This task returns a grid definition from an array of rasters whose spatial extent encompasses the area where the rasters overlap.
The output grid definition can be used as input to tasks such as BuildLayerStack Task, RegridRaster Task, and RegridRasterSeries Task.
Example
This example creates a new grid definition that is based on the geometric intersection of two different images. The images are available from our ENVI Tutorials web page. Click the API Gridding Examples link to download the .zip file to your machine, then unzip the files.
- MODIS Land Surface Temperature (MOD11_L2) swath image from 07 March 2009, georeferenced to a UTM Zone 54 coordinate system using ENVI's Georeference MODIS tool, corrected for bowtie artifacts, spatially subsetted, and scaled by 0.02 so that the pixel values are in Kelvins.
- Suomi NPP VIIRS Land Surface Temperature EDR image from 07 March 2014, georeferenced to a Geographic Lat/Lon (WGS-84) coordinate system, and spatially subsetted.
Since the first input raster is in a UTM Zone 54 coordinate system, that will be the coordinate system of the output grid definition.
e = ENVI()
File1 = 'MODIS_LST_2009-03-07.dat'
MODISRaster = e.OpenRaster(File1)
File2 = 'VIIRSLST2014-03-07.dat'
VIIRSRaster = e.OpenRaster(File2)
Task = ENVITask('CalculateGridDefinitionFromRasterIntersection')
Task.INPUT_RASTERS = [MODISRaster, VIIRSRaster]
Task.Execute
LayerTask = ENVITask('BuildLayerStack')
LayerTask.INPUT_RASTERS = [MODISRaster, VIIRSRaster]
LayerTask.GRID_DEFINITION = Task.OUTPUT_GRIDDEFINITION
LayerTask.Execute
DataColl = e.Data
DataColl.Add, LayerTask.OUTPUT_RASTER
View = e.GetView()
Layer = View.CreateLayer(LayerTask.OUTPUT_RASTER)
Print, Task.OUTPUT_GRIDDEFINITION
Syntax
Result = ENVITask('CalculateGridDefinitionFromRasterIntersection')
Input properties (Set, Get): INPUT_RASTERS, PIXEL_SIZE
Output properties (Get only): OUTPUT_GRIDDEFINITION
Properties marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Properties marked as "Get" are those whose values you can retrieve but not set.
Methods
This task inherits the following methods from ENVITask:
AddParameter
Execute
Parameter
ParameterNames
RemoveParameter
Properties
This task inherits the following properties from ENVITask:
COMMUTE_ON_DOWNSAMPLE
COMMUTE_ON_SUBSET
DESCRIPTION
DISPLAY_NAME
NAME
REVISION
TAGS
This task also contains the following properties:
INPUT_RASTERS (required)
Specify an array of rasters from which to calculate the grid definition. The first raster will determine the coordinate system and pixel size of the grid definition, unless they are later modified.
OUTPUT_GRIDDEFINITION
This is a reference to the output ENVIGridDefinition.
PIXEL_SIZE (optional)
Specify a two-element array with the [x,y] pixel size of the output grid definition.
Version History
API Version
4.3
See Also
ENVITask, CalculateGridDefinitionFromRasterUnion Task, BuildGridDefinitionFromRaster Task, BuildLayerStack Task, ENVIGridDefinition, ENVIGridDefinition::Intersection, ENVISpatialGridRaster, RegridRasterSeriesByIntersection Task