3D Graphics: Proximity

Proximity

Use to control the position of a particular satellite, aircraft, missile, ship, or launch vehicle in the 3D Graphics window.

Area of Uncertainty

To control the display of the area of uncertainty, select Show, determine the color and width of the line, and select whether to display labels and text for one of the following types:

Control Box. The Control Box defines a volume around the object that moves with the object. The width, height and length specified for the control box is relative to the geometric center of the box and therefore, is only half the total width, height, or length displayed. Click More... to define the following control box properties.

Tangential. Indicates how far along the velocity vector the box extends.

Cross-track. Indicates how far along the orbit normal the box extends.

Normal. Indicates how far along the orbit plane the box extends.

Line Style. Specifies a line style type.

Tangential Offset. The distance to offset the box (forward or backward) along the velocity vector. A positive value moves the box forward along the velocity vector.

Cross Track Offset. The distance to offset the box (left or right) along the velocity vector. A positive value moves the box right along the vector 90 degrees clockwise from the velocity vector.

Normal Offset. The distance to offset the box (up or down). A positive value moves the box down, towards the ground.

Use Translucency. Valid values are 0 - 100, where 0 is opaque and 100 is transparent.

Bearing Box. The Bearing Box defines a volume, relative to a bearing from the North, around an object. Click More... to define the following bearing box properties

Length. Indicates the length of the box, along the bearing. The value must be greater than 0.

Length Offset. The distance to offset the box (forward or backward) along the bearing. A positive LengthOffset value moves the box forward.

Width. Indicates the width of the box, across the bearing. The value must be greater than 0.

Width Offset. The distance to offset the box (left or right) along the bearing. A positive value moves the box to the right.

Height. Indicates the height of the box.

Height Offset. The distance to offset the box (up or down). A positive value moves the box down, towards the ground.

Line Style. Specifies a line style type.

Bearing. The bearing value, relative to North.

Use Translucency. Valid values are 0 - 100, where 0 is opaque and 100 is transparent.

Bearing Ellipse. Defines an ellipse, relative to a bearing from the North, around the object. Click More... to define the following bearing ellipse properties

Semi-Major Axis. Defines the major axis for the ellipse. The value must be greater than 0.

Major Axis Offset. The distance to offset the ellipse (forward or backward) along the bearing. A positive MajorAxisOffset value moves the ellipse forward.

Semi-Minor Axis. Defines the minor axis for the ellipse. The value must be greater than 0.

Minor Axis Offset. The distance to offset the ellipse (left or right) along the bearing. A positive MinorAxisOffset value moves the ellipse to the right.

Granularity. Indicates the number of points used to draw the ellipse. Lower numbers create a better ellipse and higher numbers make the ellipse draw faster.

Line Style. Specifies a line style type.

Bearing. The bearing value, relative to North.

Line of Bearing. Defines a line of bearing which is drawn from an origin in the direction of a bearing. Click More... to define the following line of bearing properties

Origin Latitude. Specifies the latitude for the origin of the line of bearing.

Origin Longitude. Specifies the longitude for the origin of the line of bearing.

Origin Altitude. Specifies the altitude for the origin of the line of bearing.

Line Style. Specifies a line style type.

Bearing. The bearing value, relative to North.

Length. The length of the line of bearing. The value must be greater than 0.

Bearing Error. Displays two additional lines, which are drawn in the direction of the bearing +/- the bearing error. Valid values are 0 to 180 degrees.

Error Color. The color of the bearing error lines.

Error Line Width. The line width of the bearing error lines.

Geostationary Box

You can define a geostationary box as a planar rectangle centered at a fixed longitude in space. The box is used to visually check that a GEO satellite stays within a certain area. The box remains stationary in Earth-fixed space.

Show. If selected, a geostationary box displays at a fixed longitude in space.

Longitude. The center longitude of the box at the initial condition of the satellite at epoch.

North/South. The length of the box from North to South.

East/West. The length of the box from East to West.

Radius. The distance from the center of the Earth to the center of the box. The default value takes the satellite's initial conditions into account.

If the satellite drifts quickly out of the geostationary box, the radius value may be incorrect and need to be adjusted manually. The default radius value is calculated based on the propagator you choose with the assumption that the satellite is a GEO.

To see satellite drift as it relates to the geostationary box, choose an SGP4 or HPOP propagator. If you choose a propagator such as two-body, J2 or J4, it is possible that the radius you choose may be one at which the satellite displays no drift.

Color. If selected, choose the color in which the box is displayed.

Reposition. Click this button to align the box using recently updated radius and longitude data for the satellite. This feature is useful if the satellite's position has changed since the box was first created, since the box maintains its original position unless you reposition it. The box is positioned at the longitude of the satellite at the satellite's epoch time.

Note: If you use the Geostationary box for a non-Geostationary satellite, the box still shows in the 3D Graphics window but should not be relied upon.

How To. . .