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##### measures.baseline - Function

1.4.1 define a baseline measure

Description

baseline defines a baseline measure from the CLI. It has to specify a reference code, baseline quantity values (see introduction for the action on a scalar quantity with either a vector or scalar value, and when a vector of quantities is given), and optionally it can specify an offset, which in itself has to be a baseline. Allowable reference codes are ITRF and the direction ones.
Note that additional ones may become available. Check in CASA with:

print "\t----\t baseline Ex 1 \t----"
print me.listcodes(me.baseline())
#{’normal’: [’J2000’, ’JMEAN’, ’JTRUE’, ’APP’, ’B1950’, ’BMEAN’, ’BTRUE’,
# ’GALACTIC’, ’HADEC’, ’AZEL’, ’AZELSW’, ’AZELNE’, ’AZELGEO’, ’AZELSWGEO’,
# ’AZELNEGEO’, ’JNAT’, ’ECLIPTIC’, ’MECLIPTIC’, ’TECLIPTIC’, ’SUPERGAL’,
# ’ITRF’, ’TOPO’, ’ICRS’], ’extra’: []}

The baseline quantity values should be either longitude (angle), latitude(angle) and height(length); or x,y,z (length). See quantity for possible angle formats.

Arguments

 Inputs rf reference code allowed: string Default: ITRF v0 longitude or x allowed: any Default: variant v1 latitude or y allowed: any Default: variant v2 height or z allowed: any Default: variant off optional offset baseline measure allowed: record Default:
Returns
record

Example

print "\t----\t Ex 2 \t----"
print me.baseline(’itrf’,’30deg’,’40deg’,’10m’)
#{’m0’: {’value’: 0.52359877559829882, ’unit’: ’rad’},
# ’m1’: {’value’: 0.6981317007977319, ’unit’: ’rad’},
# ’m2’: {’value’: 9.9999999999999982, ’unit’: ’m’},
# ’refer’: ’ITRF’,
# ’type’: ’baseline’}
print me.doframe(me.observatory(’atca’))
print me.doframe(me.source(’1934-638’))
print me.doframe(me.epoch(’utc’,qa.unit(’today’)))
print me.measure(me.baseline(’itrf’,’30deg’,’40deg’,’10m’), ’J2000’)
#{’m0’: {’value’: 0.58375325605991979, ’unit’: ’rad’},
# ’m1’: {’value’: 0.69758519780286155, ’unit’: ’rad’},
# ’m2’: {’value’: 9.9999999999999964, ’unit’: ’m’},
# ’refer’: ’J2000’,
# ’type’: ’baseline’}

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