UB Virtual Reality Laboratory

Distributed Data Fusion (DDF) Testbed : Visualization and
Simulation Support

Goal
We are a part of a multidisciplinary group working together to design and develop a DDF testbed to develop, evaluate and test algorithms to perform networking, sensor simulation, target tracking and fusion in a battlefield environment. Our contribution to this work has been providing visualization and simulation support for this testbed.

Abstract
The aim of this project is to develop a one of a kind, best in class simulation system which can be used to emulate a battlefield environment. In this environment algorithms for networking, tracking and data fusion can be developed, tested and evaluated. The battlespace simulation is an inherently 3 dimensional geospatial set up. The algorithmic inputs (ground truth, velocity, geo spatial information etc) and outputs (network assignments, covariance, estimates and tracks) are also 3 dimensional in nature. Most software (COTS) available to support this problem does not provide adequate 3 dimensional support. The key challenge to this problem is to provide a dedicated 3D interface for supporting the simulation and visualizing it. The simulation support tools we have developed for this purpose is divided into two modules. One module is dedicated to providing the user a 3D space where problems/scenarios of specific nature can be developed. The other module provides the viewer with an interactive 3D set up where in simulation results are displayed. The challenges for which we have provided solutions include:
1) Geospatial data management and display
2) Covariance, tracks and estimate display (Information Visualization)
3) Management and display of entity information
4) Waypoint/path specification and scenario creation for air target and ground target tracking
5) Real time simulation visualization
6) Support for simulation scaling with respect to entities, time, playground size and entity details

Screen Shots from VizSim
- Scenario Details:
- Batch mode scenario
- 10 Friendlies and 10 Targets
- Air tracking scenario
- Theater : Buffalo – East


	Basic Interface (left) and Buffalo-East Scenario Loaded

	Buffalo-East Alternate Viewpoint (left) and Result Set 1

	Result Set 2 (left) and Result Set 2

Project Summary

Design of Simulation Scenarios
- Complex & Time Consuming Process
- Requires Geospatial Information
- Sensor Target Information
- Simulation Parameters

Visualization should enable:
- Understanding of Simulation Output
- Intuitive Interface
- Decision Making Support

User Friendly GUI & Interactivity
- Dialog based Modeling
- Mouse based spatial interaction
- Runtime generation of 3D icons

Visualization of:
- Vehicle Data Information
- Terrain Information
- Vehicle dynamics information
- Path Generation

Need for GIS Support:
Terrain features and cultural artifacts affect the creation of scenarios and influence the fusion algorithms during simulation. This close tie of DDF simulation with geospatial information demands adequate support for terrain database generation.



	In our DDF Testbed, we use Digital Elevation Model (DEM) files for getting terrain data and Digital Line Graph (DLG) files for getting vector map data of the desired location. Data from DEM files is efficiently triangulated to compute the Triangular Irregular Network (TIN) that gives the terrain skin. The vector maps of the region providing cultural and other important data such as roads, rivers, manmade structures and foliage information are accurately draped onto this terrain to provide adequate geographic information to users for scenario creation.

Simulation Controls:
- Playback simulation control: Play or pause, Stop, Reset and Advance to desired time step
- Toggle control over properties
- Simulation input: Fusion parameters & Networking parameters
- Provisions for database management



	Simulation Setup: - Simulation runs in real time with visualization - Optimized visualization (Scenegraph, Render culling, Running on minimum, Interactive “4D” visualization) -Carry out analysis



	Information Visualization: - Simulation Results - Provide Insight into Fusion using Viz. - Result visualization (Tracks, Covariance, Estimates, Network connections) - Display of results based on preference - Interactivity

Architecture and Implementation
- Dedicated Class Structure
- C++ , Qt, Open Inventor and Linux
- Tested on PIV 3.0 Ghz Machine with RedHat 9.0, 1 Gb RAM and 128 Mb Video Card.

People
Dr. Tarun Singh (Dept. of Mechanical Engineering)
Dr. T. Kesavadas (Dept. of Mechanical Engineering)
Govindarajan Srimathveeravalli
Chandresh Mehta

Sponsors

Publications
[1] Srimathveeravalli, G., Subramanian, N., and Kesavadas, T., "A Scenario Generation Tool for DDF Simulation Testbeds", 2004 Winter Simulation Conference (WSC '04), Washington DC, Dec 5-8, 2004. (In process).