1. MEOSAR Beacon Modernization Discussion
RCC-SARSAT Conference February 2010
Dan Lemon

2. Beacon Modernization Objectives
Overcome limitations of current 406 MHz beacons operating through the LEOSAR-GEOSAR system
Identify operational ‘requirements’ of SAR personnel…things they need or want…for new beacons operating through MEOSAR
Develop Cospas-Sarsat and other national and international standards for new beacons and for the MEOSAR ground system that match the ‘requirements’
Expand beacon usage within communities that should use beacons
Dramatically improve Cospas-Sarsat performance and capabilities

3. Today’s Session
Provide some background on the beacon modernization effort
Allow you to discuss SAR requirements for new beacons that will operate through the MEOSAR system
Prepare you to complete, and to help other RCC controllers to complete, the NOAA questionnaire which is due by 15 March

5. Cospas-Sarsat System Evolution
LEOSAR system launched for MHz ELTs and EPIRBs
406 MHz EPIRBs and ELTs introduced
GEOSAR system added
121.5 MHz EPIRBs ‘outlawed’
406 MHz PLBs introduced
Satellite processing of MHz alerts terminated
MEOSAR system and beacons under development

6. Assumptions
MEOSAR space segment launches will remain on schedule, and the MEOSAR ground system coverage will be about 98% in 2015
New beacons will be appearing on the market initially within the timeframe
MEOSAR will be compatible with existing 406 MHz beacons, but the LEOSAR system will not process the new beacons
Some new beacons will have a return link capability that will operate outside the Cospas-Sarsat System

7. LEO-GEOSAR Limitations/Concerns
Non-continuous satellite coverage for system located alerting
Sub-optimal probability of detection of beacons
Need for at least three bursts for a location during what could be a short satellite exposure time
Frequent dependence on low elevation satellites
Need for very precise beacon oscillators to support Doppler locating and ambiguity resolution…one cost driver for beacons
Long average time to deliver located alerts

8. Beacon Limitations/Concerns
Beacon cost, size and weight
Power hungry…beacon operating 24 hours needs a battery able to produce 1,728 five watt signals plus any homing signals and other functions
Mix of complex coding protocols
Sub-optimal for 406 MHz homing
GPS capability is not ubiquitous
Transmissions of 406 and MHz signals are both compromised by sharing an antenna
Communications are one-way

9. MEOSAR Characteristics
More than ten times as many satellites as LEOSAR providing continuous global coverage
Optimum satellite altitudes with larger footprints
Single beacon burst locating
Better accuracy
Single location per beacon signal (no ambiguity)
Better probability of detection
System located alerts delivered in less than ten minutes

10. MEOSAR/New Beacon Needs and Wants for SAR?
System locations?
Encoded locations?
Time to first alert?
Alert intervals?
Homing?
Operating time?
Alert message content?
Temperature extremes?
Return Link?

11. NOAA Voluntary Questionnaire on New Beacons that will Operate through the Future Cospas-Sarsat Medium Earth Orbit Search and Rescue (MEOSAR) System
Due 15 March 10