The data in the SAR image is corrected by subtracting the quadratic phase error, and by adding the same quadratic phase error for comparing, both results are transformed to time domain, then we get two comparing images, where the fixed background clutter have same sharpness, the moving targets have different sharpness.

Minimum entropy autofocus is a typical parametric autofocus method which is used to estimate and correct quadratic phase error.

Based on single long baseline interferometer,this paper adopts the method of the secondary phase difference to steer clear of the 2π ambiguity in order to realize the fast a.

This algorithm controls the process of simplification by quadric error and the edge collapse operation is used to simplify meshes.

An improved phase error estimation algorithm;

Experimental Research on Separated Phase Error from Sound Intensity Measurement System;

Study on phase error calibration method for stepped frequency radar;

FEL small signal gain reduction due to phase error of undulator;

the influence of Gauss/Super-Gauss beam s waist radius,phase error and order number upon diffractive field was discussed.

Undulator rms phase error is expressed as function of the magnet peak field distribution.