splitter; a transmission light polarization measuring device is fixedly mounted on a first rotatable supporting arm; a reflected light polarization detecting device is fixedly mounted on a second rotatable supporting arm; the sampleplatform, the first rotatable supporting arm and the second rotatable supporting arm are positioned in the same plane and are provided with the same rotation center; and the rotation center is positioned on the main optical axis. By adopting the comprehensive polarization measuring device, the polarization reflectivity, the transmissivity, the reflection depolarization ratio and the transmission depolarization ratio of the optical thin film elements in different shapes, which are positioned at different incidence angles, can be measured at the same time, and thereby the need of various ArF laser optical thin film elements on polarization performance assessment can be met to the maximum limit.