SATELLITE AIDED SEARCH AND RESCUE,

INSAT-3D: migration from GEOSAR & LEOSAR to MEOSAR

About sas&r

SAS&R stands for satellite aided search and rescue It may be called as SARSAT(Search and rescue,

satellite aided tracking). The beginnings of SARSAT date back to October 1972. The SARSAT system was developed in a joint effort by

the United States, Canada , and France. In the United States, the SARSAT system was

developed by NASA. Once the system was functional, its operation was

turned over to NOAA where it remains today

HOW SARSAT WORKS

1. Search and Rescue (SAR) instruments are flown on Low Earth Orbiting (LEO) and Geostationary Orbiting (GEO) satellites.

2. ELTs, EPIRBs, and PLBs operation.

3. Signals to LUTS

4. The LUT processes the data and transmits an alert message to its respective Mission Control Center (MCC)

5. The MCC performs matching and merging of alert messages with other received messages

6. The RCC investigates the beacon alert and launches assets to find the parties in distress when necessary.

PICTORIAL REPRESANTATION OF SARSAT

EMERGENCY BEACONS

1. Emergency Position Indicating Radio Beacon (EPIRB) 

2. Emergency Locator Transmitters (ELTs)

3. Personal Locator Beacons (PLBs)

satellites

INSAT-3D GSAT-7 GSAT-10 INSAT-3A KALPNA

PAYLOADS OF INSAT-3D

6 channel multi-spectral Imager Outgoing Long wave Radiation (OLR) Quantitative Precipitation Estimate (QPE) Atmospheric Motion Vector (AMV) Upper Troposphere Humidity (UTH) Sea Surface Temperature (SST) Land Surface Temperature (LST) Water Vapor Wind Vector

19 channel Sounder Data Relay Transponder (DRT) Search and Rescue Transponder

PAYLOADS

SOUNDER Temperature, Humidity profiles and Integrated Ozone Geo-potential Height (GH) Layer Precipitable Water Total Precipitable Water Lifted Index (LI) Wind Index (WI) Dry Microburst Index (DMI) Potential Temperature Dierential Ozone estimate

Medium Earth Orbit Search and Rescue (MEOSAR) System

GEOSAR systems provide location information only if this information is available from an external source (i.e. global navigation receiver in the beacon) and transmitted in the 406 MHz beacon message;

obstructions blocking the beacon to satellite link cannot be overcome because the satellite is stationary with respect to the beacon; and

the beacon to satellite to LUT communication link budget is less robust than the LEOSAR system because of the greater distances involved (decreasing the probability that 406 MHz beacon messages are properly detected by the GEOSAR system).

Payloads of GSAT-10 Communication Payloads

12 Ku-band transponders each with 36 Mhz usable bandwidth employing 140 W Travelling Wave Tube Amplifier (TWTA) with footprint covering Indian mainland with an Edge of Coverage Effective Isotropic Radiated Power (EIRP) of 51.5 dBW and Andaman & Nicobar islands with an EIRP of 49.5 dBW

12 C-band transponders each with 36 MHz usable bandwidth employing 32 W TWTA with footprint covering Indian mainland and West Asia with an Edge of Coverage EIRO of 40 dBW

6 Lower Extended C-band transponders each with 36 MHz usable bandwidth employing 32 W TWTA with footprint covering Indian mainland and island territories with an Edge of Coverage EIRP of 38 dBW and 37

Navigation Payload

Two-channel GAGAN payload operating in L1 and L5 bands provides Satellite-based Navigation services with accuracy and integrity required for civil aviation applications over Indian Air Space.

Future Scope and Enhancement

Initial investigations identified many possible SAR alerting benefits that might be realized from a MEOSAR system, including

near instantaneous global coverage with accurate independent location capability,

robust beacon to satellite communication links, high levels of satellite redundancy and availability,

resilience against beacon to satellite obstructions, and the possible provision for additional (enhanced) SAR

services, such as a ground to beacon return link.

CONCLUSION

Cospas-Sarsat is an international satellite system for search and rescue (SAR) distress alerting that was established in 1979 by Canada, France, the USA and the former USSR

43 countries and organizations share in the management of the System.

At the end of 2009, more than 28,000 people had been rescued through the use of the System.

Because of LEOSAR satellite orbit patterns, there can be delays between beacon activation and the generation of an alert message.

So we will move on the MEOSAR for fast and furious action.