A Modification to the Goldstein RadarInterferogram Filter

We present a modification to the adaptive Goldstein radar interferogram filter which improves the quality of interferometry products. The proposed approach makes the Goldstein filter parameter alpha dependent on coherence, suchthat incoherent areas are filtered more than coherent areas. This modification minimizes loss of signal while still reducing the level of noise

The Sentinel-1 constellation for InSAR applications: Experiences from the InSARAP project

The two-satellite Copernicus Sentinel-1 (S1) constellation became operational in Sep 2016, with the successful in-orbit commissioning of the S1B unit. During, the commissioning phase and early operational phase it has been confirmed that the interferometric performance of the constellation is excellent, with no observed phase anomalies. In this work, we show an analysis of selected performance parameters for the S1 constellation, as well as initial results based on the available data from the first months of operations

How notifications affect engagement with a behaviour change app: Results from a micro-randomised trial

Background: Drink Less is a behavior change app to help higher-risk drinkers in the United Kingdom reduce their alcohol consumption. The app includes a daily notification asking users to “Please complete your drinks and mood diary,” yet we did not understand the causal effect of the notification on engagement nor how to improve this component of Drink Less. We developed a new bank of 30 new messages to increase users’ reflective motivation to engage with Drink Less. This study aimed to determine how standard and new notifications affect engagement. Objective: Our objective was to estimate the causal effect of the notification on near-term engagement, to explore whether this effect changed over time, and to create an evidence base to further inform the optimization of the notification policy. Methods: We conducted a micro-randomized trial (MRT) with 2 additional parallel arms. Inclusion criteria were Drink Less users who consented to participate in the trial, self-reported a baseline Alcohol Use Disorders Identification Test score of ≥8, resided in the United Kingdom, were aged ≥18 years, and reported interest in drinking less alcohol. Our MRT randomized 350 new users to test whether receiving a notification, compared with receiving no notification, increased the probability of opening the app in the subsequent hour, over the first 30 days since downloading Drink Less. Each day at 8 PM, users were randomized with a 30% probability of receiving the standard message, a 30% probability of receiving a new message, or a 40% probability of receiving no message. We additionally explored time to disengagement, with the allocation of 60% of eligible users randomized to the MRT (n=350) and 40% of eligible users randomized in equal number to the 2 parallel arms, either receiving the no notification policy (n=98) or the standard notification policy (n=121). Ancillary analyses explored effect moderation by recent states of habituation and engagement. Results: Receiving a notification, compared with not receiving a notification, increased the probability of opening the app in the next hour by 3.5-fold (95% CI 2.91-4.25). Both types of messages were similarly effective. The effect of the notification did not change significantly over time. A user being in a state of already engaged lowered the new notification effect by 0.80 (95% CI 0.55-1.16), although not significantly. Across the 3 arms, time to disengagement was not significantly different. Conclusions: We found a strong near-term effect of engagement on the notification, but no overall difference in time to disengagement between users receiving the standard fixed notification, no notification at all, or the random sequence of notifications within the MRT. The strong near-term effect of the notification presents an opportunity to target notifications to increase “in-the-moment” engagement. Further optimization is required to improve the long-term engagement. International Registered Report Identifier (IRRID): RR2-10.2196/1869

Zakres interpretowalności osiadań terenu za pomocą satelitarnej interferometrii radarowej (InSAR)

W ramach pierwszego etapu prac badawczych związanych z projektem ESA AO-3 127, dotyczącym interferometrycznych badań osiadań terenu nad wyrobiskami podziemnymi GZW, użyto 13 obrazów SAR otrzymanych z satelitów ERS-1 i ERS-2, na podstawie których wygenerowano łącznie 29 interferogramów. Dane te obejmują cztery części obszaru GZW w różnych okresach wegetacyjnych. Na podstawie analiz interferogramów i obrazów koherencji oraz ich interpretacji w oparciu o dane naziemne dokonano oceny interpretowalności danych ERS InSAR dla obszaru GZW. W artykule przedstawiono analizę jakości wybranej części opracowanych danych. Oszacowano wpływ poszczególnych czynników tak zewnętrznych (pogoda, klimat, charakter zagospodarowania powierzchni) jak i wewnętrznych systemu obróbki interferometrycznej na jakość otrzymanych wyników. Na konkretnym przykładzie przedstawiono sposoby wykorzystania danych InSAR w zakresie wykrywania osiadań

Recent tectonic activity of the Tatra Mts and Podhale (Poland) studied by InSAR and PSInSAR

The paper presents some preliminary results of PSInSAR (persistent scatterers SAR interferometry) processing of the Tatra Mts. and Podhale area in southern Poland. The research is carried out within the framework of a GEO-IN-SAR project aimed to study the recent tectonic activity of selected locations in Poland. As the input for PSInSAR processing 51 ERS-1/2 SAR scenes has been used by obtaining 50 interferograms covering the period from 1992 to 2000. The resulted few hundred PS (Persistent Scatterers) points show relative 1 mm/year uplift of the Zakopane area in respect to Nowy Targ. However, the preliminary interpretation along the transect Zakopane–Nowy Targ shows more complex pattern suggesting recent activity of some faults

The integration of optical and InSAR data for land subsidence monitoring and its impact on environment of the Upper Silesian Coal Basin

