The frequency-modulated continuous wave(FMCW)ladar is a useful sensor for remote sensing applications and has been widely used in both the military and civilian fields for precise geospatial data acquisition.Typically...The frequency-modulated continuous wave(FMCW)ladar is a useful sensor for remote sensing applications and has been widely used in both the military and civilian fields for precise geospatial data acquisition.Typically,the FMCW-ladar signal is collected by use of the hetero-dyne detection through the dechirping so as to decrease the sampling rate commensurate with the bandwidth.In this manuscript,we proposed a novel scheme for processing the FMCW-ladar signal acquired through the simplified heterodyne detection,and the sampling rate was the same as that in the dechirp detection.Based on the time-frequency relation of the FMCW-ladar signal,two algorithms were proposed to post-process the echo acquired by the simplified heterodyne detection with the sub-Nyquist sampling rate.For the FMCW-ladar echo data acquired by the simplified heterodyne detection with the same sampling rate as in the traditional dechirp detection,the algorithms can achieve the unambiguous range image retaining the range resolution commensurate with the transmitted chirp bandwidth.The effectiveness of the scheme was validated by simulation and real data processing experiments.The capability of the proposed scheme provides an alternative for the FMCW-ladar system without use of the dechirp detection,which can benefit the future FMCW-ladar and microwave photonics radar applications in the remote sensing.展开更多
文摘The frequency-modulated continuous wave(FMCW)ladar is a useful sensor for remote sensing applications and has been widely used in both the military and civilian fields for precise geospatial data acquisition.Typically,the FMCW-ladar signal is collected by use of the hetero-dyne detection through the dechirping so as to decrease the sampling rate commensurate with the bandwidth.In this manuscript,we proposed a novel scheme for processing the FMCW-ladar signal acquired through the simplified heterodyne detection,and the sampling rate was the same as that in the dechirp detection.Based on the time-frequency relation of the FMCW-ladar signal,two algorithms were proposed to post-process the echo acquired by the simplified heterodyne detection with the sub-Nyquist sampling rate.For the FMCW-ladar echo data acquired by the simplified heterodyne detection with the same sampling rate as in the traditional dechirp detection,the algorithms can achieve the unambiguous range image retaining the range resolution commensurate with the transmitted chirp bandwidth.The effectiveness of the scheme was validated by simulation and real data processing experiments.The capability of the proposed scheme provides an alternative for the FMCW-ladar system without use of the dechirp detection,which can benefit the future FMCW-ladar and microwave photonics radar applications in the remote sensing.
