caldeviceTab.html

CALDEVICE Calibration device characteristics.


Name	Format	Units	Measure	Comments

Columns

Key
ANTENNA_ID	Int			Antenna identifier
FEED_ID	Int			Feed identifier
SPECTRAL_WINDOW_ID	Int			Spectral window identifier
TIME	Double	s	EPOCH	Time interval mid-point
INTERVAL	Double	s		Time interval

Data description
NUM_CALLOAD	Int			Number N_cl of NCAL or TLOAD
(NUM_PHASECAL_TONE_FREQ)	Int			Number N_pct of phase tone frequencies

Data
(NCAL)	Double( N_cl)			Noise calibration
(TLOAD)	Double( N_cl)			Load temperature
(CALEFF)	Float( N_r, N_cl)			Calibration device efficiency/coupling coefficient
(PHASECAL_TONE_FREQ)	Double( N_pct)	Hz	FREQUENCY	Phase calibration tone frequencies

Notes: This table contains the characterics of devices used for the calibration. NUM_RECEPTORS is known through the FEED_ID. The load observed at a given time is specified in the STATE table via the item CALLOAD_NUM when REF is TRUE. Note that a single row MAIN table is associated to a collection of states as indexed from STATE_ID , each state for each antenna according to its position in the ANTENNA_ARRAY collection. State parameters may or may not be different from one antenna, feed, spectral window combination to an other as described here concerning the calibration devices.
Note that N_r, the number of receivers, is specified in the FEED table.
Note also that none of the items in the data section are mandatory but obviously at least one of these must be specified.
N.B.: Additional calibration device properties will have to be defined if necessary.

ANTENNA_ID: Antenna identifier, as referenced in the ANTENNA_ARRAYcollection in the CONFIG_DESCRIPTION table. The value of the identifier may be set to -1 if the parameters are valid for all the antenna, the values for these parameters being taken as values by default. These defaults can be supersede specifying their values for given ANTENNA_ID.
FEED_ID: Feed identifier, as referenced in the FEED_LISTcollection in the CONFIG_DESCRIPTION table.
SPECTRAL_WINDOW_ID: Spectral window identifier. A value of -1 indicates the row is valid for all spectral windows. If a specific spectral window has its own feed characteristics these have to be defined separately using a value > 0, to override the global specifications for that specific window.
TIME: Mid-point of time interval for which the parameters in the row are valid. The same reference used for the TIME column in the MAIN must be used.
INTERVAL: Time interval. It should be the same as in the FEED table.
NUM_CALLOAD: Number of calibration noise or load N_load available for this feed.
NUM_PHASECAL_TONE_FREQ: Number N_pct^of phase-cal tone frequencies.
NCAL: Noise calibration temperatures (0 if not added) Either NCAL or TLOAD must be provided but not both simultaneously.
TLOAD: Physical temperatures of the load for each calibration device. Either NCAL or TLOAD must be provided but not both simultaneously.
CALEFF: Calibration device efficiency/coupling efficiencies. These efficiencies may not be strictly identical for the different receivers.
PHASECAL_TONE_FREQ: Phase-cal tone frequencies. Note that these frequencies are in general antenna independent such that a value of -1 ANTENNA_IDcan be used.