Separating survey data for multiple survey sources where first survey data along a first axis measured by a survey sensor device is received, the first survey data responsive to activations of the plurality of survey sources at respective azimuths with respect to the survey sensor device. Second survey data is rotated towards a first azimuth of a first of the plurality of survey sources. The rotated second survey data is used as a model of interference caused by a subset of the plurality of survey sources excluding the first survey source. In other examples, a time dithering technique is performed to separate survey data for multiple survey sources.