• Acta Optica Sinica
  • Vol. 40, Issue 16, 1628001 (2020)
Zhen Dong, Lin Sun*, Xirong Liu, Yongji Wang, and Tianchen Liang
Author Affiliations
  • College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
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    DOI: 10.3788/AOS202040.1628001 Cite this Article Set citation alerts
    Zhen Dong, Lin Sun, Xirong Liu, Yongji Wang, Tianchen Liang. CDAG-Improved Algorithm and Its Application to GF-6 WFV Data Cloud Detection[J]. Acta Optica Sinica, 2020, 40(16): 1628001 Copy Citation Text show less
    Comparison of AVIRIS(solid line) and GF-6 WFV(dashed line) data spectral response curves at different bands. (a) 1st band; (b) 2nd band; (c) 4th band; (d) 6th band
    Fig. 1. Comparison of AVIRIS(solid line) and GF-6 WFV(dashed line) data spectral response curves at different bands. (a) 1st band; (b) 2nd band; (c) 4th band; (d) 6th band
    Comparison of raw image and simulated image of the Wisconsin area, USA. (a) Raw GF-6 WFV image; (b) simulated GF-6 WFV image
    Fig. 2. Comparison of raw image and simulated image of the Wisconsin area, USA. (a) Raw GF-6 WFV image; (b) simulated GF-6 WFV image
    Flow chart of GF-6 WFV data cloud detection algorithm
    Fig. 3. Flow chart of GF-6 WFV data cloud detection algorithm
    Cloud detection results of GF-6 WFV data under different cloud cover conditions. (a) 2018-09-02; (b) 2019-06-07; (c) 2019-04-21; (d) 2018-11-03; (e) 2018-12-01; (f) 2018-09-23
    Fig. 4. Cloud detection results of GF-6 WFV data under different cloud cover conditions. (a) 2018-09-02; (b) 2019-06-07; (c) 2019-04-21; (d) 2018-11-03; (e) 2018-12-01; (f) 2018-09-23
    Cloud detection results of GF-6 WFV data before and after bright surface removal. (a) 2018-12-30; (b) 2019-04-21; (c) 2019-05-04
    Fig. 5. Cloud detection results of GF-6 WFV data before and after bright surface removal. (a) 2018-12-30; (b) 2019-04-21; (c) 2019-05-04
    Partial image vectorization results. (a) Vectorization result of vegetation image; (b) vectorization result of urban area image
    Fig. 6. Partial image vectorization results. (a) Vectorization result of vegetation image; (b) vectorization result of urban area image
    Table 1. Typical examples of bright surface pixels in the pixel dataset
    Single bandMulti bandBand ratio
    B1>0.27B1>0.18 & B4>0.340.80<B1/B7<1.08
    B7>0.26B1>0.22 & B7>0.260.99<B2/B8<1.20
    B2>0.14 & B4>0.360.47<B3/B7<1.14
    B2>0.18 & B7>0.260.91<B3/B8<1.07
    B3>0.14 & B6>0.32
    B3>0.14 & B7>0.26
    B4>0.36 & B5>0.20
    B4>0.36 & B8>0.18
    B5>0.20 & B6>0.32
    Table 2. Band combination and threshold selected under the original CDAG method
    BandAverageMulti-band dispersion
    B1,B2,B5A1=(B1+B2+B5)/3[(B1-A1)/A1+(B2-A1)/A1+(B5-A1)/A1]<0.015
    B1,B2,B5A2=(B1+B3+B7)/3[(B1-A2)/A2+(B3-A2)/A2+(B7-A2)/A2]<0.023
    B1,B5,B7A3=(B1+B5+B7)/3[(B1-A3)/A3+(B5-A3)/A3+(B7-A3)/A3]<0.057
    B2,B3,B7A4=(B2+B3+B7)/3[(B2-A4)/A4+(B3-A5)/A4+(B7-A4)/A4]<0.018
    B2,B5,B7A5=(B2+B5+B7)/3[(B2-A5)/A5+(B5-A5)/A5+(B7-A5)/A5]<0.055
    B3,B5,B7A6=(B3+B5+B7)/3[(B3-A6)/A6+(B5-A6)/A6+(B7-A6)/A6]<0.043
    Table 3. Band and threshold selected by three-band dispersion combination
    Multi bandMulti band+Band difference
    B1>0.30 & B2>0.32 & B7>0.28B1>0.31 & B3>0.35 & B3-B7<0.015
    B1>0.31 & B3>0.36 & B7>0.27B1>0.31 & B4>0.39 & B4-B7<0.075
    B2>0.33 & B3>0.37 & B7>0.28B2>0.34 & B6>0.35 & B6-B7<0.035
    B2>0.34 & B5>0.35 & B7>0.29
    Table 4. Band and threshold selected by the bright surface detection algorithm
    Underlying surfaceImageCR /%ER /%MR /%SR /%
    176.580.4823.4299.52
    Bare soil288.459.7311.5591.27
    384.142.4915.8697.51
    185.462.7914.5497.21
    Building288.637.3811.3792.62
    383.793.4216.2196.58
    190.360.289.6499.72
    Vegetation290.870.669.1399.34
    388.040.1511.9699.85
    182.550.5317.4599.47
    Water277.660.2022.3499.80
    385.430.6114.5799.39
    Total85.162.3914.8497.69
    Table 5. Accuracy evaluation of cloud pixel detection results
    Zhen Dong, Lin Sun, Xirong Liu, Yongji Wang, Tianchen Liang. CDAG-Improved Algorithm and Its Application to GF-6 WFV Data Cloud Detection[J]. Acta Optica Sinica, 2020, 40(16): 1628001
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