ROSE-a higher resolution, amplitude coded, HF oblique ionosonde system

Flight Systems Department at RAE Farnborough has a research programme studying the characteristics of the ionosphere and how the ionosphere affects radio communications in the high frequency (HF) radio band. The results of this research programme are being used to improve short term ionospheric forecasting and also to aid in the design of robust modulation and coding schemes which will be implemented in future data modems. To support this research programme extensive use has been made of radio sounding techniques to remotely probe the ionosphere. These radio sounding systems are known as ionosondes. They are essentially radars which emit pulses or chirp waveforms and which measure the group delay of the return signal bounced back from the ionosphere. The receiver may be co-located with the transmitter, in which case the ionosonde is a vertical sounder, or the transmitter and receiver may be separated by distances of up to several thousand kilometres in which case the system is known as an oblique sounder.<>