ITRF is the basis for modern national geodetic systems and the metrological basis for any position based information, including mapping, 3D modeling, and GIS. The ITRF provides the foundation for nearly all ground-based and space-based observations in Earth system science and supports a variety of applications, such as: land surveying, floodplain mapping, navigation, precision agriculture, and location-based services.
The primary challenge driving advances in geodesy is the study of long-term Earth system processes, such as tectonic deformation, and indicators of global climate change, including sea-level rise and ice sheet melting. While these processes are often imperceptibly slow, they are singularly important to society and simply could not be monitored and understood without the precise observations acquired through global geodetic networks. The IGS publicly available geodetic products, together with the reference frame stations allow further densifying and providing a universal access to the ITRF.
Each reference frame station plays a valuable role in contributing to and accessing the ITRF, and may be considered some of the highest-quality GNSS stations in the world. This quality directly impacts the level of accuracy that can be achieved by using the ITRF. There are numerous advantages for an organization or station operator to support the IGS reference frame station network, including:. Requirements for IGS reference frame stations include: a high-quality monument on stable crustal bedrock with excellent sky visibility; a long observing history; high-quality, consistent, continuous, and complete raw data; minimal changes to equipment and its surroundings; and a commitment to keep the station operating for as long as possible.
These requirements are stringent in order to ensure reliable measurements around the world for monitoring processes such as sea-level change, which occur at the millimeter level.
Limitations in a reference frame negatively impact the accuracy of numerous scientific and positioning applications, especially in the region immediately surrounding the station. Supporting the ITRF. About Advantages Main Requirements Links. Main Requirements. Over 15, product users, some of whom comprise the backbone of the worldwide geodetic community, ensure that new technologies and systems are integrated into routine IGS products.
Responsive to this innovation, the IGS develops and publicly releases standards, guidelines, and conventions for the collection and use of GNSS data and products. The foundation of the IGS is a global network of over permanent and continuously operating stations of geodetic quality. It is a service of the International Association of Geodesy IAG and is a collaborative effort involving dozens of scientific, academic and government organizations. It also helps maintain the orientation of the ITRF.
There are five main operational components to the IGS : data providers, data centers, analysis centers, working groups and the central bureau. These are described in further detail in the chart below:. Updated station data is available on a daily basis. The IGS products are derived from this data.
Products are available at various latencies to reflect the requirements of different applications. Ultra-rapid products are available in near real-time, but are the least precise. Rapid products are provided within one to two days and have greater precision. The final products provide the best precision and are available within ten days to four weeks depending on the product. The IGS also provides antenna calibration data for antennas in its network and site logs containing station metadata.
Under this joint management, the IGS continues to maintain a very high level of product availability.
0コメント