关于通量footprint函数的问题

X1a0wu

是matlab 新手，老师给了我一个绘制footprint的函数
函数如下
FFP Input
%    All inputs as scalars
%    zm        = Measurement height above displacement height (i.e. z-d) [m]
%    z0        = Roughness length [m] - enter [NaN] if not known
%    umean     = Mean wind speed at zm [ms-1] - enter [NaN] if not known
%                Either z0 or umean is required. If both are given,
%                z0 is selected to calculate the footprint
%    h         = Boundary layer height [m]
%    ol        = Obukhov length [m]
%    sigmav    = Standard deviation of lateral velocity fluctuations [ms-1]
%    ustar     = Friction velocity [ms-1]
%
%    Optional input (varargin):
%    Enter as calc_footprint_FFP(...,'OptionalInput',InputValue)
%    wind_dir  = Wind direction in degrees (of 360) for rotation of the footprint     
%    r         = Percentage of source area for which to provide contours, must be between 10% and 90%.
%                Can be either a single value (e.g., "80") or an array of percentage values
%                (e.g., "[10:10:80]")
%                Expressed either in percentages ("80") or in fractions of 1 ("0.8")
%                Default is [10:10:80]. Set to "NaN" for no output of percentages
%    nx        = Integer scalar defining the number of grid elements of the scaled footprint.
%                Large nx results in higher spatial resolution and higher computing time.
%                Default is 1000, nx must be >=600.
%    rslayer   = Calculate footprint even if zm within roughness sublayer: set rslayer = 1
%                Note that this only gives a rough estimate of the footprint as the model is not valid within
%                the roughness sublayer. Default is 0 (i.e. no footprint for within RS).
%                z0 is needed for estimation of the RS.
%    crop      = Crop output area to size of the 80% footprint or the largest r given if crop=1
%
% FFP output
%    FFP          = Structure array with footprint data for measurement at [0 0 zm] m
%    FFP.x_ci_max = x location of footprint peak (distance from measurement) [m]
%    FFP.x_ci     = x array of crosswind integrated footprint [m]
%    FFP.f_ci     = array with footprint function values of crosswind integrated footprint [m-1]
%    FFP.x_2d     = x-grid of 2-dimensional footprint [m], rotated if wind_dir is provided
%    FFP.y_2d     = y-grid of 2-dimensional footprint [m], rotated if wind_dir is provided
%    FFP.f_2d     = Footprint function values of 2-dimensional footprint [m-2]
%    FFP.r        = Percentage of footprint as in input, if provided
%    FFP.fr       = Footprint value at r, if r is provided
%    FFP.xr       = x-array for contour line of r, if r is provided
%    FFP.yr       = y-array for contour line of r, if r is provided
%                   For array of percentage values, structure entries can be accessed
%                   as FFP(1).r, FFP(1).xr, etc.
%    flag_err     = 1 in case of error, 0 otherwise
%
%
% Example
%    [FFP,flag_err]=calc_footprint_FFP(20,0.01,NaN,2000,-10,0.9,0.5,'wind_dir',30,'r',[10:20:80])

X1a0wu

我搞不懂输出的数据具体是什么意思啊

还有如何将输出 的数据在已有的卫星图上 绘制成足迹区呢

bbs

这是计算通量源区相对贡献的程序，是Kljun编写的，详细情况看其论文，Kljun N., Calanca P., Rotach M. W.,  Schmid H. P., A simple two-dimensional parameterisation for Flux Footprint Prediction (FFP). Geosci. Model Dev., 8, 3695–3713, 2015。你画通量源区图用到FFP.xr,FFP.yr数据的可能性较大。

392375609

我现在也在用ffp来画源区，但是这个模型的输出参数也是很不明白。。。

appy!!!

楼主你有木有画出来，求指导

蓝胖子

https://footprint.kljun.net/
作者自己做的网站，上面共享了matlab版代码和python版代码。但我一直不太懂sigmav要怎么算，这个量到底是啥意思呢？有大佬知道吗？sigmav是u的标准差吗？

pengyuanzhu

bbs 发表于 2020-3-23 12:37
这是计算通量源区相对贡献的程序，是Kljun编写的，详细情况看其论文，Kljun N., Calanca P., Rotach M. W., ...

您好！请问您对las的源区图有了解吗，或者在什么网站能够得到代码，打扰您了！