Earth observation methods

DTU Space has competencies in systems, methods and their application in connection with Earth observation. This means that methods and techniques are developed using in-depth knowledge of the system and its requirements. This work is of great importance to the European Union’s GMES initiative (Global Monitoring of the Environment and Security), for example, whose objective is to carry out satellite-based monitoring of several factors relating to climate, the environment and security.

One of the focus areas for DTU Space and for Danish tele-measuring activities in general, is monitoring the crysosphere, especially in and around Greenland. The monitoring of the cryosphere is extremely important in order to gain a deeper understanding of climate change and its future repercussions for mankind.

DTU Space develops and applies methods for identifying glacier movement using Interferometric SAR (Synthetic Aperture Radar), also called InSAR, as well as other techniques in cases where InSAR is ineffective. The purpose of such research is to develop more precise and reliable methods for determining the speed field. DTU Space is currently working under an ESA contract to develop a special interferometric data processing system for processing InSAR data from large areas such as Greenland’s ice cap. 

An interesting new technique in this connection is polarimetric interferometry, which DTU Space has used to gather airborne SAR data from the ice cap to more accurately map the ice surface. This technique can result in a better characterisation of the ice and of how far the radar signal penetrates the ice. The degree of penetration is vital when using radar to determine the surface height and changes to this, as it is otherwise impossible to distinguish between actual changes and changes in penetration depth.

DTU Space is involved in developing methods for monitoring sea ice in the Arctic and Antarctic for use in both navigation and climate models. The Institute has developed a unique data processing web system for use in research projects and by operational users.

DTU Space develops methods for processing and interpreting polarimetric SAR data, in particular methods for detecting and mapping changes. The Institute is also engaged in change detection, crop classification and sea ice classification in connection with the Radarsat-2, TerraSAR and ALOS satellites. This research has made it clear that it is necessary to have a better understanding of the dispersion conditions of different objects in order to develop precise and reliable methods.