La astronomía geodésica es aquella parte de la geodesia (o de la astronomía) que tiene por objeto... more La astronomía geodésica es aquella parte de la geodesia (o de la astronomía) que tiene por objeto la determinación de las coordenadas geográficas astronómicas, Latitud y Longitud, de puntos de la superficie terrestre y de acimutes astronómicos A de direcciones en la Tierra. Estas determinaciones se realizan por métodos astronómicos de observación de estrellas en posiciones convenientes, utilizándose principalmente métodos de cálculo de trigonometría esférica y de álgebra matricial junto al ajuste de observaciones por mínimos cuadrados. Las principales aplicaciones geodésicas de los resultados obtenidos son la determinación de la figura de la Tierra (geoide) y la compensación astrogeodésica de redes.Peer reviewe
Mare Nostrum: geomed report-2
GEOMED is a project for the determination of the geoid and of the Sea Surface Topography in the M... more GEOMED is a project for the determination of the geoid and of the Sea Surface Topography in the Mediterranean Sea. The existing set of data available on the Mediterranean in already quite significant and it is going to be improved in these years because of the new altimetric data coming from ERS1 and the TOPEX-POSEIDON missions. In the execution of the project we use, mainly, radar altimetric data (f rom SEASAT, GEOSAT and ESR1 missions) gravimetrie data, bathymetric models, as well as land gravi ty data set and DTMs of ...
International Association of Geodesy Symposia, 2006
The Institute of Astronomy and Geodesy is measuring sea level variations in Lanzarote Island by t... more The Institute of Astronomy and Geodesy is measuring sea level variations in Lanzarote Island by two automated tide gauges of precision since 1993. In order to obtain "real" sea level variations a permanent GPS station has been installed near the tide gauges. The goal of this GPS station is to measurement vertical crustal movements in order to obtain absolute sea level variations removing these movements from tide gauge data.
In the historical territory of Gipuzkoa, a new gravity network has been settled down. The network... more In the historical territory of Gipuzkoa, a new gravity network has been settled down. The network will be the reference for the future gravity related geodetic tasks. The network has eleven stations with a maximum distance between two consecutive stations of about 20 km. Also, it is connected with the absolute gravity station of the IAG in Madrid by means of a round trip itinerary with gravity measurements in Madrid, Aranda del Duero, Miranda de Ebro and Donostia with distances between stations of about 150 km. This last station of Donostia has been considered as reference station for the itineraries that configure the net of Gipuzkoa. To obtain the gravity values in the 11 stations, three round trip itineraries have been performed, where the starting and closing measure is the station of Donostia. The used instrument has been a gravimeter LaCoste & Romberg model GRAVITON-EG-1194. The relative precision of this gravimeter is in the order of the 4 or 5 µGal, that together with the absolute gravity value of the station of the IAG in Madrid, which is known with an absolute precision of ±9.0x10 -8 ms -2 , guarantee a final precision of 10 µGal. The coordinates of the stations have been determined by GPS in the WGS84 system. This, together with the software packages used, ensure that the tidal and derive corrections are within the mentioned precision. A total of 924 gravity observations have been made and the adjustment shows a mean standard error of 2 µGal, very below the theoretical precision, what guarantees the reliability of the results.
The Canarian archipelago is the emerged part of an important volcanic formation located on the oc... more The Canarian archipelago is the emerged part of an important volcanic formation located on the oceanic-continental limit of the African plate, at 100 Km of the northwest coast of Africa. The study of seven GPS observations campaigns carried out in the years 2001 to 2009, by staff from the Faculty of Mathematics of the Complutense University of Madrid (UCM), to monitor possible deformations in this region is shown in this poster. Three geodetic networks with different purposes have been designed: the micro network of Jameos del Agua, around a permanent GPS station, the network of the island of Lanzarote and the network of the Canarian Archipelago covering all the seven islands. The stations of the networks are located at strategic points for the study of possible deformations, there are included a permanent station in Lanzarote (LACV), established in 1999, stations from the IGS network (MAS1 y LPAL) as well as stations from REGCAN95 network of the Instituto Geográfico Nacional (IGN).
3) Astronomía y Geodesia. Facultad de Matemáticas. Universidad Complutense. Madrid [email protected]... more 3) Astronomía y Geodesia. Facultad de Matemáticas. Universidad Complutense. Madrid [email protected] (4) GEOLan Donosti SL. Portuetxe 53B, Of. 314 -20.018 San Sebastián. [email protected] SUMMARY GPS Precise Point Positioning (PPP) has become, over the last years, an excellent alternative to the double-differencesbased GPS models. The high accuracies achieved in daily sessions, as well as the computation speed make PPP an option that many Analysis Centers (ACs) have considered to be given as an extra service. However, most PPP processing Software is protected by copyright laws and "online" services can not be provided. This paper shows an implementation of an online-PPP processing Service which is based in the GNU LGPL GPS-Toolkit. To check the software, velocities of the four station of the Active Gipuzkoa Network are computed and the results are checked with the Bernese solutions.
Data series corresponds to sea-level rise recorded by the tide gauge from 9.7.2009 to 31.12.2012 ... more Data series corresponds to sea-level rise recorded by the tide gauge from 9.7.2009 to 31.12.2012 with a sampling frequency of 5 minutes.
The main goal of this work is to study and compare the results obtained from the harmonic analysi... more The main goal of this work is to study and compare the results obtained from the harmonic analysis of tide gauge records in the Pasaia harbour (Gipuzkoa, Spain). In February 2007, the University Complutense of Madrid and the company GEOLan Donosti S.L., with the financial support of the Provincial Council of Gipuzkoa, installed a depth sensor in the Pasaia harbor. One of the most important objectives of this institutional collaboration is to carry out studies related with local sea level changes. Thus, in this work we study the sea level observations recorded in Pasaia for a period of three years (2009 to 2011). The harmonic analysis of the time series have been carried out using different scientific software (SLPR2, Versatile_TIDANA and VAV) so that, we have compared the results obtained depending on the methodology and processing options used for each program. As a consequence of these studies we have obtained the harmonic constant for the main tidal constituents in Pasaia Harbor.
In order to get sea level variations in the Pasaia harbour (Cantabrian Sea in the north of Spain)... more In order to get sea level variations in the Pasaia harbour (Cantabrian Sea in the north of Spain) an automatic precision tide gauge was installed in 2007. To obtain absolute sea level variations isolated from crustal movements or local deformations, a permanent GNSS station has also been installed in a nearby building of the tide gauge. A high-accuracy vertical tie between the reference point of the GNSS antenna and the tide gauge bench mark is carried out yearly.
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Papers by Miguel Sevilla