Calibration of Radar RCS Measurement Errors by Observing the Luneburg Lens Onboard the LEO Satellite

Abstract

Accurate radar RCS measurements are critical to the feature recognition of spatial targets. A calibration method for radar RCS measurement errors is proposed for the first time in the context of special target tracking by observing the Luneburg Lens onboard the LEO satellite. The Luneburg Lens has favorable RCS scattering properties for the radar microwave. Thus, the laboratory RCS measurements of the Luneburg Lens, with some fixed incident frequency and with different incident orientations for the radar microwave, will be implemented in order to build a database. The incident orientation for the radar microwave in the satellite body frame will be calculated by taking advantage of the precise orbit parameters, with errors only at the magnitude of several centimeters and within the actual satellite attitude parameters. According to the incident orientation, the referenced RCS measurements can be effectively obtained by the bilinear interpolation in the database. The errors of actual RCS measurements can thus be calibrated by comparing the referenced and the actual RCS measurements. In the RCS measurement experiment, which lasts less than 400 s, the actual RCS measurement errors of the Luneburg Lens are nearly less than 0 dBsm, which indicates that the RCS measurement errors of the spatial targets can be effectively calculated by the proposed calibration method. After the elaborated calibration, the RCS measurements of the spatial targets can be accurately obtained by radar tracking.

Millimeter-Wave High-Gain Dual-Polarized Flat Luneburg Lens Antenna with Reflection Cancellation

“…The corresponding flat lens has the same radius and a thickness as 2 × b = 5 mm, and it was decomposed into 12 equal-thickness layers along either the axis (longitudinal direction) or radius of the cylinder, as shown in Figure 2b. A compression rate of R/b = 6 was adopted for the FLL design, and the dominate range of the transformed permittivity was enlarged from the original [1,2] to [6,12], multiplied by the compression ratio. Each layer of both two lenses were modeled with perfect dielectrics whose permittivities are specified with the desired value, and the dielectric loss was omitted during simulation.…”