PhD Project in the research field of Satellite Altimetry
Tallinn University of Technology (TalTech)
Tallinn University of Technology (TalTech) is the flagship of Estonian engineering and technology education. TalTech is Estonia’s most innovative university, as confirmed by the Estonian universities’ reputation survey. TalTech is especially known for its innovation in the field of digital technologies and engineering. The amount of full-time students exceeds 11,000 (incl. 1600 students international degree students) from 94 different countries and over 1,800 employees from 51 different countries.
Founded in 1918, TalTech is located in Tallinn, the capital of Estonia. TalTech is ranked 601-650 in the QS World University Rankings with subfields such as Engineering and Technology, and Business Administration ranked 451-500. At TalTech, creative technologies are developed, such as self-driving cars or the TTÜ100 satellite. We offer an opportunity to study in a modern digital campus where many of the most recent technologies are tested and implemented on the daily basis.
For more details see https://www.ttu.ee/?id=94518
Ocean Sciences (OS)
Doctoral thesis topic: Development of improved Satellite Altimetry Retracker specifically for the Baltic Sea
Background: Modern satellite altimetry (SA) missions (Sentinel-3, Cryosat-2, Jason-2,3 etc.) have the potential for determining accurate sea surface heights (SSH). It is known however that SA data products over coastal areas contain certain limitations, e.g. due to under-examined wet tropospheric correction, land and calm water interference, heterogeneous atmospheric forcings, etc. This project focuses on improving the range estimation by applying specialized developed retracking schemes. Retracking is necessary for the methodology employed in processing the range. Retracking can be study area dependant. For instance, reflected radar pulses are usually recorded against time in waveforms. Over the open ocean, waveforms normally conform well to the Brown model by the least squares estimation. Fitting to this waveform usually yields the required measurements of range (from which SSH is deduced). It has been found that about 5-10 km off the coastline a significant portion of the radar waveforms depart from the Brown model (increasing toward the coast). The factors that influence this anomaly includes land contamination, ‘bright targets’ in the footprint (patches of very calm water in sheltered areas) etc. At coast it is influenced by archipelagos, areas of calm waters and many other processes (e.g upwelling jets, filaments etc.) that may influence the range that is calculated. Thus the necessity for a retracking methodology designed for the coastal area is required in order to obtain accurate SA-SSH estimates.
Tasks: The PhD candidate shall develop an improved Satellite Altimetry (SA) retracker designed specifically for the Baltic Sea area. This development requires examining the SSH from various satellite altimetry (SA) missions (Sentinel-3, Cryosat-2, Jason-2,3 etc.) using the raw measurements along with different retracking methods. Detailed examination of the altimeter radar echoes and corrections applied shall be performed. Validation of SA derived SSH with in-situ data (tide gauges, airborne laser scanner, GNSS) is expected using statistical techniques of the various data sets. From these results a specific algorithm shall be designed to fit radar signals from different satellite missions and under different sea state (e.g. waves, upwellings, fronts etc.). The candidate is expected to assist in project related field campaigns. This study is part of the Estonian Research Council supported research for developing an iterative approach for near-coast marine geoid modelling by using re-tracked satellite altimetry, in-situ and modelled data.
The applicants should fulfil the following requirements:
University degree (M.Sc.) in geodesy, geomatics oceanography and other earth sciences. Consideration will also be given to applicants whose previous degrees are in appropriate related disciplines, such as Mathematics, Physics or Software Engineering.
Skills in data analysis, mathematics and statistical analyses (to be trained) and model development (to be trained)
Ability for independent research as part of a team, interest in the presentation and publication of scientific results.
Advanced computer literacy and programming skills.
Good command of the English language (speaking and writing).
The PhD candidate is expected to be at full time position for a duration of 4 years. The candidate is obligated to participate and fulfil the requirements of Tallinn University of Technology PhD programme. Additional funds will be provided (and whence applicable the associated funding can be applied for) for research trainings, conferences and international mobility/stays abroad with durations of up to 6 months.
For inquiries regarding the position and more information consult the project website http://gece.ttu.ee/~geoid/ and e-mail addresses therein.
The documents required for application are the following:
1) an application
2) a curriculum vitae incl. data on education as well as research and development activities;
3) an original and a copy of an education certificate and the diploma supplement;
In case an education certificate acquired in a foreign country, TalTech has the right to request an assessment and recommendation from the Estonian ENIC/NARIC Centre or submit the relevant information request to verify the data
4) a copy of the passport, an identity card or a residence permit card;
5) a motivation letter in English.
Application documents can be submitted through the admission system https://estonia.dreamapply.com/
For the details of application procedure please consult https://www.ttu.ee/studying/phd-studies/admission-4/