Thesis projects


Thesis topics in the remote sensing department

Remote sensing of vegetation
  •  Derivation of Clumping Index from MODIS BRDF data product over Estonia.    
     Supervisor Jan Pisek, Tartu Observatoorium, jan.pisek@to.ee 

Clumping index quantifies the level of foliage grouping within distinct canopy structures relative to a random distribution. Moderate Resolution Imaging Spectroradiometer (MODIS) observations provide a means to characterize the anisotropy of surface reflectance (Schaaf et al., 2002), which has been shown to contain information on the structure of vegetated surfaces (Chen et al,.2003). The objective of this study would be to test if MODIS kernel-driven BRDF model parameters can be used to compute the clumping index over Estonia.

  •  Characterizing leaf angle distribution function using digital photography. 
     Supervisor Jan Pisek, Tartu Observatoorium, jan.pisek@to.ee 

The leaf inclination angle distribution function (LIAD) describes the leaf inclination angle distribution as the probability density function.  Despite its profound importance in the calculation of various canopy parameters, most studies assume spherical LIAD because of the difficulty in estimating leaf inclination angles. Ryu et al. (2010) recently proposed a simple and reproducible method using a digital camera and an angle measurement tool of a public domain image processing software. The objective of this research is to verify the performance of the method with actual direct measurements of leaf angles for different trees in Järvselja

Remote sensing of water bodies
  •  Absorption parameters in Estonian small lakes: variation in seasonal scale.
     Supervisor Kersti Kangro, Tartu Observatory, kersti.kangro@to.ee   

The underwater light climate is affected by particles present in the water column. Boreal small lakes are generally turbid with phytoplankton, suspended matter and coloured dissolved organic matter as the main absorbers. This study focuses on the variation of absorption by those substances, whereas laboratory work is also required. According to European Water Framework Directive there are 8 lake types in Estonia. The purpose of this study is to investigate if and how the absorption parameters vary seasonally in different lake types.

  •  Deriving optical properties of water from remote sensing data
     Supervisor Krista Alikas, Tartu Observatory, krista.alikas@to.ee   

QAA and GSCM models are widely used in the remote sensing applications to derive bio-optical properties of water. The input for the models is the remote sensing reflectance and output are the absorption and scattering coefficients that describe the optical properties of the waters. These coefficients are in turn the input for higher order algorithms (e.g. chlorophyll a concentration) or are essential parameters for deriving primary production or modelling carbon cycle. Therefore their derivation from remote sensing data is with high importance. The topic involves testing the QAA and GSCM models on the bio-optical and validating the results on the Sentinel-3/OLCI products. The results obtained during this project could be further proceed in the master studies.

  •  Sentinel-3/OLCI possibilities for applying EU Water Framework Directive (2000/60/EU)
     Supervisors Krista Alikas and Kersti Kangro, Tartu Observatory, krista.alikas@to.ee   

EU Water Framework Directive (WFD) requires all EU member states to monitor and report the ecological status of the waterbodies larger than 0.5km2. To classify the ecological status of the water, the phytoplankton parameters form an essential group, from where the chlorophyll a, phytoplankton biomass, cyanobacterial biomass, the intensity and frequency of the blooms can be monitored by Sentinel-3/OLCI data. The aim of the topic is to derive and compare the WFD compatible products from in situ and Sentinel-3 data and continue the time series that have been already produced earlier.

  •  Mapping of the satellites usable for remote sensing of coastal areas and lacustrine waters
     Supervisors Martin Ligi and Krista Alikas, Tartu Observatory, martin.ligi@to.ee   

During the thesis, the students has to compile a set of conditions a satellite sensor has to meet in order to use the data for water remote sensing. Afterwards a list of missions that are currently active or planned to the near future are researched in order to find missions that meet the previously compiled criteria. The list must include possible positive and negative aspects of using the sensor under investigation. As the end result - a list of satellites will be created that is currently missing and the scientist of the field can benefit from the research.

Remote sensing of atmosphere
  • Direct influence of karbon dioxide on Estonian climate
    Supervisor Erko Jakobson, erko.jakobson@to.ee

The aim of this project is to investigate changes in temperature due to absorption of infrared radiation for different projectd carbon dioxide concentrations using atmospheric radiative trasfer model FUTBOLIN. 

  • Changes in spectra of diffuse ultraviolet radiation in Tõravere
    Supervisor Margit Aun, margit.aun@to.ee

Measurements of diffuse UV radiation started in Tõravere at summer 2016. First analyses of collected spectra will be carried out and changes in spectra due to changes in climate factors will be investigated.

  • Ultraviolet radiation satellite products and their comparison with Tõravere measurements.
    Supervisor Margit Aun, margit.aun@to.ee

The aim of this project is to give an overview of available information on UV radiation for Tõravere and compare the results with spectral measurements carried out at Tõravere.

The aim of this project is to give an overview of information about available ozone products from satellite measurements for Estonia, analyze recent ozone values in Estonia and find larger deflections from the average values (for example 2011).

Radar remote sensing