GNSS
- Wolfgang Scheucher
- Manfred Beckmann
ICAO Annex 10, Volume I defines Global Navigation Satellite System (GNSS) as follows:
A worldwide position and time determination system that includes one or more satellite constellations, aircraft receivers and system integrity monitoring, augmented as necessary to support the required navigation performance for the intended operation.
The GNSS navigation service is provided using various combinations of the elements installed on the ground, on satellites and/or on board the aircraft:
a) Global Positioning System (GPS)
The satellite navigation system operated by the United States.
b) Global Navigation Satellite System (GLONASS)
The satellite navigation system operated by the Russian Federation.
c) aircraft-based augmentation system (ABAS)
An augmentation system that augments and/or integrates the information obtained from the other GNSS elements with information available on board the aircraft.
d) satellite-based augmentation system (SBAS)
A wide coverage augmentation system in which the user receives augmentation information from a satellite-based transmitter.
e) ground-based augmentation system (GBAS)
An augmentation system in which the user receives augmentation information directly from a ground-based transmitter.
f) ground-based regional augmentation system (GRAS)
An augmentation system in which the user receives augmentation information directly from one of a group of ground-based transmitters covering a region.
g) aircraft GNSS receiver
The position information provided by the GNSS to the user shall be expressed in terms of the World Geodetic System — 1984 (WGS-84) geodetic reference datum.
PANS-AIM AD 2.19/AD 3.18 "Radio navigation and landing aids" list some publication requirements for Global Navigation Satellite System (GNSS) and some of its elements.
1) ... type of supported operation for... basic GNSS, SBAS, and GBAS...
3) ... service provider, reference path identifier(s) (RPI), as appropriate;
6) ... elevation of GBAS reference point to the nearest metre or foot, and the ellipsoid height of the point to the nearest metre or foot. For SBAS, the ellipsoid height of the landing threshold point (LTP) or the fictitious threshold point (FTP) to the nearest metre or foot;
7) service volume radius from the GBAS reference point...
If the ground-based augmentation system (GBAS) serves more than one aerodrome, description of the aid shall be provided under each aerodrome.
Note
As this is information, which was for the first time defined within the PANS-AIM , and these publication requirements were not part of the previous ANNEX 15 content, it is still not clear if and how this information shall be covered by AIXM 5.
Until further clarification on this matter no coding guidelines will be provided for this subject as most probably there will be changes on the requirements.
AIXM 5.1(.1) issue_027_GBAS/SBAS
The data type for the Navaid.type attribute, CodeNavaidServiceType does not provide a dedicated value for GBAS or GNSS or SBAS.