LISA Pathfindersignals, inputs, outputs, observations
M Hewitson for the LPF teamLPF School, ESTEC, 28th Feb 2012
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Contents
•signals, inputs, outputs•observations
2Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Input Signals
•Guidance signals•Actuation Commands•Commanded forces
3
controllersensor signal decoupling to actuator
Guidance[m, rad]
Actuation[m s-2, m2 s-2]
CommandedForce
[N, Nm]
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Output Signals
4
•Output in form of telemetry•We can downlink a subset of available
parameters•Per investigation, we define a Science Data
Mode• tells MOC which packets to downlink
•Data is converted to engineering values by MOC and delivered to STOC
•Data analysis starts from AOs
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Science Data Modes
•Choose ICE telemetry• small subset of data to downlink at the start of SC
pass• choose from one of the predefined ICE packets
•Choose Rest• choose sampling frequency (1,2,5,10)• choose packets to downlink
• all come at chosen sampling frequency• one may be at 10 Hz (unfiltered)
• include diagnostics? (yes/no)
5Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Telemetry flow
6Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
What outputs can we get?
7
coords
OB & PM
OB PM
DMU (@ 10Hz)
dT = 3*0.1 = 0.3s
OBC
Data Conversion
Inv OMS Conversion
DFACS
Measurement Processing
Sensor Mapping
OMS outputs [m]
Guidance &Ctrl Err Calc
Guidance
Controller
guidancetest output
[m]
err signaloutput [m]
ctrl output [m s^-2]
Decoupling
external commanded
output [m s^-2]
ActuationCommands
commandedforce outputs
[N]
X
FEEPS Algorithm
CapAct AlgorithmFEEP commands
[N] CapAct Algo
Sigma Delta
[V]
[N]
Cap Act Raw
CommandedVoltages [V]
Cap Act CommandedVoltages [V]
OBC
Data Conversion
DelaydT = ((int)0.5)*0.1 = 0s
Individual ThrusterCommands [N]
1
2
3
4
5
6
7
8
9
10
o_i [m]
g_i [N/kg]
FEEP Testinputs [N]
v_i [V]
1
2
3
4
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Signal Names
8
SC Name DFACS Name LTP DA Name
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance on x1
•In science mode 1 full optical:• x1 control coordinate controls SC x position relative
to TM1• measurement taken from OMS X1 IFO
9
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Commandedguidance
signal = P1 + P2 sin (P3 t + P4)
o1
F_cmd_X
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Cross-couplings: x1 -> ?
•Commanding x motion on SC doesn’t result in only x motion• FEEP cross-coupling
• static misalignments• beam flutter
•x motion of SC is not only sensed by X1 IFO• imperfect common-mode rejection -> X12 IFO sees
some SC x motion•x motion of SC couples to both TMs through
residual stiffness• gravitational coupling (TM-SC, TM-TM)• electrostatic stiffness from actuation voltages
10Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x1: observations
11
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x1: observations
11
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
~1mH
z
~1.7
mHz
~3.3
mHz
~6.7
mHz
~13.
3mHz
~26.
7mHz
~53.
3mHz
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x1: observations
11
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
~1mH
z
~1.7
mHz
~3.3
mHz
~6.7
mHz
~13.
3mHz
~26.
7mHz
~53.
3mHz
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x1: observations
11
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
~1mH
z
~1.7
mHz
~3.3
mHz
~6.7
mHz
~13.
3mHz
~26.
7mHz
~53.
