Correction of DOM data production topic under ENVI

Normal shooting images are usually produced by selecting some ground control points on the image, and using the digital elevation model (DEM) data within the range of the original image, tilt correction and projection correction are performed simultaneously for the image, and the image is re-sampled into a direct image. After splicing multiple normal images and performing color balancing, the cropped images within a certain range are normal images. As a data source of GIS, the forward image features topographic maps and image features are rich in information, which enriches the representation of geographic information systems.

This section mainly uses worldview2 data for correction. The procedure is as follows:

1) Add coordinate system (envi4.8)

Add beijing54 Coordinate System

Edit .. \ ITT \ idl80 \ products \ envi48 \ map_proj \ datum.txt and save the following line.

D_beijing_1954, quersovsky, 0, 0, 0

Start ENVI and define beijing54's 20-degree projection. The detailed parameter settings are as follows:

Figure 1
Custom beijing54 projection Coordinate System

2) use worldview2 data for testing

Start metadata (UTM projection), reference image (beijing54 projection), and DEM Data (beijing54 projection, 30 m). Select 8 control points for correction:

Figure 2
Control Point Distribution

Figure 3
Eight Control Points

3) correction output parameters

 

Figure 4
Calibration output

4) Result Accuracy Test

Accuracy Evaluation is performed using the calibration results and the method of selecting the source image points. Nine points are selected, and the total error is about 1 pixel.

Figure 5
Precision Test