Software ergospace®
Simulation of electromagnetic waves propagation in complex 3D environments
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ergospace® is the first software that uses the deterministic method of Ray Tracing to simulate the
propagation of electromagnetic waves in 3D complex environments. It calculates direct paths as well as reflected, diffracted,
transmitted or diffused paths and thus highlights shadowing effects induced by the environment. ergospace® is
a powerful tool to analyze performances of telecommunication or navigation systems.
- 3D scenes : VRML 1.0 and 2.0, DXF and BD ALTI® (IGN) formats. - Transmitters : satellites, pseudolites, repeaters, jammers. ergospace® uses the CNES space mathematics library (MSLIB). - Simulation parameters : start and stop dates, sampling, maximum number of reflexions, transmissions and diffractions, receiver's speed... Electromagnetic waves propagation simulation is carried out through the link budget and the error budget calculations: Link budget : The link budget is established at each step of simulation and for each ray. ergospace® calculates the signal power and the noise power. The link budget takes into account : - Signal emission power - Cabling losses - Free-space lost - Antenna gains for transmitters and the receiver - Losses due to the gas components of the atmosphere - Losses due to the signal interactions with the environment Error budget : ergospace® takes into account intrinsic errors : - Transmitter clocks drifts - Receiver clock drifts It also calculates extrinsic errors : - Ionosphere errors - Troposphere errors - Errors due to multipaths - Receiver errors. Outputs : Electromagnetic waves modelization is vectorial. Each calculated ray owns an amplitude, a phase and an attenuation. Doppler shift is determined and the composite power for a given channel is given by vectorially summing all electromagnetic waves reaching the receiver. ergospace® allows to evaluate performances of a GNSS by the calculations of D.O.P. (Dilution Of Precision) and accuracies. The software also highlights direct visibilities of satellites. ergospace® owns a cartography module that allows to analyze performances of a system in terms of availibility, geometry and accuracy, for each point of a 3D scene. The Indoor module builds power cartographies . |
Propagation modelization in divers environments
ergospace® simulates electromagnetic waves propagation in 3D complex environments. Il owns and uses different modules for a really realistic simulation. OutDoor Module : The OutDoor Module is the base module of the software ergospace®. Simulations take place in urban environments. InDoor Module : Simulations take place inside or next to buildings. Diffractions and transmissions effects are important. Carrier Module : The carrier module highlights antenna carrier interactions with the electromagnetic signals. The carrier geometry is taken into account in calculations of rays. Antenna pattern is affected by this carrier geometry. Some environments cannot be statically modelled because of their permanent moves as for example sea surface, trees and forests. That is why ergospace® includes some modules that statically model the environment and the signal propagation within this environment. Sea Module : The sea module models the electromagnetic signals reception at sea, particularly complex phenomenon being given the environment and many parameters to take into account (salinities, speed and direction of the wind, temperature).ergospace® statistically models the sea surface. Two models are used for electromagnetic calculations : The Kirchhoff approximation and the Two Scales Model. Forest Module : Simulations take place in forest environment. Waves propagation calculation are calculated differently according to the environment density. Indeed, statistic approximations can be done for a dense environment (Amazonian forest for example), but isolated trees or sparse forests require a more complex interaction calculation. For the Isolated tree model, the software ergospace® builds a 3D tree by using a cylindric modelization, each cylinder representing a branch (or trunk). The Ray Tracing method is then used and attenuations due to tree foliages are considered. For the Dense forest model, calculations are not the same above the canopy and below the canopy. Above, diffusion is calculated. And below, interaction for each branch in a ray given around the receiver is determined. |
© 2001-2008 Ergospace
Last update: June 2008 |