From a21dc48f0c534e14517d99b98b4c84f90188abce Mon Sep 17 00:00:00 2001
From: Jean-Baptiste Bayle <j2b.bayle@gmail.com>
Date: Tue, 24 Aug 2021 22:46:21 +0200
Subject: [PATCH] Add TDIR assistance tone
---
lisainstrument/instrument.py | 41 ++++++++++++++++++++++++++++++------
1 file changed, 34 insertions(+), 7 deletions(-)
diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index 0ed00d2..2b1c9b9 100644
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -68,7 +68,7 @@ class Instrument:
# Laser sources
laser_asds=28.2, central_freq=2.816E14,
# Laser phase modulation
- modulation_asds='default', modulation_freqs='default',
+ modulation_asds='default', modulation_freqs='default', tdir_tone=None,
# Clocks
clock_asds=6.32E-14, clock_offsets=0, clock_freqoffsets='default',
clock_freqlindrifts='default', clock_freqquaddrifts='default',
@@ -112,6 +112,7 @@ class Instrument:
on each MOSA [s/sqrt(Hz)], or 'default' for a default set of levels with a factor
10 higher on right-sided MOSAs to account for the frequency distribution system
modulation_freqs: dictionary of modulation frequencies [Hz], or 'default'
+ tdir_tone: tuple (amplitude [Hz], frequency [Hz]) for TDIR assistance tone, or None
clock_asds: dictionary of clock noise amplitude spectral densities
clock_offsets: dictionary of clock offsets
clock_freqoffsets: dictionary of clock frequency offsets [s^-1], or 'default'
@@ -196,6 +197,15 @@ class Instrument:
else:
self.modulation_freqs = ForEachMOSA(modulation_freqs)
+ if tdir_tone is not None:
+ self.tdir_tone_amplitudes = ForEachMOSA(tdir_tone[0])
+ self.tdir_tone_frequencies = ForEachMOSA(tdir_tone[1])
+ logger.debug("Using assistance tone for TDIR (amplitude=%s, frequency=%s)",
+ self.tdir_tone_amplitudes, self.tdir_tone_frequencies)
+ else:
+ self.tdir_tone_amplitudes = ForEachMOSA(0)
+ self.tdir_tone_frequencies = ForEachMOSA(0)
+
# Clocks
self.clock_asds = ForEachSC(clock_asds)
self.clock_offsets = ForEachSC(clock_offsets)
@@ -579,6 +589,16 @@ class Instrument:
self.simulate_noises()
+ ## TDIR tone
+
+ self.tdir_tones = ForEachMOSA(lambda mosa:
+ 0 if self.tdir_tone_amplitudes[mosa] == 0 \
+ else self.tdir_tone_amplitudes[mosa] * numpy.sin(
+ 2 * numpy.pi * self.tdir_tone_frequencies[mosa]
+ * (self.physics_t + self.local_timer_deviations[mosa[0]])
+ )
+ )
+
## Local beams
logger.info("Simulating local beams")
@@ -1204,7 +1224,7 @@ class Instrument:
logger.debug("Computing carrier fluctuations for primary local beam %s", mosa)
self.local_carrier_fluctuations[mosa] = \
- self.laser_noises[mosa] + self.glitch_lasers[mosa]
+ self.laser_noises[mosa] + self.glitch_lasers[mosa] + self.tdir_tones[mosa]
logger.debug("Computing upper sideband offsets for primary local beam %s", mosa)
self.local_usb_offsets[mosa] = self.offsets_freqs[mosa] \
@@ -1212,7 +1232,7 @@ class Instrument:
logger.debug("Computing upper sideband fluctuations for primary local beam %s", mosa)
self.local_usb_fluctuations[mosa] = \
- self.laser_noises[mosa] + self.glitch_lasers[mosa] \
+ self.laser_noises[mosa] + self.glitch_lasers[mosa] + self.tdir_tones[mosa] \
+ self.modulation_freqs[mosa] * (self.clock_noise_fluctuations[sc(mosa)] + self.modulation_noises[mosa])
def lock_on_adjacent(self, mosa):
@@ -1236,7 +1256,8 @@ class Instrument:
+ self.central_freq * self.backlink_noises[mosa]
self.local_carrier_fluctuations[mosa] = adjacent_carrier_fluctuations \
+ self.offsets_freqs[mosa] * self.clock_noise_fluctuations[sc(mosa)] \
- + self.central_freq * self.oms_ref_carrier_noises[mosa]
+ + self.central_freq * self.oms_ref_carrier_noises[mosa] \
+ + self.tdir_tones[mosa]
logger.debug("Computing upper sideband offsets for local beam %s "
"locked on adjacent beam %s", mosa, adjacent(mosa))
@@ -1250,7 +1271,8 @@ class Instrument:
+ self.central_freq * self.backlink_noises[mosa]
self.local_usb_fluctuations[mosa] = adjacent_usb_fluctuations \
+ self.offsets_freqs[mosa] * self.clock_noise_fluctuations[sc(mosa)] \
- + self.central_freq * self.oms_ref_usb_noises[mosa]
+ + self.central_freq * self.oms_ref_usb_noises[mosa] \
+ + self.tdir_tones[mosa]
def lock_on_distant(self, mosa):
"""Compute carrier and upper sideband offsets and fluctuations for locked laser to distant beam.
@@ -1282,7 +1304,8 @@ class Instrument:
- (self.central_freq + self.local_carrier_offsets[mosa]) * self.local_ttls[mosa] / c
self.local_carrier_fluctuations[mosa] = distant_carrier_fluctuations \
+ self.offsets_freqs[mosa] * self.clock_noise_fluctuations[sc(mosa)] \
- + self.central_freq * self.oms_isc_carrier_noises[mosa]
+ + self.central_freq * self.oms_isc_carrier_noises[mosa] \
+ + self.tdir_tones[mosa]
logger.debug("Computing upper sideband offsets for local beam %s "
"locked on distant beam %s", mosa, distant(mosa))
@@ -1305,7 +1328,8 @@ class Instrument:
- (self.central_freq + self.local_usb_offsets[mosa]) * self.local_ttls[mosa] / c
self.local_usb_fluctuations[mosa] = distant_usb_fluctuations \
+ self.offsets_freqs[mosa] * self.clock_noise_fluctuations[sc(mosa)] \
- + self.central_freq * self.oms_isc_usb_noises[mosa]
+ + self.central_freq * self.oms_isc_usb_noises[mosa] \
+ + self.tdir_tones[mosa]
def simulate_locking(self):
"""Simulate local beams from the locking configuration."""
@@ -1433,6 +1457,9 @@ class Instrument:
self.glitch_tms.write(hdf5, 'glitch_tms')
self.glitch_lasers.write(hdf5, 'glitch_lasers')
+ logger.debug("Writing TDIR assistance tone to %s", output)
+ self.tdir_tones.write(hdf5, 'tdir_tones')
+
logger.debug("Writing laser noise to '%s'", output)
self.laser_noises.write(hdf5, 'laser_noises')
--
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