3mHz
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Cross-coupling: perfect IFO•signal in o12
arises from difference of stiffness• here we use
8e-7 s-2
12Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Cross-coupling: matched stiffness on x, perfect IFO
13Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Cross-coupling: matched stiffness
14
common mode rejection at 10,000
Cap. Act. force commanded
on TM2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
FEEP cross-talk
•Trying to move SC along x results in angular motion
15Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Open-loop gains
16Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Open-loop gains
16
science band
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance on x2
•In science mode M1 full optical:• x2 control coordinate controls x position of TM2
relative to TM1• measurement taken from OMS X12 IFO
17
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Commandedguidance
o12
F_cmd_x2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Cross-couplings
•Actuation on x is not perfect• other degrees-of-freedom are disturbed
•Back-reaction on SC• 2kg/423kg• small signal should be present in X1 IFO output
18Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x2: observations
19
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x2: observations
19
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x2: observations
19
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Guidance x2: observations
19
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
SC motion: back reaction
20
x 1.96/422.7
high loop gain
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Cap. Act. Cross-talk
21Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Actuation on x1• In science mode 1 full optical:
• actuation commands on x1 drive SC along x using FEEPs
• decoupling matrix decides this
22
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Decouplingx1
F_cmd_X
o1
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Decoupling
23
Theta Eta Phi x1 y1 z1 theta1 eta1 phi1 x2 y2 z2 theta2 eta2 phi2
SC
X 0 0 0 422.7 -6.7452 250.7 0 0 0 0 6.7452 -250.7 0 0 0
SC
Y 0 0 0 0 216.97 0 94.262 0 0 0 205.73 0 0 0 0
SCZ 0 0 0 0 0 216.97 2.5362 0 0 0 0 205.73 0 0 0
SCTheta 0 0 0 0 2.6419 -0.033726 109.11 0 0 0 -2.6419 0.033726 0 0 0
SC
Eta 0 0 0 0 3.1702 -309.35 0.012681 0 0 0 -3.1702 309.35 0 0 0
SC
Phi 0 0 0 0 509.77 -3.1702 0.99335 0 0 0 -509.77 3.1702 0 0 0
TM1
x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
y 0 0 0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM1z 0 -0.36848 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1theta -0.0006912 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
eta 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0 0
TM1
phi 0 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0
TM2
x 0 0 0 0 0 0 0 0 0 -1.96 0 0 0 0 0
TM2
y 0 0 -0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM2z 0 0.36848 0 0 0 0 0 0 0 0 0 0 0 0 0
TM2theta 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0 0
TM2
eta 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0
TM2
phi 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Decoupling
23
Theta Eta Phi x1 y1 z1 theta1 eta1 phi1 x2 y2 z2 theta2 eta2 phi2
SC
X 0 0 0 422.7 -6.7452 250.7 0 0 0 0 6.7452 -250.7 0 0 0
SC
Y 0 0 0 0 216.97 0 94.262 0 0 0 205.73 0 0 0 0
SCZ 0 0 0 0 0 216.97 2.5362 0 0 0 0 205.73 0 0 0
SCTheta 0 0 0 0 2.6419 -0.033726 109.11 0 0 0 -2.6419 0.033726 0 0 0
SC
Eta 0 0 0 0 3.1702 -309.35 0.012681 0 0 0 -3.1702 309.35 0 0 0
SC
Phi 0 0 0 0 509.77 -3.1702 0.99335 0 0 0 -509.77 3.1702 0 0 0
TM1
x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
y 0 0 0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM1z 0 -0.36848 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1theta -0.0006912 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
eta 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0 0
TM1
phi 0 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0
TM2
x 0 0 0 0 0 0 0 0 0 -1.96 0 0 0 0 0
TM2
y 0 0 -0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM2z 0 0.36848 0 0 0 0 0 0 0 0 0 0 0 0 0
TM2theta 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0 0
TM2
eta 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0
TM2
phi 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example:
24
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Decouplingx1
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example:
24
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Decouplingx1
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example:
24
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Decouplingx1
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example:
24
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Decouplingx1
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Actuation on x2
•In science mode M1 full optical:• actuation commands on x2 drive TM2 along x using
Cap. Act.• decoupling matrix decides this
25
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Decouplingx2
o12
F_cmd_x2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Decoupling
26
Theta Eta Phi x1 y1 z1 theta1 eta1 phi1 x2 y2 z2 theta2 eta2 phi2
SC
X 0 0 0 422.7 -6.7452 250.7 0 0 0 0 6.7452 -250.7 0 0 0
SC
Y 0 0 0 0 216.97 0 94.262 0 0 0 205.73 0 0 0 0
SCZ 0 0 0 0 0 216.97 2.5362 0 0 0 0 205.73 0 0 0
SCTheta 0 0 0 0 2.6419 -0.033726 109.11 0 0 0 -2.6419 0.033726 0 0 0
SC
Eta 0 0 0 0 3.1702 -309.35 0.012681 0 0 0 -3.1702 309.35 0 0 0
SC
Phi 0 0 0 0 509.77 -3.1702 0.99335 0 0 0 -509.77 3.1702 0 0 0
