gnss notam - SIA - DGAC

8, AVENUE ROLAND GARROS - BP 40 245
F-33698 MERIGNAC CEDEX
http://www.sia.aviation-civile.gouv.fr
SUBJECT: NOTAM GNSS - CORRECT VERSION
SALES DEPARTMENT
☎ : 33 (0)5 57 92 56 68
Fax : 33 (0)5 57 92 56 69
✉ : sia-commercial
@aviation-civile.gouv.fr
TECHNICAL SERVICE
☎ : 33 (0)5 57 92 57 57
Fax : 33 (0)5 57 92 57 77
✉ : etp.sia@regis-dgac.net
SFA : LFFAYNYX
AIC
A 01B/06
CAR-SAM-NAM
PUB : MAR 16
1 INTRODUCTION
The Global Navigation Satellite System (GNSS) makes the implementation of area navigation (RNAV) possible for
en-route, terminal area and approach operations.
The GNSS is based on the possible use of 2 basic constellations, GPS and GLONASS, as also 3 Augmentation
Systems:1) ABAS: Airborne Based Augmentation System, 2) GBAS: Ground Based Augmentation System,
3) SBAS: Satellite Based Augmentation System.
In France, the use of the GPS constellation augmented by an internal integrity service in the airborne navigation system,
of ABAS type, constitutes the framework of RNAV (GNSS) non precision approach procedures.
This AIC aims at describing the GNSS NOTAM issued by the aeronautical information service with a view for operators
to preparing their flights to aerodromes where such procedures exist.
2 RAIM FUNCTION (RECEIVER AUTONOMOUS INTEGRITY MONITORING)
The GNSS/ABAS system is affected by limitations due to the number of satellites in GPS constellation in sight or correctly
operating.
RAIM function allows to check the state of signals received from GPS satellites constellations. It issues an alert indicating
a possible unacceptable position error when an inconsistency is detected among all ranges transmitted by satellites.
This function is not available when the number of received satellites is not sufficient or their geometry is poor.
3 PRE FLIGHT PLANNING
During the pre-flight planning phase, the availability of RAIM (or equivalent algorithm) at the destination should be
verified by the operator (RAIM available 15 min before Estimated Time of Arrival (ETA) until 15 min after ETA).
For that purpose, he can use:
- Either the onboard equipment predictive tool or an equivalent software. In this case, information on the possible
unavailability of satellites must be entered in the equipment or software predictive program. Such information are
obtained through NOTAM related to the operating condition of satellites in GPS constellation (see paragraph 4)
- Or predictions computed by software or tools available on the Internet, like Augur, which was developed by
Eurocontrol (http://augur.ecacnav.com/). Predictions are proposed for both baro-aided and non baro-aided
equipment. (1)
- Or predictions provided by the French aeronautical information service through RAIM NOTAM (see paragraph 5).
These RAIM NOTAM are available only for baro-aided equipment.
In case of predicted RAIM or even general GNSS unavailability, the crew is meant to use other radio navigation means,
select another destination or delay its flight.
(1) “In order to know whether to look at "baro-aided" or "non baro-aided" predictions, it is necessary to know whether a
barometric altitude input is provided or not to the installation aboard the aircraft of interest.
RAIM availability demands that a minimum number of satellites be received. Barometric aiding reduces this number
by one.”
ENG
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AIC N° 01B/06
4 NOTAM RELATED TO THE OPERATING CONDITION OF SATELLITES IN GPS CONSTELLATION
- They are distributed by the US Coast Guard Station, Washington DC (ICAO identification: KNMH).
They can be obtained:
- Either by direct consultation of the USA data bank, via AFTN, by using the following service message format:
SVC RQ INT LOC = KNMH addressed to KDZZNAXX. (available on http://www.navcen.uscg.gov/ado/GpsActiveNanu.asp) ;
- Or by direct consultation of the French aeronautical data bank (BDA):
o by consulting a flight assistance and information regional office,
o using a MINITEL and checking off the "GPS NOTAM" box of the selection criteria,
o via OLIVIA interface (http://olivia.aviation-civile.gouv.fr/ or terminals located within aerodromes), choose
«NOTAM» then «bulletin d’aérodrome» headings. «NOTAM GPS» and «IFR» boxes must be ticked off, then click
«OK».
5 NOTAM RELATED TO THE AVAILABILITY OF THE AUTONOMOUS INTEGRITY MONITORING FUNCTION (RAIM):
These NOTAM are transmitted for every French aerodrome where RNAV/GNSS procedures are provided, whenever an
unavailability of the autonomous integrity monitoring function (RAIM) concerning the following 24 hours is predicted. The
RAIM unavailability predictions are only provided for baro-aided equipment.
DGAC does not provide NOTAM for predicted unavailability of less than 5 minutes.
The mask angle taken into account for the predictions is set to 5°.
In metropolitan France, these NOTAM are issued by the French AIS every 24 hours, before 02:00 (Coordinated Universal
Time), for each concerned aerodrome.
For overseas needs, the following offices will distribute NOTAM for the concerned aerodromes:
- PAPEETE INO for French Polynesia: NTAAYNYX.
- Cayenne Rochambeau INO for French Guiana: SOCAYNYX.
- TRINIDAD and TOBAGO INO for French West Indies: TPPPYNYX.
- FIDJI INO for New Caledonia: NFOFYNYX.
- ANTANANARIVO (MADAGASCAR) INO for La Réunion and Mayotte: FMMMYNYX.
- OTTAWA INO for Saint Pierre and Miquelon: CYHQYNYX.
NOTAM format is as follows:
• Q code (subject code): GA (specific GNSS operation for aerodromes).
• Operating condition code: LS (Subject to interruption).
Example of a NOTAM for the following unavailability of the RAIM function in Toulouse :
• the 1st of August 2004 from 04H48 to 04H55.
• the 2d of August 2004 from 21H35 to 21H40.
French version
(A2162/05 NOTAMN
Q) LFBB/QGALS/I/NBO/A/000/999/
4100N00200E005
A) LFBO B) 0508010200 C) 05080200159
E) FONCTION BARO AIDED GPS RAIM INDISPO-
NIBLE POUR NPA
0508010448 TIL 0508010455
English version
(A2162/05 NOTAMN
Q) LFBB/QGALS/I/NBO/A/000/999/
4100N00200E005
A) LFBO B) 0508010200 C) 05080200159
E) BARO AIDED GPS RAIM UNAVBL FOR NPA
0508010448 TIL 0508010455
0508012135 TIL 0508012140.
0508012135 TIL 0508012140
6 DURING THE FLIGHT
During the flight, the effective operation of the procedure shall be based on onboard real time GNSS signal availability
information, independently from the pre-flight RAIM prediction.
ENG
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