Daniel Raucoules
BRGM, DRP (Risks and Prevention Department), Department Member
- Daniel Raucoules received the Ph.D. degree from Université Montpellier II, Montpellier, France, in 1997 and the “Hab... moreDaniel Raucoules received the Ph.D. degree from Université Montpellier II, Montpellier, France, in 1997 and the “Habilitation à Diriger des Recherches” degree from the University of Orléans, Orléans, France, in 2011.Since 1999, he has been a Researcher with the French National Geological Survey (BRGM), Orléans, France, in the domain of spaceborne remote sensing tools (mainly radar interferometry and image correlation) applied to the measurement of ground surface deformation. His research interests (carried out in the framework of French and international projects) include methodological developments on techniques and their application to thematics dealing with ground motion, seismo-tectonic deformation, fluid injection/extraction, and post-mining.edit
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While the understanding and modelling of relative sea level rise (SLR) due to ocean density and mass changes have greatly improved over the past few decades, SLR contributions due to vertical ground motions (VGMs) remain a major source of... more
While the understanding and modelling of relative sea level rise (SLR) due to ocean density and mass changes have greatly improved over the past few decades, SLR contributions due to vertical ground motions (VGMs) remain a major source of uncertainty. Here, VGMs relate to ground motions that have imprints of a few kilometers, as opposed to broad scale land motion such as Glacial Isostatic Adjustment (GIA). VGMs are caused by processes such as natural resource extraction or the load of anthropogenic infrastructure on recent sediment deposits or natural processes (e.g. sismotectonics, volcanism, landslide), all of which vary in space and time, and can strongly inflate SLR locally.Here, we present a pan-European analysis of relative sea-level changes in Europe considering VGMs based on trends retrieved from the European Ground Motion Service (EGMS). EGMS allows identifying hot spots of robust subsidence along the European coastline such as the north Adriatic coast in Italy, areas such as Palavas (France), Groningen (Netherlands) and many coastal infrastructures such as dikes in La Rochelle (France) where subsidence was not documented earlier. Hence the service delineates where subsidence can have a significant impact to relative sea-level changes in coastal areas. This satisfies a major need from coastal adaptation stakeholders concerned with SLR. EGMS results are complemented and compared with VGMs estimates from permanent Global Navigation Satellite System (GNSS) network stations. The precision of the measurements is discussed: VGMs from GNSS stations derived from 4 different solutions (ULR, NGL, JPL and GFZ) allow accounting for uncertainty in trends estimation techniques. We estimate VGMs residual trends after removing the effect of the GIA from geophysical modelling, but also the effect of contemporary mass redistribution on solid Earth deformation. The results from both GNSS and EGMS suggest that the precision of ground motion velocities can be in the order of a millimetre per year.Overall, these estimates and their uncertainty can be used to produce a new coastal pan-European relative sea-level set of projections that respond to one major user need, namely the identification of areas where sea level rise is amplified by subsidence. However two other user needs remain unachieved: the local attribution of observed sea-level changes to components with a submillimetric per year accuracy and a quantified projection of subsidence, which would at least require subsidence models.
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Before the satellite altimetry era, tide gauges are the unique source of information to monitor global sea level rise due to anthropogenic climate change. As sea level changes display regional variability, its global mean can be estimated... more
Before the satellite altimetry era, tide gauges are the unique source of information to monitor global sea level rise due to anthropogenic climate change. As sea level changes display regional variability, its global mean can be estimated by averaging trends from good quality tide gauge. This leads to sea level rise rates of 1.65 +/- 0.2 mm/yr during the 20th century. However, this value and the related uncertainties are subject to discussion: 1. the network of available tide gauges is distributed in an uneven way: most of datasets available cover the Northern hemisphere, whereas previous studies suggest that sea level rise has been different in the northern and southern hemispheres. 2. over the altimetry era (1992-present), the sea level budget can be estimated by summing each contributing factor (mountain glaciers, ice sheets, thermosteric effects, land water storage), within uncertainties reaching 10 to 15% for each component. The same validation is more difficult for the recent period, because less data are available, thus questioning again the precise rate of mean sea level over the 20th century.
