Long range 3D imaging through atmospheric obscurants using array-based single-photon LiDAR.

Single-photon light detection and ranging (LiDAR) has emerged as a strong candidate technology for active imaging applications. In particular, the single-photon sensitivity and picosecond timing resolution permits high-precision three-dimensional (3D) imaging capability through atmospheric obscurants including fog, haze and smoke. Here we demonstrate an array-based single-photon LiDAR system, which is capable of performing 3D imaging in atmospheric obscurant over long ranges. By adopting the optical optimization of system and the photon-efficient imaging algorithm, we acquire depth and intensity images through dense fog equivalent to 2.74 attenuation lengths at distances of 13.4 km and 20.0 km. Furthermore, we demonstrate real-time 3D imaging for moving targets at 20 frames per second in mist weather conditions over 10.5 km. The results indicate great potential for practical applications of vehicle navigation and target recognition in challenging weather.

Compact long-range single-photon imager with dynamic imaging capability.

Single-photon light detection and ranging (LiDAR) has emerged as a strong candidate technology for active imaging applications. Benefiting from the single-photon sensitivity in detection, long-range active imaging can be realized with a low-power laser and a small-aperture transceiver. However, existing kilometer-range active imagers are bulky and have a long data acquisition time. Here we present a compact co-axial single-photon LiDAR system for kilometer-range 3D imaging. A fiber-based transceiver with a 2.5 cm effective aperture was employed to realize a robust and compact architecture, while a tailored temporal filtering approach guaranteed the high signal-to-noise level. Moreover, a micro-electro-mechanical system scanning mirror was adopted to achieve fast beam scanning. In experiment, high-resolution 3D images of different targets up to 12.8 km were acquired to demonstrate the long-range imaging capability. Furthermore, it exhibits the ability to achieve dynamic imaging at five frames per second over a distance of ∼1km. The results indicate potential in a variety of applications such as remote sensing and long-range target detection.

Super-resolution single-photon imaging at 8.2 kilometers.

Single-photon light detection and ranging (LiDAR), offering single-photon sensitivity and picosecond time resolution, has been widely adopted for active imaging applications. Long-range active imaging is a great challenge, because the spatial resolution degrades significantly with the imaging range due to the diffraction limit of the optics, and only weak echo signal photons can return but mixed with a strong background noise. Here we propose and demonstrate a photon-efficient LiDAR approach that can achieve sub-Rayleigh resolution imaging over long ranges. This approach exploits fine sub-pixel scanning and a deconvolution algorithm tailored to this long-range application. Using this approach, we experimentally demonstrated active three-dimensional (3D) single-photon imaging by recognizing different postures of a mannequin model at a stand-off distance of 8.2 km in both daylight and night. The observed spatial (transversal) resolution is ∼5.5 cm at 8.2 km, which is about twice of the system's resolution. This also beats the optical system's Rayleigh criterion. The results are valuable for geosciences and target recognition over long ranges.

[Gene Polymorphism 24 Rare Blood Group Antigens of 11 RBC Blood Group Systems in Manchu Population of Harbin Area in China].

OBJECTIVE: The purpose of this study was to investigate the 24 kinds of antigen gene polymorphism chara-cteristics in 11 RBC blood group systems of Manchu population blood donor in Harbin Area of China, so as to better perform the clinical blood transfusion and to avoid adverse transfusion reactions. METHODS: Twenty-four antigen genes (GYPB (S/S), Duffy, Kell, Dombrock, Diego, Kidd, Scianna, Colton, Lutheran, Yt, Mur) were assessed by the polymerase chain reaction sequence specific primers (PCR-SSP) in 11 blood type systems, including Fya, Fyb; K, K; Doa, Dob; Dia, Dib; JKa, JKb; Sc1,Sc2; Coa, Cob; Lua, Lub; Yta, Ytb; Kpa, Kpb; Mur, Mur2 among 200 Manchus in Harbin. RESULTS: The gene frequency of blood type system in Harbin Manchu GYPB (S/S) was as follows: S=0.0625, s=0.9325; the gene frequency of duffy blood type system: Fya=0.0525, Fyb=0.9475; Gene frequency of Dombrock type system was as follows: Doa=0.1250, Dob=0.8750; Gene frequency of Diego type system: Dia=0.0275, Dib=0.9725; the gene frequency of Kidd blood type system: JKa=0.5650, JKb=0.4350; the gene frequency of Mur blood type system: Mur1 = 0.0050, Mur2 = 0.9950; the Kell, Scianna, Colton, Lutheran and Yt type blood type system displayed a monomorph distribution and the genotype was kkKpbKpb,Sc1Sc1,CoaCoa, LubLub, YtaYta, respectively. CONCLUSION: The distribution of GYPB(S/s),Duffy,Dombrock, Diego, Kidd and Mur blood type system in Harbin Manchu has been found to be characterized by polymorphism, and the distribution of kell, scianna, colton, lutheran and ye blood type system has been found to be characterized by oligomorphism. The gene destribution of dombrock and Kidd blood group systems is unique in Harbin Manchu.