Links
[1] https://www.e-navigation.nl/content/gps-reference-station-parameters
[2] https://www.e-navigation.nl/content/gps-null-frame
[3] https://www.e-navigation.nl/content/dgps-radiobeacon-almanac
[4] https://www.e-navigation.nl/content/gps-partial-correction-set
[5] https://www.e-navigation.nl/content/gps-special-message