Len Kersley

Professor
BSc PhD (Edinburgh) Photograph of Len Kersley.

Contact

Email: lek@aber.ac.uk
Office: 111, Physical Sciences Building, Penglais Campus
Phone: (0)1970 622 813
Fax: (0)1970 622 826

Research

Len Kersley leads the Radio and Space Physics Group on a research programme based on experimental studies using radio transmissions from satellites. The activities encompass both pure science investigations of the geophysics of the ionised atmosphere and applied work on the effects of the atmospheric propagation environment on the radio signals. Early studies included measurements of ionospheric electron content using both Faraday rotation and group delay observations from satellites in geostationary orbit, leading to investigations of atmospheric gravity waves. Interest in the geophysics of the high-latitude ionosphere developed in the 1980's with a series of projects investigating radio-wave scintillation and ionospheric irregularities at sub-auroral, auroral and polar latitudes.

More recent work has been concerned with the development of radio tomographic imaging of the ionosphere, a new technique for the imaging of the spatial distribution of ionospheric electron density. The method is now being applied to studies of the signatures in the ionosphere at high latitudes of the physical processes responsible for interaction between the solar wind and the magnetosphere, using a chain of four receivers for NNSS satellite signals at sites in the Arctic (Ny-Ålesund, Longyearbyen, Bjørnøya and Tromsø).

Collaborative work involves auroral optical observations, use of incoherent scatter radars (EISCAT and the EISCAT Svalbard radar) and other ground-based and satellite measurements. A parallel project, involving five receiving sites in UK (Unst, Lossiemouth, Hawick, Aberystwyth, Dartmouth), is concerned with the use of tomographic images in the improvement of ionospheric nowcasting and modelling for practical applications to the performance of radio systems. A new investigation has begun into the use of transmissions from GPS satellites for ionospheric measurements and in particular the combination of GPS and NNSS observations to investigate the plasma content of the high protonosphere.

Recent Research Grants

  • L Thomas, L Kersley, S E Pryse and P J S Williams, PPARC, Studies of the ionosphere in the auroral zone and polar cap, £688,404 (1.4.94 - 31.3.98)
  • L Kersley, EOARD, Ionospheric structure over northern Europe, £39,984 (1.1.95 - 31.12.95)
  • L Kersley and S E Pryse, NERC, Ionospheric tomography in Antarctica, £45,340 (1.6.95 - 31.5.98)
  • L Kersley, Radiocommunications Agency, Scintillation at 400 MHz and 1.5 GHz, £29,994 (1.1.96 - 31.12.96)
  • L Kersley, P J S Williams, S E Pryse, N J Mitchell and W P Wilkinson, PPARC, Studies in solar-terrestrial physics, £697,026 (1.4.1996 - 31.3.2000)
  • L Kersley, DERA, Tomographic imaging of the high-latitude ionosphere for application to radio systems and ionospheric models, £114,509 (1.10.96-30.9.99)
  • L Kersley, DERA, Tomographic imaging of the high-latitude ionosphere for application to radio systems and ionospheric models (additional award), £16,035 (1.10.96-30.9.99)
  • L Kersley and S E Pryse, EOARD, TEC measurements for GPS comparisons and ionospheric tomography £11,916 (1.4.97 - 31.3.98)

Biography

After attending Hawick High School, Professor Kersley read Natural Philosophy at the University of Edinburgh, obtained his PhD in experimental fluid dynamics going on to become an assistant lecturer there. He came to Aberystwyth in 1965 as a physics lecturer with research interests in radio and atmospheric physics using signals from satellites. The research took him to USA for 12 months as a National Academy of Sciences Senior Research Associate and more recently led to the development of ionospheric radio tomography, a technique in which Aberystwyth has a world lead, employing radio receivers in both Arctic and Antarctic regions to map the polar-cap plasma. Professor Kersley's work has practical applications in radio communications and navigational systems. He has been a vice-chairman of the Beacon Satellite Group of the International Union of Radio Science, editor of its proceedings and is author of more than 160 papers. A glider pilot in his younger days, Professor Kersley now continues an interest in ornithology and greatly values being able to walk to work.