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Research Interests: Geology, Remote Sensing, Radar, Subsidence, Interferometry, and 9 moreEnvironmental Issues, Geomatic Engineering, Remote Sensing of the Nearshore Environment, Sar Interferometry, Long Term Monitoring, Vegetation Cover, Ground Subsidence, Interferometric Synthetic Aperture Radar, and Radar Interferometry
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The presented study consisted in processing ALOS-2 SM1 images by sub-pixel correlation and conventional differential SAR interferometry in order to assess the potential of these new data in the context of landslide deformation mapping. We... more
The presented study consisted in processing ALOS-2 SM1 images by sub-pixel correlation and conventional differential SAR interferometry in order to assess the potential of these new data in the context of landslide deformation mapping. We selected the test site on la Reunion Island because of the presence of the well known Hell-bourg landslide, studied in the past by Remote Sensing methods, using both X, C and L-band interferometry. The study showed that even with a reduced data set, consisting of 7 images with time spans up to 120 days, ALOS-2 PALSAR data represent a unique tool for landslide displacement monitoring in the highly vegetated context of La Reunion Island. Both the L-band and the high spatial resolution (1.8m) allow better performances in the motion measurement than other SAR data such as C-band SAR, medium resolution L-band data or high resolution X-band with weeks time-span). We showed that the total deformation occurred between January 2016 and august 2014 reached up to 1.5m in azimuth and 70cm in slant range. The motion presents partitioning in different regimes. From the offset results, we can clearly delineate the trace of the scarps and the sectors with different velocity regimes. Time Series suggested us that significant motion occurred on a relatively short period between November 2014 and end January 2015. We suggest that this could be related to heavy rains occurring during the wet season. The use of L-band (or larger wavelength when available) with the higher possible resolution therefore appears as the more adapted Space-borne Earth Observation tools for monitoring of very slow to slow landslides in a tropical semi-vegetated context. In this perspective the current ALOS-2 has obvious interest, provided that we access to at least bimestrial acquisitions.
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Research Interests: Geology and Seismology
Research Interests: Geography and Humanities
In this paper we present a method to restitute the volcanic gas/ash Plume Elevation Model (PEM) from optical satellite imagery. As the volcanic plume is moving rapidly, conventional satellite based photogrammetric height restitution... more
In this paper we present a method to restitute the volcanic gas/ash Plume Elevation Model (PEM) from optical satellite imagery. As the volcanic plume is moving rapidly, conventional satellite based photogrammetric height restitution methods do not apply as the epipolar offset due to plume motion adds up to the one generated by the stereoscopic view. This is because there are time-lags of tens of seconds between conventional satellite stereoscopic acquisitions, depending on the stereo acquisition mode. Our method is based on a single satellite pass. We exploit the short time lag and resulting baseline that exist between the multispectral (MS) and the panchromatic (PAN) bands to jointly measure the epipolar offsets and the perpendicular to the epipolar (P2E) offsets. The first are proportional to plume height plus the offsets due to plume velocity in the epipolar direction. The second, are proportional to plume velocity in the P2E direction only. The latter is used to compensate the effect of plume velocity in the stereoscopic offsets by projecting it on the epipolar direction assuming a known plume direction, thus improving the height measurement precision. We apply the method to Landsat 8 data taking into account the specificities of the focal plane modules. We focus on the Holuhraun 2014 fissure eruption (Iceland). We validate our measurements against ground based measurements. The method has potential for detailed high resolution routine measurements of volcanic plume height/velocity. The method can be applied both to other multi focal plane modules push broom sensors (such as the ESA Sentinel 2) and potentially to other push-broom systems such as the CNES SPOT family and Pléiades.
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ABSTRACT The role that the oblique reverse fault projecting to the surface at the Bam-Baravat escarpment (BBE) played in the slip accommodation of the 2003 (Mw 6.5) Bam earthquake is still unclear, regardless of many seismological and... more
ABSTRACT The role that the oblique reverse fault projecting to the surface at the Bam-Baravat escarpment (BBE) played in the slip accommodation of the 2003 (Mw 6.5) Bam earthquake is still unclear, regardless of many seismological and geodetic studies following this event. In this study, we correlate pre- and post-seismic very high spatial resolution panchromatic satellite images to map coseismic surface deformation along the northern segment of the BBE, a few hundred meters east of the urban area of Bam. Using a new approach based on principal component analysis (PCA) on offset measurements, we obtain 1.8 +/- 0.6 cm east slip component and 2-6 +/- 0.6 cm south slip component along the fault segment. Our results are consistent with ground observations over the study area and support the idea of the reactivation of the shallow part of this fault segment.
