IGS is the acronym for International GNSS Service. This organization was founded in 1994 by international geodesy organizations and was formerly called the International GPS Service to increase the accuracy of the determination of GPS satellite orbits. The creation of IGS was to ensure open access, high-quality GNSS data products. The products enable access to the definitive global reference frame for scientific, educational, and commercial applications which is of tremendous benefit to the public and a key support element for scientific advancements. The mission, products, and the services rendered by this international organization are all pointed out in this article. Continue reading to find out more.
The International GNSS Service (IGS) for which GNSS stands for Global Navigation Satellite System, has a mission to provide- on an openly available basis- the highest-quality GNSS data, products and services in support of the terrestrial reference frame, Earth observation and research; positioning, navigation and timing; and other applications that benefit science and society.
The fundamental to the IGS are key values that are shared across the organization. These key values are;
- Dedicated engagement with policy entities to raise mutual awareness of IGS and geodesy in general.
- Technical evolution through ‘friendly competition’.
- Effective reliability through redundancy of IGS components
- Advocacy of an open data policy with the data and products openly available.
- Welcome contributions from and participation with all organizations.
In order to ensure that the organization conducts its business in an orderly and optimal way, there were some guiding documents that were created. These guiding documents are;
- The IGS Terms of Reference, which lays the foundation for the organization;
- The Strategic Plan, which outlines the organization’s short and long-term goals and objectives;
- The Site Guidelines for all IGS sites; and
- Charters and other policy documents for IGS components.
This is a voluntary federation of over 200 self-funding agencies, universities, and research institutions in more than 100 countries, working together to provide the highest precision GPS satellite orbits in the world. This organization provides free and open access to the highest precision products available for scientific advancement and public benefits. The products support a wide range of applications that touch millions of users in virtually all segments of the global economy.
Another remark to the IGS is giving products that support the realization of the International Terrestrial Reference Frame while providing access to tracking data from over 400 worldwide reference stations. The organization supports geodetic research, scholarly publications, works for the continuous development of new applications and products through working groups and pilot projects. The organization also functions as a component of the Global Geodetic Observing System (GGOS) and member of the World Data System (WDS).
The network refers to all the networks used by IGS to produce its reliable products. These networks are placed in different locations, cities, and countries worldwide. IGS collects, archives, and freely distributes Global Navigation Satellite System (GNSS) observation data sets from a cooperatively operated global network of ground tracking stations.
The IGS network stations can be located in some countries like China, Ghana, U.S., Argentina, Australia, Chile, Thailand, Cabo Verde, Japan, France, Canada, Brazil, Benin, Poland, Nigeria, South Korea, Senegal, South Africa, U.K., Israel, Italy, Ecuador, Ukraine, India, Turkey, Spain, and Finland.
The IGS stations provide continuous tracking using high accuracy receivers and have data transmission facilities allowing for rapid data transmission to the data centers. The stations must meet physical and operational requirements as provides by the IGS Site Guidelines.
The organization, IGS, operates a global network of GNSS ground stations, data centers, and data analysis centers to provide data and derived data products that are essential for Earth science research, multi-disciplinary positioning, navigation, and timing (PNT) applications, and education. The products include;
- GNSS satellite ephemerides/ satellite & station clocks.
- Earth rotation parameters.
- Global tracking station coordinates and velocities.
- Satellite and tracking station clock information.
- Zenith tropospheric path delay estimates.
- Global ionosphere maps.
All these products listed out are products of the IGS organization and they support Earth science analyses and other efforts such as;
- Monitoring the troposphere and ionosphere.
- Determining orbits of scientific satellites, and other diverse applications.
- Improving and extending the International Terrestrial Reference Frame (ITRF) maintained by the International Earth Rotation and Reference Systems Service (IERS).
- Monitoring deformation of the Earth.
- Monitoring Earth rotation.
The IGS final products have the highest quality and internal consistency of all IGS products. the products are made available on a weekly basis by each Friday with a delay of up to 13 to 20 days. These final products are the basis for the IGS reference frame and are intended for those applications demanding high consistency and quality.
The IGS rapid products have a quality nearly comparable to that of the final products. The products are made available on a daily basis with a delay of about 17 hours at the end of the previous observation day. The results difference noticed between the final product and the rapid products by the user of IGS products are usually insignificant for most applications.
The Ultra-rapid products were started to reduce the age of prior, discontinued predicted orbits. These products started in November 2000 and the products are available for real-time and near real-time sue.