# Processing Narrative ## Mooring Description A Teledyne-RDI Sentinel Workhorse 614.4 kHz ADCP was deployed, mounted at 2.5 meters on a GTMBA Atlas taut mooring bridle facing downward, from 2008-10-13 until 2009-06-18 at a nominal location of 0-23w. The ADCP was configured to perform a 2 minute ensemble average every hour over 47 bins separated by 0.75 meters. As configured the ADCP reported the depth of the first bin was 1.77 meters from the transducers. In addition to the ADCP, there were also two Nortek Aquadopps, two Sontek Argonauts, and one Teledyne RDI DVS current meters deployed on this mooring with nominal depths of 7, 12, 17, 22, and 27 meters. ## Original ADCP Data The ADCP data, "SENT_3974.mat", was downloaded and converted to Matlab using the Teledyne-RDI WinADCP software. In Matlab, the initial data structure was as follows: adcp = struct with fields: RDIFileName: 'C:\Users\fey\Desktop\023WA000.pd0' RDISystem: 'Broadband 614.4 kHz' RDIPingsPerEns: 120 RDISecPerPing: 1 RDIEnsDate: '08/10/10' RDIEnsTime: '11:59:00.00' RDIEnsInterval: 14.2857 RDIBin1Mid: 1.7700 RDIBinSize: 0.7500 SerBins: [1×47 double] SerEnsembles: [6050×1 double] SerYear: [6050×1 double] SerMon: [6050×1 double] SerDay: [6050×1 double] SerHour: [6050×1 double] SerMin: [6050×1 double] SerSec: [6050×1 double] SerHund: [6050×1 double] AnP100thDeg: [6050×1 double] AnR100thDeg: [6050×1 double] AnH100thDeg: [6050×1 double] AnT100thDeg: [6050×1 double] AnDepthmm: [6050×1 double] AnOrienUP: [6050×1 double] AnBIT: [6050×1 double] AnBatt: [6050×1 double] SerEA1cnt: [6050×47 double] SerEA2cnt: [6050×47 double] SerEA3cnt: [6050×47 double] SerEA4cnt: [6050×47 double] SerEAAcnt: [6050×47 double] SerC1cnt: [6050×47 double] SerC2cnt: [6050×47 double] SerC3cnt: [6050×47 double] SerC4cnt: [6050×47 double] SerCAcnt: [6050×47 double] SerEmmpersec: [6050×47 double] SerNmmpersec: [6050×47 double] SerVmmpersec: [6050×47 double] SerErmmpersec: [6050×47 double] SerMagmmpersec: [6050×47 double] SerDir10thDeg: [6050×47 double] SerPG1: [6050×47 double] SerPG2: [6050×47 double] SerPG3: [6050×47 double] SerPG4: [6050×47 double] The definitions of some of these fields are: - SerEmmpersec: east, U, or Zonal current velocity component in mm/sec. - SerNmmpersec: north, V, or Meridional current velocity component in mm/sec. - SerVmmpersec: vertical current velocity component in mm/sec. - SerErmmpersec: error velocity in mm/sec. - SerMagmmpersec: speed or magnitude of current in mm/sec. - SerDir10thDeg: direction of current in 10th of degrees. ## Initial ADCP Processing The initial ADCP processing consisted of the following steps: 1. The original time and date variables were replaced with an array of Matlab datenum values called 'datenum'. 2. The time stamp of the ensembles was adjusted one minute forward to the center of the averaging interval. 3. The bin depths were computed and added as 'depths'. 4. All the timeseries variables were trimmed to a period >= anchor drop + 2 hours and < release fired. The resulting date range is '2008-10-13 03:00:00' until '2009-06-18 17:00:00'. 5. The substructure 'GTMBA' was added to store the mooring metadata. 