Viewing Segments | Adding, Removing, and Modifying Segments

Multi-Segment Attitude Profiles

On the Basic Attitude properties page of a vehicle object, select the Multi-Segment option to set up sequences of basic, targeted, and file-based attitude profiles. The Multi-Segment option allows viewing of current segments, and it provides methods to add and change segments. These two capabilities are described below.

Viewing current attitude segments

Current attitude segments display in a list with the following information:

Parameter Description
Name The name of the type of attitude segment, depending on the source of the segment
  • For Basic segments: A short name based on a phrase describing the specific attitude profile
  • For Targeted segments: The name of the target object (see note below)
  • For File segments: The name of the external file
Periods of slewing preceding and following target acquisition are named 'Slew'.
Source The source of the attitude segment: Basic, Targeted, or File
Number A sequential identifier indicating the order in which the segments are applied
Start Time The time at which STK begins using the segment to define the vehicle's attitude
Stop Time The time at which STK stops using the segment to define the vehicle's attitude

Control the display of current segments by selecting the check boxes View Basic segments, View Target segments, and View File segments. Basic Segments are always applied to the overall attitude profile. Target Segments and File Segments boxes must be checked for those segments to be applied to the attitude profile and thus appear in the list above them.

  • The View segments selections only affect the appearance of attitude segments in the list. For example, if View Target segments is not selected, any targeted profiles in the sequence continue to apply. To prevent them from applying, you must clear the Target Segments box.
  • Astrogator Maneuver segments can create attitude segments that override the attitude setting of the vehicle as shown by the Attitude page.

Adding, removing, and modifying segments

Editing options for an attitude profile in a Multi-Segment sequence depend on the source of the profile: Basic, Targeted, or File.

Basic segments

Editing options for basic attitude segments appear in the Basic Segments frame. To add a new basic attitude segment to the sequence, click Add segment.... To edit, copy, or remove an existing basic attitude segment, highlight it in the list and click Edit segment..., Copy segment..., or Remove segment... as desired.

In the window that displays when you click Add segment..., Edit segment..., or Copy segment..., provide the following information:

Parameter Description
Name This is the name of the segment. You can replace the default name with a name of your choice.
Start Time This is the time at which the segment begins. If the Start Time for the present segment precedes that for another segment, then the Stop Time for the present segment coincides with the Start time for the later segment. Otherwise, the Stop Time for the present segment is the end of the vehicle time frame. For more information on the options available for start and stop times, see the Time Options topic.
Type Select a predefined attitude profile from the drop-down menu and specify any applicable parameters.

Target segments

To add a targeted attitude segment to the Multi Segment sequence or edit an existing one, click Add/Edit segment... and proceed as you would for a Standard Target Pointing profile.

Attitude targets defined by latitude/longitude/altitude points are displayed on the Basic Attitude properties page but can only be added and edited using Connect.

File segments

Editing options for attitude segments from an external file appear in the File Segments frame. To add a file segment, click Add segment.... In the window, enter the path and name of the attitude file or click the ellipsis () button and browse for a path and file name. After a file has been selected, the File Start and Stop times are displayed. For more information on the options available for start and stop times, see Time Options. Select one of the following save options:

Option Description
Always read data from attitude file Attitude data is not saved as part of the vehicle profile. This option is generally preferable because the vehicle's attitude data is updated automatically with changes in the external attitude file.
Import and save attitude data Attitude data is saved as part of the vehicle profile. This option is convenient in some circumstances (e.g., when sharing vehicle files).

To select a Reference Attitude other than ECI for the interpretation of data from the attitude file, clear the Use Default (ECI) option, click Select..., and make your choice.

Click OK to add the file segment to the Multi-Segment sequence or Cancel to return to the Attitude page without adding a segment.

To remove a file segment from the sequence, highlight it in the list and click Remove segment....