Two descriptions are introduced and analyzed for a reflectivity estimation and detection scheme that does not involve measurement of photons scattered by the target. One description, provided by the Hamiltonian dynamics of the full transmitter/receiver optical system, incurs an exponential cost in transmitter intensity for a given estimation sensitivity but is linearly improved with the intensity of the thermal background. The other description, based on optical quantum circuits, exhibits sensitivity around a factor of 1/2 of the optimal entanglement-assisted scheme, but incurs an inverse linear reduction in sensitivity with increasing thermal background. The results have applications for the design of optically active receivers based on combining echo-seeded spontaneous parametric downconversion and induced coherence due to photon indistinguishability.
Analytical performance evaluation of quantum radar architectures: From single-photon to entangled-noise radars
Quantum Remote Sensing Lab, Quantum Metrology Group, Iranian Center for Quantum Technologies (ICQT)（量子远程传感实验室，量子计量组，伊朗量子技术中心）；Laser and Plasma Research Institute, Shahid-Beheshti University（激光与等离子体研究所，沙希德·贝赫什蒂大学）；Department of Physics, University of Tehran（德黑兰大学物理系）
Quantum Radar System Using Born-Feynman path integrals approach
Department of Quantum Computing, Quantum Research And Centre of Excellence（量子计算系，量子研究中心与卓越中心）；Department of Quantum material, Egreen Quanta（量子材料系，Egreen Quanta）
Indian Institute of Technology Delhi（印度理工学院德里分校）；Centre for Applied Research in Electronics, Indian Institute of Technology Delhi（印度理工学院德里分校应用电子研究中心）；Bharti School of Telecom Technology and Management, Indian Institute of Technology Delhi（印度理工学院德里分校巴蒂电信技术与管理学院）
Time resolution at the quantum limit of two incoherent sources based on frequency resolved two-photon-interference
University of Portsmouth（朴茨茅斯大学）；School of Mathematics and Physics, University of Portsmouth（朴茨茅斯大学数学与物理学院）；Quantum Science and Technology Hub, University of Portsmouth（朴茨茅斯大学量子科学与技术中心）；Institute of Cosmology and Gravitation, University of Portsmouth（朴茨茅斯大学宇宙学与引力研究所）
An integrated photonic millimeter-wave receiver with sub-ambient noise temperature
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL)（洛桑联邦理工学院物理研究所）；Center of Quantum Science and Engineering, EPFL（洛桑联邦理工学院量子科学与工程中心）；Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences（中国科学院上海微系统与信息技术研究所）；Department of Electrical Engineering, Colorado School of Mines（科罗拉多矿业大学电气工程系）
Quantum target ranging with Hetero-Homodyne detection
Department of Combinatorics and Optimization and Institute for Quantum Computing, University of Waterloo（滑铁卢大学组合优化系与量子计算研究所）；Agency for Defense Development（国防发展局）
