removal of systematic seasonal atmospheric signal from interferometric synthetic aperture radar ground deformation time series applying the multidimensional small baseline subset interferometric synthetic aperture radar algorithm to about 1500 envisat and radarsat 2 interferograms spanning 2003 2013 we computed time series of ground deformation over naples bay area in italy two active volcanoes vesuvius and campi flegrei are located in this area in close proximity to the densely populated city of naples for the first time and with remarkable clarity we observed decade long elevation dependent seasonal oscillations of the vertical displacement component with a peak to peak amplitude of up to 3 0 cm substantially larger than the long term deformation rate 0 6 cm yr analysis utilizing surface weather and radiosonde data linked observed oscillations with seasonal fluctuations of water vapor air pressure and temperature in the lower troposphere the modeled correction is in a good agreement with observed results the mean absolute and rms differences are 0 014 cm 0 073 cm and 0 087 cm respectively atmospherically corrected time series confirmed continuing subsidence at vesuvius previously observed by geodetic techniques

tide model accuracy in the amundsen sea antarctica from radar interferometry observations of ice shelf motion 1 this study assesses the accuracy of tide model predictions in the amundsen sea sector of west antarctica tide model accuracy in this region is poorly constrained yet tide models contribute to simulations of ocean heat transfer and to the removal of tidal signals from satellite observations of ice shelves we use two satellite based interferometric synthetic aperture radar insar methods to measure the tidal motion of the dotson ice shelf at multiple epochs a single difference technique that measures tidal displacement and a double difference technique that measures changes in tidal displacement we use these observations to evaluate predictions from three tide models tpxo7 1 cats2008a opt and fes2004 all three models perform comparably well exhibiting root mean square deviations from the observations of 9 cm single difference technique and 10 cm double difference technique care should be taken in generalizing these error statistics because 1 the dotson ice shelf experiences relatively small semidiurnal tides and 2 our observations are not sensitive to all tidal constituents an error analysis of our insar based methods indicates measurement errors of 7 and 4 cm for the single and double difference techniques respectively a model based correction for the effect of fluctuations in atmospheric pressure yields an 6 improvement in the agreement between tide model predictions and observations this study suggests that tide model accuracy in the amundsen sea is comparable to other antarctic regions where tide models are better constrained these methods can be used to evaluate tide models in other remote antarctic waters

greenland flow variability from ice sheet wide velocity mapping using radarsat synthetic aperture radar data we have mapped the flow velocity over much of the greenland ice sheet for the winters of 2000 01 and 2005 06 these maps provide a detailed view of the ice sheet flow including that of the hundreds of glaciers draining the interior the focused patterns of flow at the coast suggest a strong influence of bedrock topography differences between our two maps confirm numerous early observations of accelerated outlet glacier flow as well as revealing previously unrecognized changes the overall pattern is one of speed up accompanied by terminus retreat but there are also several instances of surge behavior and a few cases of glacier slowdown comprehensive mappings such as these at regular intervals provide an important new observational capability for understanding ice sheet variability

influence of ionospheric electron density fluctuations on satellite radar interferometry evidence is presented that auroral zone ionospheric disturbances can influence satellite radar interferometry sri obtained with the radarsat ers and jers 1 satellites fluctuations in ionospheric electron density can lead to an azimuth shift modulation in synthetic aperture radar sar imagery which can be detected using sri measurements of azimuth shift in sri can help to differentiate ionospheric from tropospheric propagation problems and to understand better the impact of the ionosphere on spaceborne sar further sri azimuth shift modulation may be useful in mapping patterns of polar auroral zone ionospheric disturbances over large distances

tributaries of west antarctic ice streams revealed by radarsat interferometry interferometric radarsat data are used to map ice motion in the source areas of four west antarctic ice streams the data reveal that tributaries coincident with subglacial valleys provide a spatially extensive transition between slow inland flow and rapid ice stream flow and that adjacent ice streams draw from shared source regions two tributaries flow into the stagnant ice stream c creating an extensive region that is thickening at an average rate of 0 49 meters per year this is one of the largest rates of thickening ever reported in antarctica