TM1
x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
y 0 0 0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM1z 0 -0.36848 5.79E-17 0 0 0 0 0 0 0 0 0 0 0 0
TM1theta 0.0006912 0 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
eta 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0 0
TM1
phi 0 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0
TM2
x 0 0 0 0 0 0 0 0 0 -1.96 0 0 0 0 0
TM2
y 0 0 -0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM2z 0 0.36848 -5.79E-17 0 0 0 0 0 0 0 0 0 0 0 0
TM2theta 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0 0
TM2
eta 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0
TM2
phi 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Decoupling
26
Theta Eta Phi x1 y1 z1 theta1 eta1 phi1 x2 y2 z2 theta2 eta2 phi2
SC
X 0 0 0 422.7 -6.7452 250.7 0 0 0 0 6.7452 -250.7 0 0 0
SC
Y 0 0 0 0 216.97 0 94.262 0 0 0 205.73 0 0 0 0
SCZ 0 0 0 0 0 216.97 2.5362 0 0 0 0 205.73 0 0 0
SCTheta 0 0 0 0 2.6419 -0.033726 109.11 0 0 0 -2.6419 0.033726 0 0 0
SC
Eta 0 0 0 0 3.1702 -309.35 0.012681 0 0 0 -3.1702 309.35 0 0 0
SC
Phi 0 0 0 0 509.77 -3.1702 0.99335 0 0 0 -509.77 3.1702 0 0 0
TM1
x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
y 0 0 0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM1z 0 -0.36848 5.79E-17 0 0 0 0 0 0 0 0 0 0 0 0
TM1theta 0.0006912 0 0 0 0 0 0 0 0 0 0 0 0 0 0
TM1
eta 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0 0
TM1
phi 0 0 0 0 0 0 0 0 -0.0006912 0 0 0 0 0 0
TM2
x 0 0 0 0 0 0 0 0 0 -1.96 0 0 0 0 0
TM2
y 0 0 -0.36848 0 0 0 0 0 0 0 0 0 0 0 0
TM2z 0 0.36848 -5.79E-17 0 0 0 0 0 0 0 0 0 0 0 0
TM2theta 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0 0
TM2
eta 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912 0
TM2
phi 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -0.0006912
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example
27
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Decouplingx2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example
27
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Decouplingx2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example
27
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Decouplingx2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Example
27
OMS X12 DMU
DFACS
Cap. Act.Algo
Cap. Act
commanded force on TM 2 x
SC Dynamics
Decouplingx2
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Commanded force on SC
•Same as actuation on x1•Just scaled by SC mass
28
OMS X1 DMU
DFACS
FEEPSAlgo
FEEPS
commanded force on X
SC Dynamics
Decouplingx1
F_cmd_X
o1
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Commanded force on TM1 x
•In science mode M1 full optical:• open loop force on TM1 along x• at low frequency (high gain) SC follows• X1 IFO observes no signal (at low f)• X12 IFO sees full signal
• TM2 follows more slowly
29
injection
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
How much motion do we expect to observe in X1?
•Apply 0.25 nN force on TM1at 53mHz•Displacement:
30
x =F
!
2m1
[N]
[s�2][kg]
x =2.5⇥ 10�10
(2⇡ · 0.053)2 · 1.96[N]
[s�2][kg]= 1.15[nm]
•Loop gain at 53mHz is about 2• so we should observe about 0.6 nm
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X1: relative position of SC and TM1 along x
31
~1mHz ~1.7mHz ~3.3mHz~6.7mHz
~13.3mHz
~26.7mHz~53.3mHz
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X1: relative position of SC and TM1 along x
31
~1mHz ~1.7mHz ~3.3mHz~6.7mHz
~13.3mHz
High-gain, SCfollows TM1 closely
~26.7mHz~53.3mHz
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X1: relative position of SC and TM1 along x
31
~1mHz ~1.7mHz ~3.3mHz~6.7mHz
~13.3mHz
High-gain, SCfollows TM1 closely
~26.7mHz~53.3mHz
Low-gain, SCcan’t follow
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Check IS reading
•Measures TM to SC (TM housing)
32Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
SC motion
•We apply 52nN of force on SC•This results in a motion of 1.1nm•BUT it’s out of phase with the 1.1nm motion of
TM1 by about XX degrees• relative motion observed with X1 is about 0.6nm
33Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X12: relative x position of TM1 and TM2
34Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X12: relative x position of TM1 and TM2
34Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
How much do we expect to observe in X12?
•At 53 mHz the suspension loop is essentially open• TM2 doesn’t move• X12 should see the full motion of TM1 relative to the
bench (SC)
35
detrended version of last
signal
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Check IS•IS measures position of TM2 relative to SC (TM
housing)
36Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Commanded force on TM2 x•In science mode M1 full optical:
• open loop force on TM2 along x• suspension loop has no gain above 1mHz• TM2 will just move as commanded• X1 will observe ~0
• back reaction->SC motion• X12 will observe full motion of TM2
37
injection
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
How much with TM2 move?
38
•Apply 0.25 nN force on TM1at 53mHz•Displacement:
x =F
!
2m1
[N]
[s�2][kg]
x =2.5⇥ 10�10
(2⇡ · 0.053)2 · 1.96[N]
[s�2][kg]= 1.15[nm]
•Loop gain at 53mHz is close to 0• so we should observe 1.15 nm
Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X1 observation
39Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
IFO X12 observation
40Monday, February 6, 12
M Hewitson, LPF Inputs etc, LPF School, ESTEC, 28th Feb 2012
Confirm with IS measurement
41
~1.2nm
~6pm
Consistent with ratio of masses
~1/200
Monday, February 6, 12