A Method to Correct the Frequency Shift of Broadening Bragg Peaks Contaminated by Ionosphere

摘要

In the high frequency OTHR (over-the-horizon radar), the contaminated ionosphere will lead to the sea clutter shift and broadening in Doppler domain, which in turn has obvious affection on the detection of ships and other targets. Considering that the signal of the sky wave OTHR is severely reflected by ionosphere, a method is proposed to correct the sea clutter based on centroid in the RD (Range-Doppler) spectrum. In other words, we can use centroid of range dimension combined with that of Doppler dimension to calculate the center frequency of two Bragg peaks. Moreover, in the following experiments, the method is verified to be effective by utilizing real data. As is shown in the simulation results, this correction method can enjoy a good performance in frequency correcting.