Scientific Legacy and Current Contributions of the Royal Institute and Observatory of the Spanish Navy: Impact on Geophysics, Geodesy, and other Scientific and Social Fields.

The Geophysics Section of the Royal Institute and Observatory of the Navy (ROA) is structured into three main services: Seismology, Geomagnetism, and Space Geodesy, in addition to an auxiliary Meteorology service and participation in maritime scientific campaigns. Since its foundation, the ROA has played a pioneering role in Spain, being a member of the Spanish Commission of Geodesy and Geophysics and collaborating with international institutions across all its fields of activity, such as ILRS, IGS, INTERMAGNET, and GEOFON, as well as organizations like NASA and ESA, among others.

The Geomagnetism Service, established in 1879, studies the Earth's magnetic field and its variations to conduct scientific research. After several relocations due to electromagnetic interference, the current geomagnetic observatory is located at Cortijo de Garrapilos (Cádiz) and has been a member of INTERMAGNET since 2006. The Seismology Service dates back to 1898, when one of the 12 seismographs of the first global seismic network, promoted by geologist John Milne, was installed at the ROA. The current infrastructure is distributed across Spain and North Africa, including a short-period network for regional seismicity in the Gulf of Cádiz and the Alboran Sea, long-period stations for global seismicity, and the international Western Mediterranean network, in which prestigious institutions such as UCM and GFZ participate. The ROA has been involved in space geodesy with artificial satellites since the early days of the space era, starting just one year after the launch of the first SPUTNIK (1958) with the Baker-Nunn camera. This technique was followed by laser ranging (SLR) in 1975, when a station capable of tracking collaborative satellites was installed. By 1980, the station was exclusively operated by ROA personnel. Since then, the station has undergone constant upgrades to maintain a high level of operability. Today, it contributes to national and international tracking networks such as ILRS-EUROLAS and EU SST-S3T. Additionally, the ROA adopted GPS in the 1980s for geodetic studies and currently manages a GNSS network comprising 17 permanent stations spanning the southern Iberian Peninsula and North Africa. Maritime campaigns include studies in the Spanish Exclusive Economic Zone (EEZ), with objectives such as hydrographic surveys and geophysical exploration for seabed characterization. Since 1987, the ROA has also participated in Antarctic campaigns.

The Geophysics Section of the ROA combines tradition and advanced technology to contribute to the understanding of the Earth and space, consolidating its position as a national and international benchmark in the study of geophysical and geodetic processes. Evidence of this includes recent or ongoing scientific work over the past years: four doctoral theses (three of them in progress), various articles in high-impact journals, participation in numerous scientific projects, and extensive contributions to conferences. In this way, the ROA, through the Geophysics Section, fosters collaboration in geodesy through its active participation in international networks, addressing global scientific and societal challenges with cutting-edge technology and a multidisciplinary approach.