decadal volcanic deformation in the central andes volcanic zone revealed by insar time series 1 decadal trends of volcanic deformation in the central andes volcanic zone cvz are identified with interferometric synthetic aperture radar insar stacks and time series velocity maps covering an area 19 s 27 s and 66 w 69 w we combine over 750 ers and envisat interferograms from two descending and three ascending tracks these tracks cover 100 000 km 2 and span 1992 2011 our analysis extends observations at cerro blanco uturuncu and lazufre volcanic centers and uncovers two previously undocumented deformation centers cerro overo in northern chile and putana volcano in southwest bolivia cerro overo exhibits a transition from steady 0 4 cm yr deflation to 0 5 cm yr inflation over several years putana volcano underwent a short lived episode of uplift between 13 september 2009 and 31 january 2010 with a maximum uplift of 4 0 cm cerro blanco continues 1 0 cm yr deflation since 1995 uplift at lazufre began between 1997 and 2000 and has gradually accelerated to 3 5 cm yr since 2005 uturuncu volcano continues 1 0 cm yr monotonic uplift since 1992 and shows evidence for a broad moat of subsidence surrounding the uplifting region four of the nine deformation events in the cvz are not obviously associated with a particular volcanic edifice furthermore there is significant spatial and temporal variability of these deformation events within a small geographic area

atmospheric propagation heterogeneities revealed by ers 1 interferometry spaceborne synthetic aperture radar sar repeat pass interferometry is a technique based on the exploitation of the interference pattern of two sar images acquired in similar geometric conditions at two different dates this measure contains geometric atmospheric topographic and land deformation information in this paper we focus on the atmospheric information first we show theoretically that an adequate processing is sufficient to remove homogeneous atmospheric effects and that heterogeneities as tropospheric turbulences rain falls and ionospheric phenomena can be detected with sar interferometry then we interpret several observations and we present interferometric images of cumulus and turbulences due to relief sar interferometry could be a new remote sensing tool for the study of tropospheric turbulences at a high horizontal resolution 40 m

measurement of ice sheet topography using satellite radar interferometry detailed digital elevation models dems do not exist for much of the greenland and antarctic ice sheets radar altimetry is at present the primary in many cases the only source of topographic data over the ice sheets but the horizontal resolution of such data is coarse satellite radar interferometry uses the phase difference between pairs of synthetic aperture radar sar images to measure both ice sheet topography and surface displacement we have applied this technique using ers 1 sar data to make detailed i e 80 m horizontal resolution maps of surface topography in a 100 km by 300 km strip in west greenland extending northward from just above jakobshavns isbrae comparison with a 76 km long line of airborne laser altimeter data shows that we have achieved a relative accuracy of 2 5m along the profile these observations provide a detailed view of dynamically supported topography near the margin of an ice sheet in the final section we compare our estimate of topography with phase contours due to motion and confirm our earlier analysis concerning vertical ice sheet motion and complexity in ers 1 sar interferograms

using multiple radarsat insar pairs to estimate a full three dimensional solution for glacial ice movement 1 multiple sar interferograms are used to solve for the full 3 dimensional displacement of the surface of the henrietta nesmith glacier in northern ellesmere island canada the approach exploits the incidence angle flexibility of different ascending and descending beam modes and the azimuth angle diversity which occurs when different incidence angles are used at high latitudes line of sight displacements are estimated in 3 different orientations from the terrain corrected unwrapped differential phase and used to solve for the displacements in a local east north up frame uncertainty in the absolute line of sight displacements limits the absolute accuracy for vertical displacement however the relative solution coupled with knowledge of the surface slope allows spaceborne mapping of relative glacier thickening or thinning with unprecedented spatial resolution and with an accuracy of order a millimeter per day

reconstructing movement history of frozen debris lobes in northern alaska using satellite radar interferometry abstract frozen debris lobes fdls are slow moving landslides along permafrost affected slopes and consist of soil rock organic debris and areas of massive infiltration ice based on their proximity to the adjacent infrastructure their size and their flow dynamics fdls represent potential geohazards eight fdls fdl a b c d 4 5 7 11 within the dalton highway corridor in the brooks range alaska usa are the subject of this paper we examined temporal and spatial variation of fdl displacement using medium resolution synthetic aperture radar sar images and differential sar interferometry dinsar techniques european remote sensing satellite 1 2 ers 1 2 and phased array type l band synthetic aperture radar palsar acquisitions were used to generate coherent interferograms to study the displacement history of fdls for 1995 1996 and 2006 2010 we conducted an initial assessment of the capability of satellite insar to monitor fdl movement depending on data resolution season and vegetation coverage which also helped us to select useful interferograms with multi temporal interferometric displacement maps we found that seven investigated fdls fdl 7 was excluded from this sub experiment due to limited data coverage demonstrated strong spatial and seasonal variations in their movement patterns with maximum displacement rates typically occurring in october and minimum displacement rates during february or march which is consistent with previously published field study results overall through this study we 1 delineated the active fdls during the winter period using a wrapped palsar interferogram 2 analyzed the spatial variation of the deformation field within each fdl body 3 modeled the seasonal changes of fdl deformation rates through the analysis of multi temporal ers tandem interferograms and 4 integrated insar derived deformation rates with those obtained through historical imagery analysis to determine long term deformation rates results from this study fill the gaps left in the historical imagery analysis and provide important seasonal and spatial deformation data which are essential in the development of a mitigation plan as these features approach infrastructure we also summarize our research experience studying these moving features using satellite radar interferometry and believe this can be useful for future studies of similar features

