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A Simulator for the LWA. Masaya Kuniyoshi (UNM). Outline. 1.Station Beam Model 2.Asymmetry Station Beam 3.Station Beam Error 4.Summary. (Aaron Cohen LWA Memo Series [55]). 256 dipoles. (Leonid Kogan LWA Memo Series [21]). 2π. ( D ・ u ). Ψ =. j. j. λ. 2π. ( D ・ S ). Φ =. j.
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A Simulator for the LWA Masaya Kuniyoshi (UNM)
Outline 1.Station Beam Model 2.Asymmetry Station Beam 3.Station Beam Error 4.Summary
256 dipoles (Leonid Kogan LWA Memo Series [21])
2π ( D・ u ) Ψ = j j λ 2π ( D・ S ) Φ = j j λ 。 。 = Zenith S (0,0 ) 。 。 S (10,0 ) Simulation model for a station beam 255 E(θ,φ)=ΣGaussian(θ,φ)exp(iP )exp(Ψ-Φ)+Noise j j j j=0 Gaussian(θ,φ) = individual primary beam Station beam Station beam φ[degree] φ[degree] θ[degree] θ[degree]
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern θ[°] (angle form zenith)
Symmetry Normalized Power Pattern θ[°] (angle form zenith)
Asymmetry Normalized Power Pattern θ[°] (angle form zenith)
Asymmetry Normalized Power Pattern θ[°] (angle form zenith)
Normalized Power Pattern 8° 9° 13° 28° θ[°] (angle form zenith)
80MHz 20MHz 50MHz Asymmetry rate HPBW left side/ HPBW right side θ[°] angle from zenith
S θ Dsinθ D As the angle θgoes from 0 to π/2, the value of cosθ(differentiation of sinθ) gets smaller. As a result, the beam becomes asymmetric. This effect increases as the frequency decreases.
θ =-70° Zenith = 0 ° Beam pattern peak θ (degree)
θ =-60 ° Zenith = 0 ° Beam pattern peak θ (degree)
θ =-50 ° Zenith = 0 ° Beam pattern θ (degree)
θ =-40 ° Zenith = 0 ° Beam pattern θ (degree)
θ =-30 ° Zenith = 0 ° Beam pattern θ (degree)
θ =-20 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =-10 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =0 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =10 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =20 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =30 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =40 ° Zenith = 0 ° θ
θ =50 ° Zenith = 0 ° Beam pattern θ θ (degree)
θ =60 ° Zenith = 0 ° Beam pattern peak θ θ (degree)
θ =70 ° Zenith = 0 ° Beam pattern peak θ θ (degree)
θ =-70 ° Grating lobe Zenith = 0 ° λ ・57.3≒43° d Beam pattern Grating lobe θ (degree)
θ =-60 ° Grating lobe Zenith = 0 ° Beam pattern Grating lobe θ (degree)