Reconstruction of Beat Signal in Radar Altimeter Using Signal Processing

The frequency modulated continuous wave (FMCW) radar principle has been used in altimeter to measure altitude above the surface of the Earth. Traditionally it has been used in short range application due to its unambiguous range. The enhanced range resolution is a factor for FMCW radars compared with other types of radars. There are theoretical restrictions in the range resolution. This paper deals with reconstruction of beat signal in the discontinuous region of its samples. Furthermore, the signal processing methods like FFT calculations that are used for FMCW radar signals and the possible improvement techniques for these methods are discussed. This technique overcomes the discontinuities in the turnaround region of radar altimeter beat signal for improved FFT measurement. The irregularities are due to the delay of received signal in that region and to overcome this problem, we take the similar samples from both sides of the turnaround region and reconstruct the original signal.