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.
Motion measurement errors and autofocus in bistatic SAR
This paper discusses the effect of motion measurement errors (MMEs) on measured bistatic synthetic aperture radar (SAR) phase history data that has been motion compensated to the scene origin. We characterize the effect of low-frequency MMEs on bistatic SAR images, and, based on this characterization, we derive limits on the allowable MMEs to be used as system specifications. Finally, we demonstrate that proper orientation of a bistatic SAR image during the image formation process allows application of monostatic SAR autofocus algorithms in postprocessing to mitigate image defocus.
Economics of General-Purpose Assembly Robots
Summary A study of the comparative economics of various automatic assembly systems using general-purpose assembly robots is described. In the study, use is made of a “typical” candidate assembly whose profile is obtained from statistical analysis of actual products submitted by interested companies. It is shown that the choice of assembly system and the various parts presentation methods depends on three main factors, namely: the annual production volume per shift, the number of parts in the product and the equipment payback period.