ADS data case

Production of 1:2000 Topographic Map for New Countryside Construction in a City   

 Project Description:

In 2015, Wuhan Visiontek Technology Co., Ltd. actively undertook a city-rural integration new rural surveying and mapping guarantee service project in a city in central China, with a hilly terrain.

 Project Description:

Provide 1:2000 scale all-element topographic map results and mdb results. The plane coordinate system adopts the 1980 Xi’an coordinate system and the 1985 national elevation datum.

 Project scope:

The area of a certain jurisdiction is about 39.57 square kilometers

 Project requirements:

Need to provide 1:2000 full-element topographic map results and mdb results, the accuracy is controlled within 0.5 meters in the plane position, and within 0.35 meters in the elevation.

Project duration:

2015.3.23--2015.4.23

The specific production process flow chart of the project is as follows:

 The specific implementation plan is as follows:

1. Data source introduction:

 Leica ADS80 airborne digital aerial photogrammetry system is currently a relatively advanced push-broom airborne digital aerial photogrammetry system. ADS80 integrates a high-precision inertial navigation and orientation system (IMU) and a global satellite positioning system (GPS), using a three-line array with 12,000 pixels (pixel size 0.0065mm) (the SH81 model camera has 11, and the SH82 model camera has 12 ) CCD scanning and professional single large aperture telecentric (telecentric) lens, one flight can simultaneously obtain front view (27°), bottom view (0°), rear view (14°) with 100% three-degree overlap , Continuous and seamless, full-color three-dimensional images, color images and color infrared images with the same image resolution and good spectral properties.

2. Orientation process:

The ADS data orientation has been completed by Party A. This time only the Visiontek MapMarix all-digital photogrammetry workstation is needed to import the Xpro orientation results.

2.1 Import of Xpro aerial triangle results

2.11 Data preparation

Since Xpro's aerial triangulation result coordinate system is generally WGS84 coordinate system, the conversion of the coordinate system may be involved in the later period. This project needs to transform its aerial triangulation result projection to the 1980 Xi'an coordinate system, so two sets of control points or seven parameters are required , the coordinate conversion uses two sets of control points.

2.1.2 Project creation and related parameter setting

 2.2 Accuracy inspection of Xpro aerial triangle results

The solution adopted for the accuracy check of aerial triangulation results is: import the fragmented points or some check points collected in the field to the Visiontek MapMarix full digital photogrammetry workstation to do the accuracy check, as shown in the figure below

After internal testing, the accuracy of the aerial triangulation is in line with the accuracy requirements of digital aerial photogrammetry and aerial triangulation GB/T 232236-2009 Edition 1:2000

3. DLG product production

Using Visiontek MapMatrix all-digital photogrammetry workstation for stereo digital mapping. Mainly follow the principle of "internal business positioning, field business qualitative". Use ads data to build a three-dimensional model, collect all-element data to generate graphic files. The operation method adopts "two inside and two outside", that is, image control in the field, surveying and mapping in the field, repairing and testing, and editing in the house. The collection of terrain elements is carried out in accordance with GB/T 13923-2006 "Basic Geographic Information Element Classification and Code".

DLG partial renderings 

4. Office Editor

In-house editing uses Visiontek MapMatrix4.2 all-digital photogrammetry workstation to directly export DWG results and mdb results

5. Acceptance and submission of results

After all the projects are completed, the binding results shall be sorted according to relevant regulations and the following materials shall be submitted:

1. A set of data discs (graphic files in DWG format)

2. A technical design book

3. A technical summary

4. An inspection report

This project passed the one-time acceptance