地球观测数据卫星分发系统(GEONETCast)借助通信卫星，把从地面站点、航空和航天平台获取的观测数据、产品传送给广大的用户。GEONETCast当前由CMACast，EUMETCast和GEONETCast Americas 3个区域系统组成，作为地球观测组织（GEO）提出的全球综合地球观测系统（GEOSS）的全球地球观测数据和信息卫星分发系统，旨在满足9个社会受益领域的用户需求。GEONETCast建立在现有区域系统之上，利用GEO的协调机制，共同确定GEONETCast系统的整体计划和要求。各区域系统在科研项目和业务建设的支持下，不断发展完善。未来要保障GEONETCast健康、良性和可持续的业务运行，还需要加强4个方面的工作:①区域系统之间的互相通信；②保持GEONETCast的开放性和动态性，发展更多的数据提供者提供地球观测数据；③发展更多的数据使用者；④数据政策。

GEONETCast provides reliable, worldwide and continuous access to  information and is a core infrastructure and early success of the Group on Earth Observations (GEO)’s Global Earth Observation System of Systems (GEOSS). GEONETCast is a low cost global environmental information delivery system which transmits the satellite-based, airborne-based and in situ data, products and services from the Global Earth Observation System of Systems (GEOSS) to various users through communication satellites using multi-cast, broadband capability. GEONETCast is coordinated within the framework of the GEO by the GEONETCast Implementation Group comprising the China Meteorological Administration (CMA), European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization (WMO).Data from each region can be disseminated outside the original region through data-exchange links between regions, such as through dedicated lines, overlapping satellite footprints, or use of the Internet or other existing networks. The data GEONETCast delivers is specifically targeted to address nine society benefit areas such as natural and human-induced hazards, environment and health, environmental-related energy issues, climate change, water management, weather, ecosystem management, sustainable agriculture, and desertification and biodiversity, with the aim of reaching a global coverage and allowing  the timely reception of the data at very low cost by nearly anyone on the planets. The GEONETCast develops with the regional systems’ enhancement. The CMACast is upgraded and enhanced by CMA in the support of the operational construction from the former FENGYUNCast. CMA, in cooperation with other domestic organizations, has donated 27 user stations to 19 foreign countries in the past years and greatly improved the data sharing in Asia and Pacific regions. The GEONETCast for and by developing countries (DevCoCast) project, funded by the 7th Framework Programme for Research and Technological Development (FP7) of the European Commission, involves developing countries more closely in the GEONETCast initiative. In order to secure the sustainable operation of the GEONETCast, the four aspects should be strengthened. The first is to construct the data communication channels between two regional systems. The second is to mobilize various kinds of the Earth observations data from the various data providers. The third is to cultivate more end users. The fourth is to consolidate the data policy.