高分解能衛星WorldView-2によるアルベドの算定:コミュニティレベルでの熱環境評価への利用

スクリーンショット(2013-01-09 12.43.22)

スクリーンショット(2013-01-09 12.45.29)

 

スクリーンショット(2012-12-27 15.33.33)

 

 

 

 

 

 

 

 

 

 

都市の熱環境を決定する要素の一つとして、地表面の被覆状況が挙げられる。地表面被覆を構成する素材は熱的特性や放射特性、蒸発散に影響を及ぼす。特に都市キャニオン内の夏季の暑熱化を考える場合、被覆面の反射率(アルベド)や蒸発効率(水分の蒸発のしやすさの指標)などが重要になってくる。また、熱帯夜を考える場合は、被覆面の熱容量などの要素も必要となる。

http://www.env.go.jp/air/report/h15-02/02_3_4.pdf

暑熱化

スクリーンショット 2013-02-04 20.32.39

 

 

 

 

 

 

 

スクリーンショット 2013-02-13 21.27.36

The image is referenced from

Radiometric Use of WorldView-2 Imagery

Narrowband to broadband conversions of land surface albedo I Algorithms

Wave TheakakaraNASA 1973

Athul Thekkekara

 

Entropy

スクリーンショット(2013-01-09 12.27.06)

 

 

 histogram programs source

N:階調数 11bit (WorldView-2の場合), P(i):画像中の階調iの確率分布。P(i)は画像中の階調iの画素数を画像全体の画素数で割って求める。

logの底は2。

Albedo

スクリーンショット(2013-01-18 13.39.59)

 

 

absCalFactor from IMD file

RPC file : RPB

 

calcHist ( &bgr_planes[0], 1, 0, Mat(), b_hist,1, &histSize, &histRange, uniform, accumulate);

  • images – Source arrays. They all should have the same depth, CV_8U or CV_32F , and the same size. Each of them can have an arbitrary number of channels.
  • nimages – Number of source images.
  • channels – List of the dims channels used to compute the histogram. The first array channels are numerated from 0 to images[0].channels()-1 , the second array channels are counted from images[0].channels() to images[0].channels() +images[1].channels()-1, and so on.
  • mask – Optional mask. If the matrix is not empty, it must be an 8-bit array of the same size as images[i] . The non-zero mask elements mark the array elements counted in the histogram.
  • hist – Output histogram, which is a dense or sparse dims -dimensional array.
  • dims – Histogram dimensionality that must be positive and not greater thanCV_MAX_DIMS (equal to 32 in the current OpenCV version).
  • histSize – Array of histogram sizes in each dimension.
  • ranges – Array of the dims arrays of the histogram bin boundaries in each dimension. When the histogram is uniform ( uniform =true), then for each dimension i it is enough to specify the lower (inclusive) boundary L_0 of the 0-th histogram bin and the upper (exclusive) boundary U_{\texttt{histSize}[i]-1} for the last histogram bin histSize[i]-1 . That is, in case of a uniform histogram each of ranges[i] is an array of 2 elements. When the histogram is not uniform ( uniform=false ), then each of ranges[i] contains histSize[i]+1 elements:L_0, U_0=L_1, U_1=L_2, ..., U_{\texttt{histSize[i]}-2}=L_{\texttt{histSize[i]}-1}, U_{\texttt{histSize[i]}-1} . The array elements, that are not between L_0 and U_{\texttt{histSize[i]}-1} , are not counted in the histogram.
  • uniform – Flag indicating whether the histogram is uniform or not (see above).
  • accumulate – Accumulation flag. If it is set, the histogram is not cleared in the beginning when it is allocated. This feature enables you to compute a single histogram from several sets of arrays, or to update the histogram in time.

Program Source 1

histogram for Entropy

PanSharpen-Brovey

WorldView-2

  • legacy bands
  • new bands

using OpenCV

install CMake

WorldView-2:2010/11/27 IMAGES

BAND_C: Coastal Blue (400-450 nm)

BAND_B: Blue (450-510 nm)

BAND_G: Green (510-580 nm)

BAND_Y: Yellow (585-625 nm)

BAND_R: Red (630-690 nm)

BAND_RE: Red-Edge (705-745 nm)

BAND_N: NIR1 (770-895nm)

BAND_N2: NIR2 (860-1040 nm)

instruction