STK Premium (Air) or STK Enterprise
You can obtain the necessary licenses for this tutorial by contacting AGI Support at support@agi.com or 1-800-924-7244.
Capabilities Covered
This lesson covers the following STK Capabilities:
- Aviator Pro
Problem Statement
The Relative Course strategy is a horizontal plane strategy in which the aircraft flies to a constant relative course to a stationary or moving object. This strategy is required if you want to employ the Relative Flight Path Angle vertical plane strategy.
| Field | Description |
|---|---|
| Target |
Select an object in the scenario that the aircraft will target during the maneuver. |
| Pos/Vel Strategies |
Position and velocity strategies for the target object. The following strategies are available:
|
| Tgt Pos/Vel Resolution |
The frequency of sampling of the target object's position and velocity; interpolation of the object's position will be performed between sample points. The lowest recommended value for this property is 0.1 sec, but the lowest possible value is 0.001 sec. At the lowest value, STK's Aviator capability will use the native position and velocity of the target object; this can result in dramatically slow performance when the target object is another Aviator aircraft, since STK is performing double integration calculations in such a case. |
| Relative Course |
Select Relative or True to specify whether the aircraft's course will be relative to the target or to True North, respectively, and specify the angle of the course. |
| Anchor Offset |
In Track and Cross Track offsets from the center point of the target; for example, to specify the landing area when flying relative to an aircraft carrier. The anchor point logic is used when a lateral separation from the course line is very large. The logic results in a vehicle path that is as direct toward the anchor point as possible, while arriving on course at the anchor point. This logic is most relevant to landing evolutions from random starting conditions. In these cases, it is important to arrive at a specified course at a distance from the end of the runway without wasting time and fuel on less direct turns to the final approach. |
| Use Approach Turn Mode | If selected, the base leg of the maneuver will be flown with a constant radius turn into the final (upwind) leg; otherwise, two turns will be performed, with the Maneuver Factor determining how aggressive the turns will be. |
Maneuver Factor
The Maneuver Factor defines a dimensionless factor that influences how tightly or gently the aircraft will maneuver. At its most aggressive setting, the factor will force the strategy to achieve the specified performance values; at its most gentle setting, the factor will allow the strategy to tolerate the most deviation from those values.
Control Limits
Select a method to define the control limits (which constrain performance) of the aircraft during the maneuver.
Closure Mode
Select a rule that defines the closure requirement for the maneuver.
- Not Set - the maneuver will continue whether or not the aircraft is closing with the target.
- Closure Required - the maneuver will stop if closure stops, unless the aircraft is within the Downrange Offset from the target.
- High Off Boresight(HOBS) - the maneuver will stop if closure stops, unless the aircraft is within the HOBs Max Angle Off and HOBs Angle Tolerance values; for example, this mode allows you to perform an intercept maneuver to a target that is initially behind the aircraft.
This strategy can be used in conjunction with the Relative Flight Path Angle strategy to model carrier operations.