Chris Rapley - Academia.edu (original) (raw)
Uploads
Papers by Chris Rapley
Several advanced altimeter concepts are described, in the context of instruments for future altim... more Several advanced altimeter concepts are described, in the context of instruments for future altimetric missions. These include developments in on-board 'smart' adaptive processing algorithms and corresponding advances in radar hardware technology, which would allow significantly-increased coverage of land and land ice surfaces. Beam-limited altimeters overcome the fundamental disadvantages of pulse-limited instruments over these surfaces, and allow considerably lower transmitter powers, though at the expense of large antenna structures and severe spacecraft pointing constraints. Several additional concepts for antenna signal processing are presented, utilising multiple antenna beams to give increased spatial coverage as well as improved performance over nonocean surfaces.
Bulletin of the American Astronomical Society, 1981
Environmental Research Letters
Physics World, 2008
Why did you originally decide to study physics? I was very interested in science and it was a tos... more Why did you originally decide to study physics? I was very interested in science and it was a toss up between physics and chemistry. In the end, somebody I used to compete with at school decided to do chemistry, so I chose to study physics at Oxford University.
We review the limitations of the Seasat altimeter over terrain, and summarise the results concern... more We review the limitations of the Seasat altimeter over terrain, and summarise the results concerning the scientific and applications potential of pulse-limited altimeter data.
Climate change risk assessments act as a bridge between climate science research and climate poli... more Climate change risk assessments act as a bridge between climate science research and climate policy. The UCL Policy Commission for Communicating Climate Science brought together 30 policy makers, climate scientists and research funders in a workshop to explore how climate change risk assessments can be made more effective drivers of climate change mitigation policy. The Report summarises the outcomes of the event including barriers and opportunities for progress.
Environmental Research Letters
Much has changed in the two decades since I (JL) proposed that scientists should re-examine their... more Much has changed in the two decades since I (JL) proposed that scientists should re-examine their obligations to society in order to serve society better. Today, more environmental scientists are actively sharing their science broadly, conducting use-inspired science (sensu Stokes) in addition to basic science, engaging with society, and crafting solutions to problems not just diagnosing them—all very welcome and exciting developments. For the most part, however, environmental scientists have taken on these extra duties because they believed it was the right thing to do and despite the considerable impediments that exist within academia. But make no mistake, the culture of academia continues to impede progress. As a result, although the above actions have had demonstrable effect, their collective impact falls far short of what is needed if society is to tackle effectively the disruption underway due to climate change, ocean acidification, biodiversity loss, pandemics, and more. Acti...
The Bent Crystal Spectrometer (BCS) onboard the NASA Solar Maximum Mission was part of the X-ray ... more The Bent Crystal Spectrometer (BCS) onboard the NASA Solar Maximum Mission was part of the X-ray Polychromator, which observed numerous ares and bright active regions from February to November 1980, when operation was suspended as a result of the failure of the spacecraft ne pointing system. Observations resumed following the Space Shuttle SMM Repair Mission in April 1984 and continued until November 1989. BCS spectra have been widely used in the past to obtain temperatures, emission measures, and turbulent and bulk ows during ares, as well as element abundances. Instrumental details including calibration factors not previously published are given here, and the in-orbit performance of the BCS is evaluated. Some signicant changes during the mission are described, and recommendations for future instrumentation are made. Using improved estimates for the instrument parameters and operational limits, it is now possible to obtain de-convolved, calibrated spectra that show ner detail than ...
Several advanced altimeter concepts are described, in the context of instruments for future altim... more Several advanced altimeter concepts are described, in the context of instruments for future altimetric missions. These include developments in on-board 'smart' adaptive processing algorithms and corresponding advances in radar hardware technology, which would allow significantly-increased coverage of land and land ice surfaces. Beam-limited altimeters overcome the fundamental disadvantages of pulse-limited instruments over these surfaces, and allow considerably lower transmitter powers, though at the expense of large antenna structures and severe spacecraft pointing constraints. Several additional concepts for antenna signal processing are presented, utilising multiple antenna beams to give increased spatial coverage as well as improved performance over nonocean surfaces.
Bulletin of the American Astronomical Society, 1981
Environmental Research Letters
Physics World, 2008
Why did you originally decide to study physics? I was very interested in science and it was a tos... more Why did you originally decide to study physics? I was very interested in science and it was a toss up between physics and chemistry. In the end, somebody I used to compete with at school decided to do chemistry, so I chose to study physics at Oxford University.
We review the limitations of the Seasat altimeter over terrain, and summarise the results concern... more We review the limitations of the Seasat altimeter over terrain, and summarise the results concerning the scientific and applications potential of pulse-limited altimeter data.
Climate change risk assessments act as a bridge between climate science research and climate poli... more Climate change risk assessments act as a bridge between climate science research and climate policy. The UCL Policy Commission for Communicating Climate Science brought together 30 policy makers, climate scientists and research funders in a workshop to explore how climate change risk assessments can be made more effective drivers of climate change mitigation policy. The Report summarises the outcomes of the event including barriers and opportunities for progress.
Environmental Research Letters
Much has changed in the two decades since I (JL) proposed that scientists should re-examine their... more Much has changed in the two decades since I (JL) proposed that scientists should re-examine their obligations to society in order to serve society better. Today, more environmental scientists are actively sharing their science broadly, conducting use-inspired science (sensu Stokes) in addition to basic science, engaging with society, and crafting solutions to problems not just diagnosing them—all very welcome and exciting developments. For the most part, however, environmental scientists have taken on these extra duties because they believed it was the right thing to do and despite the considerable impediments that exist within academia. But make no mistake, the culture of academia continues to impede progress. As a result, although the above actions have had demonstrable effect, their collective impact falls far short of what is needed if society is to tackle effectively the disruption underway due to climate change, ocean acidification, biodiversity loss, pandemics, and more. Acti...
The Bent Crystal Spectrometer (BCS) onboard the NASA Solar Maximum Mission was part of the X-ray ... more The Bent Crystal Spectrometer (BCS) onboard the NASA Solar Maximum Mission was part of the X-ray Polychromator, which observed numerous ares and bright active regions from February to November 1980, when operation was suspended as a result of the failure of the spacecraft ne pointing system. Observations resumed following the Space Shuttle SMM Repair Mission in April 1984 and continued until November 1989. BCS spectra have been widely used in the past to obtain temperatures, emission measures, and turbulent and bulk ows during ares, as well as element abundances. Instrumental details including calibration factors not previously published are given here, and the in-orbit performance of the BCS is evaluated. Some signicant changes during the mission are described, and recommendations for future instrumentation are made. Using improved estimates for the instrument parameters and operational limits, it is now possible to obtain de-convolved, calibrated spectra that show ner detail than ...