1.3.1.0 measures.doppler

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measures.doppler - Function

1.3.1 define a doppler measure
Description

doppler defines a doppler measure from the CLI. It has to specify a reference code, doppler quantity value (see introduction for the action on a scalar quantity with either a vector or scalar value),

and optionally it can specify an offset, which in itself has to be a doppler. Allowable reference codes are: RADIO Z RATIO BETA GAMMA OPTICAL TRUE RELATIVISTIC.
Note that additional ones may become available. Check in CASA with:

print "\t----\t doppler Ex 1 \t----"
print me.listcodes(me.doppler())
#{’normal’: [’RADIO’, ’Z’, ’RATIO’, ’BETA’, ’GAMMA’, ’OPTICAL’,
# ’TRUE’, ’RELATIVISTIC’], ’extra’: []}

The doppler quantity values should be either non-dimensioned to specify a ratio of the light velocity, or in velocity.

Arguments


Inputs
rf	reference code
	allowed:	string
	Default:	RADIO
v0	doppler ratio/velocity
	allowed:	any
	Default:	variant
off	optional offset doppler measure
	allowed:	any
	Default:	record

Returns
anyrecord

Example

Examples both give same doppler:

print "\t----\t doppler Ex 2 \t----"
print me.doppler(’radio’,’0.4’)
#{’m0’: {’value’: 119916983.2, ’unit’: ’m/s’},
# ’refer’: ’RADIO’,
# ’type’: ’doppler’}
print me.doppler(’radio’,qa.mul(qa.quantity(’0.4’),qa.constants(’c’)))
#{’m0’: {’value’: 119916983.2, ’unit’: ’m/s’},
# ’refer’: ’RADIO’,
# ’type’: ’doppler’}

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