1. SEARCH AND RESCUE SATELLITE AIDED TRACKING (SARSAT)

2. Introduction History User Segment Space segment
Use of GPS in Location Protocol Beacons
LEOSAR and GEOSAR systems
Advantages/Disadvantages of each system
USMCC and SAR
Future of SARSAT

3. Introduction COSPAS = COsmicheskaya Systyema Poiska Aariynyich Sudov
Which loosely translates into: “The Space System for the Search of Vessels in Distress”
SARSAT = Search And Rescue Satellite Aided Tracking

4. It’s about saving lives… In short, Cospas-Sarsat works
Introduction
It’s about saving lives…
The Cospas-Sarsat Program protects life and property by providing accurate, timely, and reliable distress alert and location information to search and rescue authorities.
In short, Cospas-Sarsat works
to take the “search”
out of Search & Rescue

5. Introduction
Services are provided world-wide and free of charge for the user in distress
Alerts are provided using satellite and ground systems to detect, process, and relay the transmissions of emergency beacons operating on 406 MHz

6. History
First beacons were 121.5/243 MHz Emergency Locator Transmitters (ELTs) designed for military aircraft in the 1950’s.
U.S. Congress mandated ELTs on all U.S. aircraft after Boggs-Begich tragedy in SE Alaska in early 1970’s. Canada follows suit.
Problems soon emerge:
No identification of aircraft/beacon
Designed for audible detection by over-flying aircraft
No means of accurately locating ELTs

7. History
1978: Canada, France and the USA agree to co-operate on the development of the SARSAT low-altitude polar orbiting system to:
Locate existing MHz beacons
Develop a new technology for improved performance = 406 MHz
Russia declares its interest in co-operating with the objective of ensuring inter-operability of their COSPAS system with SARSAT.
Cooperative venture: Governments were looking for additional cooperative efforts after success of Apollo-Soyuz and the humanitarian nature of SAR was an easy fit…

8. History 1982: First Cospas satellite
Cospas-1 (USSR) launched in June 1982.
First rescue in September 1982
1983: Second Cospas and First Sarsat satellites
NOAA-8 satellite (USA) with Canadian (SARR) and French (SARP) instruments
1985: System declared operational
406 MHz beacon technology arrives

9. Over 40 Countries Participate
International Participation
Over 40 Countries Participate

10. Research & Development Representative to Cospas-Sarsat Program
U.S. SARSAT Program
SARSAT is a part of the international Cospas-Sarsat Program. The four multi-department agencies involved in the U.S. portion of SARSAT are:
Inland SAR
Maritime SAR
Research & Development
System Operation
Representative to Cospas-Sarsat Program

11. COSPAS-SARSAT User Segment
The system consists of a network of satellites, ground stations, mission control centres, and rescue coordination centres.
When an emergency beacon is activated, the signal is received by a satellite and relayed to the nearest available ground station. The ground station, called a Local User Terminal, processes the signal and calculates the position from which it originated. This position is transmitted to a mission control centre where it is joined with identification data and other information on that beacon.The mission control centre then transmits an alert message to the appropriate rescue coordination centre based on the geographic location of the beacon. If the location of the beacon is in another country's area of responsibility, then the alert is transmitted to that country's mission control centre.
The SARSAT system uses satellites in low-earth and geostationary orbits to detect and locate aviators, mariners, and land-based users in distress.
The system is designed to provide distress alert and location data to assist search and rescue (SAR) operations, using spacecraft and ground facilities to detect and locate the signals of distress beacons operating on 406 Megahertz (MHz) or 121.5 MHz.
EPIRB
ELT
PLB

12. Emergency Beacons EPIRBs ELTs PLBs SSAS
The search and rescue satellite system provides alerting services for the following types of beacons:
Emergency Locator Transmitters (ELTs) for aviation use
Emergency Position-Indicating Radio Beacons (EPIRBs) for maritime use
Personal Locator Beacons (PLBs) for applications which are neither aviation or maritime
Beacons operating at 406 MHz and 121.5 MHz are compatible with the Cospas-Sarsat System; however, the operational capabilities of the System are different for these two types of beacons.
An analogue MHz distress beacon is a small electronic device that emits a radio signal to help rescue authorities locate your position in a life-threatening emergency. The signal is picked up by polar-orbiting satellites and aircraft monitoring the MHz frequency.
When these devices are detected by satellite, you can be located to within 20 kilometres. Aircraft can home on your beacon signals leading them directly to the target. Detection takes an average of 90 minutes in Australia but can be up to five hours.
The 406 MHz distress beacon emits both an analogue MHz signal and a digital 406 MHz signal. The digital signal carries a code which identifies the beacon while the analogue signal is to enable aircraft to home on location. That digital code can be cross referenced with a database of registered 406 MHz beacon owners held at AMSA which identifies who is in trouble and what type of situation they are in. This enables the search and rescue authorities to tailor a response to the emergency situation.
A 406 MHz beacon narrows its position to within 5 kilometres. This can be reduced to just 120 metres if the beacon includes a Global Positioning System. Detection of 406 MHz beacons can be near instantaneous from a geo-stationary satellite.
SSAS

