Access Coordinate Frames
Access calculations compute azimuth, elevation, and range between the primary and associated objects based on the local coordinate system of the primary object, as follows:
- Facilities, places, targets - Local Horizontal (LH)
- Satellites, missiles, and launch vehicles - ECI VVLH (Elevation measured positive toward -Z)
- Ships, aircraft, and ground vehicles - ECF VVLH (Elevation measured positive toward -Z)
When using the ECF VVLH frame, if the primary velocity is near zero then STK may switch to an LH fram to avoid an error condition.
Local Horizontal (LH) coordinate system
Vehicle Velocity Local Horizontal (VVLH) coordinate system