changes in west antarctic ice stream velocities observation and analysis 1 we have produced a map of velocity covering much of the siple coast ice streams the map confirms earlier estimates of deceleration on whillans ice stream comparison with bed elevation data indicates that subglacial topography and the location of consolidated sediment play a strong role in determining the location of the tributaries feeding the ice streams force balance estimates based on these data indicate that the tributaries have beds nearly an order of magnitude stronger than those beneath many of the ice streams we have used a theoretical analysis to examine the controls on fast flow this analysis suggests that ice plains very wide ice streams are inherently unstable this instability may be responsible for the current deceleration on the ice plain of whillans ice stream and the shutdown of ice stream c 150 years ago thinning induced reductions in driving stress may also explain some of the observed deceleration particularly in upstream areas the active portions of ice stream c coincide well with the areas where we estimate that melt should be taking place current topography and inferences of large thickening following a shutdown suggest the upstream migration of a stagnation front that initiated at the ice plain uncertainty remains about the basal conditions on ice stream d while the basal resistance on ice stream e is large enough to ensure basal melting

glacier velocities and dynamic discharge from the ice masses of baffin island and bylot island nunavut canada speckle tracking of alos palsar fine beam data from 2007 2011 are used to determine the surface motion of major ice masses on baffin island and bylot island in the southern canadian arctic archipelago glacier velocities are low overall with peaks of 100 m a 1 and means of 20 60 m a 1 common along the main trunk of many outlet glaciers peak velocities on penny and bylot island ice caps tend to occur near the mid sections of their primary outlet glaciers while the fastest velocities on all other glaciers usually occur near their termini due to relatively large accumulation areas draining through narrow outlets estimates of ice thickness at the fronts of tidewater terminating glaciers are combined with the velocity measurements to determine a regional dynamic discharge rate of between 17 mt a 1 and 108 mt a 1 with a mid point estimate of 55 mt a 1 revising downward previous approximations these velocities can be used as inputs for glacier flow models and provide a baseline dataset against which

kinematic inversion of first arrivals of refracted waves a combined approach the inversion of first arrival times of refracted waves in media with laterally varying parameters can be performed using the refraction tomography technique tomographic inversion implemented as a linearized constrained least squares iterative scheme requires some a priori information on either refractor depth or velocity above the refractor however such information may be unavailable on the other hand in many cases a reasonable estimate of the average velocity distribution above the refractor can be obtained by a nontomographic technique such as the generalized reciprocal method grm i propose a combined approach to the inversion problem that uses the advantages of both the refraction tomography and grm techniques and which does not require additional information not contained in first arrival times the approach is based upon two assumptions which prove to be true in most situations the first is that a reasonable local estimate of refractor velocity can be obtained by tomographic inversion independently of other model parameters and the second is that the derivative of the velocity analysis function as defined by the grm gives a good local approximation of the refractor slowness the proposed combined inversion scheme can be described as a three step procedure in the first step the laterally varying refractor velocity is estimated by tomographic inversion in the second step local estimation of laterally varying average velocity above the refractor is performed by the grm on the basis of the previously estimated refractor velocity in the third step the estimated values of the average velocity are used as the corresponding constrained initial parameters for tomographic inversion

ice flow of the antarctic ice sheet we present a reference comprehensive high resolution digital mosaic of ice motion in antarctica assembled from multiple satellite interferometric synthetic aperture radar data acquired during the international polar year 2007 to 2009 the data reveal widespread patterned enhanced flow with tributary glaciers reaching hundreds to thousands of kilometers inland over the entire continent this view of ice sheet motion emphasizes the importance of basal slip dominated tributary flow over deformation dominated ice sheet flow redefines our understanding of ice sheet dynamics and has far reaching implications for the reconstruction and prediction of ice sheet evolution