13. COSPAS-SARSAT User Segment Activation: Manual
Automatic (Hydrostatic/G-Switch)
Signal:
406 MHz (Digital)
121.5 MHz (Analog) Homing
Applications:
Maritime - Emergency Position-Indicating Radio Beacon (EPIRB)
Aviation - Emergency Locator Transmitter (ELT)
Personal/Land - Personal Locator Beacon (PLB)
Security – Ship Security Alerting System (SSAS)
* Most U.S. general aviation ELTs are still MHz which are no longer monitored by Cospas-Sarsat

14. Positive Attributes of 406 MHz
Every beacon has unique 15 hex identification
Unique ID allows registration with contact information
Non-Distress activations can be terminated with a phone call
Reduces stress on SAR assets
More powerful transmitter (5 watts vs. 75 milliwatts) and digital signal increases accuracy of location by Doppler processing
The system can discriminate between real beacon transmissions and non- beacon transmissions which reduces the resources spent on tracking interfering sources
Global coverage provided by store and forward capability of Cospas- Sarsat satellites
Increased system capacity due to short duration transmission, and spreading of frequency allocation

15. COSPAS-SARSAT
User Segment

16. Satellites Types 2 Types of Satellites:
Low Earth Orbiting Search And Rescue (LEOSAR)- 6 on Orbit
- Altitude: 500 miles in “Pole-Pole” orbit
- Performs Doppler locating function (primary means of locating…not GPS)
- Stores & Forwards alerts continuously for 48 hours (provides worldwide coverage and total system redundancy)
Geostationary Orbiting Search And Rescue (GEOSAR)- 5 on Orbit
- Altitude: 23,000 miles in fixed orbit
- Performs instantaneous alerting function. No locating capability unless beacon is equipped with GPS.
- Coverage from 70N – 70S

17. LEOSAR Satellites
Polar orbiting take approximately minutes to orbit
Orbit is approximately 850 km in altitude
Earth rotates 25 degrees longitude per orbit
Provides global coverage
Presently, 5 operational
(S7, S8, S10, S11, S12 and S13)

18. 3 distinct orbit planes w 2 satellites in each plane
LEOSAR Satellites
Polar orbiting and min. per orbit
Orbit is 850 km in altitude
Earth rotates 25 degrees longitude per orbit
Provides global coverage twice per day
Presently, 6 operational
(S7, S8, S10, S11, S12 and S13)
3 distinct orbit planes w 2 satellites in each plane

19. LEOSAR Instantaneous Coverage
Real Time Tracking available at :

20. LEO Local and Global Coverage
Detection of a 406 MHz beacon may use mutual visibility between beacon, satellite and ground station (LUT)
406 MHz beacon detections can be stored on board the satellite and re-broadcast later
Local Coverage

21. Determining Beacon Locations
From LEO Doppler Data T1 T2 T3
850 km
3400 km
Distress
Beacon
GEOMETRY FOR OVERHEAD PASS
Frequency
High
Actual
Low
Time
DOPPLER SHIFT CAUSES FREQUENCY TO APPEAR HIGHER THAN ACTUAL
DOPPLER SHIFT CAUSES
FREQUENCY TO APPEAR
LOWER THAN ACTUAL
TIME OF CLOSET APPROACH (AND ACTUAL FREQUENCY)

22. Resolving Ambiguity Two Pass Solution for a Beacon Located in Brazil2 1
Two Pass Solution for a Beacon Located in Brazil
LEGEND: ground tracks of successive spacecraft orbits
1A, 1B Real and Image solutions from pass 1
2A, 2B Real and Image solutions from pass 2 1 2

23. GEOSAR Satellites At a fixed point 36,000 km above the Earth’s surface
Continually monitors a large area of Earth’s surface
Covers up to +/- 75o latitude
Presently have 6 operational (Electro-1, GOES-12, GOES-13, GOES-15, INSAT-3A, and MSG 3)
No Doppler shift capability

24. GEOSAR Satellites Indian National Satellite Meteosat Second Generation
(INSAT)
Meteosat Second Generation
(MSG)
GEOSAR Satellites

25. GEOSAR Satellites (Cont.)
Geosynchronous Operational and Environmental Satellite
(GOES)
GEOSAR Satellites (Cont.)
Electro – L1
Meteorological Satellite

26. GEOSAR Coverage Worldwide real-time coverage
Real Time Tracking available at :

27. Advantages of LEOSAR System
Locates beacons using Doppler shift processing. GEOSAR system does not have Doppler capability.
Provides global coverage for 406 MHz. GEOSAR system does not cover the polar areas.
Provides improved detection probability for obstructed beacons that can’t be seen by GEOSAR such as mountain ranges or canyons (see next slide)
Receives higher power levels from beacons, which increases the probability for beacon detection.
Advantages of LEOSAR System
over the GEOSAR System

