Contribution of Cryosat-2 SAR/SARin Data to Local Vertical Datum Validation and height System Unification in Turkey


Erol S., Erol B., Koç Ö., Işık M. S.

The 27th IUGG General Assembly, Montreal, Canada, 8 - 18 July 2019, pp.1

  • Publication Type: Conference Paper / Summary Text
  • City: Montreal
  • Country: Canada
  • Page Numbers: pp.1
  • Istanbul Technical University Affiliated: Yes

Abstract

Improvements in satellite altimetry made it possible to determine the sea level at the coastal areas with higher accuracy. Especially, the latest satellite altimetry missions with Synthetic Aperture Radar (SAR) and interferometric SAR (SARin) mode, such as Cryosat-2, have a higher resolution in along-track and cross-track which provides a better observation near coastal areas by reducing the gap between tracks. This improvement is of great importance to estimate the sea level heights, vertical movements, and the definition of local vertical datum (LVD). In this study, the main focus is analyzing the data of 8 tide gauge stations from Turkey National Sea Level Monitoring System (TUDES) and Cryosat-2 SAR data over 9 years to validate the regional geoid model through the surrounding coastlines of Turkey and analyze the possible contribution of Cryosat-2 data to mean sea level determination. Monthly tide gauge sea levels are obtained by applying weighted and Demerliac filters to daily data. Tide gauge and satellite altimetry observations are analyzed using the Least Squares Spectral Analysis (LSSA) method for the Mediterranean and Black Sea. The obtained results on sea level variations according to this method are used to estimate the ellipsoidal height depending on two different assumptions. From the obtained information, as the final step, the gravity potential for the regional vertical datum and its difference with the conventional value of W0 is determined to connect the LVD to the International Height Reference System (IHRS). (This study is supported by ITU research project MGA-2018-41592)