6. The ADCP configuration variables were collected into the substructure named 'RDI'. ## Current Meter Processing The 7 and 17 meter Aquadopp current meters were corrected with a declination of -15.9 degrees and data trimmed with the same limits as the ADCP data. The 12 and 22 meter Argonaut current meters were corrected with a declination -16.0 degrees, flagged for vandalism and excessive transducer noise, and trimmed with the same limits as the ADCP data. ## ADCP Compass Correction It was determined that the ADCP compass data was incorrect due to magnetic interference from the mooring bridle and ADCP mount hardware. The direction from four of the current meters was compared with the nearest ADCP bins to compute a compass correction value for each ensemble. It is important to note that one of the Aquadopps, initially mounted at 7 meters, was found to have been moved ~1.3 meters upward by vandalism. From pressure data it was possible to precisely determine the time at which the Aquadopp changed depth. The following comparisons were used: - ADCP bin 4 versus ~5.7m Aquadopp (from '2008-12-28 00:00:00' until recovery) - ADCP bin 9 versus 12m Argonaut - ADCP bin 19 versus 17m Aquadopp - ADCP bin 22 versus 22m Argonaut From all these differences a mean was calculated for every compass degree. Using this mean compass error as a function of degree, the ADCP direction data was adjusted and the vector components recalculated. ## ADCP Data Flagging The ADCP current data was identified as bad during two intervals. First the current data was flagged during high values of pitch and roll. The other period of bad data coincides with the same vandalism event mentioned in the current meter processing. ## Final ADCP Data The final profile data "adcp.mat", including direction corrections and data flagging, was output from Matlab with the following structure: adcp = struct with fields: SerBins: [1×47 double] SerEnsembles: [5967×1 double] AnP100thDeg: [5967×1 double] AnR100thDeg: [5967×1 double] AnH100thDeg: [5967×1 double] AnT100thDeg: [5967×1 double] AnDepthmm: [5967×1 double] AnOrienUP: [5967×1 double] AnBIT: [5967×1 double] AnBatt: [5967×1 double] SerEA1cnt: [5967×47 double] SerEA2cnt: [5967×47 double] SerEA3cnt: [5967×47 double] SerEA4cnt: [5967×47 double] SerEAAcnt: [5967×47 double] SerC1cnt: [5967×47 double] SerC2cnt: [5967×47 double] SerC3cnt: [5967×47 double] SerC4cnt: [5967×47 double] SerCAcnt: [5967×47 double] SerEmmpersec: [5967×47 double] SerNmmpersec: [5967×47 double] SerVmmpersec: [5967×47 double] SerErmmpersec: [5967×47 double] SerMagmmpersec: [5967×47 double] SerDir10thDeg: [5967×47 double] SerPG1: [5967×47 double] SerPG2: [5967×47 double] SerPG3: [5967×47 double] SerPG4: [5967×47 double] GTMBA: [1×1 struct] RDI: [1×1 struct] datenum: [5967×1 double] depths: [1×47 double] This structure is a modified version of the original data. The fields added to the structure are "GTMBA", "RDI", "datenum", and "depths": - The "RDI" field is a structure containing the instrument configuration variables extracted from the PD0 data file by WinADCP. - The "GTMBA" field, also a structure, contains GTMBA mooring metadata. - The "datenum" field is an array of Matlab datenum values representing the data/time axis for the data. - The "depths" field is an array of depths calculated for the ADCP bins from the mooring metadata and instrument configuration. ## Final Current Meter Data The current meter data is saved as "current_meters.mat". This file contains Nortek Aquadopp and Sontek Argonaut current meter processed data. This data is stored in the Matlab variable "current_meters" as a structure array with the following fields: current_meters = 1×5 struct array with fields: instrument depth datenum u v spd dir orientation mooring location deployed recovered - The "instrument", "orientation", "mooring", "location", "deployed", and "recovered" fields are all character arrays of metadata. - The "depth" field is the nominal transducer depth. - The "datenum" field is an array of Matlab datenum values representing the data/time axis for the data. - The "u", "v", "spd", and "dir" fields contain the current data in units of cm/sec and degrees.