28. Beacon Detection with Obstruction
GEO Satellite
Path of LEO satellite.
Beacon
RF Coverage

29. Advantages of GEOSAR System
over the LEOSAR System
Near instantaneous detection.
Near instantaneous location determination for beacons with GPS capacity
Continuous monitoring of ~1/3 of Earth’s surface

30. Advantages of a combined LEOSAR/GEOSAR System
Real Time Tracking available at :

31. Location Protocol Beacons
4 GPS Satellites
Use of GPS in
Location Protocol Beacons
LUT
C/S Satellites
406 MHz Message with
Embedded GPS location
15% of beacons are Location Protocol

32. 406 MHz Beacon with GPS Receiver Location Protocol Beacons
C/S Satellites
4 GPS Satellites
LUT
406 MHz Message with
Embedded GPS location
GPS Satellites
24-satellite constellation
4 satellites in view at all times
Minimum of 3 satellites needed to compute locations. Additional satellites improve accuracy.
Transmit time and orbital data
406 MHz Beacon with GPS Receiver
Uses satellite-beacon time difference to calculate distance from each GPS satellite
Uses GPS satellite orbital data and distance from beacon to calculate beacon location.
Encodes location in 406 MHz message.
Use of GPS in
Location Protocol Beacons

33. Ground Segment

34. LEOLUTS and GEOLUTS (Cospas-Sarsat Ground Stations)
LEOSAR Local User Terminals
(LEOLUT)
Track COSPAS and SARSAT satellites (POES & METOP)
Recover beacon signals
Perform error checking
Perform Doppler processing
Send alert to Mission Control Center
GEOSAR Local User Terminals
(GEOLUT)
Track GOES, MSG, & INSAT satellites
Recover beacon signals
Perform error checking
Send alert to Mission Control Center

35. Ground Segment
57 LEOLUTs in 46 Locations

36. Ground Segment
23 GEOLUTs in 20 Locations

37. Mission Control Centres (MCCs)
Receive alerts from national LUTs and foreign MCCs.
Validate, match and merge alerts to improve location accuracy and determine the correct destination.
Query 406 MHz Registration Database and transmit registration info with distress alert.
Transmit alerts (SIT msgs) to Rescue Coordination Centers (RCCs) and SAR Points of Contact (SPOC) and filters redundant data.
Most MCC functions are handled automatically…no manual intervention = efficiency!
NOTE: for 406 MHz only
USMCC
Suitland, Maryland

38. Importance of Registration
Identification
Digital data transmitted by beacon provides nationality and type of beacon
Tail number or other identifying information can be encoded into the beacon
Registration Database provides additional information such as owner/operator, and can include specifics on aircraft or vessel
Use of Registration Database to contact owner or emergency POC; this allows rescue forces to get more detailed information such as nature of emergency, severity of injuries, number of people involved, etc. and can help determine if alert is actual distress
In most cases, false alerts are resolved prior to launch of resources, saving taxpayer $$

39. 406 MHz Beacon Users in the U.S.

40. Search and Rescue Segment

41. U.S. SAR Partners Search and Rescue Partners: Cospas-Sarsat Lead,
Satellite Information
SAR Services
DOC
DOI
Research and Development
SAR Facilities
DOD
NASA
SAR Facilities
Regulations for Radio Facilities
FCC
DHS

42. Rescue Coordination Centers (RCC)
Receive SARSAT Distress Alerts from MCCs
Coordinate the Rescue Response

43. US RCCs & their Search and Rescue Areas of Responsibility
AKRCC Elmendorf AFB
RCC
CLEVELAND
RCC
JUNEAU
RCC
SEATTLE
RCC
BOSTON
NOTE: for 406 MHz only
AFRCC
Tyndall AFB
RCC
NORFOLK
RCC
HONOLULU
RCC
ALAMEDA
RCC
GUAM
RCC
SAN JUAN
RCC
MIAMI
RCC
NEW ORLEANS

44. National Rescue Data Number rescued world-wide since 1982: over 32,000
Number rescued in United States since 1982: 7,000
CY 2012 – 263 Rescues in 111 Events
Rescues at sea:   182 people rescued in 54 incidents
Aviation rescues:    people rescued in 13 incidents
Terrestrial rescues:  people rescued in 44 incidents

45. Future Enhancements Current Limitations GEOSAR:
Coverage limited to 70N to 70S
Fixed geometry to emergency beacon
No Doppler or independent location capability
LEOSAR:
Waiting time
Payload configuration fixed
System:
Performance variations between SAR payloads
System reliability

46. Future Enhancements
Repeaters will be flown on Medium Earth Orbit (MEO) satellites
Will utilize 3 Global Navigation Satellite System (GNSS) constellations
GPS (USA)
GLONASS (Russia)
Galileo (Europe)
Current plan is to have 24
US MEOSAR instruments
72 MEOSAR instruments total

47. Future Capability – Medium Earth Orbit SAR System (MEOSAR)
Future Enhancements
Future Capability – Medium Earth Orbit SAR System (MEOSAR)
Improved Position Accuracy
Decrease in waiting time
Robust Space Segment which operates even if some of the satellites fail

48. Any Questions?