by Staff Writers
Paris (ESA) Mar 13, 2014
Soaring high above Earth as they speed through space, satellites are difficult targets to track. Now a new approach developed in Europe is helping ground stations to acquire signals faster and more accurately than ever before.
During launch, a satellite is flung into orbit with tremendous force, attaining speeds of over 28 000 km/h - about 40 times faster than a commercial airliner.
A critical moment is when the satellite separates from its rocket and starts transmitting radio signals. A receiving station on the ground has to be ready and waiting, pointed at precisely the right spot in the sky to catch the transmission, which is a highly focused and narrow beam. And it's moving fast.
"Traditionally, even the best stations - like ESA's 15 m and 35 m-diameter dishes - are only sensitive across an arc of just a few degrees," says Magdalena Martinez de Mendijur, a systems engineer at ESA's Operations Centre in Germany.
"If the antenna is not pointed perfectly, or if the satellite zips by out of its 'field of view' before acquisition, the signal could be missed altogether."
A cutting-edge difference
The system mounts a circular array of eight small radio-frequency sensors around the rim of an existing dish antenna.
"The signals received by these eight are combined, and the system can estimate the direction of arrival of the incoming radio beam, and the entire dish can be repointed directly at the satellite with great precision and accuracy, even when the incoming signal is weak or distorted," says Magdalena.
It was fitted to the 15 m dish at ESA's Space Astronomy Centre in Spain in 2013. Since then, it has been extensively tested, catching signals from missions including CryoSat-2, XMM, GOCE and Swarm.
ESA partners with European industry
"A future version should improve this to just two seconds."
The technology was developed by Spanish company Isdefe, partly supported by ESA's General Support Technology Programme, which converts promising engineering concepts into mature products.
The system has been patented in Spain and is being patented in Europe, and will be developed into a full commercial product.
"This is an excellent example of how technology research supported through ESA funding and technical and managerial supervision can be developed by European industry into world-class products and services," says Juan Miro, Head of ESA's Ground Systems Engineering department.
General Support Technology Programme (GSTP)
Read the latest in Military Space Communications Technology at SpaceWar.com
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|