Research Interests: Geodesy, Geology, Geophysics, Image Processing, Principal Component Analysis, and 13 moreSeismology, Geomatic Engineering, Satellite Imagery, Satellite, Satellite Geodesy, Geophysical, Very High Resolution, Escarpment, High Spatial Resolution, Urban Area, geodetic datum, Satellite Image, and surface deformation
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Research Interests: Geography, Geology, Remote Sensing, Volcano, Volcanic ash, and 3 moreDigital Elevation Model, Plume, and Mount
Differential Synthetic Aperture Radar (SAR) interferometry has been widely used to monitor centimetric surface deformations in geophysical applications. In this letter, this technique is applied to study the displacement field in an urban... more
Differential Synthetic Aperture Radar (SAR) interferometry has been widely used to monitor centimetric surface deformations in geophysical applications. In this letter, this technique is applied to study the displacement field in an urban area. A set of six European Remote Sensing satellite (ERS)-1/2 SAR images has been used to detect, map and quantify the subsidence occurring in the city of
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Synthetic Aperture Radar interferometry (InSAR) is a particularly interesting tool whenever aiming at assessing ground deformation phenomena. It allows a regional scale monitoring, but also an historical assessment of the deformation by... more
Synthetic Aperture Radar interferometry (InSAR) is a particularly interesting tool whenever aiming at assessing ground deformation phenomena. It allows a regional scale monitoring, but also an historical assessment of the deformation by using the existent SAR image archives (dating back to the beginning of 1992 for the ERS-1/2 sensors of the European Space Agency). In this paper, we review the core aspects of SAR interferometry techniques and illustrate them using application examples related to urban or mining ground deformation.
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The proposed novel “BathySent” approach for coastal bathymetric mapping, using the Copernicus Sentinel-2 mission, as well as the assessment and specification of the uncertainties of the derived depth results, are the objectives of this... more
The proposed novel “BathySent” approach for coastal bathymetric mapping, using the Copernicus Sentinel-2 mission, as well as the assessment and specification of the uncertainties of the derived depth results, are the objectives of this research effort. For this reason, Sentinel-2 bathymetry retrieval results for three different pilot sites in Greece (islands of Kos, Kasos, and Crete) were compared with ground-truth data. These data comprised high-resolution swath bathymetry measurements, single-beam echosounder measurements at very shallow waters (1–10 m), and the EMODnet DTM 2018 release. The synthetic tests showed that the “BathySent” approach could restitute bathymetry in the range of 5–14 m depth, showing a standard deviation of 2 m with respect to the sonar-based bathymetry. In addition, a comparison with the “ratio model” multispectral technique was performed. The absolute differences between conventional Earth Observation-based bathymetry retrieval approaches (i.e., linear ra...
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The 4.9 Mw earthquake of 11 November 2019 at Le Teil (France) occurred at a very shallow depth (about 1 km), inducing the surface rupture of La Rouvière fault. The question was raised shortly after about the potential impact of a nearby... more
The 4.9 Mw earthquake of 11 November 2019 at Le Teil (France) occurred at a very shallow depth (about 1 km), inducing the surface rupture of La Rouvière fault. The question was raised shortly after about the potential impact of a nearby surface quarry. Thanks to satellite differential interferometry, here, we revealed the existence of a secondary surface rupture of the quasi-parallel Bayne Rocherenard fault. A newly processed seismic cross-section allowed us to shape the three-dimensional geometry of the local three-fault system. Assuming that the earthquake was triggered by the impact of meteoric water recharge, our numerical simulations show that the hydraulic pressure gradient at depth was at a maximum during the period of 2010–2019, just before the seismic event. The estimated overpressure at the intersection of the two faults, which is the most probable place of the hypocenter, was close to 1 MPa. This hydraulic effect is about two and a half times larger than the cumulative ef...
