Super-resolution is offered by an active receiving array and special signal-processing procedures as an additional and new capability. The necessary SNR will be available by approaching target formations. The procedure for super-resolution is derived from likelihood-estimation theory. The resulting parametric target model fitting algorithm, combined with stochastic approximation, is recommended. It is applicable to coherent target signals. One prominent application is resolving the multipath problem, especially for locating low-flying targets above the sea.

Chapter Contents:

• 12.1 Introduction
• 12.2 Parametric estimation
• 12.2.1 Resolution limit from Cramér-Rao inequality
• 12.3 Experimental verification of super-resolution
• 12.4 Resolution by angular spectral estimation algorithms
• 12.4.1 Resolution and the dimension of the signal subspace
• 12.4.2 Estimation of the signal subspace dimension
• 12.5 Expectation maximisation (EM) and space alternating expectation maximisation (SAGE)
• 12.6 Root-MUSIC
• 12.7 ESPRIT procedure with least square (LS) and total least square (TLS)
• 12.7.1 Total least square procedure
• 12.8 Experimental active receiving array system
• 12.9 Error consequences
• 12.10 Array calibration
• 12.10.1 Autocalibration for a uniform linear array
• 12.10.2 Iterative algorithm for gain and phase calibration
• 12.10.3 Angular ambiguity
• 12.10.4 Experimental autocalibration
• 12.10.5 Extension to calibration of mutual coupling
• 12.10.6 Autocalibration for a volume array
• 12.10.7 Estimation of antenna element position errors
• 12.10.8 Experimental super-resolution in angle
• 12.10.9 Autocalibration in case of multipath propagation
• 12.11 Conclusions
• References

Inspec keywords: array signal processing; radar resolution; radar antennas; signal resolution; antenna arrays; receiving antennas; approximation theory; stochastic processes

Other keywords: signal-processing procedures; stochastic approximation; super-resolution; active receiving array; target formations; array processing; coherent target signals; SNR; parametric target model fitting algorithm; low-flying targets; likelihood-estimation theory; multipath problem

Subjects: Interpolation and function approximation (numerical analysis); Antenna arrays; Signal processing and detection; Radar equipment, systems and applications; Other topics in statistics