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GPS Constellation Active Nanu Status
GPS CONSTELLATION STATUS FOR 07/04/2015

Plane Slot SVN PRN Block-Type Clock Outage Date Nanu-Type Nanu-Subject
A 1 65 24 IIF CS
A 2 52 31 IIR-M RB
A 3 64 30 IIF RB
A 4 48 7 IIR-M RB
B 1 56 16 IIR RB
B 2 62 25 IIF RB
B 3 44 28 IIR RB
B 4 58 12 IIR-M RB
B 5 71 26 IIF RB 20 APR 2015 USABINIT 2015028 - SVN71 (PRN26) USABLE JDAY 110/2222
B 6 51 20 IIR RB
C 1 57 29 IIR-M RB
C 2 66 27 IIF RB
C 3 59 19 IIR RB
C 4 53 17 IIR-M RB
D 1 61 2 IIR RB
D 2 63 1 IIF RB
D 3 45 21 IIR RB
D 4 67 6 IIF RB
D 5 46 11 IIR RB
D 6 34 4 IIA RB 09 JUL 2015 FCSTMX 2015065 - SVN34 (PRN04) FORECAST OUTAGE JDAY 190/0300 - JDAY 190/1500
E 1 69 3 IIF RB
E 2 47 22 IIR RB
E 3 50 5 IIR-M RB
E 4 54 18 IIR RB 24 APR 2015 FCSTCANC 2015030 - SVN54 (PRN18) FORECAST OUTAGE CANCELED
E 5 23 32 IIA RB
E 6 40 10 IIA CS
F 1 41 14 IIR RB
F 2 55 15 IIR-M RB
F 3 68 9 IIF RB
F 4 60 23 IIR RB
F 6 43 13 IIR RB
GENERAL INFORMATION NANUs
2014038

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014038 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
THE PURPOSE OF THIS NOTIFICATION IS TO INFORM USERS OF AN UPCOMING EVENT RELATED TO THE GPS SATELLITE CONSTELLATION. AIR FORCE SPACE COMMAND WILL BE IMPLEMENTING CNAV MESSAGES ON THE GPS L2C AND L5 SIGNALS BEGINNING J118/1430Z WITH UPDATES FROM THE CONTROL SEGMENT APPROXIMATELY TWICE PER WEEK. THE MESSAGE POPULATED SIGNAL CONTENT WILL INCLUDE BROADCAST MESSAGE TYPES (MT) 10, 11, 12, 30, AND 33. THERE ARE NO PLANNED GPS SATELLITE OUTAGES OR DEGRADATIONS FOR THIS ACTIVITY. L2C AND L5 CNAV MESSAGES SHOULD BE TRANSPARENT TO GPS RECEIVERS THAT DO NOT PROCESS L2C OR L5 CNAV MESSAGES. THESE POPULATED SIGNALS ARE INTENDED TO FACILITATE USER FAMILIARIZATION AND DEVELOPMENT OF COMPATIBLE USER EQUIPMENT.

NOTE: UNTIL FURTHER NOTICE, THE L2C AND L5 SIGNALS ARE CONSIDERED PRE-OPERATIONAL. A PRE-OPERATIONAL SIGNAL MEANS THE AVAILABILITY AND OTHER CHARACTERISTICS OF THE BROADCAST SIGNAL MAY NOT COMPLY WITH ALL REQUIREMENTS OF THE RELEVANT INTERFACE SPECIFICATIONS AND SHOULD BE EMPLOYED AT THE USERS? OWN RISK. THEREFORE THESE SIGNALS SHOULD NOT BE USED FOR SAFETY-OF-LIFE OR OTHER CRITICAL PURPOSES. ANY MILITARY OR CIVIL USERS WHO ENCOUNTER USER EQUIPMENT PROBLEMS FOLLOWING MESSAGE POPULATION OF THE L2C AND L5 SIGNALS SHOULD CONTACT THE APPLICABLE POCS IDENTIFIED BELOW AS SOON AS POSSIBLE. AVIATION USERS SHOULD FILE REPORTS CONSISTENT WITH FAA-APPROVED PROCEDURES.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2014039

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014039 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
REFERENCE NANU 2014038. UPDATE:


THE PURPOSE OF THIS NOTIFICATION IS TO INFORM USERS THAT THE CNAV MESSAGES ON THE GPS L2C AND L5 SIGNALS BEGINNING ON APPROXIMATELY J118/1430Z, WILL INCLUDE BROADCAST MESSAGE TYPES (MT) 10, 11, 30, AND 33, BUT WILL EXCLUDE BROADCAST MT 12.


