POINTING Antenna pointing information.

Name

Format

Units

Measure

Comments

Columns

Key

ANTENNA_ID

Int Antenna identifier

TIME

Double s EPOCH Time interval mid-point

INTERVAL

Double s Time interval

Data

NAME

String Pointing position desc.

NUM_POLY

Int Series order Npoly

TIME_ORIGIN

Double s EPOCH Origin for the polynomial

POINTING_DIRECTION

Double(2,( Npoly+1)) rad DIRECTION Antenna pointing direction

TARGET

Double(2,( Npoly+1)) rad DIRECTION Target direction

(OFFSET)

Double(2,( Npoly+1)) rad DIRECTION A priori pointing corrections

(SOURCE_OFFSET)

Double(2,( Npoly+1)) rad DIRECTION Offset from source

(ENCODER)

Double(2) rad DIRECTION Encoder values

POINTING_MODEL_ID

Int Pointing model identifier

POINTING_TRACKING

Bool True if tracking the target direction

PHASE_TRACKING

Bool True if tracking the phase reference position

(OVER_THE_TOP)

Bool True if over the top

Notes: This table contains information concerning the primary pointing direction of each antenna as a function of time.
Note that the pointing offset for individual feeds on a given antenna are specified in the FEED sub-table with respect to this pointing direction.
ANTENNA_ID
Antenna identifier
TIME
Mid-point of the time interval over which the data in the row are valid. Require to use the same TIME Measure reference as in MAIN
INTERVAL
Time interval
NAME
Pointing direction name; user specified
NUM_POLY
Series order for the polynomial expressions in POINTING_DIRECTION1  and OFFSET
TIME_ORIGIN
Time origin of the polynomial expression in POINTING_DIRECTION and OFFSET.
POINTING_DIRECTION
Antenna pointing direction, optionnaly expressed as polynomial coefficients. The final result is interpreted as a Direction Measure using the specified Measure reference.
TARGET
Target pointing direction, optionnaly expressed as polynomial coefficients. The final result is interpreted as a Direction Measure using the specified Measure reference. This is the true expected position of the source, including all coordinate corrections such as precession, nutation etc...  
OFFSET
The a priory pointing corrections applied by the telescope in pointing to the DIRECTION position, optionally expressed as polynomial coefficients. The final result is interpreted as a Direction Measure using the specified Measure reference.
Note that these are pointing offsets applied on top of the pointing model. They correct anything not accounted by the model (thermal variations, atmospheric refraction, ...)  
SOURCE_OFFSET
The commanded offset from the source position, if offset pointing is being used.
ENCODER
The current encoder values on the primary axes of the mount type for the antenna, expressed as a Direction Measure. These are absolute values.  
POINTING_MODEL_ID
Pointing model identifier
POINTING_TRACKING
True if tracking the nominal pointing position
PHASE_TRACKING
True if tracking the nominal phase reference direction
OVER_THE_TOP
True if the antenna was driven to this position “over the top” (az-el mount).