ArcMap

Compute Block Adjustment

Summary

This tool is used to compute the adjustments to the mosaic dataset. This tool will create a solution table that can be used to apply the actual adjustments.

Usage

  • Use the output control points from the Compute Tie Points tool as the input control points for this tool.

  • The output solution table from this tool will be used in the Apply Adjustment tool.

Syntax

ComputeBlockAdjustment_management (in_mosaic_dataset, in_control_points, transformation_type, out_solution_table, {out_solution_point_table}, {maximum_residual_value}, {adjustment_options})
ParameterExplanationData Type
in_mosaic_dataset

The input mosaic dataset that will be adjusted.

Mosaic Layer; Mosaic Dataset
in_control_points

The control point table that includes tie points and ground control points.

You can use the output from the Compute Tie Points tool, or a refined control point table edited by the Block Adjustment Window.

Feature Layer
transformation_type

Choose which type of transformation will be used when adjusting the mosaic dataset.

  • POLYORDER0 —A zero-order polynomial is used in the block adjustment computation. This is commonly used when your data is in flat area.
  • POLYORDER1 —A first-order polynomial (affine) is used in the block adjustment computation. This is the default.
String
out_solution_table

The output solution table containing the adjustments.

Table
out_solution_point_table
(Optional)

The output solution points table. This will be saved as a polygon feature class. This output can be quite large.

Feature Class
maximum_residual_value
(Optional)

A threshold that is used in block adjust computation. When polynomial transformation type is either POLYORDER0 or POLYORDER1, the units for this parameter will be in map units.

The block adjustment computation is an iterative process. This value will control when the block adjustment iterations should stop. The iterations will continue till the residuals are below the maximum value, or when ten iterations have been completed—even if the residuals are above the maximum value specified. The default value is 0.7.

The adjustment_options parameter also allows you to specify a maximum residual threshold value by setting a MaxResidualFactor. If both the maximum_residual_value and MaxResidualFactor are specified, the tool will ignore the MaxResidualFactor.

Double
adjustment_options
[[name, value],...]
(Optional)

Additional options that can fine-tune the adjustment computation.

  • MinResidual —The minimum residual value, which is the lower threshold value. When polynomial transformation is either POLYORDER0 or POLYORDER1, the units will be in map units and default minimum residual will be 0. The minimum residual value and the maximum residual parameter are used in detecting and removing points that generate large errors from the block adjustment computation.
  • MaxResidualFactor —The maximum residual factor, is a factor used to generate maximum (upper threshold) residual. If maximum_residual_value parameter is not defined, it will use the MaxResidualFactor * RMS to calculate the upper threshold value.The minimum residual value and the maximum residual parameter are used in detecting and removing points that generate large errors from block adjustment computation.
  • _BAO —The output file that contains the output information from the triangulation engine.
  • _BAI —The output file that contains the input information for the triangulation engine.
Value Table

Code sample

ComputeBlockAdjustment example 1 (Python window)

This is a Python sample for the ComputeBlockAdjustment tool.

import arcpy
arcpy.ComputeBlockAdjustment_management(
     "c:/BD/BD.gdb/redQB", "c:/BD/BD.gdb/redQB_tiePoints", 
     "POLYORDER1", "c:/BD/BD.gdb/redQB_solution"
ComputeBlockAdjustment example 2 (stand-alone script)

This is a Python script sample for the ComputeBlockAdjustment tool.

#compute block adjustment, case 2

import arcpy
arcpy.env.workspace = "c:/workspace"

#Compute block adjustment
mdName = "BD.gdb/redlandsQB"
in_controlPoint = "BD.gdb/redlandsQB_tiePoints"
out_solutionTable = "BD.gdb/redlandsQB_solution"

arcpy.ComputeBlockAdjustment_management(mdName, in_controlPoint, 
     "POLYORDER1", out_solutionTable)
ComputeBlockAdjustment example 3 (stand-alone script)

This is a Python script sample for the ComputeBlockAdjustment tool.

#compute block adjustment, case 3

import arcpy
arcpy.env.workspace = "c:/workspace"

#Compute block adjustment specifying an output point table and 
#an setting an adjustment option
mdName = "BD.gdb/redlandsQB"
in_controlPoint = "BD.gdb/redlandsQB_tiePoints"
out_solutionTable = "BD.gdb/redlandsQB_solution"
out_solutionPoint = "BD.gdb/redlandsQB_solutionPoint"
engineOption = "_BAI c:/workspace/bai.txt; _BAO c:/workspace/bao.txt"

arcpy.ComputeBlockAdjustment_management(mdName, in_controlPoint, 
     "POLYORDER1", out_solutionTable, out_solutionPoint,"0.5", 
     engineOption)

Environments

Licensing information

  • ArcGIS Desktop Basic: No
  • ArcGIS Desktop Standard: Yes
  • ArcGIS Desktop Advanced: Yes

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