Europe's SSTL new ocean winds and waves measuring method - video

The video shows in about 20 times real time speed the motion of the TechDemoSat-1 satellite over an orbit, indicated by a white cross on the world map. 

The specular reflections targeted by the SGR-ReSI are shown by yellow spots, and the measurement tracks are shown in yellow. 

The four Delay Doppler Map channels from the SGR-ReSI are shown at the top right. The spreading horseshoe shape is caused by reflections being received away from the specular point, and a rougher ocean causes more spreading. 

When reflections are received from over land and over ice, there is much less spreading. 

The red band on the map indicates the collection of “raw” unprocessed data, which takes a few minutes to transfer before the processed Delay Doppler Maps resume.

Credit: SSTL

Surrey Satellite Technology Ltd (SSTL) has successfully demonstrated an innovative method of measuring winds and waves from space, using GNSS Reflectometry.

This paves the way for a cost effective satellite system supporting the maritime sector and the organisations that rely on this information and it also offers improvements to weather services and climate research.

The measurements were taken from an instrument developed by SSTL, the SGR-ReSI, (Space GNSS Receiver Remote Sensing Instrument) which is flying on-board TechDemoSat-1, a technology demonstration satellite which was launched in July 2014.

TechDemoSat-1

SSTL's SGR-ReSI collects the signals from GPS and other navigation satellites after they have been reflected off the ocean surface and processes them into images called Delay Doppler Maps, from which ocean roughness and wind speed measurements at the sea surface can be interpreted.

The technique works in a similar way to existing scatterometric radar from satellites, however it eliminates the need for a transmitter and can process up to four reflections from different GPS satellites simultaneously, presenting an opportunity for collecting data more regularly and in a denser grid across the globe.

By flying the receivers on a constellation of small satellites GNSS Reflectometry data could be used to map all of the Earth's ocean surface with refreshed data every couple of hours.

This would be of enormous benefit to the maritime industry who depend on wave height and wind speed predictions for optimum ship routing, insurance claims, oil and gas rig operations, undersea cable laying and fishing conditions.

Such wind speed and wave height measurements are currently very difficult to make over the open ocean in timely manner and in a dense enough grid to be useful.

Luis Gomes, Director of Earth Observation and Science at SSTL, commented: "We are very excited about the future application of this development which extends the applications of small satellites.

"For instance, a constellation of 18 SGR-ReSIs could cover most of the world's oceans every few hours providing a real time wind and wave height service."

"These do not need to be dedicated satellites as the SGR-ReSI can be easily accommodated as a hosted payload on small satellites with a different primary mission. Our aim is to deploy such a constellation in the next two years."

The SGR-ReSI can pick up GPS reflections not only off the ocean, but also off land, snow and ice, opening up other potential new opportunities for remote sensing - for example, measuring the thickness of sea ice, snow depth, soil moisture levels and the classification of vegetative foliage.

SSTL, supported by the European Space Agency, is now working on preparing the ground processing and web interface that will allow users access to the measurements over the internet with a short delay.

ESA Galileo: EU selects CGI to support Galileo Commercial Service Initiative

CGI has a long track record of supporting the European space industry, which includes having delivered the Constellation Control Facility that controls Galileo's 30 satellites, as well as developing software that underpins the missions of more than 200 individual satellites.

CGI has been awarded a contract to build the core infrastructure for the first demonstrator for the Galileo Commercial Service, part of the emerging European Global Navigation Satellite System (GNSS).

The contract was awarded by the European Commission Directorate General for Enterprise and Industry (DG ENTR).

When operational, Galileo satellites will take satellite navigation to a whole new level. Users will be able to rely on the service for their most critical positioning applications, especially when used in conjunction with other systems, such as GPS.

It will be especially useful in urban areas, on mountains and at high latitudes where GPS-only coverage can be intermittent.

The demonstrator application will show how Galileo can provide positioning services that are accurate to the centimetre, as well as its innovative position-authentication services could lead to further commercial uses.

Once complete, the demonstrator will be made available to other GNSS service providers to test across vertical markets, including transport, insurance and personal mobility.

The Galileo Commercial Service was introduced with the goal of creating a potential revenue source to support the future maintenance of EU satellite navigation services.

It provides added value to the Galileo Open Service with the expectation that new services will be based on its encrypted and guaranteed signal, which delivers a higher data throughput rate and increased positioning accuracy.

"The Commercial Service has many added benefits beyond its original designation as a potential revenue source for the Galileo system," said Steve Smart, vice president of the EU wing of the US corporation, Space, Defense and National Security at CGI in the UK.

"It will maximise the program's ability to provide the best navigation services possible to the public and commercial sectors, and will create economic value for the EU in general. We are proud to say we are playing a key role in this innovative process."

The European Commission DG ENTR is working in partnership with the European GNSS Agency (GSA) and the European Space Agency, in collaboration with member states.

The objective is to provide the operational Commercial Service, and its associated exploitation model, in the following years.

CGI has a long track record of supporting the European space industry, which includes having delivered the Constellation Control Facility that controls Galileo's 30 satellites, as well as developing software that underpins the missions of more than 200 individual satellites.