B777 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Situational Awareness
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Other / Unknown
General None Reported / Taken
ATC Equipment / Nav Facility / Buildings; Environment - Non Weather Related; Human Factors
During climb-out with a Notam warning of GPS jamming in the area; we did receive an ADS-B L ICAS message around the mid 20s.  We complied with the checklist and a few moments later we received an ADS-B R ICAS message.  While running through that checklist we noticed the ANP was 1.02.  After we finished the checklist we were approaching our level-off so I waited to do any other investigation until the level off was complete.  Just after level-off; the ANP went back to .02 and the alerts were gone.  We let Control know and did write up the alerts in the maintenance log.
Captain reported experiencing GPS jamming as was predicted by NOTAM.