Adaptive active reconstruction algorithm for dynamic clearance frequency-sweep interference signals

The Doppler effect of a moving target affects the measurement accuracy of frequency-sweep interferometry ranging. Existing clearance reconstruction methods using virtual constructors can suppress the Doppler error. But the method only passively selects the optimal clearance in a certain range, with accuracy and speed dependent on the scanning range and step size. To resolve this, an adaptive active clearance reconstruction algorithm is proposed to reconstruct the absolute distance without prior estimate the initial clearance of each sweep period. A variational optimization model is constructed to actively separate the initial clearance phase from the velocity integral phase using spectrum differences. The separated modes are updated with curve fitting. Finally, the clearance is constructed by two separate modes, and the adaptive reconstructed clearance change is realized. Simulation and experiments show that the proposed method is more accurate than the existing virtual construction method when the demodulation speed is the same.