BETA

Loads or returns the $\beta$ angles used by the coordinate system to correct for the small errors in the mechanical alignment of the beam steering mirror's azimuth axis[8].

Mnemonic:

The BETA command allows the adjustment of the $\beta$ angles on the ZY.

Syntax:

BETA [ $<\beta_{1}, \beta_{2}>$]

$\beta_{1}$: The angle between the azimuth $y$ axis and the ranger $y$ axis, with rotation about the ranger $x$ axis.

$\beta_{2}$: The angle between the azimuth $x$ axis and the ranger $x$ axis, rotating about the ranger $y$ axis.

Return values:

Success:

BETA 1, $\beta_{1}$, $\beta_{2}$

Failure:

BETA 0, err_msg

$\beta_{1}$: The new or current $\beta_{1}$ value

$\beta_{2}$: The new or current $\beta_{2}$ value

err_msg: Should the command fail, this value will be an error message string, explaining the cause of failure. Failure can be due to an incorrect number of parameters (0 or 2 parameters are legal, but 1 is not) or because of errors converting the ASCII parameters to legal floating point values.

Remarks:

The command BETA must be called with valid $\beta_{1}$ and $\beta_{2}$ angles, or the ZY may be unable to point with good accuracy[8], depending on the accuracy of the mechanical assembly. If, for example, the mechanical assembly were close to perfect, the default values of $0.0$ for $\beta_{1}$ and $\beta_{2}$ would work well. However, the small errors in the assembly could mean the difference between acquiring a target or just missing it. Ideally, this command should be executed as part of the ZY initialization.

Example:

     send: BETA 0.00087266, 0
  receive: BETA 1, 0.00087266, 0

     send: BETA
  receive: BETA 1, 0.00087266, 0

See also:

ALPHA, BP, D0, INITZY, MO