Staff Publications

  • Dabas, R S & Kersley, L, Radio tomographic imaging as an aid to modelling of ionospheric electron density, Radio Sci 38, 1035-1055 (2003)
  • Pryse, S E, Smith, A M, Kersley, L & McCrea, I W, EISCAT Svalbard Radar observations of ionospheric signatures of magnetopause reconnection during a changing IMF Bz polarity, Ann. Geophysicae, 20, 477-486, (2002)
  • Moen, J, Walker, I K, Kersley, L & Milan, S E, On the generation of cusp HF-backscatter irregularities, J. Geophys. Res., 107, A4, art.no.1044, (2002)
  • Dabas, R. S., and Kersley, L., Adaptive modelling of the ionosphere over Europe using radio tomographic images. Proc. International Beacon Satellite Symposium, Boston, USA, 317-320 (2001).
  • Dabas, R. S., and Kersley, L., Radio tomographic imaging as an aid to modelling of ionospheric electron density. Proc. COST271 Workshop, Sopron, Hungary, Wk.Gp. 2 paper 01, pp7.(2001).
  • Kersley, L, Ionospheric and Radio Propagation Research in the UK, Quaderni di Geofisica, 15, 89-96, (2001).
  • Kersley, L., and Berry, S. T., Plasma structures in the polar-cap ionosphere under various quasi-static IMF conditions, Proc. International Beacon Satellite Symposium, Boston, USA, 288-292 (2001).
  • Rogers, N. C., Mitchell, C. N., Heaton, J. A. T., Cannon, P. S., and Kersley, L., The application of radio tomographic imaging to hf oblique incidence ray tracing, Radio Sci., 36, 1591, (2001).
  • Walker, I. K., Pryse, S. E., and Kersley, L., The role of radio tomography in the study of ionospheric footprints of space-weather processes, Proc. International Beacon Satellite Symposium, Boston, USA, 150-153 (2001).
  • Heaton, J. A. T., Cannon, P. S., Rogers, N. C., Mitchell, C. N., and Kersley, L., Validation of electron density profiles derived from oblique ionograms over the UK, Radio Sci., 36, 1149-1156, (2001).
  • Pryse, S. E.., Smith A. M. & Kersley, L., Dayside ionospheric response to changes in IMF polarity: optical and plasma-flow observations. Ann. Geophysicae, 18, 782-788, (2000).
  • Pryse, S. E.., Smith, A. M., Walker, I. K. & Kersley, L., Multi-instrument study of footprints of magnetopause reconnection in the summer ionosphere, Ann. Geophysicae, 18, 1118-1127 (2000).
  • Smith, A. M., Pryse, S. E.. & Kersley, L., Polar patches observed by ESR and their possible origin in the cusp region, Ann. Geophisicae, 18, 1043-1053, (2000).
  • Bishop, G.J., Kersley, L., Lunt, N., Bailey, G.J., Mazzella, A.J., GPS TEC, the ionosphere and the plasmasphere, Proc. Ionospheric Effects Symposium, Alexandria, VA, USA, (editor J.M. Goodman), 151-158, (1999).
  • Heaton, J.A.T., Cannon, P.S., Rogers, N.C., Mitchell, C.N. & Kersley, L., Validation of electron density profiles derived from oblique ionograms, Proc. NCAP-99, York, Institute of Electrical Engineers, 461, 341-344, (1999).
  • Heaton, J.A.T., Cannon, P.S., Rogers, N.C., Mitchell, C.N. & Kersley, L., Electron density profiles derived from oblique ionograms, Proc. Ionospheric Effects Symposium, Alexandria, VA, USA (editor J M Goodman), 186-191, (1999).
  • Kersley, L., The application of radio tomography to ionospheric mapping and high latitude geophysics, Proc. Ionospheric Effects Symposium, Alexandria, VA, USA (editor J.M. Goodman), 58-65, (1999).
  • Kersley, L., Factors affecting the accuracy of GPS TEC measurements: modelling and experiments, Proc. GPS TEC Workshop, Rutherford Appleton Laboratory, pp2, (1999).
  • Lunt, N., Kersley, L. & Bailey, G.J., The influence of the protonosphere on GPS observations: Model simulations, Radio Sci., 34, 725-732, (1999).
  • Lunt, N., Kersley, L., Bishop, G.J., Mazzella, A.J., & Bailey, G.J., The effect of the protonosphere on the estimation of GPS TEC: Validation using the SUPIM model, Radio Sci., 34, 1261-1271, (1999).
  • Lunt, N., Kersley, L., Bishop, G.J. & Mazzella Jr., A.J., The contribution of the protonosphere to GPS total electron content: Experimental measurements, Radio Sci., 34, 1273-1280, (1999).
  • Lunt, N., Kersley, L., Bishop, G.J., Mazzella Jr., A.J. & Bailey, G.J., The protonospheric contribution to GPS TEC: Two-station measurements, Radio Sci., 34, 1281-1285, (1999).
  • Lunt, N., Kersley, L., Bailey, G.J., Bishop, G.J. & Mazzella, A.J., Effects of the protonosphere on GPS systems: modelling and observations, Proc. NCAP-99, York, Institute of Electrical Engineers, 461, 200-203, (1999).
