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 To unsubscribe, visit: http://www navcen uscg gov/?pageName=listServerForm