Aurora Australis Southern Ocean oceanographic data, voyage 1, 2002-2003 - ADCP data

Oceanographic measurements conducted on voyage 7 of the Aurora Australis of the 2002-2003 season. These data are ADCP (Acoustic Doppler Current Profiler) data. These data were collected/collated by Mark Rosenberg. Final ADCP data for voyage au0201 (SAZ mooring turnaround and iceberg B9B experiment), Aurora Australis Voyage 1 2002/2003, 17th Oct 2002 to 18th Nov 2002. * The complete ADCP data for cruise au0201 are in the file: au020101.cny (ascii format) a0201dop.mat (matlab format) * The "on station" ADCP data (specifically, the data for which the ship speed was less than or equal to 0.35 m/s) are in the files: au0201_slow35.cny (ascii format) a0201dop_slow35.mat (matlab format) * The file bindep.dat shows the water depths (in metres) that correspond to the centre of each vertical bin. * The data are 30 minute averages. Each 30 minute averageing period starts from the time indicated. (so, e.g., an ensemble with time 120000 is the average from 120000 to 123000). * ADCP currents are absolute - i.e. ship's motion has been subtracted out. * Note that the top few bins can have bad data from water dragged along by the ship. * Beware of data when the ship is underway - it's often suspect. MATLAB VECTORS AND MATRICES: ============================ header info ----------- for header info: column number corresponds to 30 minute average number botd = mean bottom depth (m) over the 30 minute period cnav = GPS info: don't worry about it cruise = cruise number date = ddmmyy (UTC) ibcover = a bottom track parameter: don't worry about it icover = percentage of 30 minute averageing period covered by acceptable 3 minute ensembles lastgd = deepest accepted bin in this profile lat = mean latitude over the 30 minute period (decimal degrees) lon = mean longitude over the 30 minute period (decimal degrees) nbins = no. of bins logged (=60) shipspeed = scalar resultant of shipu and shipv shipu = ship's E/W velocity over the ground over 30 minute period (m/s, +ve east) shipv = ship's N/S velocity over the ground over 30 minute period (m/s, +ve north) time = hhmmss, time (UTC) at start of 30 minute averageing period dectime = time in decimal days from start of year 2002 (e.g. midday on January 2nd = 1.5000) adcp data --------- for adcp data matrices: row number corresponds to bin number column number corresponds to 30 min. average no. bindep = depth (m) to centre of each bin in the profile (will be the same for all profiles) ipcok = percentage of the profile period for which there was good data in this bin (N.B. data=NaN when ipcok=0) qc = a quality control value for each bin - see below speed = scalar resultant of u and v u = east/west current (m/s, +ve east) v = north/south current (m/s, +ve north) ASCII FORMAT FILE: ================== * The file starts with a 3 line header. * Then comes each 30 min. ensemble, as follows: First, a 1 line header, containing date (UTC) (dd-mmm-yyyy) time (UTC) (hh:mm:ss) % of 30 min average covered by acceptable 3 min. ensembles deepest