|
波浪骑士是测量海浪的经典设备，目前市场最常见的有荷兰Datawell公司的Waverider产品，其成熟产品主要有两种：加速度计类型和GNSS类型。 Datewell Waverider , ]# `6 y+ J# }8 y
波浪骑士采集的数据有专门的软件进行读取和处理，本文以Datawell 数据为例简单总结处理方法。 O# G; l5 v) p4 m
软件下载下载Waves5软件并安装，安装无需注册。
' w3 Z' {( l1 |# @. [3 W
导入数据新建项目，并将存放数据的文件夹导入。之后，数据文件将在左侧栏的Logged中显示。其数据格式主要有raw,hxv,wvs,spt。9 M9 z$ Y# ]6 d3 x
& W; N3 g3 S- O% u* K& T
数据格式
! Q9 B+ c- [/ G! J1、hxv:Raw buoy messages, q: h$ x* W' z, ?) v+ o5 G
[C] 纯文本查看 复制代码 Meaning: HeXadecimal Vectors
Description: Stream of raw buoy messages
Buoys: DWR MkI, MkII, MkIII
From: HF receiver
Format: Ascii/Text, hexadecimal
该数据包含了浮标的原始记录，半小时一个文件，通过右侧工具栏可以查看统计信息、波浪功率密度谱、二维和三维方向谱。数据样例 [C] 纯文本查看 复制代码 00A4,8B53,80C0,0501,92B7
00A5,A1AB,8040,0101,A978
00A6,C3D7,00D0,0502,5EDF
00A7,65C6,0160,1C01,8E58
数据格式 [C] 纯文本查看 复制代码 Format
SSNN,YYYY,HHHN,NNWW,WPPP
SS: status
00: correct
01: transmission error, repaired
02: transmission error, not repaired
03: all-0 or all-1 vector
04: synchronizing
05: = 04 + 01
06: = 04 + 02
07: = 04 + 03
NN: index, 0-255, modulo 256
YYYY: spectral/system word
HHH: heave (vertical displacement), 12 bit, sign-magnitude
NNN: north displacement, 12 bit, sign-magnitude
WWW: west displacement, 12 bit, sign-magnitude
PPP: Parity, BCH(63,51)-code
2、raw: raw buoy displacements
, J+ X9 B5 S O) \5 p[C] 纯文本查看 复制代码 Meaning: RAW displacements
Description: the heave, north, west displacements @ 1.28 Hz
Buoys: DWR MkI, MkII, MkIII
From: post-processing
Format: Ascii/Text, decimal
该数据包含了浮标的位移信息，通过右侧工具栏可以查看时间序列、波浪功率密度谱、二维和三维方向谱。数据样例： [C] 纯文本查看 复制代码 0, 13, 3, -13
0, 3, 13, -13
0, 15, 17, -11
0, -10, 2, -1
4 L3 p7 H b- _7 b- }' @. u5 i& R7 r
数据格式 [C] 纯文本查看 复制代码 Format sta, hv, no, we
sta: status
0 to 7: see *.HXV
16: one of the three displacements outside +/- 4s.
32: two of the three displacements outside +/- 4s.
48: all three displacements outside +/- 4s.
64: dummy vector to replace unreceived vector
128: gap in GPS link (DWR-G buoys only)
hv: heave [cm]
no: north displacement [cm]
we: west displacement [cm]
3、WVS:the chronological list of upcross waves
: _, N: j7 u+ ]% H; q[C] 纯文本查看 复制代码 Meaning: upcross WaVeS data
Description: the chronological list of upcross waves
Buoys: DWR MkI, MkII, MkIII
From: post-processing
Format: Ascii/Text, decimal
: I2 C6 B5 i+ u
该数据包含了按时间排列的波浪主要信息，通过右侧工具栏可以查看波峰、波谷和周期信息。数据样例 [C] 纯文本查看 复制代码 2012-01-25T05:00:00.000,100, 116, 4.1, 78, 4.0, 62, 3.9, 40, 3.2, 0.534,553
171, 28, -21, 4.071
451, 14, -7, 2.835
385, 8, -20, 2.637
15, 32, -49, 3.230
数据格式 [C] 纯文本查看 复制代码 FormatSummary (12 parameters) .
Timestamp: date and time (ISO8601)
Coverage: percentage of raw data used in constructing the upcross waves [%]
Hmax: maximum wave height [cm]
T(Hmax): period of the highest wave
H[1/10]: mean height of the highest 1/10 of the waves [cm]
T(H[1/10]): mean period of the highest 1/10 of the waves
H[1/3]: mean height of the highest third of the waves [cm]
T(H[1/3]): mean period of the highest third of the waves
Hav: mean height of all waves [cm]
Tav: mean period of all waves
eps: bandwidth parameter [-]
NumWaves: number of upcross waves [-]
List of upcross waves (NumWaves x 4 matrix) .
rank, crest, trough, period
rank: index of wave when sorted ascendingly (1 = highest)
crest: maximum heave within present upcross wave
trough: minimum heave within present upcross wave
period: duration of present upcross wave
NB: the wave height of an upcross wave is the difference between crest and trough.
