A Low-Power and Small-Size HF Backscatter Radar for Ionospheric Sensing

A new high-frequency backscatter radar (Wuhan Ionospheric Oblique Backscattering Sounding System) for ionospheric sensing and study has been developed. With the new system design, oblique backscatter sounding and oblique sounding can be achieved in this radar just through simply loading appropriate software. Furthermore, due to alternate transmission and reception in equal interval, this radar can detect the ionospheric state in the range of a few thousand kilometers and achieve the largest gain of applied pseudorandom sequences. In addition, this radar usually obtains 27-dB gain from phase coded pulse compression and 21-dB gain from coherent spectral integration using pseudorandom code, pulse compression, and coherent spectral integration techniques. This radar also exploits merits of Peripheral component interconnect eXtensions for Instruments (PXI) bus technology and is designed as a modular and compact PXI-based system. Details of system design, sounding timing, and signal-processing algorithm are described. Except for the antenna systems and power amplifier, this radar's dimension is 177.8 times 431.8 times 457.2 mm. With this radar, the oblique backscatter ionogram and Dopplerionogram can be clearly obtained in the range of a few thousand kilometers with 100-W power. The oblique ionogram for propagation over a distance of several kilometers can also be clearly acquired at the time of oblique backscatter sounding. The initial observations obtained with this radar are included to demonstrate its performance.