Motion measurement errors analysis for the “one-active” LASAR
The influences of the motion measurement errors (MMEs) to the 3D SAR imaging are analyzed based on the “one-active” LASAR system in this paper. Firstly, the principle and the spatial ambiguity function (AF) of the “one-active” LASAR are introduced. Then the 3D MMEs are introduced according to three forms: the 3D velocity errors and the 3D acceleration errors, the sine vibration errors and the array vibration errors. The 3D SAR system's maximum allowable MMEs are obtained and the influences of the 3D MMEs to the 3D AF are analyzed by the numerical simulation. Finally, the ground experiments and its results are presented, which validate the feasibility of the “one-active” LASAR.
A 3D imaging radar for small unmanned airplanes - ARTINO
In this paper a 3D imaging radar concept, suitable for an unmanned aerial vehicle (UAV), and its status is presented. The concept combines a real aperture, realized by a linear array of nadir pointing antennas, and a synthetic aperture, which is spanned by the moving airplane. The radar front-end uses frequency modulated continuous wave (FMCW) technique with direct down-conversion in Ka band. This technique reduces the power consumption of the radar and the size of the antennas. In comparison to complex and cost intensive phased array approaches, it requires only a moderate number of antennas and microwave components. The scope of this paper is to present an overview of the front-end architecture, design, and realization status
Geometric accuracy in airborne SAR images
Uncorrected across-track motions of a synthetic aperture radar (SAR) platform can cause both a severe loss of azimuthal positioning accuracy in, and defocusing of, the resultant SAR image. It is shown how the results of an autofocus procedure can be incorporated in the azimuth processing to produce a fully focused image that is geometrically accurate in azimuth. Range positioning accuracy is also discussed, leading to a comprehensive treatment of all aspects of geometric accuracy. The system considered is an X-band SAR. >