The inversion of electron density from total electron content (TEC) measurements of GPS radio occultation is investigated by means of simulated data from the International Reference Ionosphere IRI-2001 and observations by the GPS/MET satellite experiment. In both cases a meridional slice of electron density is derived for northern summer solstice June/July 1995 from the midnight to the noon sec...

Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electro...

the compact gravity inversion including the minimization of moment of inertia has been applied to determine the geometry of anomalous bodies which cause much more depth esolution. the new algorithm is based on lewi's (1996) procedure including the minimum moment of inertia. the method is used with good results to several 3-dimensional synthetic models and real examples. the advantage of us...

In order to carry out geoacoustic inversion in low signal-to-noise ratio (SNR) conditions, extended duration observations coupled with source and/or receiver motion may be necessary. As a result, change in the underlying model parameters due to time or space is anticipated. In this paper, an inversion method is proposed for cases when the model parameters change abruptly or slowly. A model para...

Radio occultation (RO) has been proven to be a powerful technique for ionospheric electron density profile (EDP) retrieval. The Abel inversion currently used in RO EDP retrieval has degraded performance in regions with large horizontal gradients because of an assumption of spherical symmetry as indicated by many studies. Some alternative methods have been proposed in the past; the global ionosp...

This paper presents a geoacoustic inversion scheme relying on the inversion of signal close to marine mammals vocalizations on a single hydrophone in shallow waters. Our method makes best use of the multipath propagation of vocal calls and of their time-frequency signature to extract an observable used by the inversion algorithm to estimate sea bottom features. This method requires vocalization...

S U M M A R Y Geophysical inversion is often ill-posed because of inaccurate and insufficient data. Regularization is often applied to the inversion problem to obtain a stable solution by imposing additional constraints on the model. Common regularization schemes impose isotropic smoothness on solutions and may have difficulties in obtaining geologically reasonable models that are often suppose...

Structural rearrangements, including copy-number alterations and inversions, are increasingly recognized as an important contributor to human genetic variation. Copy number variants are readily measured via array-based techniques like comparative genomic hybridization, but copy-neutral variants such as inversion polymorphisms remain difficult to identify without whole genome sequencing. We intr...

Abstracr Synthetic aperture processing yields an effective lateral r solution for intravascular ultrasound imaging. This processing is generally performed with time domain summation. In this paper, we derive a new synthetic aperture inversion method based on the Fourier domain. The analysis of the image formation shows that the frequency modulation of the PSF could be useful to improve the ...

Minimum-structure inversion has been widely used in both hydrocarbon and mineral exploration for decades. However, models obtained with this method typically exhibit smooth variation of physical properties and smeared-out boundaries, and may not give detailed information about the target being investigated. In this paper we present a constrained joint inversion of surface and borehole gravity t...