6.1.3. Spatial Subsetting

6.1.3.1. Operation


Operation name:Spatial Subsetting
Description:This Operation provides the functionality to select data of a region of interest. All data outside will be discarded.
Utilised in:Use Case #9 Workflow

6.1.3.2. Options


name:polygon subsetting
description:spatial subsetting of data inside a polygon

name:polygon subsetting by selection from a list of main regions
description:analysis of propagation of uncertainties during geometric adjustment

name:point subsetting
description:selection of a spatial point to retrieve all temporal in formation of that point

6.1.3.3. Input data


name:longitude (lon, x)
type:floating point number
range:[-180.; +180.] respectively [0.; 360.]
dimensionality:vector
description:grid information on longitudes

name:latitude (lat, y)
type:floating point number
range:[-90.; +90.]
dimensionality:vector
description:grid information on latitudes

name:height (z)
type:floating point number
range:[-infinity; +infinity]
dimensionality:vector
description:grid information on height/depth

name:time (time, t)
type:integer or double
range:[0; +infinity]
dimensionality:vector
description:days/months since …

name:variable
type:floating point number
range:[-infinity; +infinity]
dimensionality:cube or 4D
description:values of a certain variable

6.1.3.4. Output data


name:subset of variable
type:floating point number
range:[-infinity; +infinity]
dimensionality:vector or cube or 4D
description:values of a certain variable for the chosen area of interest

6.1.3.5. Parameters


name:lon, x (longitudinal position)
type:floating point number
valid values:[-180.; +180.] resp. [0.; 360.]
description:longitudinal coordinate of point of interest

name:lat, y (latitudinal position)
type:floating point number
valid values:[-90.; +90.]
description:latitudinal coordinate of point of interest

name:lon1, x1 (longitudinal position)
type:floating point number
valid values:[-180.; +180.] respectively [0.; 360.]
default value:minimum longitude of input data
description:longitudinal coordinate limiting rectangular area of interest

name:lon2, x2 (longitudinal position)
type:floating point number
valid values:[-180.; +180.] resp. [0.; 360.]
default value:maximum longitude of input data
description:longitudinal coordinate limiting rectangular area of interest

name:lat1, y1 (latitudinal position)
type:floating point number
valid values:[-90.; +90.]
default value:minimum latitude of input data
description:latitudinal coordinate limiting rectangular area of interest

name:lat2, y2 (latitudinal position)
type:floating point number
valid values:[-90.; +90.]
default value:maximum latitude of input data
description:latitudinal coordinate limiting rectangular area of interest

more coordinates necessary for non-rectangular areas and 3D data


6.1.3.6. Example

#     Fortran example code for spatial subsetting/sub-setting
c     Spatial Subsetting
c-----Example region: n3.4
      x1=190.
      x2=240.
      y1=-5.
      y2=5.

      data_new=0.

      do t=1,nt
        do y=1,ny
          do x=1,nx
            if(lat(y).lt.y1.or.lat(y).gt.y2)then
              continue
            elseif(lon(x).lt.x1.or.lon(x).gt.x2)then
              continue
            else
              data_new(x,y,t)=data_old(x,y,t)
            endif
          enddo !x
        enddo !y
      enddo !t
c-----------------------------------------------------------