Office: Obs O25
Office Tel: (01223) 337543
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Research Themes: Instrumentation, Surveys and Projects
Research interests include:
From the beginning, my career has been aimed at improving our knowledge of the most distant galaxies and quasars. The radio sources I have surveyed for my PhD thesis were difficult to identify with optical counterparts with V~20m because of the inefficiency of the detectors used at the time. I found a British company (now called E2V Technologies ) working on a new detector called the Charge Coupled Device (CCD). I then built and used for astronomy only the second cooled scientific CCD camera system in the world (after JPL, 1979). I collaborated with E2V for ~ 30 years (from 1978), an association that was critical to the vast number of high quality CCDs made by E2V and used on most telescopes and spacecraft today. The ubiquity of CCD detectors in digital cameras, video cameras and mobile phones has its foundations in this work. This programme resulted in the first use of cooled CCD cameras for astronomical spectroscopy (Anglo-Australian Telescope, 1980).
The first CCDs were extremely nonuniform and detecting faint galaxies only a tiny fraction of the sky brightness requires precision flatfield correction. This led me to develop and use for the first time the CCD drift scan technique (1982), allowing ultra-deep imaging to galaxy densities of 150,000 per square degree, with V~27.5m (1984) about 1000 times fainter than before yet not equalled until the Hubble Deep Field North was observed 12 years later (1996). This technique is central to the success of the current, highly productive Sloan Digital Sky Survey(SDSS) Telescope.
The high redshift of these objects produced a demand for a near infrared survey instrument. I designed and built the Cambridge Infrared Survey Instrument (CIRSI) used on telescopes around the world from 1996-2003. This work has received over 600 citations. The performance and area of coverage of CIRSI was only exceeded in 2005.
Atmospheric turbulence badly limits imaging resolution of the more distant galaxies. The advantages of working from space were clear and so I became a senior member of the Faint Object Camera Team of the Hubble Space Telescope, the only instrument removed from HST fully working as when launched (1979-2004). In parallel it became clear that higher angular resolution might be possible with innovative instrument designs. This led to the first demonstration of optical aperture synthesis (University of Hawaii 2.2m telescope, 1986). Instrumental and computer processing limitations meant its further development had to wait 15 years. However, this work demonstrated the potential of radio astronomy closure phase techniques for optical astronomy. A successful PPARC grant application (with Baldwin and Warner) allowed us to build COAST, the first optical aperture synthesis interferometer (1987-2002). COAST required high efficiency photon counting detectors so I developed for COAST the first photon counting avalanche used for astronomy (from 1994, and still in use today).
In recent years I have received in excess of £1.1 million of funding, including a grant of £626,000 in the middle of 2008 despite the fierce cutbacks in funding by the STFC. The development, by E2V Technologies of the first electron multiplying CCDs reopened the possibility of using techniques demonstrated in 1985 for overcoming atmospheric turbulence limitations. EMCCDs allowed Lucky Imaging to be developed by CDM and collaborators into a routine method for delivering Hubble Space Telescope resolution from ground-based telescopes. Lucky Imaging essentially uses high-speed imaging to freeze turbulent motions and distortions of images. They are then selected and combined on a variety of sharpness criteria. Numerous research papers have been published using these methods which are being implemented on a number of telescopes around the world.
More recently Lucky Imaging has been twinned with low order adaptive optics techniques to allow us achieve even higher resolution from ground-based telescopes. Indeed the highest resolution images ever taken in the visible or infrared either from the ground or from space have recently been taken and published by CDM. These have about 3 times the angular resolution of the Hubble Space Telescope.
I have published over 180 research papers (about half in refereed journals: the mainstream academic journals seldom accept instrumentation papers, saying they are physics and engineering rather than astronomy, so much of that work is reported to conference proceedings). My citation "H" parameter on refereed papers currently stands at 32. In addition there are another 8 papers currently in press and a further 7 published in life science instrumentation.
As well as the above activities in astronomy instrumentation I hold patents for technologies used in virtually every instrument involved in sequencing the human genome and which were critically important in achieving the necessary sequencing throughput to make the project viable. Other patents cover x-ray, neutron beam and transmission electron microscope imaging. I have also developed surveillance imaging systems for crime prevention that have dramatically improved the range and quality that can be achieved in the presence of atmospheric turbulence.
My teaching record is excellent both as a lecturer and organiser of the Part II Astrophysics course. We have a very advanced set of procedures for evaluating teaching quality in the Institute of Astronomy. My own ratings given by the students are the most consistently high of anyone in our department.
Recently my activities have further extended to fundraising for the Institute. We are in an advanced state of raising funds for an international collaborative astronomy project that will substantially enhance the research effort in Cambridge as well as overseas (where the majority of money will be spent).
Professor of Image Science in the Institute of Astronomy, University of Cambridge.
B.Sc. University of Edinburgh, 1966
PhD University of Cambridge, 1969, Supervisor: Professor Sir Martin Ryle FRS., Thesis title: `The Evolution of Extragalactic Radio Sources'.
Jackson-Gwilt medal of the Royal Astronomical Society, 2010.