This research used EM1000 multibeam data in the equiangle mode (150 degrees). The beamwidth of beams after intersection of transmit and receive beam patterns is ~2.4 degrees (3dB sector), but the outer beams log extra traces beyond these limit to allow bottom phase detection. The "extended" outer beams have their traces with intensities varying ~10dB (~20 DN_value). They recover an area of ~28% of the entire swath. Therefore, normalization of outer beams improves the quality of large amount of logged data. The figures below show the trace patterns for the entire swath and for the first beam (~4.5 degrees beamwidth in the range of ~20 DN_values):
Backscatter Intensities of the Entire Swath
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Backscatter Intensities of the Beam 0
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