Abstract: Angular resolution is the dominant factor for determining the extraction ability of a point cloud target.An angular resolution model is derived from average modulation transfer function(AMTF).The AMTF model is affected by sampling interval AMTFS、spot size AMTFb and quantization AMTFq.An accuracy assessment formula for sampling intervals and spot size was derived through an analysis of the error factor of sampling interval and spot size.The Linearization of AMTF model was based on the relationship among AMTF model、the sampling interval and spot size;The standard deviation of the cut-off frequency is derived according to the error propagation law;and an accuracy evaluation for angular resolution is achieved according to the relationship between cut-off frequency and angular resolution.