Using Turbulence Scintillation To Assist Object Ranging From A Single Camera Viewpoint

Image distortions caused by atmospheric turbulence are often treated as unwanted noise or errors in many image processing studies. Our study, however, shows that in certain scenarios the turbulence distortion can be very helpful in enhancing image processing results. This paper describes a novel approach that uses the scintillation traits recorded on a video clip to perform object ranging with reasonable accuracy from a single camera viewpoint. Conventionally, a single camera would be confused by the perspective viewing problem, where a large object far away looks the same as a small object close by. When the atmospheric turbulence phenomenon is considered, the edge or texture pixels of an object tend to scintillate and vary more with increased distance. This turbulence induced signature can be quantitatively analyzed to achieve object ranging with reasonable accuracy. Despite the inevitable fact that turbulence will cause random blurring and deformation of imaging results, it also offers convenient solutions to some remote sensing and machine vision problems, which would otherwise be difficult

Multi-Aperture Laser Transmissometer System For Long-Path Aerosol Extinction Rate Measurement

We present the theory, design, simulation, and experimental evaluations of a new laser transmissometer system for aerosol extinction rate measurement over long paths. The transmitter emits an ON/OFF modulated Gaussian beam that does not require strict collimation. The receiver uses multiple point detectors to sample the sub-aperture irradiance of the arriving beam. The sparse detector arrangement makes our transmissometer system immune to turbulence-induced beam distortion and beam wander caused by the atmospheric channel. Turbulence effects often cause spatial discrepancies in beam propagation and lead to miscalculation of true power loss when using the conventional approach of measuring the total beam power directly with a large-aperture optical concentrator. Our transmissometer system, on the other hand, combines the readouts from distributed detectors to rule out turbulence-induced temporal power fluctuations. As a result, we show through both simulation and field experiments that our transmissometer system works accurately with turbulence strength C2n up to 10−12 m−2∕3 over a typical 1-km atmospheric channel. In application, our turbulence- and weather-resistant laser transmissometer system has significant advantages for the measurement and study of aerosol concentration, absorption, and scattering properties, which are crucial for directed energy systems, ground-level free-space optical communication systems, environmental monitoring, and weather forecasting

A Multi-Aperture Laser Transmissometer For Detailed Characterization Of Laser Propagation Over Long Paths Through The Turbulent Atmosphere

We present an experimental evaluation of a multi-aperture laser transmissometer system which profiles long-term laser beam statistics over long paths. While the system was originally designed to measure the aerosol extinction rate, the beam profiling capabilities of the transmissometer system also allows experimental observations of Gaussian beam statistics in weak and strong turbulence. Additionally, measurement of long-term beam spread at the receiver allows the system to estimate a path-averaged C n2 , including in strong turbulence regimes where scintillometers experience saturation effects. Additionally, a phase-frequency correlation technique for synchronizing with transmitter ON/OFF modulation in the presence of background ambient light is presented. In application, our ruggedized and weather resistant laser transmissometer system has significant advantages for the measurement and study of aerosol concentration, absorption, scattering, and turbulence properties over multi-kilometer paths, which are crucial for directed energy systems, ground-level free-space optical communication systems, environmental monitoring, and weather forecasting

Comparing Measurements Of Rtd Probe Systems And Sonic Anemometers

Ground to air temperature gradients are the drivers of optical turbulence. Different systems can measure temperature fluctuations. C2T and C2n are derived from RTD probe systems and sonic anemometers mounted at several heights and compared

Redox-enabled electronic interrogation and feedback control of hierarchical and networked biological systems

Abstract Microelectronic devices can directly communicate with biology, as electronic information can be transmitted via redox reactions within biological systems. By engineering biology’s native redox networks, we enable electronic interrogation and control of biological systems at several hierarchical levels: proteins, cells, and cell consortia. First, electro-biofabrication facilitates on-device biological component assembly. Then, electrode-actuated redox data transmission and redox-linked synthetic biology allows programming of enzyme activity and closed-loop electrogenetic control of cellular function. Specifically, horseradish peroxidase is assembled onto interdigitated electrodes where electrode-generated hydrogen peroxide controls its activity. E. coli’s stress response regulon, oxyRS, is rewired to enable algorithm-based feedback control of gene expression, including an eCRISPR module that switches cell-cell quorum sensing communication from one autoinducer to another—creating an electronically controlled ‘bilingual’ cell. Then, these disparate redox-guided devices are wirelessly connected, enabling real-time communication and user-based control. We suggest these methodologies will help us to better understand and develop sophisticated control for biology

Discovery and in Vivo Evaluation of (<i>S</i>)‑<i>N</i>‑(1-(7-Fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)‑9<i>H</i>‑purin-6-amine (AMG319) and Related PI3Kδ Inhibitors for Inflammation and Autoimmune Disease

The development and optimization of a series of quinolinylpurines as potent and selective PI3Kδ kinase inhibitors with excellent physicochemical properties are described. This medicinal chemistry effort led to the identification of <b>1</b> (AMG319), a compound with an IC₅₀ of 16 nM in a human whole blood assay (HWB), excellent selectivity over a large panel of protein kinases, and a high level of in vivo efficacy as measured by two rodent disease models of inflammation