Superconducting Gravimeter Data from Pecný - Level 1

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. The Geodetic Observatory Pecný (GOPE) is located in the Czech Republic, about 40 km south-east of Prague, in the Central Bohemian hilly land at the elevation of about 500 m. It is surrounded by a mixed wood. Except for one local road the next nearest local road is about 1 km apart, the nearest railway is 5.2 km, the nearest village 1 km (Ondřejov). The bigger river (Sázava) flows through the valley at a distance of 5 km from the observatory at the height of about 300 m. No construction or other technological works (mines, industrial plants etc.) run either in the close surroundings or at longer distance. The hill Pecný is in the old metamorphic paleozoic synclinal zone of the Čerčany Chlum neighbouring with the Central Bohemian granitic massif and the perm massif of Černý Kostelec. From the geological point of view, GOPE was established in very stable region. GOPE is operated by the Research Institute of Geodesy, Topography and Cartography (RIGTC) and was established in 1957. GOPE has been involved in tidal observations with spring gravimeters since the early seventies of the last century, cooperation with the International Center for Earth Tides (ICET) has been dated since 1990. GOPE belongs to the core stations of ECGN - European Combined Geodetic Network, established by the EUREF IAG Subcommission. Since February 2007, the observatory type of one sphere superconducting gravimeter OSG-050 was running in the old gravimetric laboratory (OGL) of GOPE located in the cellar of the main building of GOPE (Latitude: 49.9137 N, Longitude: 14.7856 E, Elevation: 534.58 m), about 1.8 m under the ground of the surrounding relief. Almost uninterrupted 10-year time series of gravity record with OSG-050 has been carried out till October 2017, when the OSG-050 has been moved to the new gravimetric laboratory (NGL) situated in the top of the hill Pecný, less than 100 m from OGL. NGL (Latitude: 49.9141 N, Longitude: 14.7868 E, Elevation: 545.10 m) provides 3 concrete pillars in the ground level, which are founded to the bedrock (4 m below the ground). Two pillars are used for repeated observations with absolute gravimeters (AG) and in the third pillar, located in a separate room, the OSG-050 is running continuously. All rooms are thermally stabilized by air-conditioning systems. Due to the excellent stability of the station and the facilities to inter-compare different AGs, the GOPE was developed as a regional comparison site which serves as a reference for the Czech Gravimetric Network. Since 2001, repeated absolute measurements with interval of one month have been carried out in OGL and later in NGL to achieve continuous drift-free gravity time series by combination of absolute and superconducting data. At the area of the station, meteorological (precipitation, air temperature, humidity, air pressure) and hydrological (ground water and soil moisture) parameters are measured by different sensors. These data are available through auxiliary data in the IGETS database. Raw gravity and local atmospheric pressure records sampled at second and the same records decimated at 1‐minute samples are provided as Level 1 products of the IGETS network.

国际地球动力学与地球潮汐服务机构（International Geodynamics and Earth Tide Service, IGETS）由国际大地测量协会（International Association of Geodesy, IAG）于2015年创立。IGETS承接了全球地球动力学计划（Global Geodynamics Project, GGP，1997-2015）的相关工作，依托国际联网的超导重力仪（superconducting gravimeter, SG）数据，为大地测量与地球物理研究活动提供支撑。佩奇尼大地测量观测站（Geodetic Observatory Pecný, GOPE）坐落于捷克共和国布拉格东南约40公里的中波希米亚丘陵地带，海拔约500米，周边被混交林环绕。观测站附近仅有一条本地道路，其余最近的本地道路距其约1公里，最近的铁路站点位于5.2公里外，最近的村庄为翁德热约夫（Ondřejov），距离仅1公里。萨扎瓦河（Sázava）作为较大河流，流经距观测站5公里的河谷，河谷海拔约300米。观测站周边及更远区域均无建筑或工程作业（矿山、工厂等）。佩奇尼山地处切尔恰尼赫鲁姆的古变质古生代向斜带，毗邻中波希米亚花岗岩地块与切尔尼科斯特列茨二叠纪地块。从地质学视角来看，GOPE所在区域稳定性极佳。GOPE由大地测量、地形与制图研究所（Research Institute of Geodesy, Topography and Cartography, RIGTC）运营，始建于1957年。自上世纪70年代初起，该站便开始使用弹簧重力仪开展潮汐观测，自1990年起与国际地球潮汐中心（International Center for Earth Tides, ICET）建立合作关系。GOPE是EUREF IAG分会组建的欧洲联合大地测量网（European Combined Geodetic Network, ECGN）的核心台站之一。2007年2月，一台球形超导重力仪OSG-050在GOPE主楼地下室的旧重力实验室（Old Gravimetric Laboratory, OGL）投入运行，该实验室距周边地表约1.8米，坐标为北纬49.9137°、东经14.7856°，海拔534.58米。依托OSG-050获取的近乎连续的10年重力观测时序一直持续至2017年10月，随后OSG-050被搬迁至距OGL不足100米的佩奇尼山山顶的新重力实验室（New Gravimetric Laboratory, NGL）。NGL坐标为北纬49.9141°、东经14.7868°，海拔545.10米，内设3根浇筑于基岩（地下4米处）的混凝土观测墩。其中2根用于绝对重力仪（absolute gravimeter, AG）的重复观测，第三根设于独立房间内，用于OSG-050的连续观测。所有房间均通过空调系统实现热稳定控制。得益于该台站优异的环境稳定性以及多台绝对重力仪的比对条件，GOPE已发展为区域重力比对基准站点，作为捷克重力网的参考基准。自2001年起，该站在OGL及后续迁至的NGL均以每月一次的间隔开展绝对重力测量，通过融合绝对与超导重力数据，获取无持续漂移的重力时序序列。观测站内还通过各类传感器监测气象参数（降水、气温、湿度、大气压力）与水文参数（地下水、土壤湿度），此类辅助数据可通过IGETS数据库获取。IGETS网络的Level 1级产品包括每秒采样的原始重力与本地大气压力记录，以及经降采样得到的1分钟分辨率数据。