From ff8409e7cb557339b5f92b5859c26cdc9f372dcc Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Bayle <j2b.bayle@gmail.com>
Date: Tue, 13 Dec 2022 15:30:39 +0100
Subject: [PATCH] Rename TCB sync noise to MOC time correlation
---
lisainstrument/instrument.py | 28 ++++++++++++++++------------
lisainstrument/noises.py | 13 +++++++------
2 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index cfb0339..e05d46b 100755
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -87,8 +87,8 @@ class Instrument:
# Optical pathlength noises
backlink_asds=3E-12, backlink_fknees=2E-3, testmass_asds=2.4E-15, testmass_fknees=0.4E-3,
oms_asds=(6.35E-12, 1.25E-11, 1.42E-12, 3.38E-12, 3.32E-12, 7.90E-12), oms_fknees=2E-3,
- # TCB synchronization
- sync_asds=0.42,
+ # MOC time correlation
+ moc_time_correlation_asds=0.42,
# Tilt-to-length (TTL)
ttl_coeffs='default',
sc_jitter_asds=(5E-9, 5E-9, 5E-9), sc_jitter_fknees=(8E-4, 8E-4, 8E-4),
@@ -155,8 +155,9 @@ class Instrument:
testmass_fknees: dictionary of cutoff frequencies for test-mass noise [Hz]
oms_asds: tuple of dictionaries of amplitude spectral densities for OMS noise [m/sqrt(Hz)],
ordered as (isi_carrier, isi_usb, tmi_carrier, tmi_usb, rfi_carrier, rfi_usb)
- sync_asds: dictionary of amplitude spectral densities for TCB synchronization noise [s/sqrt(Hz)],
- the default ASD seems rather high, this is due to the small sampling rate (default 1 / 86400s)
+ moc_time_correlation_asds: dictionary of amplitude spectral densities for MOC time
+ correlation noise [s/sqrt(Hz)], the default ASD seems rather high, this is due
+ to the small sampling rate (default 1 / 86400s)
oms_fknees: dictionary of cutoff frequencies for OMS noise
ttl_coeffs: tuple (local_phi, distant_phi, local_eta, distant_eta) of dictionaries of
tilt-to-length coefficients on each MOSA [m/rad], 'default' for a default set of
@@ -318,8 +319,8 @@ class Instrument:
else:
self.clock_freqquaddrifts = ForEachSC(clock_freqquaddrifts)
- # TCB synchronization
- self.sync_asds = ForEachSC(sync_asds)
+ # MOC time correlation
+ self.moc_time_correlation_asds = ForEachSC(moc_time_correlation_asds)
# Clock-noise inversion
self.clockinv_tolerance = float(clockinv_tolerance)
@@ -940,7 +941,7 @@ class Instrument:
logger.debug("Computing MOC time correlations")
physics_to_telemetry = lambda _, x: x[::self.physics_upsampling * self.telemetry_downsampling]
- self.moc_time_correlations = self.tcb_sync_noises \
+ self.moc_time_correlations = self.moc_time_correlation_noises \
+ self.the_wrt_tcb_withinitial.transformed(physics_to_telemetry)
## TDIR tone
@@ -1546,10 +1547,13 @@ class Instrument:
noises.dws(self.physics_fs, self.physics_size, self.dws_asds[mosa])
)
- ## TCB synchronization noise
+ ## MOC time correlation noise
- self.tcb_sync_noises = ForEachSC(lambda sc:
- noises.tcb_sync(self.telemetry_fs, self.telemetry_size, self.sync_asds[sc])
+ self.moc_time_correlation_noises = ForEachSC(lambda sc:
+ noises.moc_time_correlation(
+ self.telemetry_fs,
+ self.telemetry_size,
+ self.moc_time_correlation_asds[sc])
)
## Angular jitters
@@ -1902,8 +1906,8 @@ class Instrument:
self.oms_rfi_carrier_noises.write(hdf5, 'oms_rfi_carrier_noises')
self.oms_rfi_usb_noises.write(hdf5, 'oms_rfi_usb_noises')
- logger.debug("Writing TCB synchronization noise to '%s'", output)
- self.tcb_sync_noises.write(hdf5, 'tcb_sync_noises')
+ logger.debug("Writing MOC time correlation noise to '%s'", output)
+ self.moc_time_correlation_noises.write(hdf5, 'moc_time_correlation_noises')
logger.debug("Writing spacecraft angular jitter to '%s'", output)
self.sc_jitter_phis.write(hdf5, 'sc_jitter_phis')
diff --git a/lisainstrument/noises.py b/lisainstrument/noises.py
index 57b854b..a49ff2e 100644
--- a/lisainstrument/noises.py
+++ b/lisainstrument/noises.py
@@ -321,19 +321,20 @@ def dws(fs, size, asd):
logger.debug("Generating DWS measurement (fs=%s Hz, size=%s, asd=%s rad/sqrt(Hz))", fs, size, asd)
return violet(fs, size, 2 * pi * asd)
-def tcb_sync(fs, size, asd):
- """TCB synchronization noise.
+def moc_time_correlation(fs, size, asd):
+ """MOC time correlation noise.
- High-level noise model for the uncertainty we have in estimating
- the TCB timer deviations, i.e., the equivalent TCB times for the
+ High-level noise model for the uncertainty we have in computing the MOC
+ time correlation (or time couples), i.e., the equivalent TCB times for the
equally-sampled TPS timestamps.
Assumed to be a white noise in timing,
- S_tcbsnc(f) [s] = asd^2.
+ S_moc(f) [s] = asd^2.
Args:
asd: amplitude spectral density [s/sqrt(Hz)]
"""
- logger.debug("Generating TCB synchronization noise (fs=%s Hz, size=%s, asd=%s s/sqrt(Hz))", fs, size, asd)
+ logger.debug("Generating MOC time correlation noise (fs=%s Hz, size=%s, "
+ "asd=%s s/sqrt(Hz))", fs, size, asd)
return white(fs, size, asd)
--
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