如何计算REAL系统的拼接参数

[ZPYin]

REAL具有如下六个探测通道：

• 532高空平行通道
• 532低空平行通道
• 532高空垂直通道
• 532低空垂直通道
• 607高空拉曼通道
• 607低空拉曼通道

在实际使用过程中需要将对应的高低空通道信号进行融合，形成统一的信号剖面，用于数据反演。代码中提供将高低空通道信号进行融合的功能，位于lidarPreprocess.m中。融合算法通过将低空信号转换到与高空信号同等的强度，然后以过渡区间为基准，对高低空信号进行组合。

将通道进行组合的参数为拼接参数，理论上只与高低空通道的透过率差异相关。在更换接收通道的滤光片后需要重新获取拼接参数。代码库中包含计算拼接参数的代码，可通过如下方式调用：

LEMain('D:\Coding\Matlab\CMA-lidar-evaluation\configBkp\Wuhan_Real\REAL_QL.yml', 'flagReadData', true, 'flagDebug', true, 'flagQL', true);

其中需要的配置文件样本如下：

################################################################################
# lidar configuration file
# DON'T use Chinese characters!!!
################################################################################

resultPath: D:\Data\REAL\20220421
dataSavePath: D:\Data\REAL\20220421
figFormat: png   # figure format to be exported

# data loader configuration
# Load lidar data to a specified directory (defined by `dataSavePath`)
dataLoaderCfg:
  REAL:   # lidar No.1
    dataPath: D:\Data\REAL\20220421\detectRange-test
    dataFilenamePattern: .*   # all files
    # data type
    # 1: WHU standard 1064 nm lidar
    # 2: WHU non-standard 1064 nm lidar
    # 3: CMA standard data format in binary
    # 4: Dasun visibility lidar
    # 5: REAL
    dataFormat: 5
    chTag: ['532sh', '532pl', '532sl', '607h', '607l', '532ph']   # 355e; 355p; 355s; 387; 407; 532e; 532p; 532s; 607; 1064e; 1064p; 1064s; 532pl; 532sl; 607l; 532ph; 532sh; 607h
    nMaxBin: 2030   # number of bins

dataVisualCfg:
  REAL:
    lidarNo: 11   # lidar number. (see ./docs/lidarList.md)
    chTag: ['532sh', '532pl', '532sl', '607h', '607l', '532ph']   # 355e; 355p; 355s; 387; 407; 532e; 532p; 532s; 607; 1064e; 1064p; 1064s; 532pl; 532sl; 607l; 532ph; 532sh; 607h
    figVisible: 'on'   # whether display figures
    preprocessCfg:
      hOffset: 0   # height offset. (m)
      tOffset: 0   # time offset. (min)
      deadTime: [3.5, 3.5, 3.5, 30.4, 3.5, 3.5]   # deadtime (ns). If it's empty, deadtime correction is disabled.
      bgBins: [1800, 1900]   # [start index, stop index] for background correction
      nPretrigger: 55   # if nPretrigger < 0, move signal up
      bgCorFile: ''   # data file of dark measurement results
      overlapFile: ''
    vdrCompose: ['532p', '532s', 0.85, 0]   # VDR: [pChannel, sChannel, gainRatio, offset]
    tRange: '2022-04-21 20:10:00 ~ 2022-04-21 21:00:00'
    hRange: 
      - [0, 10000]
      - [0, 10000]
      - [0, 10000]
    sigRange:
      - [1e3, 5e11]   # 532s
      - [1e1, 1e10]   # 532p
      - [0, 0.4]   # 607
    cRange:   # color range for Range-corrected signal
      - [0, 1e10]   # channel 1
      - [0, 1e10]   # channel 1
      - [0, 1e10]   # channel 1
    title: 
      - 'REAL 532 s'
      - 'REAL 532 p'
      - 'REAL volume depolarization ratio'
    deltaT: 1   # temporal resolution (min)
    markTRange: '2022-04-21 20:10:00 ~ 2022-04-21 21:00:00'

运行以上命令后，得到的典型结果如下所示

通过观测拼接信号的好坏，可以更改lidarPreprocess.m中的拼接参数，并经过微调，让拼接结果更加复合预期即可。