Analyse av Sentinel-1 data til deteksjon og varsling av kvikkleireskredet på Gjerdrum

Denne rapporten gir en oversikt over arbeidet gjort i prosjektet «Analyse av Sentinel-1 data i forkant av kvikkleireskredet på Gjerdrum». Prosjektets formål var å undersøke om backscatter data fra Sentinel-1 satellittene kan gi nyttig informasjon fra området rundt kvikkleireskredet i Gjerdrum i Desember 2020. En ønsker spesielt å finne ut om slike data i framtiden kan brukes til å detektere endringer i terrenget som har betydning for stabilitet og eventuelt kan brukes til varslingsformål.Analyse av Sentinel-1 data til deteksjon og varsling av kvikkleireskredet på GjerdrumpublishedVersio

Avalanche debris detection using satellite-borne radar and optical remote sensing

The mountainous fjord landscape around Tromsø in Northern Norway is prone to high avalanche activity during the snow season. Large avalanches pose a hazard to infrastructure, such as buildings and roads, located between the steep mountainsides and the fjords. To forecast the spatial and temporal extent of avalanche events, knowledge of past activity is critical. For this, a complete avalanche record is needed, however, difficult to achieve. We hypothesize, that the use of satellite data can assist in mapping avalanches over large areas. During and shortly after an intense avalanche cycle in the county of Troms in March 2014, we obtained 11 high-resolution Radarsat-2 Ultrafine scenes centered over large observed avalanches, together with one Landsat-8 scene and four Radarsat-2 SCN/SCW scenes with coarser resolution, covering the entire county. We detected avalanche debris-like features visually, by applying two detection algorithms that make use of the increased backscatter in avalanche debris. This backscatter increase is due to increased snow water equivalent and surface roughness. In addition to the multi-sensor approach using high- to mediumresolution satellite data, we also used a multi-temporal approach. Repeated acquisitions of satellite data from the same area enabled redetection of avalanche debris-like features by change detection methods and, thus, confirmation of their existence. In this study, we show the usability of satellite radar data in detecting avalanches over a large area with medium resolution. Since ultra-high resolution is not available in an operational context today, our hypothesis based on our results using Radarsat-2 is that the ESA Sentinel-1 satellite could provide sufficient coverage and resolution to detect medium and large sized avalanches

Satellittbasert overvåkning av vekstsesongen på Svalbard, - status 2012

Denne rapporten omhandler satellittbasert overvåkning av vekstsesongen (fenologi) på Svalbard. MODIS-NDVI satellittdata er brukt til å kartlegge, start, slutt og lengden på vekstsesongen for årene 2000 til 2012. Kombinert optisk (MODIS) og mikrobølge (ASAR) satellittdata er brukt til å kartlegge siste og første dag med snø for åren 2005 til 2012.publishedVersio

Remote sensing of avalanches in northern Norway using Synthetic Aperture Radar

We present results from using synthetic aperture radar data (SAR) to analyse three avalanches in the county of Troms in northern Norway during the late snow season 2013. During a persistent polar low pressure activity at the end of March and the beginning of April 2013, inducing high precipitation rates in combination with high wind speeds, an extensive avalanche cycle took place in that area. Several avalanches released naturally causing fatalities, road closures and community evacuations. The main goal of our study was to investigate whether high resolution SAR could be used for detecting avalanche debris in the run-out zones. For validation purposes we used, among others, a high resolution camera operated on an Unmanned Airborne Vehicle (UAV) to acquire very accurate ortho-photos of the avalanches. The UAV-maps were of unprecedented resolution (~5 cm). The result of the analysis of the high resolution Radarsat-2 image showed that avalanches could be identified visually due to the high contrast between low radar backscatter from unperturbed snow and high backscatter (caused by increased surface roughness/snow mass) of the avalanche debris in the avalanche run-out zones. In order to assess the accuracy, the avalanche delineations were compared with results from UAV photos and photographs taken during helicopter reconnaissance flights right after the events. In two of three cases, a good correspondence was found between SAR delineated avalanches and outlines derived from optical data

