The scale factor accuracy of superconducting gravimeters （SG） can be largely improved by a high repetition rate of calibration experiments. At stations where the availability of absolute gravimeters is limited, care...The scale factor accuracy of superconducting gravimeters （SG） can be largely improved by a high repetition rate of calibration experiments. At stations where the availability of absolute gravimeters is limited, carefully calibrated spring gravimeters can be used for providing the reference signal assuming the irregular drift is properly adjusted. The temporal stability of the SG scale factor is assessable by comparing the temporal variations of M2 tidal parameters observed at neighboring SG sites or from synthetic tide models. Combining these methods reduces the SG scale factor error to a few 0.1%0. The paper addresses the particular procedure required for evaluating the calibration experiments based on spring gravimeters and presents results obtained at Conrad observatory （Austria）. Comparing the M2 amplitude factor modulation helped to reveal a SG scale factor offset of about 0.2%0 due to re-installation.展开更多
In September 2019, the Dubai Municipality of Dubai Emirate, the United Arab of Emirates, has received its first Scintrex CG-6 Autograv gravity meter. This paper describes the installation and initial gravity signals w...In September 2019, the Dubai Municipality of Dubai Emirate, the United Arab of Emirates, has received its first Scintrex CG-6 Autograv gravity meter. This paper describes the installation and initial gravity signals with the new CG-6 Autograv gravimeter. Two gravity field sites have been selected in Dubai City and Hatta mountainous area. The relative gravity field measurements have been recorded for about one month time span;two weeks in Dubai and two weeks in Hatta. Among different effects reducing the gravity measurements, the tide and drift corrections have been focused on this paper. Two tidal models have been applied to reduce the tide effect based on the automated ETGTAB of the CG-6 gravimeter and ETERNA3.3 software. The results regarding the tide correction show very small discrepancies between both models (ETGTAB and ETERNA3.3) of about 2.2 μGal and 2.6 μGal in terms of standard deviations at Dubai and Hatta gravity stations, respectively. So, the outcome of the precise tidal model of CG-6 Autograv gravimeter is reliable for tidal reduction within Dubai area and its surroundings. Regarding the drift correction, the CG-6 Autograv provides low instrument drift values about 2.44 μGal and -2.35 μGal per day for the Dubai and Hatta stations, respectively. Furthermore, it is recommended that the Hatta gravity station would be considered as a stable and trusted gravity site. For Dubai gravity station, the gravity observations are affected by some noises from traffic activities while recording the gravity signal during the working days. Therefore, it is recommended for Dubai gravity station to be measured during the weekends and at nights in order to avoid any noises affecting the CG-6 gravimeter.展开更多
This work presents the results of complex gravity observation performed at Shults Cape, Gamov peninsula (42.58°N, 131.15°E), Russia. Absolute laser gravimeter GABL type and Scintrex type relative gravimeter ...This work presents the results of complex gravity observation performed at Shults Cape, Gamov peninsula (42.58°N, 131.15°E), Russia. Absolute laser gravimeter GABL type and Scintrex type relative gravimeter were used for measurement. To investigate the accuracy of tidal corrections we compared the observed tidal parameters of the main tidal waves O1 and M2 with modeled ones computed from 6 different ocean tidal models: CSR4, FES02, FES04, GOT00, NAO99 and TPX06. After discussion a theoretical model based on TPX06 ocean tides model and DDW99 non hydrostatic body tides model was used for tidal correction of absolute gravity data. Preliminary estimate of gravity effect induced by the Tohoku-Oki earthquake of11 March 2011Mw = 9.0 at Primorye territory (Russia) was found to be 5.1 ± 2.0 μGal. Co-seismic crustal displacements revealed by GPS data at Far EastRussiacontinental coast are also investigated. Volumetric dilatation of this area is observed at +1.7 × 10-8 level.展开更多
文摘The scale factor accuracy of superconducting gravimeters （SG） can be largely improved by a high repetition rate of calibration experiments. At stations where the availability of absolute gravimeters is limited, carefully calibrated spring gravimeters can be used for providing the reference signal assuming the irregular drift is properly adjusted. The temporal stability of the SG scale factor is assessable by comparing the temporal variations of M2 tidal parameters observed at neighboring SG sites or from synthetic tide models. Combining these methods reduces the SG scale factor error to a few 0.1%0. The paper addresses the particular procedure required for evaluating the calibration experiments based on spring gravimeters and presents results obtained at Conrad observatory （Austria）. Comparing the M2 amplitude factor modulation helped to reveal a SG scale factor offset of about 0.2%0 due to re-installation.
文摘In September 2019, the Dubai Municipality of Dubai Emirate, the United Arab of Emirates, has received its first Scintrex CG-6 Autograv gravity meter. This paper describes the installation and initial gravity signals with the new CG-6 Autograv gravimeter. Two gravity field sites have been selected in Dubai City and Hatta mountainous area. The relative gravity field measurements have been recorded for about one month time span;two weeks in Dubai and two weeks in Hatta. Among different effects reducing the gravity measurements, the tide and drift corrections have been focused on this paper. Two tidal models have been applied to reduce the tide effect based on the automated ETGTAB of the CG-6 gravimeter and ETERNA3.3 software. The results regarding the tide correction show very small discrepancies between both models (ETGTAB and ETERNA3.3) of about 2.2 μGal and 2.6 μGal in terms of standard deviations at Dubai and Hatta gravity stations, respectively. So, the outcome of the precise tidal model of CG-6 Autograv gravimeter is reliable for tidal reduction within Dubai area and its surroundings. Regarding the drift correction, the CG-6 Autograv provides low instrument drift values about 2.44 μGal and -2.35 μGal per day for the Dubai and Hatta stations, respectively. Furthermore, it is recommended that the Hatta gravity station would be considered as a stable and trusted gravity site. For Dubai gravity station, the gravity observations are affected by some noises from traffic activities while recording the gravity signal during the working days. Therefore, it is recommended for Dubai gravity station to be measured during the weekends and at nights in order to avoid any noises affecting the CG-6 gravimeter.
文摘This work presents the results of complex gravity observation performed at Shults Cape, Gamov peninsula (42.58°N, 131.15°E), Russia. Absolute laser gravimeter GABL type and Scintrex type relative gravimeter were used for measurement. To investigate the accuracy of tidal corrections we compared the observed tidal parameters of the main tidal waves O1 and M2 with modeled ones computed from 6 different ocean tidal models: CSR4, FES02, FES04, GOT00, NAO99 and TPX06. After discussion a theoretical model based on TPX06 ocean tides model and DDW99 non hydrostatic body tides model was used for tidal correction of absolute gravity data. Preliminary estimate of gravity effect induced by the Tohoku-Oki earthquake of11 March 2011Mw = 9.0 at Primorye territory (Russia) was found to be 5.1 ± 2.0 μGal. Co-seismic crustal displacements revealed by GPS data at Far EastRussiacontinental coast are also investigated. Volumetric dilatation of this area is observed at +1.7 × 10-8 level.
