Block Adjustment

Feature Description

Block adjustment is a high-precision geometric correction method that uses tie points measured within a stereo or planar block network and ground control points to obtain the orientation parameters of satellite images through adjustment calculation. This method can effectively eliminate systematic errors and random errors, and is suitable for large-area image coverage or multi-image mosaic processing scenarios.

 

Function Entry

Satellite Image Processing tab ->Geometric Correction group ->Block Adjustment.

Parameter Description

  • Input Image Type: By default, the image source is the original image mosaic dataset. Here, you need to select the image type from the original image mosaic dataset that will participate in the block adjustment. Five types are provided: Panchromatic Image, Multispectral Image, Forward-Looking Image, Rear-View Image, Front View and Rear View Image. The default is Panchromatic Image.
  • Refer to the Adjustment File: When performing adjustment processing on different batches of images in the same area, you can base on the adjustment file of the processed batch to ensure that the edge matching accuracy and plane accuracy of the current batch are close to the existing results. Use the Add and Delete buttons in the toolbar to conveniently manage multiple reference adjustment files.
  • Adjustment Mode: Select the specific adjustment solution method. Two modes are provided: Unconstrained Tie Point Elevation and Constrained Tie Point Elevation. The default is Constrained Tie Point Elevation.
    • Unconstrained Tie Point Elevation: Do not update the elevation; directly use the initial elevation values of the tie points.
    • Constrained Tie Point Elevation: Update the elevation values of the tie points based on the adjustment result, iteratively.
  • Correction Model Type: Provides Linear RPC Correction Model, Quadratic Polynomial RPC Correction Model, and Cubic Polynomial RPC Correction Model. The default is Linear RPC Correction Model.
    • Linear RPC Correction Model: Suitable for cases where the internal distortion of the image is small. This model requires no less than 4 ground control points. Please add control point information through the Manage Ground Control Points function.
    • Quadratic Polynomial RPC Correction Model: Suitable for moderate internal distortion. This model requires no less than 9 ground control points. Please add control point information through the Manage Ground Control Points function.
    • Cubic Polynomial RPC Correction Model: Suitable for large internal distortion. This model requires no less than 16 ground control points. Please add control point information through the Manage Ground Control Points function.
  • Result RPC Path: Select the result save path for the adjustment. The default path is the image processing folder/Adjustment/BlockAdjustment.
  • Default Adjustment File Path: The adjustment file stores the images participating in the adjustment and the RPC file path information, in CSV format.
    • Checked: The default path and file name are the image processing folder/Adjustment/BlockAdjustment/AdjustmentFile.csv.
    • Unchecked: The default path and file name are the installation package path/AdjustmentFile.csv.
Tip:

After the function is executed successfully, detailed adjustment information and the adjustment file will be displayed in the output window. Click the path in the information to directly open the file.

Related Topics

Generate Tie Points

Manage Tie Points

Generate Ground Control Points

Manage Ground Control Points