When there is Doppler ambiguity number mutation,keystone formatting is no longer valid because of integration performance deterioration and false velocity estimation.A novel keystone formatting method based on non-bas...When there is Doppler ambiguity number mutation,keystone formatting is no longer valid because of integration performance deterioration and false velocity estimation.A novel keystone formatting method based on non-baseband interpolation is presented.It has a different half blind velocity range comparing with normal keystone formatting.Furthermore,there is non-superposition between half-blind-velocity-range of keystone formatting based on baseband and that of non-baseband interpolation.So a synthesizing keystone formatting is proposed to avoid the half-blind-velocity effect.Simulation results of the proposed method show that integration deterioration and velocity estimation falsity can be eliminated effectively.展开更多
This paper proposes a novel inverse synthetic aperture radar（ISAR） imaging method based on second-order keystone transform（KT） and Sandglass transform for group targets flying in a formation with constant accelera...This paper proposes a novel inverse synthetic aperture radar（ISAR） imaging method based on second-order keystone transform（KT） and Sandglass transform for group targets flying in a formation with constant accelerated rectilinear motion in the same radar beam. First, range curvature and range walk of each sub-target among group targets are corrected by the second-order KT combined with the quadratic phase term compensation. After range alignment, the signals in each range frequency cell can be modelled as multiple chirp signals and then the Sandglass transform is utilized to cross-range imaging, which transforms the time–frequency distribution of the signals in each range frequency cell into beelines parallel to the slow time axis simultaneously. Finally, cross-range profiles of group targets in each range frequency cell are obtained via a projection of the perk of every scatterer in the two-dimensional accumulation plane onto the frequency axis. The advantage of the proposed method is that it can align range profiles of each sub-target simultaneously and image cross-range profiles directly without separating the returned signals, which simplifies the operation procedure. Simulation results are used to demonstrate the effectiveness of the proposed method.展开更多
基金supported by the National Natural Science Foundation of China(60871070)
文摘When there is Doppler ambiguity number mutation,keystone formatting is no longer valid because of integration performance deterioration and false velocity estimation.A novel keystone formatting method based on non-baseband interpolation is presented.It has a different half blind velocity range comparing with normal keystone formatting.Furthermore,there is non-superposition between half-blind-velocity-range of keystone formatting based on baseband and that of non-baseband interpolation.So a synthesizing keystone formatting is proposed to avoid the half-blind-velocity effect.Simulation results of the proposed method show that integration deterioration and velocity estimation falsity can be eliminated effectively.
基金supported by the National Natural Science Foundation of China (No. 61372159)
文摘This paper proposes a novel inverse synthetic aperture radar（ISAR） imaging method based on second-order keystone transform（KT） and Sandglass transform for group targets flying in a formation with constant accelerated rectilinear motion in the same radar beam. First, range curvature and range walk of each sub-target among group targets are corrected by the second-order KT combined with the quadratic phase term compensation. After range alignment, the signals in each range frequency cell can be modelled as multiple chirp signals and then the Sandglass transform is utilized to cross-range imaging, which transforms the time–frequency distribution of the signals in each range frequency cell into beelines parallel to the slow time axis simultaneously. Finally, cross-range profiles of group targets in each range frequency cell are obtained via a projection of the perk of every scatterer in the two-dimensional accumulation plane onto the frequency axis. The advantage of the proposed method is that it can align range profiles of each sub-target simultaneously and image cross-range profiles directly without separating the returned signals, which simplifies the operation procedure. Simulation results are used to demonstrate the effectiveness of the proposed method.
