David Siddle

• Chair of Staff/Student Committee

Lecturer in Communications Engineering
Radio Systems Research Group

BSc (Surrey), PhD (Birmingham)
T: +44 (0)116 223 1365
F: +44 (0)116 223 1365
E: drs13@le.ac.uk

Location: Room R12, R Block, Engineering

Main Research Interests:
After gaining degrees in Physics, Dr. Siddle worked as a programmer for the Meteorological Office and National Grid, and became a member of the Engineering staff in 2005 After working on observations and modelling of off-great-circle propagation in the ionospheric mid-latitude trough, he went on to study the propagation of VHF and UHF signals in the troposphere. He has run long-term experimental studies of propagation over several trans horizon paths in the British Channel Islands in order to establish statistics for the probability of anomalous propagation in coastal areas. Sponsored by of com and submitted to the International Telecomunications Union (ITU), the work provides data to aid the planning and operation of broadcast media and mobile communications. The study showed the distinction between two different propagation regimes in the lower troposphere. One of these can be predicted to a reasonable accuracy given currently available ITU models and data from weather and tidal stations, whereas the other cannot, and may lead to  increased interference and hence disruption of communications network for around 10% of the time. The latter propagation regime type was found to be dependent on features in the troposphere at heights around 100 m which cannot be easily determined from meteorological ground stations. This is currently the subject of a further research proposal, which will use radar to detect these tropospheric features and so help communications and radar planning.

Recent Publications:
• E.M. Warrington, A.J. Stocker and D.R. Siddle. Measurement and modelling of HF channel directional spread characteristics for northerly paths. Radio Science 41, RS2006 doi: 10.1029/2005RS003294, 2006.
• D.R. Siddle and E.M. Warrington. Diurnal changes in UHF propagation over the English Channel. Electronics Letters, 41, (21), doi: 10.1049/el:20052028, 1152-1154, 2005.
• D.R. Siddle, E.M. Warrington and S.D. Gunashekar. Signal strength variations at 2 GHz for three sea paths in the British Channel Islands: observations and statistical analysis, Radio Science 42 RS4019, doi:10.1029/2006RS003616 2006
• S.D. Gunashekar, E.M. Warrington and D.R. Siddle. Signal strength variations at 2 GHz for three sea paths in the British Channel Islands: detailed discussion and propagation modelling, Radio Science 42 RS4020, doi:10.1029/2006RS003617 2006.
• A.J. Stocker, E.M. Warrington, and D.R. Siddle, Comparison between the measured and predicted parameters of HF radio signals propagating along the mid-latitude trough and within the polar cap, Radio Science 42 RS3019, doi:10.1029/2006RS003557, 2007
• A.J. Stocker, N.Y. Zaalov, E.M. Warrington and D.R. Siddle Observations of hf propagation on a path aligned along the mid-latitude trough, Advances in Space Research, In Press,
doi:10.1016/j.asr.2008.09.038,