In bistatic inverse synthetic aperture radar（ISAR）

azimuth resolution decreases when imaging space target in small rotating angle.To solve this problem

algorithm based on auto regressive（AR）model dada extrapolation is presented.Echo in azimuth direction can be deemed to obey AR model in bistatic ISAR.Based on the property

linear prediction equation is established

and the Levions recursive method in maximum Burg entropy algorithm is used to estimate the prediction coefficients.The echo in azimuth direction is extrapolated in forward and backward

and the 2D image is estimated based on the original and extrapolated data together.The azimuth resolution is increased in small rotating angle

and the defocusing problem caused by bistatic angle variance is avoided in large accumulation time.Simulation experiment validates the availability of this algorithm.