...
Users are offered the option of 'None', 'Nearest vertical bin', or 'Linear interpolation (Ott method)'. In either method, any data where the absolute pitch or roll is greater than or equal to 20 degrees, bin-mapping will not be applied and the data with be returned NaN. If the absolute values of all pitch or all roll data are greater than or equal to 20 degrees, the bin-mapping option will be overridden in the data products to 'None' (warnings will also be issued to the search status and internal logs). When the data is in Earth co-ordinates, bin-mapping cannot be applied/modified. For RDI Earth data, the nearest vertical bin method has normally been applied, while Nortek Earth data does not have bin-mapping applied. In both cases, the users' preference may be overridden. The RDI manual indicates that pitch or roll values greater than 20 degrees are not possible and nominal processing has, in the past, applied NaN values when the pitch or roll exceeds that limit. However, we have found that RDI ADCPs can accurately report higher tilts. The limit is now set to 60 degrees for pitch/roll and at or above 90 degrees of average tilt, bin-mapping is overridden to the 'None' option.
Bin-mapping is not applied to the backscatter and intensity data. Instead, we offer a vertically corrected range in the mat file products and use this range for the plots when plotting against depth. For example, if the bin spacing is 1 m, but the tilt is 10 degrees, the vertical spacing is 0.98 m.
...