ISARLAB - Inverse Synthetic Aperture Radar Simulation - Defence ...

DSTO-GD-02109. The number of samples per line to be read (starting from the starting sample) isentered in Number of Samples.The result of these steps is that the I and Q pairs are converted to a complex matrix ofdimensions ‘Number of Lines’ by ‘Number of Samples’. This data can be savedin MATLAB format and loaded later to avoid repeating these steps and to replace thereading and conversion process with a more efficient loading of data.11. Simulation11.1 Data Input Using the Load MenuThis menu allows the radar signal, the target scatterer model, the scenario, or userpreferences to be loaded. This menu has exactly the same purpose and works inexactly the same way as it did in Trial mode (described in Section 10.1). The onlydifferences between the two is the addition of the Scatterer Model and Scenarioinformation, which are applicable only for simulations, and the disabling of MatlabData loading, which has no meaning for simulations. The saving of data andinformation, however, is exactly the same in both Trial and Simulation modes.11.2 Specifying Dynamics: Scenario Setup11.2.1 PurposeThe radar’s or target’s gross motion is specified using the Scenario Setup window(Figure 17). A full description of how motion is modelled can be found in Section 3.1.The following is a summary.The radar or target motion can be described as either stationary, moving in a straightline or in a horizontal circle. These are approximations to real manoeuvres (at least inshort periods of time). Motion is defined relative to a 3-D right-handed coordinatesystem.For linear motion the X Position, Y Position and Altitude specify the positionin space and the Velocity and Acceleration are scalars that are in the direction ofHeading and parallel to the x-y plane. Heading is measured in degrees where thezero reference is the x-axis and increases in a clockwise sense (looking into the z-axistowards the origin). Climb rate is defined to be vertical velocity (parallel to the z-axisand positive for the same direction).With circular motion, the radar or target is on the circumference of a horizontal circle(parallel to the x-y plane). Hence the (X,Y) position of the radar or target and the (X,Y)position of the centre of the circle define its radius and the altitude of the radar ortarget is also the altitude of the circle. The rate of rotation is proportional to the(instantaneous) speed that is set by the user. A positive speed means the circle is37