A new generation of environmental monitoring – the DLR DESIS spectrometer begins routine operations on the ISS
October 23, 2019 | IAC 2019
A new generation of environmental monitoring – the DLR DESIS spectrometer begins routine operations on the ISS
Artist's impression of DESIS on the ISS
The DLR Earth Sensing Imaging Spectrometer (DESIS) provides hyperspectral data to support scientific, humanitarian and commercial objectives. These data contain information that can be used to assess the situation following an environmental disaster, support farmers in the targeted management of their land and serve scientists as a basis for the development of novel atmospheric correction algorithms.
Environmental impact of agriculture on the coastal region of Sierpe, Costa Rica
The impact of sewage and agricultural runoff on the water quality of the Térraba Sierpe National Wetlands, on the Pacific coast of Costa Rica, has been evaluated using data acquired by DESIS. In addition to the RGB image (the visible range of the electromagnetic spectrum; image 1), the evaluations for suspended matter (image 2), dissolved organic material (referred to as yellow matter or Colored Dissolved Organic Matter (CDOM); image 3) and phytoplankton (image 4) are shown. Since phytoplankton is the first stage of many food chains, it is important to know how this part of the local ecosystem is impacted by agricultural fertilisation.
Costa Rica – DESIS data for water quality studies allows the impact of agriculture in the Sierpe region to be analysed
This DESIS image, acquired on 25 April 2019, shows the coastal area of Sierpe, Costa Rica. The RGB spectrum can be seen (bands 16, 59 and 98, with wavelengths of 440, 550 and 650 nanometres). With its hyperspectral images, DESIS is creating a database for water quality studies in those areas of the Térraba Sierpe National Wetlands in Costa Rica that are used for agriculture.
On 23 October 2019, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and the U.S. company Teledyne Brown Engineering (TBE) will announce the start of routine operations for the 'DLR Earth Sensing Imaging Spectrometer' (DESIS). This instrument will be operated by DLR and TBE. It is the most powerful hyperspectral Earth observation instrument in orbit and addresses a wide range of applications. Its high-resolution image data will enable the development of measures for environmental protection and support the more efficient, ecological use of agricultural land.
Hansjörg Dittus, DLR Executive Board Member for Space Research and Technology stated: "This mission is already a complete success. Monitoring changes in our environment and searching for resources are among the most important tasks for our society today."
The hyperspectral Earth observation instrument provides images with a one-of-a-kind level of quality. The sensor system collects image data in 235 closely spaced spectral bands from on board the International Space Station (ISS), at an altitude of 400 kilometres. It has a ground resolution of 30 metres and a spectral resolution of 2.55 nanometres. This significantly increases the depth of information available in Earth observation data. The first images were acquired shortly after initial setup and DESIS data has already been used to identify plastic islands and oil slicks at sea. A few months ago, the high spatial resolution of DESIS made it possible to detect rare Earth elements (REE) from space for the first time.
Scientists can also use the DESIS data to investigate changes occurring in ecosystems on Earth's land surface and in its waters. For example, they can use it to assess the health of forests. The data can also be used to evaluate agricultural land in order to make meaningful yield forecasts. In addition, the data are available quickly enough to be able to provide rescue workers with detailed on-site information in the event of a disaster.
"With DESIS, DLR now has much sought-after hyperspectral data from space at its disposal for research purposes," says overall project manager Uwe Knodt, summing up the latest successes. "We are receiving requests for data from all over the world." Many countries already have hyperspectral space missions, but there is no other project with comparable imaging quality. TBE is responsible for the commercial distribution of the data. Research institutions can obtain the data from DLR for scientific purposes. Details are available on the DLR Earth Observation Center (EOC) DESIS page under the menu item 'Data Access'.
In late August 2018, German ESA astronaut Alexander Gerst unpacked DESIS and prepared it for installation, moving it to one of the airlocks on the ISS. From there, a robotic arm was used to position it on the 'Multiple User System for Earth Sensing' (MUSES) Earth observation platform, which is attached to the exterior of the space station. The project was made possible by a unique partnership between DLR and TBE that significantly reduced mission costs, particularly for the launch. TBE also partly financed the development of the instrument. DESIS is therefore a particularly cost-effective space project, and its results are setting a new standard for hyperspectral missions.
