New Cable Delay Measurement System for VGOS Stations
This paper presents the new cable delay measurement system (CDMS) designed at Yebes Observatory (IGN, Spain), which is required for the VLBI Global Observing System (VGOS) stations. This system measures the phase difference between the 5 MHz reference signal from the hydrogen maser and the 5 MHz sig...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-03-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/22/6/2308 |
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| author | Pablo García-Carreño Javier González-García María Patino-Esteban Francisco J. Beltrán-Martínez Marta Bautista-Durán Pablo Luis López-Espí José A. López-Pérez |
| author_facet | Pablo García-Carreño Javier González-García María Patino-Esteban Francisco J. Beltrán-Martínez Marta Bautista-Durán Pablo Luis López-Espí José A. López-Pérez |
| author_sort | Pablo García-Carreño |
| collection | DOAJ |
| description | This paper presents the new cable delay measurement system (CDMS) designed at Yebes Observatory (IGN, Spain), which is required for the VLBI Global Observing System (VGOS) stations. This system measures the phase difference between the 5 MHz reference signal from the hydrogen maser and the 5 MHz signal that reaches the broadband receiver through a coaxial cable, for the generation of calibration tones. As a result, the system detects the changes in the length of that coaxial cable due to temperature variations along the cable run and flexures caused by VGOS radio telescope movements. This CDMS outperforms the previous versions: firstly, it does not require a frequency counter for phase/delay measurements; secondly, it largely reduces the use of digital circuits; hence, reducing digital noise; and thirdly, it has a remotely controlled automatic calibration subsystem. The system was tested in the laboratory and in the radio telescope, and the measurements of both set-ups are shown. These measurements include the total noise, accuracy, hysteresis, and stability. The results in the radio telescope can be correlated with the different factors that affect the cable, such as temperature and flexures. The system allows to achieve an RMS noise of less than 0.5 ps, significantly improving the requirements established in VGOS. The system is currently installed in the Red Atlántica de Estaciones Geodinámicas y Espaciales (RAEGE)Yebes VGOS 13.2 m radio telescope, and will be installed in the Norwegian Mapping Authority (NMA) twin VGOS radio telescopes, in the Finnish Geospatial Research Institute (FGI) VGOS station and in the RAEGE Santa María VGOS radio telescope (Açores, Portugal). |
| first_indexed | 2024-03-09T12:40:02Z |
| format | Article |
| id | doaj.art-9bbc9cd4ae3c4a0280aaa3b955b25db7 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-09T12:40:02Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-9bbc9cd4ae3c4a0280aaa3b955b25db72023-11-30T22:19:08ZengMDPI AGSensors1424-82202022-03-01226230810.3390/s22062308New Cable Delay Measurement System for VGOS StationsPablo García-Carreño0Javier González-García1María Patino-Esteban2Francisco J. Beltrán-Martínez3Marta Bautista-Durán4Pablo Luis López-Espí5José A. López-Pérez6Yebes Observatory, Centro de Desarrollos Tecnológicos, Instituto Geográfico Nacional, Ministerio de Transportes, Movilidad y Agenda Urbana, Cerro de la Palera s.n., 19141 Yebes, SpainYebes Observatory, Centro de Desarrollos Tecnológicos, Instituto Geográfico Nacional, Ministerio de Transportes, Movilidad y Agenda Urbana, Cerro de la Palera s.n., 19141 Yebes, SpainYebes Observatory, Centro de Desarrollos Tecnológicos, Instituto Geográfico Nacional, Ministerio de Transportes, Movilidad y Agenda Urbana, Cerro de la Palera s.n., 19141 Yebes, SpainYebes Observatory, Centro de Desarrollos Tecnológicos, Instituto Geográfico Nacional, Ministerio de Transportes, Movilidad y Agenda Urbana, Cerro de la Palera s.n., 19141 Yebes, SpainYebes Observatory, Centro de Desarrollos Tecnológicos, Instituto Geográfico Nacional, Ministerio de Transportes, Movilidad y Agenda Urbana, Cerro de la Palera s.n., 19141 Yebes, SpainDepartment of Signal Theory and Communications, Escuela Politecnica Superior, Universidad de Alcala, Campus Universitario, Ctra. de Madrid a Barcelona km 33.600, 28805 Alcala de Henares, SpainYebes Observatory, Centro de Desarrollos Tecnológicos, Instituto Geográfico Nacional, Ministerio de Transportes, Movilidad y Agenda Urbana, Cerro de la Palera s.n., 19141 Yebes, SpainThis paper presents the new cable delay measurement system (CDMS) designed at Yebes Observatory (IGN, Spain), which is required for the VLBI Global Observing System (VGOS) stations. This system measures the phase difference between the 5 MHz reference signal from the hydrogen maser and the 5 MHz signal that reaches the broadband receiver through a coaxial cable, for the generation of calibration tones. As a result, the system detects the changes in the length of that coaxial cable due to temperature variations along the cable run and flexures caused by VGOS radio telescope movements. This CDMS outperforms the previous versions: firstly, it does not require a frequency counter for phase/delay measurements; secondly, it largely reduces the use of digital circuits; hence, reducing digital noise; and thirdly, it has a remotely controlled automatic calibration subsystem. The system was tested in the laboratory and in the radio telescope, and the measurements of both set-ups are shown. These measurements include the total noise, accuracy, hysteresis, and stability. The results in the radio telescope can be correlated with the different factors that affect the cable, such as temperature and flexures. The system allows to achieve an RMS noise of less than 0.5 ps, significantly improving the requirements established in VGOS. The system is currently installed in the Red Atlántica de Estaciones Geodinámicas y Espaciales (RAEGE)Yebes VGOS 13.2 m radio telescope, and will be installed in the Norwegian Mapping Authority (NMA) twin VGOS radio telescopes, in the Finnish Geospatial Research Institute (FGI) VGOS station and in the RAEGE Santa María VGOS radio telescope (Açores, Portugal).https://www.mdpi.com/1424-8220/22/6/2308VGOSRAEGEVLBIgeodesyradio telescopecable-cal |
| spellingShingle | Pablo García-Carreño Javier González-García María Patino-Esteban Francisco J. Beltrán-Martínez Marta Bautista-Durán Pablo Luis López-Espí José A. López-Pérez New Cable Delay Measurement System for VGOS Stations Sensors VGOS RAEGE VLBI geodesy radio telescope cable-cal |
| title | New Cable Delay Measurement System for VGOS Stations |
| title_full | New Cable Delay Measurement System for VGOS Stations |
| title_fullStr | New Cable Delay Measurement System for VGOS Stations |
| title_full_unstemmed | New Cable Delay Measurement System for VGOS Stations |
| title_short | New Cable Delay Measurement System for VGOS Stations |
| title_sort | new cable delay measurement system for vgos stations |
| topic | VGOS RAEGE VLBI geodesy radio telescope cable-cal |
| url | https://www.mdpi.com/1424-8220/22/6/2308 |
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