1. RECEIVER AUTONOMOUS INTEGRITY MONITORING (RAIM)
1.1 Introduction of RNP procedures in Mongolia
1.1.1 RNP and RNAV procedures are planned to be introduced for all airports in Mongolia in accordance with standards and recommended practices of ICAO.
1.2 Receiver Autonomous Integrity Monitoring (RAIM)
1.2.1 Depending on the geometric dilution of precision of the satellite constellation, signals must be received from at least 4, sometimes more than 4 satellites in order to determine the receiver’s position.
1.2.2 In addition to determining their position, aircraft receivers can also carry out a test called RAIM of the received satellite signals. This test requires a signal from further satellite which means that the minimum number of GPS satellites increases to at least 5.
1.3 RAIM prediction service
1.3.1 The requirement for at least 5 satellites from which signal can be received is not always fulfilled by the existing GPS satellite constellation. The non-availability times vary widely and are dependent on a large number of parameters such as position of the aircraft, receiver type being used, maintenance period of satellite etc.
1.3.2 Before a selected non-precision approach is activated, the pilot checks whether the GPS will be available with sufficient accuracy at the expected approach time using predictive RAIM capability. If GPS is not available with sufficient accuracy, the selected approach cannot be activated by the pilot.
1.4 RAIM prediction service of CAA
1.4.1 CAA uses a RAIM system, which was implemented by German Air Navigation Services (DFS-Deutsche Flugsicherung), for GPS availability prediction and offers NOTAM services related to GPS RAIM to the following airports in Mongolia:
No. | Location Indicator | Aerodrome name | Aerodrome Reference Point (ARP) coordinates |
|---|
| 1 | ZMAH | UVURKHANGAI/Arvaikheer | 461500N 1024806E |
| 2 | ZMAT* | GOBI-ALTAI/Altai | 462237N 0961302E |
| 3 | ZMBH | BAYANKHONGOR/Bayankhongor | 461003N 1004210E |
| 4 | ZMBN | BULGAN/Bulgan | 485121N 1032830E |
| 5 | ZMBS | KHOVD/Bulgan sum | 460602N 0913501E |
| 6 | ZMBU | SUKHBAATAR/Baruun-Urt | 463937N 1131707E |
| 7 | ZMCD* | DORNOD/Choibalsan | 480806N 1143847E |
| 8 | ZMCK* | ULAANBAATAR/ Chinggis Khaan | 473849N 1064912E |
| 9 | ZMDN | ZAVKHAN/Otgontenger | 474237N 0963126E |
| 10 | ZMDZ | UMNUGOBI/Gurvansaikhan | 433630N 1042158E |
| 11 | ZMHG | KHUVSGUL/Khatgal | 502629N 1000803E |
| 12 | ZMHH | UVURKHANGAI/Kharkhorin | 471448N 1024938E |
| 13 | ZMKB | UMNUGOBI/Khanbumbat | 430837N 1065038E |
| 14 | ZMKD* | KHOVD/Khovd | 475716N 0913739E |
| 15 | ZMMG | DUNDGOBI/Mandalgobi | 454411N 1061610E |
| 16 | ZMMN* | KHUVSGUL/Muren | 493946N 1000558E |
| 17 | ZMSF | NALAIKH/Sky friends | 474623N 1072616E |
| 18 | ZMTL | ZAVKHAN/Tosontsengel | 484419N 0981737E |
| 19 | ZMTT | UMNUGOBI/Tavantolgoi | 434625N 1053443E |
| 20 | ZMUB* | ULAANBAATAR/Buyant-Ukhaa | 475033N 1064603E |
| 21 | ZMUG* | UVS/Deglii tsagaan | 500400N 0915611E |
| 22 | ZMUH | KHENTII/Undurkhaan | 471816N 1103632E |
| 23 | ZMUL* | BAYAN-ULGII/Ulgii | 485939N 0895524E |
* Aerodrome with RNP and RNAV procedure
Note: NOTAM related to GPS RAIM prediction issued by CAA should be taken as advisories only and do not constitute an unavailability of the relevant procedure or an aerodrome closure. It remains the aircraft operator’s responsibility to evaluate the available information and determine the availability of the relevant procedure accordingly.
1.5 Publishing of NOTAM
1.5.1 NOTAM related to GPS RAIM prediction will only be issued for aerodromes with RNP and RNAV procedure.