The coordinate systems used by the byu system
down is toward the ground (the direction gravity
pulls you)
- NOTES:
- down is toward the earth
- up is away from the earth.
- Az,El - standard
astronomical definition. + elevation is downhill on hte azimuth arm
- Az,Za - standard
astronomical definition. + za in uphill on the azimuth arm.
- x,y,z - focal
plane coordinate system. When feed is rotated over the tertiary:
- x is downhill along the azimuth arm
- z is toward the tertiary from the focus position
- y is toward the stairwell of the feed tower (it is a right
handed system).
- Positioner coordinate system:
(assume the positioner is over the tertiary)
- angle: Center of
rotation is about the optical axis.
- range 0 to 360
degrees (minus a few degrees for the limits)
- 0 degrees: Increasing
the radius will move you away from the center of the rotary floor.
- When over the tertiary this will move you uphill.
- Direction: sending a
positive angle rotation to the positioner does:
- CCW when standing on the rotary floor looking down,
- CW when sitting on the tertiary looking up at the dipoles.
- radius: moves in the
x,y plane along the direction that the angle currently points
- 0 radius has the central dipole at the optical axis
- range:
- direction: positive moves away from the center of rotation.
- Focus: moves the
center of rotation closer or farther from the tertiary.
- Range:
- positive focus moves you toward the tertiary.
- 0 cm focus should be close to the focal plane.
Dipole positions:
- Notes:
- let the feed be over the tertiary, and the positioner is at
angle=0,radius=0.
- Dipole mounting on positioner.
- -40.8934 degrees (see positioner angle above) This is for
center and
- Dipole names: D1 thru D19
- D1 is at the center of the dipole array.