From de6d2d43b95623b303e4aa1b25cd17d41d40c086 Mon Sep 17 00:00:00 2001
From: Jameson Graef Rollins <jrollins@finestructure.net>
Date: Mon, 9 Jul 2018 18:59:23 -0700
Subject: [PATCH] quantum: handle frequency independent quadrature noise
This is a port of the changes added to matgwinc in
gwinc/matgwinc@a83e5053b64e6e8d3176f8fc29df631972fec451
The new pygwinc quantum curve diverges slightly from the matgwinc
version at the highest frequencies, for reasons that are not clear
to me...
---
gwinc/ifo/A+.yaml | 1 +
gwinc/noise/quantum.py | 33 +++++++++++++++++----------------
gwinc/test/A+.pkl | 4 ++--
3 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/gwinc/ifo/A+.yaml b/gwinc/ifo/A+.yaml
index 3f0ae0e2..07555d8e 100644
--- a/gwinc/ifo/A+.yaml
+++ b/gwinc/ifo/A+.yaml
@@ -255,6 +255,7 @@ Squeezer:
AmplitudedB: 12 # SQZ amplitude [dB]
InjectionLoss: 0.05 # power loss to sqz
SQZAngle: 0 # SQZ phase [radians]
+ LOAngleRMS: 30e-3 # quadrature noise [radians]
# Parameters for frequency dependent squeezing
FilterCavity:
diff --git a/gwinc/noise/quantum.py b/gwinc/noise/quantum.py
index 8a69ad17..b43f8f87 100644
--- a/gwinc/noise/quantum.py
+++ b/gwinc/noise/quantum.py
@@ -62,7 +62,7 @@ def shotrad(f, ifo):
#<<<<<<<<<<<<<<<<< Modified to include frequency dependent squeezing angle (LB)
# useful numbers
- eta = ifo.Optics.Quadrature.dc# # Homodyne Readout phase
+ eta = ifo.Optics.Quadrature.dc # Homodyne Readout phase
lambda_PD = 1 - ifo.Optics.PhotoDetectorEfficiency # PD losses
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -71,10 +71,7 @@ def shotrad(f, ifo):
if 'Squeezer' not in ifo:
sqzType = 'None'
else:
- if 'Type' not in ifo.Squeezer:
- sqzType = 'Freq Independent'
- else:
- sqzType = ifo.Squeezer.Type
+ sqzType = ifo.Squeezer.get('Type', 'Freq Independent')
# extract common parameters
if sqzType == 'None':
@@ -82,14 +79,13 @@ def shotrad(f, ifo):
alpha = 0 # Squeeze angle
lambda_in = 0 # Loss to squeezing before injection [Power]
ANTISQZ_DB = 0 # Anti squeezing in db
+ etaRMS = 0
else:
SQZ_DB = ifo.Squeezer.AmplitudedB # Squeeing in dB
lambda_in = ifo.Squeezer.InjectionLoss # Loss to squeezing before injection [Power]
alpha = ifo.Squeezer.SQZAngle # Freq Indep Squeeze angle
- if 'AntiAmplitudedB' in ifo.Squeezer:
- ANTISQZ_DB = ifo.Squeezer.AntiAmplitudedB # Anti squeezing in db
- else:
- ANTISQZ_DB = SQZ_DB
+ ANTISQZ_DB = ifo.Squeezer.get('AntiAmplitudedB', SQZ_DB) # Anti squeezing in db
+ etaRMS = ifo.Squeezer.get('LOAngleRMS', 0) # quadrature noise
# switch on squeezing type for other input squeezing modifications
if sqzType == 'None':
@@ -195,12 +191,17 @@ def shotrad(f, ifo):
Msig = Msig * sqrt(1 - lambda_PD)
# and compute the final noise
- vHD = np.array([[sin(eta), cos(eta)]])
- n = coeff * np.squeeze(sum(abs(getProdTF(vHD, Mnoise))**2, axis=1)) / \
- np.squeeze(sum(abs(getProdTF(vHD, Msig))**2, axis=1))
-
- # gwinc wants n to be 1xN
- #n = n.T
+ def HDnoise(eta):
+ vHD = np.array([[sin(eta), cos(eta)]])
+ n = coeff * np.squeeze(sum(abs(getProdTF(vHD, Mnoise))**2, axis=1)) / \
+ np.squeeze(sum(abs(getProdTF(vHD, Msig))**2, axis=1))
+ return n
+
+ if etaRMS <= 0:
+ n = HDnoise(eta)
+ else:
+ # include quadrature noise (average of +- the RMS)
+ n = (HDnoise(eta+etaRMS) + HDnoise(eta-etaRMS)) / 2
# the above is the same as
# n = coeff * (vHD * Msqz * Msqz' * vHD') / (vHD * Msig * Msig' * vHD')
@@ -216,7 +217,7 @@ def shotrad(f, ifo):
# sum(abs((vHD * Msig(:,:,k))).^2);
# end
- return n
+ return n * ifo.gwinc.sinc_sqr
def shotradSignalRecycled(f, ifo):
diff --git a/gwinc/test/A+.pkl b/gwinc/test/A+.pkl
index 08ce29cd..c62101db 100644
--- a/gwinc/test/A+.pkl
+++ b/gwinc/test/A+.pkl
@@ -1,3 +1,3 @@
version https://git-lfs.github.com/spec/v1
-oid sha256:e5594c81cf227bf8fcba4add52d9acb0b1ebc988b844402eb844adab50c11f95
-size 897493
+oid sha256:7e21d770b7514f6a9a2cf1dcc859c441c5d67e62727688a63854ebbbeef724c7
+size 897522
--
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