amplitude_modulation

legwork.strain.amplitude_modulation(position, polarisation, inclination)

Computes the modulation of the strain due to the orbit averaged response of the detector to the position, polarisation, and inclination of the source using Cornish+03 Eq.42 and Babak+21.

Note that since the majority of the calculations in LEGWORK are carried out for the full position, polarisation, and inclination averages, we include a pre-factor of 5/4 on the amplitude modulation to undo the factor of 4/5 which arises from the averaging of legwork.utils.F_plus_squared() and legwork.utils.F_cross_squared().

Additionally, note that this function does not include the factor of 1/2 from the Cornish+03 paper in order to remain in the frequency domain. More recent papers (e.g. Babak+21) define the strain as h(f)~A(f)*e^(2*i*psi(f)) and so the inner product is 1 instead of 1/2 as in Cornish+03.

Parameters

positionSkyCoord/array, optional

Sky position of source. Must be specified using Astropy’s astropy.coordinates.SkyCoord class.

polarisationfloat/array, optional

GW polarisation angle of the source. Must have astropy angular units.

inclinationfloat/array, optional

Inclination of the source. Must have astropy angular units.

Returns

modulationfloat/array

modulation to apply to strain from detector response