MEOSAR
In 2000 the United States, the European Commission (EC) and Russia began consultations with Cospas-Sarsat regarding the feasibility of installing 406 MHz SAR instruments on their medium-altitude Earth orbiting (MEO) GPS, Galileo, and GLONASS navigation satellite systems. These MEOSAR constellations—DASS, SAR/Galileo, and SAR/GLONASS—eventually could become components of a 406 MHz Cospas-Sarsat MEOSAR system.
DASS, when formally commissioned by the U.S. according to Cospas-Sarsat procedures, is expected to be integrated into the Cospas-Sarsat MEOSAR constellation. The European Galileo Navigation Space System and the Russian GLONASS navigation system have proposed SAR payloads similar to DASS as secondary missions, and intend to integrate them into a Cospas-Sarsat MEOSAR system. To streamline operation and to ensure interoperability between the three MEOSAR systems, the following interoperability requirements will need to be established. DASS, SAR/Galileo and SAR/GLONASS will all be secondary missions aboard their host vehicles.
Canadian Contribution
The Canadian government offered in July 2006 to provide DASS transponders for GPS III satellites as a continuation of their national contribution to the Cospas-Sarsat Program. The payload will be functionally similar to the POC system, though the downlink will operate at 1544 MHz instead of S-band. The system will operate as an independent GPS III payload.
Cospas-Sarsat
During DASS development, the U.S. will coordinate with Cospas-Sarsat on issues related to the uplink frequencies of 406 MHz emergency beacons to ensure that as new frequency channels are opened in the 406 MHz band by Cospas-Sarsat or new beacon transmission schemes are introduced, the DASS system continues to be compatible. Use of the 1544 MHz band (either for downlink or return messages) will be coordinated with Cospas-Sarsat and with other users that may share the downlink.
The International Cospas-Sarsat Program Agreement (ICSPA) will be reviewed to identify the possible contribution of DASS as part of the Cospas-Sarsat space segment. Other States party to the ICSPA will be invited to participate in development of the ground segment. Meanwhile, the existing LEOSAR and GEOSAR systems will continue to be the primary alerting source for several years.
The DASS D&Ewill be conducted in coordination with Cospas-Sarsat and will use the approved Cospas-Sarsat MEOSAR D&E plan, which will outline the coordination required for MEOSAR alert data distribution, data collection and analysis, and reporting. During the D&E, it is planned that other Cospas-Sarsat participants will have ground stations to receive and process 406 MHz MEOSAR distress alert data, and distribute the resulting alert data through the Cospas-Sarsat MCC network.
Successful completion of a MEOSAR D&E by Cospas-Sarsat will enable the system’s integration into the operational Cospas-Sarsat System.
Efforts toward MEOSAR integration with Cospas-Sarsat prior to full operational capability will be accomplished under the auspices of the ICSPA. However, a new or revised international agreement will be needed before MEOSAR is declared fully-operational.
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