ADDITIONALLY, THE CNAV MESSAGE HEALTH BITS WILL INDICATE THAT THE L1 AND L2 SIGNALS ARE HEALTHY, BUT THAT THE L5 SIGNAL IS UNHEALTHY. THE CNAV MESSAGE HEALTH BITS MAY FUNCTION INDEPENDENTLY FROM THE LEGACY MESSAGE HEALTH BITS AND SHOULD NOT BE CONSIDERED RELIABLE INDICATORS OF SIGNAL QUALITY OR PERFORMANCE DURING PRE-OPERATIONAL USE.


REMINDER: UNTIL FURTHER NOTICE, THE L2C AND L5 SIGNALS ARE CONSIDERED PRE-OPERATIONAL. A PRE-OPERATIONAL SIGNAL MEANS THE AVAILABILITY AND OTHER CHARACTERISTICS OF THE BROADCAST SIGNAL MAY NOT COMPLY WITH ALL REQUIREMENTS OF THE RELEVANT INTERFACE SPECIFICATIONS AND SHOULD BE EMPLOYED AT THE USERS? OWN RISK. THEREFORE THESE SIGNALS SHOULD NOT BE USED FOR SAFETY-OF-LIFE OR OTHER CRITICAL PURPOSES. ANY MILITARY OR CIVIL USERS WHO ENCOUNTER USER EQUIPMENT PROBLEMS FOLLOWING MESSAGE POPULATION OF THE L2C AND L5 SIGNALS SHOULD CONTACT THE APPLICABLE POCS IDENTIFIED BELOW AS SOON AS POSSIBLE. AVIATION USERS SHOULD FILE REPORTS CONSISTENT WITH FAA-APPROVED PROCEDURES.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2015021

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2015021 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
SUBJ: SVN38 (PRN08) DECOMMISSIONING JDAY 085/2200
1. NANU TYPE: GENERAL
NANU NUMBER: 2015021
NANU DTG: 262242Z MAR 2015
REFERENCE NANU: 2015003
REF NANU DTG: 021712Z JAN 2015
SVN: 38
PRN: 08
UNUSABLE START JDAY: 303
UNUSABLE START TIME ZULU: 1500
UNUSABLE START CALENDAR DATE: 30 OCT 2014
DECOMMISSIONING JDAY: 085
DECOMMISSIONING TIME ZULU: 2200
DECOMMISSIONING CALENDAR DATE: 26 MAR 2015

2. CONDITION: GPS SATELLITE SVN38 (PRN08) WAS UNUSABLE AS OF JDAY 303 (30 OCT 2014)
AND REMOVED FROM THE GPS CONSTELLATION ON JDAY 085 (26 MAR 2015).
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2015032

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2015032 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
ON APPROXIMATELY 30 APR 2015, SVN49 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN08. AT L-BAND ACTIVATION, SVN49/PRN08 WILL BE UNUSABLE UNTIL FURTHER NOTICE. ADDITIONALLY, NO BROADCAST ALMANACS WILL INCLUDE SVN49/PRN08 UNTIL FURTHER NOTICE.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2015039

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2015039
SUBJ: LEAP SECOND
1. CONDITION: THE INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS
SERVICE (IERS) HAS ANNOUNCED THE INTRODUCTION OF A LEAP SECOND TO
OCCUR AT THE END OF JUN 2015.

2. COORDINATED UNIVERSAL TIME (UTC) WILL SEQUENCE AS FOLLOWS:
30 JUN 2015 23 HOURS 59 MINUTES 59 SECONDS
30 JUN 2015 23 HOURS 59 MINUTES 60 SECONDS
01 JUL 2015 00 HOURS 00 MINUTES 00 SECONDS

3. FOR GPS, AS WITH PREVIOUS LEAP SECOND UPDATES, THE UTC DATA IN
THE NAVIGATION MESSAGE WILL CHANGE IN ACCORDANCE WITH IS-GPS-200.

BEFORE THE LEAP SECOND
GPS-UTC IS 16 (GPS IS AHEAD OF UTC BY 16 SECONDS)

AFTER THE LEAP SECOND
GPS-UTC WILL BE 17 (GPS WILL BE AHEAD OF UTC BY 17 SECONDS)

4. POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL



GPS Expandable Slot Designations
B D F
B5=B1F D5=D2F F5=F2F
B1-B1A D2=D2A F2=F2A