From nacho at canaryadvancedsolutions.com Tue Mar 25 01:15:22 2014 From: nacho at canaryadvancedsolutions.com (Nacho Romero) Date: Tue, 25 Mar 2014 08:15:22 +0000 Subject: [IGSSTATION-5727] GPS CNAV activation Message-ID: <53313B1A.2050407@canaryadvancedsolutions.com> Dear IGS members and participating institutions, Please note that the US Department of Transportation has announced the start of a continuous broadcast message on L2C and L5 (CNAV) from the most modern GPS satellites (IIR-M & IIF) starting during April, 2014. This decision is open for comment here: https://federalregister.gov/a/2014-04856 If you have comments please access the website and make your voice heard by 4 April, 2014. The IGS, after evaluation, will not comment on this action as we are confident that the IGS network is not at risk due to this change, and its a welcomed step towards GPS modernization. The IGS is also working to accommodate the CNAV messages in the Rinex 3 navigation files. This event is considered innocuous to the stability of the receiver network since during a limited GPS CNAV test campaign in June 2013 the IGS network was not affected, only a very specific receiver problem was detected by the IGS Multi-GNSS Experiment, which was informed to the GPS ground segment and addressed. Most modern receivers can track L2C and L5 and the CNAV messages, but the decoded messages should not be used by the receivers. The traditional L1 NAV messages (LNAV) will continue to be transmitted as usual and thus the receiver navigation files, brdc, etc, will continue unaffected. Older receivers will be completely unaffected as they do not track L2C or L5. In any case IGS Station Operators and Station Network Managers are advised to keep an eye on receivers and on their data outputs during the start of the CNAV activation. Just in case something strange is observed please stop data submission and notify the IGS (Network Coordinator, Infrastructure Committee) so that we may investigate the issues quickly. In case of doubt with your own equipment please contact the receiver manufacturer and inform the IGS. -- Best regards, Nacho Romero IGS Infrastructure Committee Chair _______________________________________________________________ Ignacio (Nacho) Romero Aerospace Engineer, PhD SAC @ ESA/ESOC/HSO-GN http://nng.esoc.esa.de http://www.canaryadvancedsolutions.com _______________________________________________________________ Este mensaje, y en su caso, cualquier fichero anexo al mismo, puede contener informacion clasificada por su emisor como confidencial en el marco de su Sistema de Gestion de Seguridad de la Informacion siendo para uso exclusivo del destinatario, quedando prohibida su divulgacion copia o distribucion a terceros sin la autorizacion expresa del remitente. Si Vd. ha recibido este mensaje erroneamente, se ruega lo notifique al remitente y proceda a su borrado. Gracias por su colaboracion. _______________________________________________________________ This message including any attachments may contain confidential information, according to our Information Security Management System, and intended solely for a specific individual to whom they are addressed. Any unauthorised copy, disclosure or distribution of this message is strictly forbidden. If you have received this transmission in error,