What is Remote Sensing?
The most common remote sensing systems measure reflected visible light, but they can also measure electromagnetic radiation that is invisible to the human eye, e.g. ultraviolet (UV), infrared (IR) or microwave radiation. The fact that satellites measure in different spectral wavelengths is utilized for obtaining information about the objects, features or properties under study.
Some meteorological satellites are located at about 36000 km above the equator, whereas other meteorological and Earth resource satellites circle Earth at about 800 km altitude. Some satellites image Earth frequently with low spatial detail, whereas others view Earth infrequently with very high spatial resolution, in some cases less than a meter. Data sets derived from satellites exist from the 1960s. Today, a large number of satellites generate data at a variety of spatial and temporal resolutions. These are useful for studying different parts of our environment, such as the atmosphere, land vegetation, oceans or ice masses.
At the Department of Physical Geography and Ecosystem Science, we work with remote sensing applications for land resources, primarily land cover and vegetation. Issues that interest us are:
- Monitoring changes in vegetation cover in different climate regions
- Extracting information about vegetation structure, such as the leaf area index (LAI)
- Extracting information about carbon uptake by vegetation, e.g. through estimation of the fraction of incoming photosynthetically active radiation absorbed by vegetation (FAPAR)
- Improving current methods for quantitative remote sensing of vegetation, e.g. handling different viewing and sun angles
- Developing methods for handling time series of remote sensing data
- Integrating remote sensing data with ecosystem models describing the development of plant stands