Table 1: SOURCE_PARAMETER: Source flux information
SOURCE_PARAMETER: Source parameter description

Name

Format

Units

Measure

Comments

Columns

Key

TIME  

Double

s

EPOCH

Time midpoint for validity

(TIME_EXTRA_PREC)  

Double

s

extra TIME precision

INTERVAL  

Double

s

Interval of validity

Data description

NUM_FREQ  

Int

Number of frequencies at which parameters are provided

NUM_STOKES  

Int

Number of stokes parameters

NUM_DEP  

Int

Number of dependencies for bootstraped fluxes.

Data

SOURCE_STOKES  

Int (NUM_STOKES)

Stokes identification

SOURCE_FLUX  

Float (NUM_FREQ,
NUM_STOKES)

Jy

Flux values

(SOURCE_SIZE)   

Float (2,NUM_FREQ)

arcsec

Sizes along major and minor axis

(SOURCE_PA)   

Float (2,NUM_FREQ)

rad

Position angle major axis

DEP_SOURCE_PAR_ID  

Int (NUM_DEP)

List of SOURCE_PARAMETER_IDs indicating dependencies.


Notes: This source parameter table provides informations for calibration sources. At the time of the observations it is a priori information. Bootstraped fluxes would be stored in this table as well. There is an optional reference to an entry in this table in the SOURCE table.
TIME
Time when the source parameters have been measured
TIME_EXTRA_PREC
Extra precision time
INTERVAL
Interval over which the parameters are believed valid. If the degree of variability of for the source is unknown, the attribute to that key would be set to 0.
NUM_FREQ
Number of frequencies for which the fluxes are provided
NUM_STOKES
Number of stokes parameters with known fluxes
NUM_DEP
Number of dependencies for bootstraped fluxes. NUM_DEP=0 for primary calibrators. The number of dependencies is internal i.e. must refer to results from data in the MS itself.
SOURCE_STOKES
List of stokes parameters (with the standard axis convention).
SOURCE_FLUX
Source fluxes
SOURCE_SIZE
Source size (would negative values be acceptable to tell they are only upper limits?)
SOURCE_PA
Position angle of major axis
DEP_SOURCE_PAR_ID
List of identifiers for the dependencies. This list is not empty only for bootstraped fluxes.

Remark: During actual observations, TIME here in SOURCE_PARAMETER  will indeed not belong to the time INTERVAL of the SOURCE  sub-table. This does not prevent to refine the calibration subsequently by appending new rows in this SOURCE_PARAMETER  sub-table and by extending accordingly the list of SOURCE_PARAMETER_IDin the SOURCE  table. Results about bootstraped fluxes during the calibration stage would also be stored in this table. The source size, or its upper limit, provides the information on valid baseline lengths in the bootstrap