  • Mitchell, C.N., Kersley, L., Pryse, S. E.., Willson, C.A., Heaton, J.A.T., Cannon, P.S. & Rogers, N.C., Imaging and modelling of the main ionospheric trough using radio tomography, Proc. NCAP-99, York, Institute of Electrical Engineers, 461, 192-195, (1999).
  • Mitchell, C.N., Kersley, L. & Cannon, P.S., The latitudinal position of the mid-latitude trough: Seasonal variations and model comparisons, Proc. 4th COST251 Workshop, Madeira, Portugal, 110-114, (1999).
  • Rogers, N.C., Cannon, P.S., Heaton, J.A.T., Mitchell, C.N. & Kersley, L., Ray tracing through tomographic images of the ionosphere, Proc. NCAP-99, York, Institute of Electrical Engineers, 461, 345-348, (1999).
  • Walker, I.K., Moen, J., Kersley, L. & Lorentzen, D.A., On the possible role of cusp/cleft precipitation in the formation of polar-cap patches, Ann. Geophysicae, 17, 1298-1305, (1999).
  • Kersley, L., Pryse, S. E.., Lunt, N., Jones, D.G. & Walker, I.K., TEC measurements for GPS comparisons and ionospheric tomography, Final Report to the EOARD, London, pp83, (1999).
  • Mitchell, C.N., Kersley, L., Pryse, S. E. & Willson, C.A., Tomographic imaging of the high-latitude ionosphere for application to radio systems and ionospheric models, Final Report to DERA, Malvern, pp89, (1999).
  • Bernhardt, P.A., McCoy, R.P., Dymond, K.F., Picone, J.M., Meier, R.R., Kamalabadi, F., Cotton, D.M., Charkrabarti, S., Cook, T.A., Vickers, J.S., Stephan, A.W., Kersley, L., Pryse, S. E., Walker, I.K., Mitchell, C.N., Straus, P.R., Na, H., Biswas, C., Bust, G.S., Kronschnabl, G.R. & Raymund, T.D., Two dimensional mapping of the plasma density in the upper atmosphere with computerized ionospheric tomography (CIT), Physics of Plasmas, 5, 2010-2021, (1998).
  • Idenden, D.W., Moffett, R.J., Williams, M.J., Spencer, P.S.J. & Kersley, L., Imaging of structures in the high-latitude ionosphere: model comparisons, Ann. Geophysicae, 16, 969-973, (1998).
  • Jones, G.O.L., Kersley, L., Heaton, J.A.T., Ciraolo, L. & Spalla, P., Ionospheric electron content across the Antarctic continent, Antarctic Science, 10, 493-501, (1998).
  • Lunt, N., Kersley, L., Bishop, G.J. & Mazzella, A.J., Protonospheric electron contents from GPS/NNSS observations, Acta Geodaetica et Geophysica Hungarica, 33, 137-146, (1998).
  • Lunt, N., Kersley, L., Bailey, G.J. & Bishop, G.J., Plasmaspheric effects on the GPS system: modelling and observations in UK, Proc. ESA Workshop on Space Weather, Noordwijk, The Netherlands, pp4, (November 1998).
  • Mitchell, C.N., Walker, I.K., Pryse, S. E.., Kersley, L., McCrea, I.W. & Jones, T.B., First complementary observations by ionospheric tomography, the EISCAT Svalbard Radar and the CUTLASS HF radar, Ann. Geophysicae, 16, 1519-1522, (1998).
  • Mitchell, C.N., Kersley, L., Pryse, S. E.., Heaton, J.A.T. & Cannon, P.S., A new approach to modelling of the main ionospheric trough over European using tomographic images, Proceedings of COST251 Workshop, El Arenosillo, Spain, pp10, (1998).
  • Mitchell, C.N., Kersley, L., Pryse, S. E.., Walker, I.K. & Cannon, P.S., The role of radio tomography in monitoring the near-earth space environment, Proc. ESA Workshop on Space Weather, Noordwijk, The Netherlands, pp4, (November 1998).
  • Moen, J., Berry, S.T., Kersley, L. & Lybekk, B., Probing discrete auroral arcs by ionospheric tomography, Ann. Geophysicae, 16, 574-582, (1998).
  • Pryse, S. E.., Kersley, L., Williams, M.J. & Walker, I.K., The spatial structure of the dayside ionospheric trough, Ann. Geophysicae, 16, 1169-1179, (1998).
  • Pryse, S. E.., Kersley, L., Mitchell, C.N., Spencer, P.S.J. & Williams, M.J., A comparison of reconstruction techniques used in ionospheric tomography, Radio Sci., 33, 1767-1780, (1998).
  • Pryse, S. E.., Kersley, L. & Williams, M.J., Electron density structures in the polar cap imaged by ionospheric tomography, Adv. Space Res., 22, 1385-1389, (1998).
  • Spencer, P.S.J., Kersley, L. & Pryse, S. E.., A new solution to the problem of ionospheric tomography using quadratic programming, Radio Sci., 33, 607-616, (1998).
  • Walker, I.K., Moen, J., Mitchell, C.N., Kersley, L. & Sandholt, P.E., Ionospheric effects of magnetopause reconnection observed using ionospheric tomography, Geophys. Res. Lett., 25, 293-296, (1998).
  • Kersley, L., Lunt, N. & Jones, D.G., TEC measurements for GPS comparisons and ionospheric tomography, Report to European Office of Aerospace and Development, pp17, (1998).