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DBGS Project

Project Title   3D Terrain Database Generation System
Project Acronym   DBGS
Contractor(s)   INDRA Espacio (Spain)

 

Project     Context
             Objectives
                   Architecture
             How it works
    Output

  


Context

Systems to generate 3D terrain databases have evolved from systems without any control over the source data. But due to some factors, like:

Image Evolution of the 3D terrain databases generation for simulation applications 
Image Capabilities of computers (graphic cards, memory‚Ķ) 
Image Use of satellite images or aerial photographs with better ground resolution, which forces the utilization of sophisticated image compression techniques  
Image Coverage of huge terrain extensions, with the corresponding very high volume of data  

The generation of 3D terrain database needs a big amount of source data. For this reason a better organized system is needed to address these factors.

At the beginning the 3D terrain generation systems were based on sets of different self standing applications used to obtain and correct source data (i.e.Erdas Image, Multigen, etc). The 3D terrain database generators directly used these corrected data. With this approach, the user had to manage all the amount of data that was manually copied into folders with appropriate format to be compiled by external publishers. 

This approach was viable while the set of data were small, but the necessity of more complex 3D terrain databases, with higher detail levels, using geo-specific images covering bigger extensions changed the required workflow.

Next step was the development of 3D Terrain Generator systems that use data stored in external file servers, where the publishers could reference and retrieve the necessary data to build new 3D terrain databases. These systems are nowadays used to build 3D terrain databases for simulators. These systems supply independent files, which must be mosaicked before generating the scenarios.

To improve functionality, the future systems must be able to store mosaicked images in spatial databases with GIS data and other spatial information, to allow the publishers to retrieve all the necessary information from the system without user interaction. The processes of publishing 3D terrain databases will then become semi-automatic.

These spatial data servers will be developed using OGC standard services to solve system portability problems and to allow the scalability of publishers for future applications. This OGC compliance will allow the interaction with other applications that also follow OGC standards.

DBGS is a system that will provide an integrated tool that is able to generate the 3D terrain databases starting from the raw data, through a set of integrated tools covering the whole data flow, largely eliminating operating difficulties. An important characteristic of DBGS is expandability, to satisfy the requirements of new 3D Terrain databases for future applications.

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Objectives

The main objective of DBGS is to provide solutions to the problem of generating terrain databases that cover huge extensions of terrain and require such a volume of data that the organization of the data in a database is mandatory.

The objective will be approached in the following way:

Image Identify the data flow required to build the terrain databases. 
Image Determine the high level functions required to cover the defined data flow. 
Image Provide a technical solution for each defined high level function. 

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Architecture

The 3D Terrain DBGS system is broken down in the functional components shown in the picture below:

 

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3D Terrain DBGS Components

 

DBGS Workflow Manager: an integration component which calls each one of the other components.

Source Data Editor: includes the software intended to correct, correlate and extract the source data in order to prepare it for the 3D terrain database generation. Also, allows the loading or these corrected, correlated and extracted data into the repository in addition with the generic textures.

Data Repository : allows storing the source data in a database with spatial capabilities, so that the source data can be found up by means of spatial queries.

Browser: provides the required functions to show the spatial information stored in the spatial database, to select a geographical region of interest and download them.

3D Terrain Publisher: implements all the functions required to build a 3D terrain database from the downloaded data.

 

Browser

Browser Architecture

 

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3D Terrain Publisher Architecture

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How it works

Image The user corrects external data using the source data editors. 
Image The user correlates the corrected data, i.e. places them in a common reference frame. 
Image The user extracts the required 3D information from the corrected and correlated data.  
Image The user loads these corrected, correlated and extracted data into the repository.  
Image When the user wants to generate a 3D terrain database uses the browser to localise the used data and downloads the working data from the repository.  
Image The user runs the publisher to compile the 3D terrain database.  
Image The user checks the output of the publisher opening the 3D terrain database using a visualisation tool.  

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Output

An example of output of the system is shown in the following pictures. The following data were user to generate this 3D scenario:

 

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DTM with 10 m of ground resolution of Frascati area.

 

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Quick bird images of Frascati area.

 

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3D models extracted using Monoscopic Module.



The DBGS final presentation was held at ESRIN on November 29, 2007.

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Page last modified on Tuesday 14 of December 2010 13:39:41 CET by .