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.
Trajectory Optimization of Sparse LASAR 3-D SAR Via Lagrange Multiplier Method
This paper discusses the antenna phase centre trajectory (APCT) design for the sparse linear array 3-D imaging SAR(LASAR). Firstly, we introduce the signal model of the sparse LASAR. Based on the model, we discuss the 3-D ambiguity function (AF) of the sparse LASAR, and reveal the relationship between the 3-D AF and the system parameters. Finally, the distribution of the pseudo-random APCF is optimized by the Lagrange multiplier method under the minimum variance criterion, and we find that when the pseudo random APCF obeys the parabolic distribution, the cross-range 2-D AF attains optimal, which has both good mainlobe and sidelobe performance.
Energy
Energy is often defined as the ability to do work. There are many forms of energy. A few examples include; Gravitational energy, Kinetic energy (energy of motion), Thermal energy (heat energy), Potential energy. Potential energy is the energy something has based on its position in the universe. A stretched elastic band has potential energy. A rock held up in the air has potential energy based on its position.