The External GNSS data Provider (EGP) is a dedicated high accuracy and reliability external GNSS data provider. The selected company by ESA in charge of providing these products to the CPOD Service is GMV through the magicGNSS solution. High rate orbits and clocks are provided with different levels of timeliness and accuracy obtained from the processing of GNSS data from their own network of sensors and stations. In case of unavailability, the Copernicus POD Service also has a back-up EGP (DLR Reticle) providing 15M orbits and clocks.
The following orbital and clock products are provided so that the POD products can be computed with the needed accuracy for each mission:
- The 15M orbits and clocks are Near Real-Time (NRT) products containing 15 minutes of data at a sampling rate of 30 seconds. They are delivered with a latency of 10 minutes. They have a requirement of 10 cm orbit RMS and 0.2 ns clock sigma.
- The 24H orbits and clocks are Near Real-Time (NRT) products with a coverage of 24 hours. The orbits are given at a sampling rate of 15 minutes, whereas the clocks are given every 30 seconds. These files are delivered hourly. They have a requirement of <10 cm orbit RMS and <0.2 ns clock sigma.
- The STC orbits and clocks (Short Time Critical) also have a coverage of 24 hours and the same sampling rates as the 24H products. However, they are delivered daily. They have a requirement of 6 cm orbit RMS and 0.1 ns clock sigma.
The IGS (International GNSS Service) and CODE (Center for Orbit Determination in Europe) final orbits, clocks and satellite biases (only for CODE products) are also retrieved and used in the computation of the NTC products and are routinely used as a reference to assess the accuracy of the EGP orbits and clocks.