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On 11 November 2019, the Le Teil Mw4.9 earthquake occurred in southeast France, in the vicinity of a surface quarry. We focus this work on the effect of hydraulic recharge linked to the infiltration of meteoric water in the fault zones in... more
On 11 November 2019, the Le Teil Mw4.9 earthquake occurred in southeast France, in the vicinity of a surface quarry. We focus this work on the effect of hydraulic recharge linked to the infiltration of meteoric water in the fault zones in the period preceding the earthquake. In the reference simulation, we used the in situ soil moisture at 30 cm depth (Berzème station) as surface boundary conditions.We describe first the local 3D fault system from an updated geological model and the boundary conditions that are used to calculate the pressure variations at depth using a double permeability model.The movement of moisture in partially-saturated media is then simulated by the Compass code (1) during the period 2015-2019. A maximum overpressure takes place near the junction of the three-fault system at around 1,200 m depth. Moreover, the calculated increase in pore fluid pressure is maximum during 2015-2019 just before the earthquake of 11 November 2019. Additionally, the surface soil mo...
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Within the framework of the CIEST2 (Cellule d'Intervention d'Expertise Scientifique et Technique new generation) and thanks to the support of CNES, the French space agency, the first phase of the Fagradalsfjall eruption was... more
Within the framework of the CIEST2 (Cellule d'Intervention d'Expertise Scientifique et Technique new generation) and thanks to the support of CNES, the French space agency, the first phase of the Fagradalsfjall eruption was exceptionally well covered by high resolution optical satellite data, through daily acquisitions of Pléiades images in stereo mode. In this study, we show how Pléiades data provided real-time information useful for the operational monitoring of the ongoing eruption. An estimation of the volume of lava emitted as well as the corresponding effusion rate could be derived and delivered to the civil protection less than 6 h after the data acquisition. This information is complementary to and consistent with estimates obtained through the HOTVOLC service using SEVIRI (Spinning Enhanced Visible and Infrared Imager) sensor on-board Meteosat Second Generation (MGS) geostationary satellites, operated by the European Space Agency (ESA), characterized by a lower spat...
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The Mw 4.9 earthquake of 11 November 2019 at Le Teil (France) occurred at a very shallow depth (about 1 km) inducing the surface rupture of La Rouvière fault, nearby of a limestone quarry. Thanks to satellite differential interferometry,... more
The Mw 4.9 earthquake of 11 November 2019 at Le Teil (France) occurred at a very shallow depth (about 1 km) inducing the surface rupture of La Rouvière fault, nearby of a limestone quarry. Thanks to satellite differential interferometry, we detected the existence of the secondary surface rupture of the quasi-parallel Bayne Rocherenard fault. A newly processed seismic cross-section allowed us to construct a local 3D fault system. Assuming that the earthquake was triggered by the transient increase in hydraulic pressure following heavy rainfall before the event, our numerical 3D simulations demonstrate that the hydraulic pressure gradient is maximum just before the earthquake at the intersection of the two faults, the most probable place of the hypocenter. This hydraulic effect is about two and a half times larger than the cumulative effect of mechanical stress release due to the mass removal from the surface quarry over the two past centuries.
Research Interests: Geology and Seismology
The systematic availability of data from the Copernicus Sentinel-1 mission, allows redundancy of pairs considered during interferometric processing. In the present work the effect of DInSAR pairs’ selection on the interferometric... more
The systematic availability of data from the Copernicus Sentinel-1 mission, allows redundancy of pairs considered during interferometric processing. In the present work the effect of DInSAR pairs’ selection on the interferometric estimates, especially for the case of relatively fast moving landslides, is investigated. Interferometric findings over a well-monitored site are validated by in-situ geodetic measurements. It was documented that significant underestimation of motion occurs for DInSAR solutions utilizing pairs covering larger temporal spans, while displacement patterns are generally maintained. The above fact is attributed mainly to the magnitude of cumulated motion at temporally long interferograms, exceeding the physical limit of SAR interferometric techniques, with pronounced underestimation issues introduced. The need for an a priori knowledge of the expected motion rates for the optimum selection of interferometric combinations for measuring ground displacements is underlined.
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Rising groundwater in abandoned mines may result in ground movements at the surface overlying underground works. Feedbacks on several abandoned coalfields show that ground uplift is generally observed, reaching in some cases several... more
Rising groundwater in abandoned mines may result in ground movements at the surface overlying underground works. Feedbacks on several abandoned coalfields show that ground uplift is generally observed, reaching in some cases several centimetres or more. Although such ground movements, slow and associated with slight slopes, are not expected to generate surface damages, the survey of potential ground movements on abandoned coalfield is necessary, especially to confirm the end of mininginduced subsidence. The most common used method for this mission is levelling. A retro-analysis of ground movements, based on Interferometric Synthetic Aperture Radar (InSAR) technique, covering more than 20 years after mine activity ceasing, has been realised on the French abandoned coalfield of Nord-Pas de Calais. This analysis aimed to extend ground movements detection capabilities in areas not covered by levelling as well as compare InSAR analysis to levelling data for evaluating the robustness of s...
