Conversión entre coordenadas geodésicas y coordenadas locales

En este artículo se aborda la conversión entre coordenadas geodésicas y coordenadas expresadas en un sistema cartesiano local, tanto en sentido directo como recíproco. La solución planteada está basada exclusivamente en conversiones de coordenadas, rotaciones y traslaciones, por lo que mantiene intacta la geometría relativa de los puntos.García-Asenjo Villamayor, L. (2017). Conversión entre coordenadas geodésicas y coordenadas locales. http://hdl.handle.net/10251/84060DE

Optimal combination and reference functions of signal-to-noise measurements for GNSS multipath detection

[EN] Multipath is the most limiting factor in many GNSS positioning applications, where it inevitably degrades the attainable precision. Among the different proposals to identify observations affected by multipath, Strode and Groves have recently proposed a method based on the comparison of GPS signal-to-noise (SNR) actual measurements with suitable reference functions previously computed in a low-multipath environment. We have found significant issues with its application to our particular GNSS experiments, however. In particular, we discuss whether the reference functions that are needed to be computed for low-multipath environments after tedious and time consuming field campaigns can be used for a future occasion, or not, as well as the possibility of applying the method to other GNSS global constellations (Galileo and GLONASS). Additionally, we elaborate on an alternative idea consisting in the use of the best combination of SNR measurements for the different signals in the different constellations in order to obtain a multipath estimator that is unbiased, universal and performs better than the use of reference functions.Pánik, P.; García-Asenjo Villamayor, L.; Baselga Moreno, S. (2019). Optimal combination and reference functions of signal-to-noise measurements for GNSS multipath detection. Measurement Science and Technology. 30(4):1-13. https://doi.org/10.1088/1361-6501/ab05aeS11330

Development of a Submillimetric GNSS-Based Distance Meter for Length Metrology

[EN] Absolute distance determination in the open air with an uncertainty of a few tenths of a millimetre is increasingly required in many applications that involve high precision geodetic metrology. No matter the technique used to measure, the resulting distances must be proven consistent with the unit of length (SI-metre) as realized in the outdoor facilities traditionally used in length metrology, which are also known as calibration baselines of reference. The current calibration baselines of reference have distances in the range of 10 to 1000 m, but at present there is no solution on the market to provide distances with submillimetric precision in that range. Consequently, new techniques such as multi-wave interferometry, two-wave laser telemeters or laser trackers are being developed. A possible alternative to those sophisticated and expensive techniques is the use of widely used Global Navigation Satellite Systems (GNSS) in order to provide a GNSS-Based Distance Meter (GBDM). The use of a GBDM as a potential technique for length metrology has been thoroughly analysed in several European research projects by using the state-of-the-art geodetic software, such as Bernese 5.2, but no definite conclusions have been drawn and some metrological questions are considered still open. In this paper, we describe a dedicated approach to build up a submillimetric GBDM able to be applied in the current calibration baselines of reference, as well as possible methods to cope with the multipath error of the GNSS signals which is the major limitation for the practical uptaking of the technique in metrology. The accuracy of the proposed approach has been tested following the length metrology standards in four experiments carried out in the Universitat Politecnica de Valencia (UPV). The results demonstrate that the proposed GBDM can provide an accuracy of a few tenths of a millimetre in the current calibration baselines of referenceThis work was partly performed within the 18SIB01 GeoMetre project of the European Metrology Programme for Innovation and Research (EMPIR). This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme. This research was also partly funded by the Spanish Ministry of Education, Culture and Sports (PRX17/00371).García-Asenjo Villamayor, L.; Baselga Moreno, S.; Atkins, C.; Garrigues Talens, P. (2021). Development of a Submillimetric GNSS-Based Distance Meter for Length Metrology. Sensors. 21(4):1-21. https://doi.org/10.3390/s2104114512121

EDM-GNSS distance comparison at the EURO5000 calibration baseline: preliminary results

