电离层探测仪回波能量积累算法

Energy accumulation algorithms for ionosonde

设计一组适用于小功率便携式电离层探测仪的预处理能量积累算法。该积累算法由基于脉间相位编码的脉冲压缩算法、基于多次探测的多普勒积累算法和群时延多普勒域二维积累算法3部分组成。实时采集的数字信号经过脉冲压缩算法处理后,回波能量均在电波历经的群时延距离附近聚集,信噪比提高,回波的相位信息被保留。然后,依据多次探测过程中的相位连续性实现多普勒积累。最后,基于数字图像处理技术和电离层回波的时延与多普勒连续散布特性提出群时延多普勒域二维积累算法,不仅可以提高短波信道的衰落区域的能量,还可以填补脉间调相体制的回波区域中的固有盲区。研究结果表明:实测数据经积累算法处理后,回波信噪比显著提高;这些积累算法可为弱回波检测提供具有更高信噪比的数据,减小探测仪的功耗,有利于设备的小型化和便携化。

A set of energy accumulation algorithms were developed for the portable ionosonde with low power consumption,which consists of phase-coded pulse compression accumulation algorithm,Doppler accumulation algorithm based on multiple times sounding,and the two dimension energy accumulation algorithm in group delay？Doppler domain.The collected signals were firstly processed by the pulse compression accumulation algorithm.The echoes could be shown at the right group path.The phase information and amplitude information for the echoes were reserved.Then the multiple times sounding data could be accumulated in the Doppler domain because of the phase continuity of the echoes.Finally,the two dimension energy accumulation algorithm which was a new algorithm derived from digital image processing technology was used based on the spread of the echoes in group delay？Doppler domain.The results show that the measured data has better SNR after preprocessing,especially for the weak signals.These energy accumulation algorithms can lower the power consumption,which leads to the miniaturization and portable use of the equipments.