We study the problem of determining an unknown microseismic event location relative to previously located events using a single monitoring array in a monitoring well. We show that using the available information about the previously located events for locating new events is advantageous compared to locating each event independently. By analyzing confidence regions, we compare the performance of...

What is long-baseline optical/IR stellar interferometry? A few years ago, many astronomers might not have been able to answer that question properly. This is today hopefully not the case anymore, because mainstream facilities, such as the VLTI, the Keck-I or the CHARA array, offer now this delicate technique to an astronomer who wants to observe his favourite object at the highest angular resol...

This research used both ERS and JERS-1 images to investigate the feasibility of differential radar interferometry (DInSAR) for mine subsidence monitoring in the state of New South Wales, Australia. DInSAR results are analysed and validated with the aid of Geographic Information System (GIS) tools. The drawbacks of using interferometric measurements for mine subsidence monitoring are discussed. ...

SAR interferometry with distributed satellites is a technique based on the exploitation of the interference pattern of two SAR images acquired synchronously. The interferogram contains geometric, atmospheric, topographic and land defomation. This paper focuses on atmospheric effects on SAR interferometry, which shows theoretically that the relationship among ionosphere TEC and troposphere param...

Phase-measurement interferometry (PM!) techniques enable quantitative measurements to be performed in optical testing, holographic interferometry, and speckle metrology. This paper will present results of error analyses of the most common errors in phase-measurement techniques. These errors include miscalibrated and nonlinear phase shifters, detector nonlinearities, detection quantization, vibr...

Current optical interferometers are affected by unknown turbulent phases on each telescope. In the field of radio interferometry, the self-calibration technique is a powerful tool to process interferometric data with missing phase information. This paper intends to revisit the application of self-calibration to optical long-baseline interferometry (OLBI). We cast rigorously the OLBI data proces...

Single-mode optical fibers are playing an increasing role in astronomical interferometry, e.g., in high-accuracy visibility measurements and in nulling interferometry. However, such observing modes typically involve only small numbers of fibers. On the other hand, some recently proposed observing techniques call for arrays of single mode fibers coupled to arrays of sub-apertures within a large ...

Interferometry has long been used in radio astronomy to enable imaging of astronomical sources with angular resolutions exceeding the diffraction limit of a single aperture. In the past decade, interferometry of the CMB has been carried out with instruments such as the CBI, DASI and VSA which exploited the inherent instrumental stability and simplicity of ell-space analysis of interferometer da...

We discuss an efficient phase preserving technique for ScanSAR focusing, used to obtain images suitable for ScanSAR interferometry. Given two complex focused ScanSAR images of the same area, an interferogram can be generated as for conventional repeat pass SAR interferometry. However, due to the nonstationary azimuth spectrum of ScanSAR images, the coherence of the interferometric pair and the ...

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion. An AO system basically consists of three main components, a wavefront sensor, a wavefront corrector and a control system. A new wavefront sen...