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This paper is an outcome of the International Space Science Institute (ISSI) Forum on “Monitoring the evolution of coastal zones under various forcing factors using space-based observing systems”... more
This paper is an outcome of the International Space Science Institute (ISSI) Forum on “Monitoring the evolution of coastal zones under various forcing factors using space-based observing systems” (http://www.issibern.ch/forum/costzoneevo/) held at ISSI, Bern, Switzerland on 11-12 October 2016 (convened by J. Benveniste, A. Cazenave, N. Champollion, G. Le Cozannet and P. Woodworth)
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Before the altimetry era, tide gauge are a unique source of information to evaluate past sea-level changes. However, they can be affected by vertical ground motions acting at different space scales. We use synthetic aperture radar... more
Before the altimetry era, tide gauge are a unique source of information to evaluate past sea-level changes. However, they can be affected by vertical ground motions acting at different space scales. We use synthetic aperture radar techniques to assess these ground motions and their consequences for geodetic instruments such as Tide Gauge, GPS, Doris stations. Summarizing results obtained at Alexandria (Egypt; Woppelmann et al., 2013), Manila (Philippines; Raucoules et al., 2013) and Dakar (Senegal; Le Cozannet et al., subm.), we identify different situations in terms of data availability and ground motion context: - when strong ground motions affect the tide gauge, the technique can easily help rejecting tide gauges records from the database of reliable datasets (case of Manila) - however, when no ground motions can be observed using InSAR in the vicinity of geodetic instruments (Case of Alexandria and Dakar), it remains challenging to reach the accuracy required to confirm that tid...
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This study focuses on the shallow deformation that occurred during the 5 years following the Parkfield earthquake (28/09/2004, Mw 6, San Andreas Fault, California). We use Synthetic Aperture Radar interferometry (InSAR) to provide precise... more
This study focuses on the shallow deformation that occurred during the 5 years following the Parkfield earthquake (28/09/2004, Mw 6, San Andreas Fault, California). We use Synthetic Aperture Radar interferometry (InSAR) to provide precise measurements of transient deformations after the Parkfield earthquake between 2005 and 2010. We propose a method to combine both ERS2 and ENVISAT interferograms to increase the temporal data sampling. Firstly, we combine 5 years of available Synthetic Aperture Radar (SAR) acquisitions including both ERS-2 and Envisat. Secondly, we stack selected interferograms (both from ERS2 and Envisat) for measuring the temporal evolution of the ground velocities at given time intervals. Thanks to its high spatial resolution, InSAR could provide new insights on the surface fault motion behavior over the 5 years following the Parkfield earthquake. As a complement to previous studies in this area, our results suggest that shallow transient deformations affected th...
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On 2018 May 10, a seismic crisis started ~50 km east of Mayotte, the easternmost of the Comoros volcanic islands. Here we analyze its first six months, from 2018 May 10 to November 14. In that period, 29 earthquakes with magnitude greater... more
On 2018 May 10, a seismic crisis started ~50 km east of Mayotte, the easternmost of the Comoros volcanic islands. Here we analyze its first six months, from 2018 May 10 to November 14. In that period, 29 earthquakes with magnitude greater than 5 occurred, the main one reaching Mw = 5.9 on 2018 May 15. In mid November, the crisis was continuing with the persistence of an unusual seismicity including episodic tremors and steady anomalous velocities measured by GNSS. The seismicity shows three successive clusters, overlapping in time and space. The coordinates of the GNSS stations also evolve in three phases, with moderate deformation during two weeks at the beginning of the crisis, quiescence from early June to early July, and the main deformation phase starting around July 10. While models of seismic dislocation cannot fit the GNSS motions, a model of deflation of magma reservoir buried in a homogenous half space fits them very well. From mid of July the deformation is steady and str...
