Polar Axis

Observation for determination of telescope polar axis to high precision. This will be done by measuring rotation of the camera axes relative to ICRS coordinate system at a range of HA's, especially near the equatorial pole.

Required observations:

  • 3 exposures at -80 declination: 0h, +3h, -3h hour angle.
  • 3 exposures at -30 declination: 0h, +3h, -3h HA.

All 6 exposures should be in same filter (r or i), 100s, and just make sure each exposure is not ruined by a super-bright star or other oddity.

No standard script is available.

Note about using HA/dec
SISPI excepts coordinates in HA/dec but it and the TCS assume that your intentions are to slew the telescope to a specific position relative to the observatory. So whenever the TCS encounters a slew request with the coordinates given in HA/dec or AZ/EL it takes the telescope out of tracking. Just be aware of this and if necessary tell the operator to turn tracking back on. Tracking will be restored automatically the next time RA/dec or offsets are sent to the TCS