Intertidal area classification with generalized extreme value distribution and Markov random field in quad-polarimetric synthetic aperture radar imagery

Classification of intertidal area in synthetic aperture radar(SAR) images is an important yet challenging issue when considering the complicatedly and dramatically changing features of tidal fluctuation. The difficulty of intertidal area classification is compounded because a high proportion of this area is frequently flooded by water, making statistical modeling methods with spatial contextual information often ineffective. Because polarimetric entropy and anisotropy play significant roles in characterizing intertidal areas, in this paper we propose a novel unsupervised contextual classification algorithm. The key point of the method is to combine the generalized extreme value(GEV) statistical model of the polarization features and the Markov random field(MRF) for contextual smoothing. A goodness-of-fit test is added to determine the significance of the components of the statistical model. The final classification results are obtained by effectively combining the results of polarimetric entropy and anisotropy. Experimental results of the polarimetric data obtained by the Chinese Gaofen-3 SAR satellite demonstrate the feasibility and superiority of the proposed classification algorithm.

Waveguide-coupled deterministic quantum light sources and post-growth engineering methods for integrated quantum photonics

Integrated photonic quantum circuits(IPQCs)have attracted increasing attention in recent years due to their widespread applications in quantum information science.While the most envisioned quantum technologies such as quantum communications,quantum computer and quantum simulations have placed a strict constraint on the scalability of chip-integrated quantum light sources.By introducing sizeconfined nanostructures or crystal imperfections,low-dimensional semiconductors have been broadly explored as chip-scale deterministic single-photon sources(SPSs).Thus far a variety of chip-integrated deterministic SPSs have been investigated across both monolithic and hybrid photonic platforms,including molecules,quantum dots,color centers and two-dimensional materials.With the rapid development of the chip-scale generation of single photons with deterministic quantum emitters,the field of IPQCs has raised new challenges and opportunities.In this paper,we highlight recent progress in the development of waveguide-coupled deterministic SPSs towards scalable IPQCs,and review the post-growth tuning techniques that are specifically developed to engineer the optical properties of these WG-coupled SPSs.Future prospects on stringent requirement for the quantum engineering toolbox in the burgeoning field of integrated photonics are also discussed.