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Before the satellite altimetry era, tide gauges are the unique source of information to monitor global sea level rise due to anthropogenic climate change. As sea level changes display regional variability, its global mean can be estimated... more
Before the satellite altimetry era, tide gauges are the unique source of information to monitor global sea level rise due to anthropogenic climate change. As sea level changes display regional variability, its global mean can be estimated by averaging trends from good quality tide gauge. This leads to sea level rise rates of 1.65 +/- 0.2 mm/yr during the 20th century. However, this value and the related uncertainties are subject to discussion: 1. the network of available tide gauges is distributed in an uneven way: most of datasets available cover the Northern hemisphere, whereas previous studies suggest that sea level rise has been different in the northern and southern hemispheres. 2. over the altimetry era (1992-present), the sea level budget can be estimated by summing each contributing factor (mountain glaciers, ice sheets, thermosteric effects, land water storage), within uncertainties reaching 10 to 15% for each component. The same validation is more difficult for the recent period, because less data are available, thus questioning again the precise rate of mean sea level over the 20th century.
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The performance of Permanent Scatterers PS Interferometry (PSI) analysis is highly limited where the presence of large vegetated cover (agricultural terrains / forests) reduces signal coherence. A possible solution relies on the... more
The performance of Permanent Scatterers PS Interferometry (PSI) analysis is highly limited where the presence of large vegetated cover (agricultural terrains / forests) reduces signal coherence. A possible solution relies on the installation on ground of artificial devices (Corner Reflectors CR) to complement the existing PS network. Yet, the number of such CRs (spatial density typically ~ 1 / km2) can be limited when the deformation pattern affects a large area (tens of km2) especially for CO2 geological storage in open aquifers. In order to support the surveillance of such sites, we address here the question of how to estimate the spatio-temporal distribution of the ground displacements over the whole area using only the sparse CR + PS network. We propose to test the feasibility of the Geostatistics Output Perturbation (GOP) method, enabling to combine the results of the reservoir model calibrated on the limited number of ground displacements’ time series and the spatial correlation between such calibrated results and the observations. A test case was constructed using the signal measured during CO2 injection (from 2004–2009) in the KB501 well of the In-Salah site, Algeria at only a few tens of spatial measurement points either corresponding to: 1. a “realistic” PS network selected in a highly vegetated region in western France and 2. a series of CR selected through a space-filling criterion. The comparison with the observations over the whole area confirmed that 80% of the temporal observations were fitted by the GOP method over the region defined by the CR network with a density of ~ 1 CR / km2. Comparisons with the calibrated model results and with the direct application of a spatio-temporal kriging confirmed the better performance of GOP as well.
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Plasma levels of total 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured in a group of 104 hospitalized depressed patients and a group of 104 age- and sex-matched normal controls. Plasma MHPG levels were found to be normally... more
Plasma levels of total 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured in a group of 104 hospitalized depressed patients and a group of 104 age- and sex-matched normal controls. Plasma MHPG levels were found to be normally distributed in both groups and significantly lower in depressives than in controls. However, this difference could be related to an increase in plasma MHPG levels with age found in controls (r = 0.601, d.f. = 102, p less than 0.01) but not in depressives (r = 0.013, d.f. = 102, NS). Men had significantly higher levels than women in both groups. There was no significant difference in plasma MHPG levels among any DSM-III-R diagnostic subgroups of depressives or between patients who were suppressors on the dexamethasone suppression test and those who were nonsuppressors. Significant correlations were found between AMDP Depression Rating Scale item and total scores and levels of plasma MHPG. Age, sex and clinical symptoms appeared to be main sources of variance in studying depressed patients and comparing them with normal controls.
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This paper presents a method for deriving shallow to intermediate (1m to 50m) coastal bathymetry from space-borne multispectral data taking advantage of the short time-lag between sensors’ bands. The idea is to quantify local waves’... more
This paper presents a method for deriving shallow to intermediate (1m to 50m) coastal bathymetry from space-borne multispectral data taking advantage of the short time-lag between sensors’ bands. The idea is to quantify local waves’ characteristics (wavelengths and celerities) that are related to the water depths using optical data: local spectral analysis can provide the significant wavelengths and inter-band offset-tracking and the corresponding celerities (knowing the inter-band time-lag). Such an approach was firstly described in [1]. However, for an application to extended areas and using large data sets (as possible with the Sentinel-2 archive), a faster technique is required: the ability of processing large areas and data acquired at different dates is required for actual operational uses. The approach we propose here is based on Fast Fourier Transform analysis in order to simultaneously extract the wavelengths and celerities.