Figure 4
From: A weighted eigenvector autofocus method for sparse-aperture ISAR imaging
![Figure 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1687-6180-2013-92/MediaObjects/13634_2012_Article_483_Fig4_HTML.jpg)
Imaging results for complete aperture data under low SNRs. (a) Eigenvector method. (b) PGA algorithm. (c) Weighted eigenvector method. (d) Envelope of the 146th range unit. (e) Average entropy value under different SNRs. (f) Entropy MSE under different SNRs.