On the Singular Spectrum of the Radiation Operator for Multiple and Extended Observation Domains

Figure 3

Two observation domains that subtend the same angular sector for the case of 𝑋_𝑠=20𝜆, 𝑋₁=20𝜆, 𝑋₂=25𝜆, 𝑧₁=100𝜆, and 𝑧₂=125𝜆. Comparison between the squared singular values of the radiation operator (denoted as actual) and the eigenvalues of the approximate model given by (21) (denoted as approx.).