Geometric

Summary

Creates a raster object by producing an orthorectified image using a sensor definition and terrain model.

Discussion

You can use this function when your raster data has rational polynomial coefficients.

For more information about how this function works, see the Geometric raster function.

The referenced raster dataset for the raster object is temporary. To make it permanent, you can call the raster object's save method.

Syntax

Geometric (raster, {geodata_transforms}, {append_geodata_xform}, {z_factor}, {z_offset}, {constant_z}, {correct_geoid}, {tolerance}, {dem})

Parameter	Explanation	Data Type
raster	The input raster.	Raster
geodata_transforms	The transformation method for the geometric function. Transformation methods include Polynomial, Projective, or Identity. (The default value is None)	String
append_geodata_xform	Specifies whether to append the geodata transform to the input raster. True—The geodata transform will be appended to the input raster. False—The geodata transform will not be appended to the input raster. (The default value is False)	Boolean
z_factor	The z-factor value to rescale to meters, if the input elevation dataset uses vertical units other than meters. (The default value is None)	Double
z_offset	The base value to be added to the elevation values in the DEM. Use this argument to offset elevation values that do not start at sea level. (The default value is None)	Double
constant_z	A constant elevation value to use for the function. (The default value is None)	Double
correct_geoid	The geoid correction converts orthometric heights using a geoid before applying an orthorectification to your imagery. Most elevation datasets, such as USGS NED or ArcGIS Online World elevation, use orthometric heights, so it is necessary to select the Geoid correction for compatibility with satellite RPCs, which require ellipsoidal heights. True—Apply the geoid (EGM96) correction to the z-values. False—Do not apply the geoid correction to the z-values. (The default value is False)	Boolean
tolerance	The maximum tolerable error in the geometric function, given in number of pixels. (The default value is None)	Double
dem	The DEM used to orthorectify the raster dataset. (The default value is None)	Raster

Return Value

Data Type	Explanation
Raster	The output raster.

Code sample

Geometric example

Orthorectifies a satellite image using a sensor model and a DEM.

# Import system modules
import arcpy
from arcpy.ia import *

# Set the local variables
raster = "C:/data/Image.JPG"
geodata_transforms = "Polynomial"
append_geodata_xform = True
z_factor = None
z_offset = None
constant_z = None 
correct_geoid = False 
tolerance = 2
dem = "C:/data/DEM.tif"


# Apply RegionGrow function
Orthorectified_raster = arcpy.ia.Geometric(raster, geodata_transforms, append_geodata_xform,
                   z_factor, z_offset, constant_z, correct_geoid,
                    tolerance, dem)

# Save the output
Orthorectified_raster.save("C:/arcpyExamples/outputs/Image_ortho.JPG")