Continuum Polarization Observations

Continuum polarization observations are selected by the keyword CPOL and observations are position switched with the normal keywords PS or DPS. (There is no special observing mode command analogous to the spectral line command PLSW.)

In continuum CPOL mode, once a PS or DPS observation is initiated, the polarimeter is rotated through 32 positions between plate angles 5 and 355. The first 32 values in the resultant scan are the antenna temperatures for source- reference, and the second and third blocks of 32 are the total power source and reference values, respectively. The plate rotation rate (for 350 rotation) is set by the keyword TSAM (must be $>$ 1 sec). The length of an observation is set with the usual TMAIN (seconds) keyword and should be an integer multiple of TSAM. TSAM Sets polarizer plate rotation rate in seconds for a 350$^\circ$ rotation and is usually 2 sec.