atmospheric limitations to repeat track radar interferometry in its recent radar imaging mission the shuttle imaging radar satellite sir c devoted three days to repeat track interferometry we have analyzed the data from a test site in the mojave desert of california although good topography 10 m on 21 m postings was obtained most of the error was caused by turbulent water vapor in the lower atmosphere spatial structure of 6 km and all smaller sizes was observed the rms one way time delay was found to be 0 24 cm essentially identical results were obtained at two wavelengths 24 and 5 7 cm

anatomy of landslides along the dead sea transform fault system in nw jordan abstract in the mountainous region north of amman jordan cenomanian calcareous rocks are being monitored constantly for their mass wasting processes which occasionally cause severe damage to the amman irbid highway satellite remote sensing data landsat tm aster and srtm and ground measurements are applied to investigate the anatomy of landslides along the dead sea transform fault system dstfs a prominent strike slip fault the joints and faults pertinent to the dstfs match the architectural elements identified in landslides of different size this similarity attests to a close genetic relation between the tectonic setting of one of the most prominent fault zones on the earth and modern geomorphologic processes six indicators stand out in particular 1 the fractures developing in n s and splay faults represent the n s lateral movement of the dstfs they governed the position of the landslides 2 cracks and faults aligned in ne sw to nnw ssw were caused by compressional strength they were subsequently reactivated during extensional processes and used in some cases as slip planes during mass wasting 3 minor landslides with ne sw straight scarps were derived from compressional features which were turned into slip planes during the incipient stages of mass wasting they occur mainly along the slopes in small wadis or where a wide wadi narrows upstream 4 major landslides with curved instead of straight scarps and rotational slides are representative of a more advanced level of mass wasting these areas have to be marked in the maps and during land management projects as high risk area mainly and may be encountered in large wadis with steep slopes or longitudinal slopes undercut by road construction works 5 the spatial relation between minor faults and slope angle is crucial as to the vulnerability of the areas in terms of mass wasting 6 springs lined up along faults cause serious problems to engineering geology in that they step up the behavior of marly interbeds to accelerate sliding during mass wasting the most vulnerable areas prone to slope instabilities are those with compressional tectonics followed by extensional movements with fault bound springs and smectite bearing marly layers interbedded with pure massive limestones the semi arid to arid climate with periodic rainfalls combined with subsurface water circulation along the joints and faults can trigger mass wasting

constructing accurate maps of atmospheric water vapor by combining interferometric synthetic aperture radar and gnss observations over the past 20years repeat pass spaceborne interferometric synthetic aperture radar insar has been widely used as a geodetic technique to generate maps of the earth s topography and to measure the earth s surface deformation in this paper we present a new approach to exploit microwave data from insar particularly persistent scatterer insar psi and global navigation satellite systems gnss to derive maps of the absolute water vapor content in the earth s atmosphere atmospheric water vapor results in a phase shift in the insar interferogram which if successfully separated from other phase components provides valuable information about its distribution psi produces precipitable water vapor pwv difference maps of a high spatial density which can be inverted using the least squares method to retrieve pwv maps at each sar acquisition time these maps do not contain the absolute total pwv along the signal path but only a part of it the components eliminated by forming interferograms or phase filtering during psi data processing are reconstructed using gnss phase observations the approach is applied to build maps of absolute pwv by combining data from insar and gnss over the region of upper rhine graben in germany and france for validation we compared the derived pwv maps with pwv maps measured by the optical sensor medium resolution imaging spectrometer the results show strong spatial correlation with values of uncertainty of less than 1 5mm continuous grids of pwv are then produced by applying the kriging geostatistical interpolation technique that exploits the spatial correlations between the pwv observations

coseismic deformation of the 2002 denali fault earthquake contributions from synthetic aperture radar range offsets 1 we investigate coseismic deformation from the 2002 denali fault earthquake using synthetic aperture radar sar range offsets through a cross correlation technique we form a range offset map from two radar amplitude images a profile across the fault at the trans alaska pipeline shows right lateral strike slip and displacement values that agree with predictions from a gps based slip model to within the uncertainty of the range offset data using a fixed strike slip dip slip ratio taken from geologic measurements we derive a lateral slip estimate from the range offsets this slip estimate shows that the largest geologic offset measurement in a region most accurately represents the full slip value we then invert a combination of the range offsets gps data and geologic surface offset data to solve for the slip distribution on a three dimensional fault model in an elastic half space the combined model displays highly variable slip with values generally increasing from west to east along the denali fault as well as four major patches of high slip on that fault as expected the combined model is nearly identical to the gps based model outside the sar coverage area within the coverage area however the combined model has better constraints and predicts slip values much closer to the geologic measurements the offset map displays asymmetrical displacements across the fault we show that a combination of a bending fault variable slip and the sar line of sight geometry can explain this asymmetry we also discuss how fault geometry influences slip and moment release along the rupture