accepted bin in the profile ship's E/W velocity over the ground over the 30min (m/s) ship's N/S velocity over the ground over the 30min (m/s) P= GPS position-derived velocity (D=direct GPS vel.; B=bottom track vel.) mean longitude over the 30 min. mean latitude over the 30 min. % of interfix period for which there was bottom depth information mean bottom depth over the 30 min. 0 0 Next, the data, from the shallowest bin to the deepest bin: for each bin, there's 4 parameters: u = east/west current (m/s, +ve east) v = north/south current (m/s, +ve north) qc = quality control value - see below ipcok = percentage of the profile period for which there was good data in this bin Note that the data are written left to right across each line, then onto the next line, etc. (so 4 bins on a full line) quality control value: ---------------------- qc = %good / (Verr+0.05) where: %good = percent good pings after logging system screening Verr = RMS error velocity (m/s). Possible range of qc is 0-20, with an expected range of 0-10; values of 0-4 indicate very poor data; values above 8 indicate very good data.本数据集为2002-2003航季「极光号（Aurora Australis）」第7航次所获取的海洋观测数据，数据类型为ADCP（声学多普勒海流剖面仪，Acoustic Doppler Current Profiler）观测数据。本数据集由Mark Rosenberg收集整理。另对应au0201航次的最终ADCP数据，该航次任务为SAZ系泊装置转运与B9B冰山实验，属于2002/2003航季「极光号」第1航次，航次时间为2002年10月17日至2002年11月18日。 * 该航次完整的ADCP数据存储于以下文件： au020101.cny（ASCII格式） a0201dop.mat（MATLAB格式） * 「驻站」ADCP数据（特指航速≤0.35m/s时段的观测数据）存储于以下文件： au0201_slow35.cny（ASCII格式） a0201dop_slow35.mat（MATLAB格式） * bindep.dat文件记录了每个垂直测层中心对应的水深（单位：米）。 本数据为30分钟平均结果，每个30分钟平均时段从标注时刻开始计算（例如，时刻标记为120000的观测集合对应120000至123000时段的平均结果）。ADCP测量的海流为绝对流速，即已扣除船体运动的影响。请注意：顶部少数测层可能存在受船体裹挟水流影响的无效数据；航行状态下的观测数据通常可信度较低，请谨慎使用。 MATLAB向量与矩阵： ============================ 头文件信息 ----------- 头文件信息的列号对应30分钟平均时段的编号： botd = 该30分钟时段内的平均海底水深（单位：米） cnav = GPS信息，无需关注 cruise = 航次编号 date = 日期格式为ddmmyy（协调世界时UTC） ibcover = 海底跟踪参数，无需关注 icover = 该30分钟平均时段内有效3分钟观测集合的占比 lastgd = 该剖面中最深的有效测层 lat = 该30分钟时段内的平均纬度（十进制度） lon = 该30分钟时段内的平均经度（十进制度） nbins = 记录的测层数（固定为60） shipspeed = 船速u与船速v的合速度标量 shipu = 该30分钟时段内船体相对于地面的东西向航行速度（单位：m/s，正东为正） shipv = 该30分钟时段内船体相对于地面的南北向航行速度（单位：m/s，正北为正） time = 该30分钟平均时段开始时刻的UTC时间，格式为hhmmss dectime = 相对于2002年1月1日的十进制天数（例如，1月2日正午对应1.5000） adcp数据 --------- adcp数据矩阵的行号对应测层编号，列号对应30分钟平均时段编号： bindep = 该剖面中每个测层中心的水深（单位：m，所有剖面的该参数均一致） ipcok = 该测层在剖面时段内有效数据的占比（注：当ipcok=0时，数据为NaN） qc = 每个测层的质量控制值，详见下文 speed = 流速u与v的合速度标量 u = 东西向海流速度（单位：m/s，正东为正） v = 南北向海流速度（单位：m/s，正北为正） ASCII格式文件： ================== * 文件开头包含3行头信息。 * 随后为每个30分钟观测集合，格式如下： 首先是1行头信息，包含： UTC日期（格式为dd-mmm-yyyy）、UTC时间（格式为hh:mm:ss）、有效3分钟观测集合占该30分钟平均时段的百分比、该剖面中最深的有效测层、该30分钟时段内船体相对于地面的东西向航行速度（单位：m/s）、该30分钟时段内船体相对于地面的南北向航行速度（单位：m/s）、P=基于GPS位置解算的航速（D=直接GPS航速；B=海底跟踪航速）、该30分钟时段内的平均经度、该30分钟时段内的平均纬度、有效海底水深信息占间隙时段的百分比、该30分钟时段内的平均海底水深、0、0。 接下来为数据部分，从最浅测层到最深测层依次排列：每个测层包含4个参数：东西向海流速度（单位：m/s，正东为正）、南北向海流速度（单位：m/s，正北为正）、质量控制值（详见下文）、该测层在剖面时段内有效数据的占比。 注：数据按每行从左到右依次写入，满行后换行（因此每行最多包含4个测层的数据）。 质量控制值： ---------------------- qc = %good / (Verr+0.05) 其中： %good = 经观测系统筛选后有效的声脉冲百分比 Verr = 均方根误差流速（单位：m/s）。 qc的取值范围为0~20，预期取值范围为0~10；0~4表示数据质量极差；大于8表示数据质量极佳。