GEO SAR interference system data acquiring method

The invention provides a GEO SAR interference system data acquiring method. According to the method, a rotation decorrelation coefficient is utilized for eliminating deltaKx having no contribution to height measurement, wherein the deltaKx is spatial spectrum shift of range direction in a ground projection direction during first track operation of a GEO SAR system; rotation decorrelation is reduced to improve correlation. Rotation decorrelation is minimized, the deltaKx is minimized through minimizing gamma r, so the spatial spectrum superposition portion of orientation direction in the ground projection direction reaches the largest. Through the method, a problem that GEO SAR interference data generated through a low track SAR interference data acquisition method based on a zero Doppler center in the prior art contains obvious rotation decorrelation is solved.