[EN] At the Pieniny Klippen Belt in Poland, the novel primary reference baseline EURO5000 is required as part of the European Research project GeoMetre to both validate refractivity-compensated EDM prototypes and investigate the metrological traceability of GNSS-based distances. Since the aimed uncertainty is 1 mm at 5 km (k = 2), the design, construction, and validation must be carefully prepared to fulfil the high standards of the GeoMetre field campaigns which are planned to be carried out in May 2022. This contribution describes the main features of the EURO5000 and presents the results of the preliminary validation which includes a first comparison between the results obtained by using precise currently available EDMs as well as GNSS techniques following the standard GNSS geodetic processing algorithms, on the one hand, and the improved GNSS-Based Distance Meter (GBDM+) approach developed at UPV, on the other hand. The preliminary validation presented in this contribution also permits (1) to detect potential problems in the use of the baseline such as potential geodynamic problems, atmospheric refraction or multipath limitations, (2) to produce a set of reliable results, and (3) to pave the way for the final field comparisons between the novel EDMs and the GBDM+ approach. The result of this metrological experiment may significantly contribute to overcome the limitations of current high-precision deformation monitoring applications that require their scale to be consistent with the SI-metre within 0.1 ppm in several km.The project 18SIB01 GeoMetre hasreceived funding from the EMPIR programme co-financedby the Participating States and from the European Union's Horizon 2020 research and innovation programme, funderID: 10.13039/100014132. Raquel Lujan acknowledges the funding from the Programa de Ayudas de Investigaciony Desarrollo (PAID-01-20) de la Universitat Politecnica deValencia.Wezka, K.; García-Asenjo Villamayor, L.; Próchniewicz, D.; Baselga Moreno, S.; Szpunar, R.; Garrigues Talens, P.; Walo, J.... (2023). EDM-GNSS distance comparison at the EURO5000 calibration baseline: preliminary results. Journal of Applied Geodesy. 17(2):101-108. https://doi.org/10.1515/jag-2022-004910110817

Evaluation of Long-Range Mobile Mapping System (MMS) and Close-Range Photogrammetry for Deformation Monitoring. A Case Study of Cortes de Pallás in Valencia (Spain)

none8openDi Stefano, Francesco; Cabrelles, Miriam; García-Asenjo, Luis; Lerma, José Luis; Malinverni, Eva Savina; Baselga, Sergio; Garrigues, Pascual; Pierdicca, RobertoDi Stefano, Francesco; Cabrelles, Miriam; García-Asenjo, Luis; Lerma, José Luis; Malinverni, Eva Savina; Baselga, Sergio; Garrigues, Pascual; Pierdicca, Robert

Transformaciones de datum

Introducción a las transformaciones de datum empleadas en Geodesia, Cartografía y Topografía para expresar las coordenadas de un objeto en diferentes sistemas de referencia geodésicos.https://polimedia.upv.es/visor/?id=79cdc560-4b68-11e7-9a30-c95bce9b1265García-Asenjo Villamayor, L. (2017). Transformaciones de datum. http://hdl.handle.net/10251/82617DE

Ajuste de redes geodésicas

Introducción al ajuste de redes geodésicas, incluyendo una descripción del proceso y los aspectos más relevantes de las coordenadas compensadas, su precisión y fiabilidad de la red.https://polimedia.upv.es/visor/?id=905570d0-4b68-11e7-9a30-c95bce9b1265García-Asenjo Villamayor, L. (2017). Ajuste de redes geodésicas. http://hdl.handle.net/10251/82619DE

Redes Geodésicas

Introducción a las redes geodésicas, incluyendo los aspectos que influyen en la calidad, concepto de solución y tipos de solución.https://polimedia.upv.es/visor/?id=a8b76850-4aa9-11e7-b066-d35c4294546bGarcía-Asenjo Villamayor, L. (2017). Redes Geodésicas. http://hdl.handle.net/10251/82605DE

Transformaciones estándar en Geodesia

Introducción a los dos modelos de transformación más empleados en Geodesia y Topografía: Bursa-Wolf y Badekas-Molodensky.https://polimedia.upv.es/visor/?id=81573eb0-4b68-11e7-9a30-c95bce9b1265García-Asenjo Villamayor, L. (2017). Transformaciones estándar en Geodesia. http://hdl.handle.net/10251/82618DE