ABSTRACT: It was demonstrated in many articles that interferometric satellite data (InSAR) from ERS-1/2 SAR sensor give the products from which a Digital Terrain Model can be extracted. A three-pass interferometry (DiffSAR) is a strong and crucial remote sensing technique to monitor of terrain movements like land subsidence. The practical results of InSAR technique application for land subsidence monitoring for the Upper Silesian Coal Basin, a densely urbanised, heavily industrialised area were demonstrated in many papers of second author. Mining subsidence causes damage to buildings and other structures, changes surface drainage patterns and can be associated to deep fracturing of the ground. Knowledge of the spatial distribution of the endangered area may help in landuse planning and compensation strategies. The main aim of the work presented in the paper was to demonstrate the synergism of optical and SAR data for environmental monitoring, precisely for land subsidence monitoring caused by coal mining activity and its impact on environment. The space maps in the form of color compositions were elaborated based on Landsat 5 optical data. To monitor the impact of coal mining activity on environment the maps showing land movements (subsidence) were elaborated from ERS SAR SLC data using Atlantis InSAR Workstation. Next, two remote sensing technologies (interferogram and multitemporal composition from ERS also with multispectral compositions from Landsat) were fused for improvement of the interpretation of land cover in the regions of subsidence. This kind of multisource spacemaps can be useful not only for environmental monitoring "ex post" but also for future urban and regional planning purposes

Application of sar interferometry to the assessment of landsliding activity on the edge of The Nowy Sącz Basin

W artykule przedstawiono wyniki badań nad możliwościami zastosowania satelitarnej interferometrii radarowej w kontekście osuwisk polskiej części Karpat. Poligonem badawczym są zbocza występujące w północno-zachodnim obrzeżeniu Kotliny Sądeckiej gdzie występują osuwiska. Na obszarze Karpat metoda InSAR boryka się z problemami związanymi z dużymi deniwelacjami terenu, dużym pokryciem szatą roślinną i długo utrzymującą się pokrywą śnieżną. Dzięki implementacji metody PSInSAR powstałej na Uniwersytecie w Delft, uzyskano punkty PS z serii 51 rejestracji ERS-1/2 SAR. Łącznie uzyskano 145 stabilnych rozpraszaczy z których część wykazuje deformacje związane z osuwiskami. Dane te mogą zostać wykorzystane w kartowaniu osuwisk i w określaniu aktywności zboczy. Dla obszaru badań przeprowadzono analizę dynamiki osuwisk. Przykładowe osuwisko w Podegrodziu charakteryzuje się dynamiką osiągającą 72.9 mm/rok. Uzyskane wyniki określone zostały jako satysfakcjonujące i pozwalające patrzeć z optymizmem w przyszłość badań nad dalszym rozwojem metodyki PSInSAR do badań osuwisk w Polsce.The paper presents preliminary results of research on a possibility of applying SAR interferometry to the assessment of landslides in the Polish part of the Carpathians. For the purpose of this study, the NW edge of Nowy Sącz basin has been chosen. Applications of InSAR (SAR Interferometry) to the Carpathians is difficult due to the rough topography, vegetation, and prolonged snow cover. Such problems were overcome by applying PSInSAR (Persistent Scatterers SAR Interferometry) which utilizes long time series of SAR data. In the present case, a set of Persistent Scatterers was collected by processing a stack of 55 ERS-1/2 SAR scenes using Delft University of Technology’s implementation of the PSI method. Some 145 highly coherent PS points were obtained; they provide evidence of a landsliding movement. The most reliable points were then used in a quantitative cartographic study to assess the movement along the slope. Analysis of landslide dynamics was carried out for the study area whereby a landslide in Podegrodzie, progressing at a rate of 72.9 mm/year was documented. The preliminary results are very promising for the development of PSInSAR methodology to study landslides in Poland

Use of SAR interferometry for the study of landslides in Polish Carpathians

The paper presents preliminary results of possible application of SAR interferometry in the studies of landslides. Two areas have been selected: Wieliczka and Nowy Sącz. The application of InSAR (SAR Interferometry) in the Carpathians is difficult due to rough topography, vegetation and long season with the snow cover. Such problems may be overridden by applying PSInSAR (Persistent Scatterers SAR Interferometry) which utilizes long time series of the SAR data. PSInSAR was used for both areas. Obtained sets of PS points show evidence of the landslide movement. The most reliable points were then used in quantitative cartographic study to qualify activity of slopes. Analysis of landslide dynamics was performed for the area of Wieliczka where, for instance, a landslide velocity movement in Lednica Górna reaches 74.8 mm/yr. The preliminary results are very promising for the development of PSInSAR methodology in the study of landslides in Poland

Airborne laser scanning data in landslide studies at the example of the Zbyszyce landslide (Outer Carpathians)

The study is focused on an active landslide located on the right bank of the Dunajec Valley in Zbyszyce. The potentials of application of the data derived from airborne laser scanning (ALS) in the context of an inventory of landslides has been presented. The ALS data used in this study covers the area of 40 km2 on the eastern side of Lake Roznowskie in the Carpathians. Scanning data were acquired on April 1, 2010, and the resulting cloud of points was used as the basis to generate the DTM with a resolution of 0,5 m. Geological interpretation of the data was conducted on the example of the largest and complex landslides in the study area located in the village Zbyszyce. Using different visualization techniques were able to determine extent of landslides and its internal morphological elements. Attempts to determine the degree of activity in different zones of the landslide have been also undertaken. Very good results were obtained in wooded areas, complementing the state of knowledge about this landslide