SSTL is supplying the EarthCARE Multi-Spectral Imager (MSI) instrument for ESA’s EarthCARE mission. With spacecraft prime being EADS Astrium GmbH, EarthCARE is a joint European-Japanese mission, addressing the need for a better understanding of the interactions between cloud, radiative and aerosol processes that play a role in climate regulation.

Scientists agree that the knowledge of processes involving clouds, aerosol and radiation is far too limited. A better understanding of these processes could for example lead to more reliable climate predictions and weather forecasts. The objective of the EarthCARE mission is the observation of clouds and aerosols from low Earth orbit. The MSI instrument will provide information on the horizontal variability of the atmospheric conditions, to identify e.g. cloud type, textures, and temperature, and will form Earth images in seven spectral bands: one visible (VIS), one near-IR (NIR), two short-wave IR (SWIR) and three thermal IR (TIR).

The images of the Earth are captured and data recorded by two cameras – the VNS camera (covering the VIS, NIR and SWIR bands) and the TIR camera. The VNS and TIR cameras are part of the MSI Optical Bench Module (OBM) which is mounted on an external spacecraft panel, connected via a harness to the MSI Instrument Control Unit (ICU). The MSI ICU is located within the interior of the satellite and is being developed by SEA (Bristol). A CAD image of the MSI OBM is shown in Figure 1.

The TIR camera is being developed by SSTL with support from ABSL (Oxford) for the TIR blackbody and University of Reading for the filters and dichroics. An expanded view of the TIR camera showing the major building blocks of the camera is shown below (see Figure 2). The VNS camera is being developed by TNO with support from XenICs for the VNS detectors.

Continue reading "EarthCARE MSI moves ahead"

Gordon Hopkinson, from SSTL's Optical Payloads Group was a physicist who made a notable contribution to the development of today’s space imaging systems

Gordon Hopkinson was one of the world’s experts in the physics of optical detectors used in a wide range of applications from digital cameras through to international space missions and even mobile phones. For three decades he was involved in detailed analysis and modelling of solid state cameras and contributed significantly to the research of their use in a wide range of applications from X-ray mammography, the mapping of the stars to the search for dark matter.

His ability to undertake detailed measurements, identify new phenomena and develop the underlying mathematical models was second to none. Gordon was also a very kind person, modest and with a high standard of integrity. He will be sorely missed by friends and colleagues both within the UK and across the world.

Hopkinson began his research at Manchester University with spells at Durham and Leicester undertaking research into astronomy, such as spectral investigations of comets and observations of zodiacal dust. His move to Leicester coincided with the emergence of the new and revolutionary solid state detectors based on silicon chips, known as Charge Coupled Devices (the heart of today’s digital cameras). The first of these were developed in the UK in 1972 by EEV (subsequently known as e2v). The Charge Coupled Devices (CCD) would replace the previous bulky vacuum tube detectors and eventually give rise to the demise of photographic film.

At Leicester University Hopkinson developed ground breaking techniques for achieving low noise performance from CCDs and together with David Lumb wrote the definitive paper on the subject. These techniques were subsequently applied to the new breed of space imaging missions and are still used to this day. He has several publications in this field and numerous citations. The research that Hopkinson undertook at Leicester would shape his professional life.

In 1983 Hopkinson moved to the Sira research and development organisation in Kent and immediately found that his expertise in CCDs was essential to fully exploit the capabilities of these devices in a range of new and highly demanding space instrumentation. Hopkinson’s first task was to support the development of the state of the art star trackers and a star mapper for a X-ray satellite mission called ROSAT, funded by the German Space Agency and launched in 1990. The ROSAT mission undertook an all-sky survey of x-ray emitting objects and led to a detailed morphology of supernova remnants and clusters of galaxies. ROSAT operated until 1999. Similar applications soon arose in the use of CCDs for first inter-satellite laser communications system (SILEX), oceanographic monitoring (MERIS) and the measurement of ozone from space (GOMOS), all of which are still in operation today providing invaluable information and capabilities to the European science community.

Hopkinson’s key expertise was not only in achieving high performance from solid state detectors but also analysing the complex effects arising from the harsh space radiation environment of protons and gamma rays. This was a special interest that led to international recognition. Of particular note was a request by the European Space Agency (ESA) for Hopkinson to undertake detailed radiation analysis on a new but highly demanding astrometric mission called GAIA. This mission aims to create the largest and most precise three dimensional chart of our Galaxy taking measurements of about one billion stars.

Hopkinson was a recognised international authority in his field of research and has published many papers, participated by invitation in NASA, ESA and Japanese working groups and acted as chairman at many international conferences. He not only received many credits for his work but through his considerable reputation and expertise sat on the Awards Committee of the Institute of Electrical & Electronic Engineers (IEEE).

Hopkinson moved with the Sira Space Group to Surrey Satellite Technology Ltd in 2006, the world leading small satellite manufacturer, and set up new facilities to continue his work. This has included continued research into detectors for space missions such as Solar Orbiter, to produce images of the Sun at an unprecedented resolution, EarthCARE, a joint European-Japanese mission addressing the need for a better understanding of the Earth’s climate, and EUCLID, with the primary goal to map and characterise the geometry of the dark universe, a feature of considerable interest to the science community.

Gordon Robert Hopkinson was born in 1952, the only child of Jessie and Alan and brought up in Nottingham. He was educated at Forest Fields Grammar School, Nottingham and went onto read Physics at Manchester University graduating with first-class honours in 1973, he then undertook a PhD graduating in 1977.

Gordon loved barbeques, walking, history, crosswords and real ale. Most family holidays involved incorporating as many of these as possible. Top of the list were camping holidays in France with barbeques every night and walking holidays in Derbyshire, where the route would be planned according to the beer.

He is survived by his wife, Jacqui, whom he married in 1980 and by their two daughters and son.

Gordon Hopkinson, detector physicist, was born on July 4th 1952. He died on September 12th 2010, aged 58.

SSTL has won a contract worth €1.6 million from Astrium GmbH, Germany to proceed with work on a new contract to develop and supply the Multi-Spectral Imager (MSI) for the European Space Agency’s (ESA) EarthCARE Mission.

Earth Explorer Missions are part of the Earth Observation Envelope Programme (EOEP). They are missions led by the European Space Agency to address primary research objectives. The EarthCARE Mission has been approved for implementation as the third Earth Explorer Core Mission. The mission will be implemented in collaboration with Japanese Aerospace Exploration Agency who will provide one of the core Instruments. The EarthCARE mission has been specifically defined with the basic objective of improving the understanding of cloud-aerosol-radiation interactions so as to include them correctly and reliably in climate and numerical weather prediction models.

The EarthCARE mission aims to improve the understanding of the Earth's radiation balance and to minimize uncertainties in climate change prediction models by acquiring accurate vertical profiles of clouds and aerosols, as well as measurements of top of the atmosphere radiance. The Multi Spectral Imager produced by SSTL will provide information on the horizontal structures of clouds, such as cloud type and cover, and cloud optical and microphysical properties. The instrument's 150 km swath will be used to extend to three dimensions the validity of the aerosol, cloud and radiance measurements made by the active EarthCARE instruments which are all directed towards the satellite ground track.

This contract is for the first stage of the Phase B design study; the full Phase B is a 15 month programme. This will be followed by a Phase C/D leading to mission launch in 2013. SSTL is supported in the MSI programme by TNO from The Netherlands who are acting as subcontractors to SSTL.