The present study deals with the determination of Mount Olympus summit (Mytikas), exploiting modern observations such as Global Navigation Satellite Systems (GNSS) and existing geodetic information. The last official Olympus height determination goes back 102 years by the Swiss surveyor M. Kurz. Since then, only unofficial measurement campaigns have taken place. There is a variety of released heights, which range from 2917 to 2919 meters. In September and October of 2022, we conducted a GNSS campaign, focusing on the area of highest Olympus peaks. Employing precise GNSS measurements (accuracy of 1–3 cm), in conjunction with height information from Greece’s National Triangulation Network (5–10 cm accuracy) and an appropriate, recent geoid model (5–6 cm accuracy), we estimate through the so-called GNSS-levelling, the height of Olympus to 2917.727 m with respect to Greece’s officially accepted mean sea level and 2918.390 m with respect to the global vertical datum. Our estimation of Olympus highest peak shows remarkable consistency at the level of 12.8 cm to that of M. Kurz in 1921.

The Hellenic Cadastre, which is expected to be fully operational by the end of 2025, represents a major modernization step in Greece’s technical and legal documentation of property rights as the successor to the country’s land registry system. It will also constitute a land administration system, since it will encompass not only property rights but also restrictions and regulations in the context of RRR. A significant technical but also legal challenge inherent to this system pertains to the resolution of deviations between surfaces calculated prior to 1990 based on older geodetic reference systems and recalculated today using the current Greek Geodetic Reference System, GGRS87. Deviations that arise from geodetic transformations between older and modern projected reference systems are compounded by limitations inherent in historical surveying techniques and in the geodetic infrastructure that was available at the time. To address this issue, we introduce the Local Area Distortion Factor (LADF), a novel metric factor designed to adjust and harmonize property areas across different geodetic systems. This real-world case study offers a practical illustration of the application of LADF, demonstrating its capacity to enhance the precision of cadastral records while preserving interpretability for both experts and non-experts. LADF can also be used to improve land adjustment processes during the implementation of urban plans, property valuation, taxation, and notary acts that are in different reference systems.

The Hellenic Cadastre, which is expected to be fully operational by the end of 2025, represents a major modernisation step in Greece's technical and legal documentation of property rights as the successor to the country's land registries system. It will also constitute a land administration system, since it will encompass not only property rights but also restrictions and regulations in the context of RRR. A significant technical but also legal challenge inherent to this system pertains to the resolution of deviations between surfaces calculated prior to 1990 based on older geodetic reference systems, and recalculated today using the current GGRS87 reference system. Deviations that arise from geodetic transformations between older and modern projected reference systems and are compounded by limitations inherent in historical surveying techniques and in the geodetic infrastructure that was available at the time. To address this issue, we introduce the Local Area Distortion Factor (LADF), a novel metric factor designed to adjust and harmonise property areas across different geodetic systems. This real-world case study offers a practical illustration of the application of LADF, demonstrating its capacity to enhance the precision of cadastral records while preserving interpretability for both experts and non-experts. LADF can also be used to improve land adjustment processes during the implementation of urban plans, property valuation, taxation and notary acts that are in different reference systems.

This case study demonstrated how modern remote sensing data can contribute to the monitoring of flooding events. The study was carried out in an area of high environmental interest, the Axios river wetlands, Greece. The spatial resolution of satellite-image-based standardised metrics was increased with the use of UAV-obtained aerial images, equipped with an RGB camera. A strong relation $(\mathrm{R}^{2}=0.85)$ was observed between the NDWI and a linear combination of RGB intensities of the aerial image, after averaging within the lower-resolution satellite-image pixels. Application of the derived model directly on a separate aerial image taken on the same day over a nearby location was highly successful in separating land from sea, in high-resolution. A more extensive evaluation is needed, with simultaneous in-situ observations, to assess the suitability of the method for flooded versus dry ground segmentation.