Before starting the acquisition, different sweep parameters were tested. Tests were carried out at receiver location 10 (easternmost part of the profile) with 40 landstreamer recorders deployed for this purpose. Given the earlier successful study of a similar setup (Malehmir et al., 2022), the intention was primarily to check if the two sources were phase-locked and synchronized. Different linear upsweeps with frequency ranges 5-120 Hz, 5-140 Hz, 10-120 Hz and 10-140 Hz, with varying lengths of 16 and 18 s were tested. Theoretical sweeps were used for the cross-correlation. After studying the corresponding shot records, 10 Hz was chosen as the starting frequency, to avoid excessive surface-wave energy excited by the source, and 140 Hz as the ending one. An 18 s sweep length was chosen to make sure enough time was given to allow buildup of both low and high frequencies.