The positioning simulation models, analyzes, and animates different configurations of satellites, fixed earth stations and moving stations. The satellite positions are defined by their orbital dynamics. The mobile stations are propagated by a general trajectory generator. The simulation tracks node (satellite, moving station, fixed station) positions, visibility from other nodes, and area coverage. You can track mobile/satellite positions from the perspective of a flat map of the earth, inertial and fixed views of the earth from space, or an observer attached to any node on earth, moving over the earth surface, flying, or in space. You can also view the density of satellite coverage for all points against a map of the earth. In the list below, the different views of positioning simulation are explained shortly. Click on the view name to load a screen shot of each view.

• The Map view shows the position of each satellite, mobile and station against a flat a map projectrion of the continents of the earth.
• The Earth Centered Intertial (ECI) view shows all satellite orbits against a background of coordinates on a globe, but does not show the position of the continents.
• The Earth Centered Fixed (ECF) view shows the position of each satellite and mobile against a globe of the earth that also shows the continents.
• The Observer view shows the satellites, mobile and fixed earth stations that are visible to an observer at a selected latitude and altitude; you can use sliders to change the latitude and altitude while the simulation is running. Time histories of relative elevation and azimuth angles can be viewed, recorded and plotted. Visibility animation shows the number of satellites in view as a function of time. An observer can be attached to any node.
• The Coverage view plots the number of satellites that are visible to an earth observer at a specific location and elevation angle constraint. An animated earth coverage map shows how current, partial, minimum / maximum, and statistical coverage patterns change as the satellites move along their orbits.
• The Coverage ECF view plots the number of satellites that are visible to an earth observer at a specific location and elevation angle constraint. An animated globe shows how current, partial, minimum / maximum, and statistical coverage patterns change as the satellites move along their orbits.
• The Circle view displays the areas on the earth surface, the mobiles and satellites can see for a given elevation constraint.
• The Circle ECF view displays the areas on a globe of the earth, the mobiles and satellites can see for a given elevation constraint.
• The 3D Earth Centered Fixed (ECF) view shows the position of each satellite against a globe of the earth with surface elevation dependent coloring and 3D shading.<br />