Understory vegetation is the most diverse and least understood component of forests worldwide. Understory communities are important as they act as drivers of overstory succession and nutrient cycling. Satellite remote sensing is the only technology currently able to provide consistent data over large areas and longer period of time. Multi-angle remote sensing enables us now to describe surface properties by means that are not possible using mono-angle data. A novel methodology working with multi-angle remote sensing data will be implemented to retrieve reflectance and track seasonal changes of forest understory structure globally. Our previously compiled unique collection of understory measurements from diverse types of forests both in Estonia and around the world would provide an excellent platform to study the dynamics and validate our results. Inclusion of understory variability in ecological models will improve prediction and forecast horizons of vegetation dynamics globally.
Start date: 1.1.2017End date: 31.12.2020
Total amount: 180 000 € (Estonian Research Council)
Estonian Research Information System webpage
In this project we study galaxies and groups of galaxies in different large-scale environments. Our goal is to find out how the large-scale environment of the cosmic web affects the formation and evolution of galaxies. The large-scale structure of the Universe can be seen as the cosmic web, where the dense superclusters and filaments surround the large underdense regions, voids. Superclusters are the largest galaxy systems known in the Universe and on large scales superclusters are the densest regions in the Universe where galaxy formation theories can be tested. We will use the best available spectroscopic galaxy surveys to study the large-scale structure of the Universe and the galaxies within. We expect to find out how the galaxy populations in superclusters differ from those in voids, and what are the characteristics of the largest supercluster systems as galaxy environments.
Total amount: 182 400 € (Estonian Research Council)
Estonian Research Information System webpage
Estonian coastal waters are shallow, with soft bottom and significantly influenced by rivers. This means that the optical properties of the water are strongly affected by suspended matter, transported to the sea by rivers or re-suspended due to strong winds. Pärnu River is the biggest in Estonia. It flows into Pärnu Bay. Although it is not well studied, it can be said the suspension characteristics and origin vary in great extent. Dynamics of the sediments at the coastal areas can have an important effect on the local ecosystems and managing ship routes. Therefore further studies are needed. In co-operation with CEFREM (Centre de Formation et de Recherche sur les Environnements Méditerranéens) laboratory (France), fieldworks during spring and summer period will be organised in the same way as was first conducted at River Rhone ROFI (Region of freshwater influence). To receive additional optical data, instruments from Estonian partners will be used. To analyse the peculiarity of sediment cloud in Pärnu River ROFI, caused by climate and salinity (brackish water of the Baltic Sea) effects, the gathered info is compared with two French river's mouths in subtropic climate: torrential mountain river of Têt and one of the biggest rivers in Europe - the Rhone river, that both are flowing into the Mediterranean Sea in southern France. The host institute has previous experience with these rivers and fieldwork will be continued on these two rivers also during this project. In addition to fieldwork data, satellite results from Sentinel-2 and Landsat-8 will be used to calculate concentrations of suspended matter and colored dissolved organic carbon; to differ mineral suspension from organic; and to test new approaches to identify particle size, geometry, concentrations and origin.
Start date: 1.3.2018End date: 28.2.2021
Total amount: 125 370 € (Estonian Research Council)
The general research is optical navigation (sometimes called visual-inertial odometry, although optical navigation is a better term), which means the use of optical observations, i.e. camera images, in conjunction with other sensor data and either structure from motion or simulataneous locazization and mapping algorithms to autonomously infer the movement of a observer. The methods also provide a 3D reconstruction of the environment or a target, which can be used to create a topographic angle sensitive multispectral map, providing information about target chemical and physical composition. The specific use case for this mission is asteroid or comet fly-by missions (the project is closely integrated to a planned F class ESA comet interceptor mission, currently in Phase 2) with possible technology transfer to unmanned ground vehicle or drone operations.
Start date: 1.9.2019End date: 31.8.2021
Total amount: 86 117 € (Estonian Research Council)
EU Copernicus programme provides an enhanced capabilities of Earth observation due to new optical instruments on board of Sentinels (2A, 2B and 3), allowing to focus besides large lakes also to smaller lakes. EO has been proposed as an operational means to support the monitoring of parameters required by WFD (transparency, extent and intensity of cyanobacterial (CY) blooms, the amount of phytoplankton, CY and Chl a). Our previous work about L. Peipsi has proved it is possible to monitor these parameters with sufficient accuracy by EO methods, thus we plan further development of suitable algorithms for estimating annual and seasonal variations of these parameters in lakes, which belong to different WFD types. This project aims to extend the knowledge of the spatio-temporal variability of the optical properties and in-water constituents of boreal lakes. New products will be validated through a number of field studies and outcome is used for fulfilling WFD reporting needs for lakes.
Start date: 1.1.2018End date: 31.12.2021
Total amount: 368 180 € (Estonian Research Council)
Forests are currently experiencing an unprecedented period of progressively drier growing conditions around the globe, which is threatening many of the functions forest ecosystems need to fulfill for human society. Yet, our understanding of how long and how severe a drought needs to be in order to provoke substantial decline in net primary productivity or even lead to ultimate death of trees is still poorly understood. Here, we combine remotely sensed data (MODIS EURO) with observations on tree mortality (ICP level I forest observations) throughout the last two decades (2000-2019). The project aims at unraveling the complex relationship between drought duration/intensity and forest growth and mortality for entire Europe at 1x1Km resolution. For this, we will apply the random forest algorithm as well as Cox proportional hazard models, both permitting us to additionally test for the effects of important co-variables (e.g. tree age, pre-drought climate, etc.).
Start date: 1.11.2020End date: 31.10.2022
Total amount: 97 060 € (Estonian Research Council)
One of the main unsolved fundamental puzzles in astrophysics is the question how galaxies form and evolve in the Universe. One of the challenges is to understand whether galaxy evolution is driven by nature or nurture, i.e. what is the relative importance of the cosmic web environment to the evolution of galaxies? In this project, we will develop new mathematical methods in order to study the co-evolution of galaxies and cosmic web. The developed methods will be applied to the currently available observational and simulated datasets, but clear focus is also set to the new upcoming large galaxy surveys. One of the next generation large galaxy surveys is the European Southern Observatory (ESO) flagship large survey 4MOST, which observes Galactic and extra-Galactic objects simultaneously. Among many fascinating topics, 4MOST allows to study the galaxy evolution in the cosmic web environment with unprecedented details and from angles never possible before. We will take full advange of this!
Start date: 1.1.2021End date: 31.12.2025
Total amount: 237 875 € (Estonian Research Council)
Superclusters of galaxies are the largest structures in the Universe with large concentration of matter in them. While the physics of clusters of galaxies has been very well studied, the same is not true in the case of superclusters. Voids, which are large empty regions in the Universe, are one of the best candidates to explain the formation of superclusters as the dark energy is higher in voids than the matter and expands the space faster inside the voids. In other words, the matter accumulates along the edges of voids to form the superclusters. We will calculate the cross-correlation between voids and superclusters and compare it with the simulations. We will also use simulations to answer the long debated question on the definition of supercluster in galaxy redshift surveys using velocity flow field of galaxies. The Giant Radio Galaxies (GRGs) are the largest structure of the radio Universe. We will measure the effects of surrounding environment on the large radio jets of GRGs.
Start date: 1.5.2021End date: 30.04.2023
Total amount: 102 294 € (Estonian Research Council)