An ultrasound system, comprising: an ultrasound data acquisition unit configured to transmit ultrasound signals toward a target object along non-steered scan lines and steered scan lines respectively steered at a predetermined steering angle with respect to the non-steered scan lines and receive echo signals to thereby form a plurality of sets of ultrasound frame data each being indicative of a target object, the plurality of sets of ultrasound frame data including a first set of ultrasound frame data formed based on the non-steered scan lines and a second set of ultrasound frame data formed based on the steered scan lines; and a processor coupled to the ultrasound data acquisition unit and configured to set a plurality of sub steering angles based on the predetermined steering angle and resample the second set of ultrasound frame data formed based on the plurality of sub steering angles, said setting being based on a permissible refraction range for the predetermined steering angle, said permissible refraction range being a steering angle angular range, in particular determinable by considering the refraction of any lens mounted on the transducer elements and the refraction of the target object, to form a plurality of sets of resampled ultrasound frame data, the processor being further configured to compare a mean absolute difference, MAD, value on a pixel basis between the first set of ultrasound frame data and with each of the other sets including the second set of ultrasound frame data and the plurality of sets of resampled ultrasound frame data to select a particular set of ultrasound frame data having the smallest MAD value from the plurality of sets of resampled ultrasound frame data including the second set of ultrasound frame data and spatially compound the selected particular set of ultrasound frame data and the first set of ultrasound frame data to form an ultrasound spatial compound image. an ultrasound data acquisition unit configured to transmit ultrasound signals toward a target object along non-steered scan lines and steered scan lines respectively steered at a predetermined steering angle with respect to the non-steered scan lines and receive echo signals to thereby form a plurality of sets of ultrasound frame data each being indicative of a target object, the plurality of sets of ultrasound frame data including a first set of ultrasound frame data formed based on the non-steered scan lines and a second set of ultrasound frame data formed based on the steered scan lines; and a processor coupled to the ultrasound data acquisition unit and configured to set a plurality of sub steering angles based on the predetermined steering angle and resample the second set of ultrasound frame data formed based on the plurality of sub steering angles, said setting being based on a permissible refraction range for the predetermined steering angle, said permissible refraction range being a steering angle angular range, in particular determinable by considering the refraction of any lens mounted on the transducer elements and the refraction of the target object, to form a plurality of sets of resampled ultrasound frame data, the processor being further configured to compare a mean absolute difference, MAD, value on a pixel basis between the first set of ultrasound frame data and with each of the other sets including the second set of ultrasound frame data and the plurality of sets of resampled ultrasound frame data to select a particular set of ultrasound frame data having the smallest MAD value from the plurality of sets of resampled ultrasound frame data including the second set of ultrasound frame data and spatially compound the selected particular set of ultrasound frame data and the first set of ultrasound frame data to form an ultrasound spatial compound image.