CALFOCUS Focus calibration results

Name

Format

Units

Measure

Comments

Columns

Key

CAL_DATA_ID

Int Calibration data identifier

CAL_REDUCTION_ID

Int Calibration reduction identifier

ANTENNA_ID

Int Antenna identifier

FEED_ID

Int Feed identifier

FREQUENCY_RANGE

Double(2) Hz FREQUENCY Frequency range used to determine the result

Data

START_VALID_TIME

Double s EPOCH Start time of result validity period

END_VALID_TIME

Double s EPOCH End time of result validity period

AZELDIR

Double(3) rad DIRECTION Azimuth and Elevation

FOCUS_OFFSET

Double(3, Nr) m Focus position offset

FOCUS_ERROR

Double(3, Nr) m Focus Offsets Uncertainties (XYZ)

FOCUS_WAS_FIXED

Bool(3) Focus Coordinate was fixed (XYZ)

FOCUS_METHOD

String Observing Method

Notes: This table contains single focus results. Nr is the number of receptors as specified in the FEED table.
CAL_DATA_ID
Calibration data identifier
CAL_REDUCTION_ID
Calibration reduction identifier
ANTENNA_ID
Antenna identifier
FEED_ID
Feed identifier(associated to antenna 1 and to antenna 2)
FREQUENCY_RANGE
Frequency range used to determine the result. Note that the list of spectral windows corresponding to this frequency range must correspond to a single receiver band, this band being known via RECEIVER_ID which is (are) in the data section of the FEED table.
START_VALID_TIME
Start time of result validity period
END_VALID_TIME
End time of result validity period
AZELDIR
contains the pointing direction of the antenna in the alt-azimuthal coordinate system as a Direction Measure (See aips++ note 233 by Wim Brouw)
FOCUS_OFFSET
The coordinates of the best focus position, relative to the nominal focus, in the X, Y, Z coordinates. For ALMA, when looking from the antenna towards the sky along the pointing direction, X is pointing horizontally towards the right, Y is pointing down perpendicular to the pointing direction, X is along the pointing direction towards the sky.
FOCUS_ERROR
Focus offset uncertainties in X, Y, Z.
FOCUS_WAS_FIXED
True for any of the coordinates that were held fixed.
FOCUS_METHOD
Method used (e.g. “Interferometry, Five point in Z”)