The Synthetic Aperture Radar(SAR)raw data generator is required to the evaluation of focusing algorithms,moving target analysis,and hardware design.The time-domain SAR simulator can generate the accurate raw data but ...The Synthetic Aperture Radar(SAR)raw data generator is required to the evaluation of focusing algorithms,moving target analysis,and hardware design.The time-domain SAR simulator can generate the accurate raw data but it needs much time.The frequency-domain simulator not only increases the efficiency but also considers the trajectory deviations of the radar.In addition,the raw signal of the extended scene included static and moving targets can be generated by some frequency-domain simulators.However,the existing simulators concentrate on the raw signal simulation of the static extended scene and moving targets at uniform speed mostly.As for the issue,the two-dimensional signal spectrum of moving targets with constant acceleration can be derived accurately based on the geometric model of a side-looking SAR and reversion of series.And a frequency-domain algorithm for SAR echo signal simulation is presented based on the two-dimensional signal spectrum.The raw data generated with proposed method is verified by several simulation experiments.In addition to reveal the efficiency of the presented frequency-domain SAR scene simulator,the computational complexity of the proposed method is compared with the time-domain approach using the complex multiplication.Numerical results demonstrate that the present method can reduce the computational time significantly without accuracy loss while simulating SAR raw data.展开更多
Objective Reversed alkane δ;C and δ;H values in many prolific shale plays all over the world have aroused much attention in the study of the formation mechanism of reversed isotope series in alkanes in the past few ...Objective Reversed alkane δ;C and δ;H values in many prolific shale plays all over the world have aroused much attention in the study of the formation mechanism of reversed isotope series in alkanes in the past few years(Zou Caineng et al., 2016). Although many researchers have put forward different hypotheses, the mechanism has not been well understood yet. The openness degree of oil and gas system展开更多
基金The work was supported by the Natural Science Foundation of Shandong Province,China.(Grant No.ZR2017BF032)。
文摘The Synthetic Aperture Radar(SAR)raw data generator is required to the evaluation of focusing algorithms,moving target analysis,and hardware design.The time-domain SAR simulator can generate the accurate raw data but it needs much time.The frequency-domain simulator not only increases the efficiency but also considers the trajectory deviations of the radar.In addition,the raw signal of the extended scene included static and moving targets can be generated by some frequency-domain simulators.However,the existing simulators concentrate on the raw signal simulation of the static extended scene and moving targets at uniform speed mostly.As for the issue,the two-dimensional signal spectrum of moving targets with constant acceleration can be derived accurately based on the geometric model of a side-looking SAR and reversion of series.And a frequency-domain algorithm for SAR echo signal simulation is presented based on the two-dimensional signal spectrum.The raw data generated with proposed method is verified by several simulation experiments.In addition to reveal the efficiency of the presented frequency-domain SAR scene simulator,the computational complexity of the proposed method is compared with the time-domain approach using the complex multiplication.Numerical results demonstrate that the present method can reduce the computational time significantly without accuracy loss while simulating SAR raw data.
基金supported by the National Natural Science Foundation of China (grant No. 41503033)Basic Foresight Program of the Ministry of science and technology, Sinopec (grant No. G5800-15-ZS-KJB050-02)the Key Laboratory Project of Gansu Province (grant No. 1309RTSA041)
文摘Objective Reversed alkane δ;C and δ;H values in many prolific shale plays all over the world have aroused much attention in the study of the formation mechanism of reversed isotope series in alkanes in the past few years(Zou Caineng et al., 2016). Although many researchers have put forward different hypotheses, the mechanism has not been well understood yet. The openness degree of oil and gas system
基金Supported by the National Natural Science Foundation of China (Grant No. 60502044)Program for New Century Excellent Talents inUniversity (Grant No. NCET-06-0861)