Subscribe free to our newsletters via your
. GPS News .




GPS NEWS
Galileo's search and rescue system passes first space test
by Staff Writers
Paris (ESA) Jan 30, 2013


Spectrum of the L-band signal received from the third Galileo satellite's Cospas-Sarsat search and rescue repeater at ESA's Redu Centre on 18 January 2013. This first switch-on represents the intial step in the expansion of the Cospas-Sarsat system into medium-Earth orbit.

The first switch-on of a Galileo search and rescue package shows it to be working well. Its activation begins a major expansion of the space-based Cospas-Sarsat network, which brings help to air and sea vessels in distress. The second pair of Europe's Galileo navigation satellites - launched together on 12 October last year - are the first of the constellation to host SAR search and rescue repeaters.

These can pick up UHF signals from emergency beacons aboard ships and aircraft or carried by individuals, then pass them on to local authorities for rescue. Once the satellites reached their 23 222 km-altitude orbits, a rigorous test campaign began. The turn of the SAR repeater aboard the third Galileo satellite came on 17 January.

"At this stage, our main objective is to check the repeater has not been damaged by launch," explains ESA's Galileo SAR engineer Igor Stojkovic.

"The first day was a matter of turning the repeater on and checking its temperature and power profiles were as predicted.

"The following day involved sending a signal to the repeater using the UHF antenna at ESA's Redu Centre in Belgium, then picking up the reply from our L-band antenna."

Redu's antenna is 20 m in diameter, so the shape of the relayed signal was captured in great detail, out of all proportion to surrounding noise.

"We can precisely measure its power, the time the relay took and so on," adds Igor.

More detailed system testing will follow, to completely prove this new type of SAR payload in orbit.

This international system has been taking the search out of search and rescue for more than three decades, saving some 31 000 lives along the way.

Cospas is a Russian acronym for 'Space System for the Search of Vessels in Distress', with Sarsat standing for 'Search and Rescue Satellite-Aided Tracking'.

Ground stations - known as Local User Terminals - pinpoint the source of distress calls using signals relayed by participating satellites, then alert local authorities.

Founded by Canada, France, Russia and the US, Cospas-Sarsat now has 43 participating countries and organisations. It began with payloads on low-orbiting satellites, whose rapid orbital motion allowed Doppler ranging of distress signals, to pinpoint their source. Their drawback is their field of view is comparatively small.

The system added payloads on geostationary satellites, which continuously see a third of the globe, but because they do not move relative to the ground they cannot locate signals directly.

The SAR repeaters on these two Galileo satellites are the first of a new class of 'MEOSAR' repeaters, combining broad field of views with the ability to quickly determine positions.

Galileo's satellites are also the first with the capability to despatch return link messages via their navigation signals, assuring those in distress that help is on the way.

An additional advantage of this new MEOSAR system is that less ground infrastructure is required - just three to four terminals are sufficient to serve all European territory.

This initial SAR unit's transponder was built by Mier Comunicaciones in Spain, with its combined receiving and transmitting antenna developed by Spain's Rymsa company.

The SAR payload of the fourth Galileo satellite is due to be switched on for testing in the coming weeks.

More detailed end-to-end testing of the repeaters will follow in the spring, using a dedicated system called the Galileo Search and Rescue Validation Test Bench based at France's Cospas-Sarsat control centre in Toulouse.

The unit can simulate multiple beacon messages for the system to find their location and relay them accordingly.

Further SAR payloads will follow these first two into orbit with the launches of follow-on Galileo Final Operational Capability satellites.

.


Related Links
Cospas-Sarsat at ESA
GPS Applications, Technology and Suppliers






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








GPS NEWS
AFRL Selects Surrey Satellite US to Evaluate Small Satellite Approach to GPS
Englewood, CO (SPX) Jan 22, 2013
The Air Force Research Laboratory (AFRL) has selected Surrey Satellite Technology US LLC (SST-US) to investigate cost reduction and augmentation of the current GPS constellation through the application of the small satellite approach. AFRL has contracted SST-US to identify and analyze how small satellites can improve aspects of GPS system performance such as accuracy, coverage, and robustn ... read more


GPS NEWS
Plants adapt to drought but limits are looming

Global Plant Diversity Hinges on Local Battles Against Invasive Species

Scarecrow gene might trigger big boost in food production

New Zealand's milk safe, government says

GPS NEWS
Quantum Communication: Each Photon Counts

Organic ferroelectric molecule shows promise for memory chips, sensors

DARPA, Industry Collaborate to Knock Down Microelectronics Barriers

New 2D material for next generation high-speed electronics

GPS NEWS
ANA keeps forecast as nine-month net profit surges

Eurocopter sets sights on S. America sales

China tests new military transport plane

NASA Super-Tiger Balloon Shatters Flight Record

GPS NEWS
Honda nine-month net profit doubles to $3.2 bn

Japan's top three automakers post record 2012 sales

Motion Control Keeps Electric Car's Four Wheels on the Road

Toyota, Nissan announce record sales for 2012

GPS NEWS
Despite optimism, tough road for immigration reform

Increasing problems for Tavan Tolgoi mine

Japan PM suggests summit with China

World tourist numbers exceed 1.0 billion in 2012: UN

GPS NEWS
Dartmouth research offers new control strategies for bipolar bark beetles

Brazil to inventory Amazon rainforest trees

Civilians fell rare Syrian trees for firewood

Prosecutors take issue with Brazil's new forestry code

GPS NEWS
New tools enable high-res observations from anywhere with internet access

Internet age navigation drives economies: studies

RapidEye Commits to Data Continuity; Discusses System Health and Life Span

Pleiades 1B captures its first images using e2v sensors

GPS NEWS
Notre Dame studies benefits and threats of nanotechnology research

A nano-gear in a nano-motor inside

New Research Gives Insight into Graphene Grain Boundaries

Chemistry resolves toxic concerns about carbon nanotubes




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement