ALBERT

Description: This work presents an analysis of dynamic displacements observed on GNSS stations in the Aegean region, induced by the two earthquakes with magnitude 7.8 and 7.5, in Southern Turkey on 06/02/2023. For this reason, GNSS data of 1Hz observation rate from continuously operating stations located across the Aegean Sea and the mainland of Greece was processed using Precise Point Positioning method. Position time-series were analyzed to estimate the amplitude of the displacement, the direction in which the maximum displacement is observed and the time of occurrence. Furthermore, emphasis is given on comparing the characteristics of the displacements observed between the two events and examine a possible correlation with the corresponding faults’ geometry for each separate event. An additional evaluation of the kinematic behavior of permanent GNSS stations located in proximity of the Hellenic subduction zone with the African plate, the latter sharing a tectonic boundary with both the Arabian and Anatolian plates was conducted. The results of this work discuss the effects that strong earthquakes can have at distances over 1000 km and along active tectonic boundaries, implying the larger-scale impact of such geohazards.

Description: Rapid advancements in space geodetic technology have generated an abundance of geodetic-quality datasets from various techniques Α combination of multi-technique datasets can provide a novel insight on tropospheric error mitigation and atmospheric studies. This study explores the use of augmenting GNSS and DORIS datasets for estimating tropospheric delay. DORIS is widely utilized for various geodetic applications such as precise orbit determination of satellites and space missions, geodetic reference frame definition, modeling of the earth's gravity field, sea level and ocean circulation studies. While current DORIS analysis tools provide advanced features and robust data processing capabilities, they are not open source and are difficult to obtain. The study describes the design of an open-source, in-house DORIS processing software as well as an innovative approach to tropospheric path delay estimation in which datasets from GNSS and DORIS are combined and processed to produce final sets of ZPD and coordinates estimates. The software utilizes the DORIS RINEX v3.0 data file format, which enables the full exploitation of the system's modernized features, including multi-channel pseudorange and carrier-phase observations. In accordance with IDS and IERS recommendations and standards, the software is designed to produce high-quality results. Special care is taken to handle system-specific noise characteristics and observation weighting. Upon completion, the software will constitute a free and open-source solution for the DORIS community, offering a valuable resource for the advancement of geodetic research.