ice sheet velocity mapping a combined interferometric and speckle tracking approach the first and second radarsat antarctic mapping missions amm 1 and 2 have now acquired interferometric synthetic aperture radar sar overmuch of the ice sheet the radarsat 24 day repeat cycle is nearly ideal for measuring slow ice motion e g 1 but application of sar interferometry is limited in faster moving areas with a 1day repeat period ers 1 2 tandem sar data are much better matched to fast motion but are not always available fortunately several authors have demonstrated the ability to measure velocity in fast moving areas by tracking sar speckle from image to image which works well even in the absence of visible features while these estimates have intrinsically lower resolution and poorer accuracy than direct phase measurements they serve well in areas where there are no data suitable for conventional interferometry this paper describes algorithms i have developed for merging interferometric and speckle tracking data from multiple swaths to form a single seamless mosaic of velocity at each point in the mosaic all the available data are combined to produce estimates of the velocity and the associated error this technique is demonstrated using radarsat data collected over lambert glacier antarctica during amm 1 and 2

correcting distortion of polarimetric sar data induced by ionospheric scintillation a correction methodology for distortions induced by ionospheric scintillation on fully polarimetric synthetic aperture radar sar data is proposed the correction is based on deriving the phase distortion induced by the ionosphere from faraday rotation estimates the estimated phase distortion is then used for correction in order to compensate the phase and time doppler history distortions the correction has to be performed at the slant range of the ionospheric layer i e on partially focused single look complex data accordingly the performance of the proposed correction methodology depends among other factors on knowledge of the altitude of the effective ionospheric layer assuming the thin ionospheric layer model its estimation from the sar data itself is therefore also addressed the methodology was applied and validated on simulated p band data for various ionospheric conditions and on real l band data acquired by the advanced land observation satellite phased array l band sar palsar

ionospheric correction of insar data for accurate ice velocity measurement at polar regions abstract interferometric synthetic aperture radar insar has become an essential tool for measuring ice sheet velocity in the polar regions at low radar frequencies e g l band 1 2 ghz but also at higher frequency e g c band 5 6 ghz the ionosphere has been documented to be an important source of noise in these data in this paper we employ a split spectrum technique and investigate its performance for correcting ionospheric effects in insar based ice velocity measurements in greenland and antarctica three case studies using alos palsar data are used to assess the performance of the split spectrum technique for ionosphere correction over a range of environmental parameters we employ several approaches to evaluate the results including visual inspection profile analysis comparison of experimental and theoretic errors comparison with reference data from other sources generation of double difference interferograms and analysis of time series of multi temporal data our experiments show that ionospheric distortions are observed regularly and in our analyzed greenland dataset and antarctic dataset the ionospheric noise reaches 14 m yr and 10 m yr respectively which exceeds the signal associated with ice motion our analysis using several different approaches demonstrates that the split spectrum technique provides an effective correction the split spectrum technique is also found to be superior to currently used approaches such as baseline fitting and multi temporal averaging the noise level is reduced by a factor of 70 in greenland test areas and 90 in antarctic test areas

constraining ice mass loss from jakobshavn isbrae greenland using insar measured crustal uplift summary jakobshavn isbrae in west greenland has been undergoing dramatic thinning since 1997 applying the interferometric synthetic aperture radar insar technique to radarsat 1 sar data we measure crustal uplift near jakobshavn isbrae caused by recent ice mass loss the crustal uplift is predominantly at long spatial wavelengths larger than 10 km and thus is difficult to separate from insar orbit errors we reduce the effects of orbit errors by removing long wavelength deformation signals using conventional insar baseline fitting methods we find good agreement between the remaining short scale insar estimated deformation rates during 2004 2008 and the corresponding short scale components of a deformation model that is based on changes in ice elevation measured by nasa s airborne topographic mapper atm we are also able to use the insar measured deformation to invert for the spatial pattern of ice thinning overall our results suggest that despite the inherent difficulties of working with a signal that has significant large scale components insar measured crustal deformation can be used to study the ice mass loss of a rapidly thinning glacier and its surrounding catchment providing both a constraint on any existing model of ice mass loss and a data source that can be used to invert for ice mass loss these new applications of insar can help to better understand a glacier s rapid response to a warming climate