Systematic detection and correction of instrument-related time shifts using seismic interferometric surface waves

Timing errors are a notorious problem in seismic data acquisition and processing. A technique is presented that allows such time shifts to be detected and corrected in a systematic fashion. The methodology relies on virtual-source responses retrieved through the application of seismic interferometry (SI). In application to recordings of ambient...

Minimizing the Zero-Flow Error in Transit-Time Ultrasonic Flow Meters

Transit-time ultrasonic flow meters are based on the fundamental idea that the flow is the only non-reciprocal effect between an upstream and downstream measurement. Non-identical transducers can be used in a reciprocal manner if the circuit is made reciprocal. In this paper we analyze the effect of driver- and readout electronics on the zero...

Flow cell coupled dynamic light scattering for real-time monitoring of nanoparticle size during liquid phase bottom-up synthesis

To tailor the properties of nanoparticles and nanocomposites, precise control over particle size is of vital importance. Real-time monitoring of particle size during bottom-up synthesis in liquids would allow a detailed study of particle nucleation and growth, which provides valuable insights in the mechanism of formation of the nanoparticles....

A feasibility study of time-lapse seismic noise interferometry for CO2 monitoring at Ketzin

Since 2008, CO2 has been injected at the demonstration site for CO2 sequestration in Ketzin, Germany. Since 2009, a permanent array of seismic receivers installed by TNO at the injection site has recorded passive data continuously. It is the intention of TNO to use seismic interferometry (SI) by cross-correlation applied to the recorded ambient...

State fusion with unknown correlation: Ellipsoidal intersection

This article focuses on the problem of fusing two prior Gaussian estimates into a single estimate, when the correlation is unknown. Existing solutions either lead to a conservative fusion result, as the chosen parametrization focuses on the fusion formulas instead of correlations, or they are computationally expensive. The contribution of this...

Towards a passive acoustic underwater system for protecting harbours against intruders

The international rules for the protection of harbors against threats and intruders typically apply to threats emanating from the land side. Protection against actions and threats from the water side is much less regulated, apart from some individual cases. Potential threats from the water side may consist of intruders including divers with and...

Time-domain cross-correlation baroreflex sensitivity: Performance on the EUROBAVAR data set

Objective: To test a new method (cross-correlation baroreflex sensitivity, xBRS) for the computation of time-domain baroreflex sensitivity on spontaneous blood pressure and heart interval variability using the EUROBAVAR data set. Methods: We applied xBRS to the 42 records in the EUROBAVAR data set, obtained from 21 patients in the lying and...

Correlator technology

The paper reviews a number of designs of cross-correlation receivers for the detection of active underwater transmissions. Particular attention is given to the various structures of phase insensitive receivers, and to the problems concerned with clipping of the input signal and the reference function.