UAV-BORNE UWB RADAR FOR SNOWPACK SURVEYS

Source at https://hdl.handle.net/11250/2649630In this report we summarize the capabilities and technical characteristics of our UAV-borne UWB radar system, designed for conducting snow surveys. We developed an ultrawideband snow sounder that is capable of imaging snow stratigraphy with a 5 cm range resolution. The radar can be carried by an octocopter UAV in order to carry out airborne snowpack surveys. During a demonstration on Andøya, we showed that the radar was capable of resolving snow stratigraphy in wet snow conditions, as well as detecting a buried person under 1.5 m of wet snow. In this report, we present the results of the demonstration in detail. We furthermore discuss capabilities and incapabilities of our radar system and offer a list of future steps to bring it to an operational status

SENBYGG

Rapporten dokumenterer resultater fra prosjektet SENBYGG der Statens kartverk er oppdragsgiver. Prosjektet har som formål å detektere bygningsendringer (nybygg, tilbygg eller revet bygg) ved hjelp av radarsatellittene Sentinel-1 A og B. I prosjektet har vi studert flere mulige metoder for endringsdeteksjon. Radarsatellitter (SAR) har relativt god oppløsning (10m) men betydelig med støy. For å redusere støyen midler vi bilder over samme område for hvert kalenderår. Endringer detekteres ved å sammenligne tilbakespredning fra to etterfølgende år. I prosjektet har vi påvist at det er fult mulig å detektere bygningsendringer i SAR bilder basert på årlige middelbilder. Man kan også redusere tidsintervallene noe, men antall feil vil øke siden støyene i bildene da blir mer merkbar.SENBYGGpublishedVersio

Improving satellite-based monitoring of the polar regions: Identification of research and capacity gaps

We present a comprehensive review of the current status of remotely sensed and in situ sea ice, ocean, and land parameters acquired over the Arctic and Antarctic and identify current data gaps through comparison with the portfolio of products provided by Copernicus services. While we include several land parameters, the focus of our review is on the marine sector. The analysis is facilitated by the outputs of the KEPLER H2020 project. This project developed a road map for Copernicus to deliver an improved European capacity for monitoring and forecasting of the Polar Regions, including recommendations and lessons learnt, and the role citizen science can play in supporting Copernicus’ capabilities and giving users ownership in the system. In addition to summarising this information we also provide an assessment of future satellite missions (in particular the Copernicus Sentinel Expansion Missions), in terms of the potential enhancements they can provide for environmental monitoring and integration/assimilation into modelling/forecast products. We identify possible synergies between parameters obtained from different satellite missions to increase the information content and the robustness of specific data products considering the end-users requirements, in particular maritime safety. We analyse the potential of new variables and new techniques relevant for assimilation into simulations and forecasts of environmental conditions and changes in the Polar Regions at various spatial and temporal scales. This work concludes with several specific recommendations to the EU for improving the satellite-based monitoring of the Polar Regions

Improving satellite-based monitoring of the Arctic polar regions: identification of research and capacity gaps

We present a comprehensive review of the current status of remotely sensed and in situ sea ice, ocean, and land parameters acquired over the Arctic and Antarctic and identify current data gaps through comparison with the portfolio of products provided by Copernicus services. While we include several land parameters, the focus of our review is on the marine sector. The analysis is facilitated by the outputs of the KEPLER H2020 project. This project developed a road map for Copernicus to deliver an improved European capacity for monitoring and forecasting of the Polar Regions, including recommendations and lessons learnt, and the role citizen science can play in supporting Copernicus’ capabilities and giving users ownership in the system. In addition to summarising this information we also provide an assessment of future satellite missions (in particular the Copernicus Sentinel Expansion Missions), in terms of the potential enhancements they can provide for environmental monitoring and integration/assimilation into modelling/forecast products. We identify possible synergies between parameters obtained from different satellite missions to increase the information content and the robustness of specific data products considering the end-users requirements, in particular maritime safety. We analyse the potential of new variables and new techniques relevant for assimilation into simulations and forecasts of environmental conditions and changes in the Polar Regions at various spatial and temporal scales. This work concludes with several specific recommendations to the EU for improving the satellite-based monitoring of the Polar Regions

Skreddeteksjon E69 Skarvbergtunnelen. (12/2018)

publishedVersio