& I5 N9 a; C0 D* a! m5 t( O
4、spt:the heave and directional spectrum * Q5 Z o- i! c) Z2 Z" B
[C] 纯文本查看 复制代码 Meaning: SPecTral data
Description: the heave and directional spectrum
Buoys: DWR MkI, MkII, MkIII
From: post-processing
Format: Ascii/Text, decimal
$ u! ~3 s, V. m' E- m$ {该数据包含了按时间排列的波浪谱信息。 数据样例： [C] 纯文本查看 复制代码 10
22.0
3.774
1.7287E-2
25.00
14.30
7
0.04125
-0.04500
0.07750
260.2
53.833
0.025,9.9040E-5,60.5,78.6,-2.95,1.71
0.030,6.6547E-4,99.8,69.2,3.77,2.47
0.035,7.6734E-3,279.8,46.3,-0.37,4.47
0.040,8.4804E-3,292.5,67.5,4.55,2.50
* Z+ P8 o4 R' s4 B, a
数据格式 [C] 纯文本查看 复制代码 Format
System file (12 parameters)
tn: transmission index (1 to 8)Hs: significant wave height [cm]
Tz: zero-upcross period
Smax: maximum of the psd S(f) [m^2/Hz]
Tref: reference temperature [°C, centigrade]
Tsea: Sea surface temperature [°C, centigrade]
Bat: Battery status (0 = empty to 7 = full)
Av: offset of the vertical accelerometer
Ax: offset of the x-accelerometer
Ay: offset of the y-accelerometerOri: buoy orientation [°]
Incli: magnetic inclination [°]
Spectrum file (64 x 6 array)
f, S(f) / Smax, Dir(f), Spr(f), Skew(f), Kurt(f)
f: wave frequency [Hz]
S(f) / Smax: relative psd (power spectral density) [-]
Dir(f): wave direction [°]
Spr(f): directional spread [°]
Skew(f): skewness of the directional distribution [-]
Kurt(f): kurtosis of the directional distribution [-]
波浪能量密度谱计算方法 能量密度谱主要包含一下信息： ! {6 R' j9 h6 W
能量：海面高度波动的方差。 能量密度谱：积分之后即能量。 周期：峰值即周期（频率）。 " z- {: _+ o- H( R, n
使用Matlab可做如下计算和测试： [C] 纯文本查看 复制代码 % Load spectral density data From SPT file
TrPath='test.spt';
TrFid = fopen(TrPath,'r'); % 路径
FormatString='%f,%f %*[^\n]'; % 读取数据的类型
Ctr = textscan(TrFid, FormatString, 'HeaderLines', 12,'EndOfLine','\r\n');
Ctr = cell2mat(Ctr); % 转矩阵
fclose(TrFid);
% Load max value of spectral density form SPT file
TrPath='test.spt';
TrFid = fopen(TrPath,'r');
FormatString='%f'; % 读取数据格式
smax = textscan(TrFid, FormatString, 'HeaderLines', 3);
smax = cell2mat(smax); % 转矩阵
fclose(TrFid);
% Calculate PSD using RAW data
wb=load('test.raw');
fs_g=1.28;% hz
len=length(wb(:,2));
[Pxx_wb,fxx_wb]=pwelch(wb(:,2)/100,fix(len/20),[],[],fs_g,'onesided');
% Plot
figure('name','wavebuoy')
plot(Ctr(:,1),Ctr(:,2)*smax(1));hold on
plot(fxx_wb, Pxx_wb);
legend('From SPT file','By matlab pwelch')
* y* r/ `* n- e7 O4 b7 W5 H3 V# m可见使用波浪骑士的原始波动数据计算PSD和SPT文件中的PSD是符合的。所以采集数据之后，既可以使用wave5进行数据处理，也可以自己编程实现，二者一致。 方向谱 波浪骑士可观测海浪的三个方向的加速度，进而可以通过交叉谱确定方向谱。 Maltab开源程序包diwasp也可以独立计算方向谱，下面比较Wave5软件和diwasp计算方向谱的差异。 Matlab程序
[C] 纯文本查看 复制代码 % WB的方向谱
folder ='C:\Users\lei\Documents\MATLAB\diwasp';
addpath( genpath(folder) );
ID.fs=1.28;
ID.depth=25;
ID.datatypes={'elev','dspx','dspy'};
ID.layout=repmat([0 0 25]',[1 length(ID.datatypes)]);
wb=load('C:\Users\lei\Documents\wavebuoy\2021\November\2021-10-24T06h30Z.raw');
ID.data=wb(:,2:4)/100;
SM.freqs = [0.01:0.002:0.7];
SM.dirs = [-180:1:180];
SM.xaxisdir = 0 ;
EP.dres = 180 ;
EP.nfft = 64;
EP.iter = 100;
EP.smooth = 'ON';
EP.method = 'DFTM';
[SMout,EPout]=dirspec(ID,SM,EP,{'PLOTTYPE',2,'FILEOUT','sampleout.spec'});
* B9 c7 `8 r4 n7 l. G结果为：
MATLAB计算的方向谱和波浪骑士自带工具显示的方向谱形态大致符合，但是角度相差了90度。原因不确定，但可能是参考轴的差异引起。后面需要进一步分析差异原因。 - S3 ~( l: `8 h& G& i' e
|
