Products Geographic information and business control systems
Homogenizing Supply Networks
Georeferenced basemaps lay the foundation for documenting supply network locations. However, localities are subjected to change if the basemap is updated or replaced by a new map. The product ITS LEHO® enables automatic updates of supply network locations to match the spatial reference of a different basemap. The following features are available in ITS LEHO®:
- automatic spatial updates corresponding with the geographic reference system of new basemaps
- the preservation of perpendicular and rectilinear characteristics
- merging processes for various basemaps
- tools for integrating island maps (e.g. for planning)
- tools for converting raster-basemaps into vector data
Homogenizing supply networks is the process whereby operational equipment is spatially adjusted to correspond with a new geodetic reference whilst taking into account geometric characteristics. One example is to switch from an individually generated basemap to ALK. The product ITS LEHO® from ITS Informationstechnik Service GmbH executes network homogenization processes automatically. ITS LEHO® can be installed as a standard module in Smallworld GIS and is designed to fully function using customized data models.
With ITS LEHO® the location of operational equipment is adjusted to the spatial reference system of the basemap and simultaneously preserves neighbouring relationships (neighbouring residual dispersion). Special emphasis is placed on conserving geometric relationships between equipment or equipment and basemap objects. In ITS LEHO® the geometries are merely shifted to a new location, leaving geometric features unchanged. As a result, all topological associations are preserved.
The need to homogenize supply networks is possible for various reasons. The most common reasons are listed below:
- Transition from individual basemaps to official maps (e.g. ALK/ALKIS)
- Combining different network documentation into one unified basemap (e.g. when companies merge)
- Tracing back the documentation of a supply network containing inhomogeneous spatial changes in the basemap (e.g. homogenizing the land registry)
The network homogenization in LEHO® is executed in five steps.
- Detecting identical points
- Determining transformation points
- Identifying geometric characteristics
- Homogenization calculation
- Executing the transformation
It is possible to define single steps and to process these individually. A detailed description for implementing each individual step in ITS LEHO® is described in the following.
1. Detecting identical Points
When searching for identical points, real-world building coordinates as well adjoining coordinates or both are identified in the new and old geodetic reference system. Once all identical points are detected, the displacement vector field is calculated for their target location. The calculated displacement vectors are saved for further evaluation processes and displayed in the visualization for control purposes. After identifying corresponding points, building and adjoining coordinates appear green and help to determine the displacement vector field of the target points (green vectors). These vectors form the basis for calculating the spatial transformation.
2. Determining transformation Points
In the second step all points which are to be adjusted during the homogenisation process are identified and earmarked (transformation points). These are all the reference points for the objects that will be altered, meaning network points, reference points for text labels, point objects and dimensions. By shifting these points and thereby also the adjoining network elements etc., the homogenization process is realized. The points that require modification are defined in a guided menu within ITS LEHO® at the beginning of the project. The visualization shows affected points depicted in red.
3. Identifying geometric Characteristics
The third step involves the so-called “sniffing out” of geometric characteristics. Relationships between various equipment or equipment and basemap objects (buildings, parcels) are determined automatically. These are for example parallel or perpendicular features which are vital for interpreting drawing plans. Typical scenarios for geometric properties are perpendicular connection pipelines and buildings, parallel-aligned powerlines or linear features between alignments and a building.
4. Homogenization Calculation
Calculating the spatial displacement whilst taking into account neighbouring associations and preserving geometric characteristics is done in the fourth step. A linear bias of an estimator is iteratively calculated for the displacement vector. The known variables are the identities and geometric properties. The unknown variable is the displacement points. The result of the homogenization process is shown in the Smallworld GIS graphic window in vector form (see figure with red vectors).
5. Executing the Transformation
The transformation is executed in the fifth step. Here the equipment and the dimensions are shifted to their new location based on the updated geodetic reference system. This is the only processing step where data is physically edited in the Smallworld GIS database. All five steps can be automatically unified into one single operational procedure. However, users can also control each individual step after it has been carried out and intervene if necessary.
With the product LEHO® of the ITS Informationstechnik Service GmbH it is possible to automatically homogenize supply networks on the basis of mathematical algorithms. The results are transparent and reproducible. In comparison to performing a manual homogenization process, ITS LEHO® is highly time-efficient and economical. The product is completely integrable into Smallworld GIS, but can also be implemented with a number of other GIS products with available interfaces.