COB Basic Cooling Rate
LWFPA
MWFPA
300
200
150
100
50
250
Time
Deg
rees
K
6Hrs to achieve
operating temperature
Cycling the Stirling Cooler: FPA Temperature Response
Deg
. K
LWFPA
MWFPAColdFingerColdFinger
Elapsed Time (Minutes)
105
100
95
90
85
65
75
70
80
60
35 1729369
Stirling Off
Stirling On
Nominal T
Max. Operating T
Summary:
1.Stirling cooler turned off for one hour2.Detectors still responsive for 30 mins3.100 mins then required to re-attain operational temperature
FPA In-Op
FPA Re-stabilized
Stirling Off – On Noise Samples
Channel 5 All Port 2
LWIR (Ch38 13.9m)
Stirling “On”
Stirling “Off”
60 Hz Stirling Noise Blow-Up
Zoom
LWIR (Ch38 13.9m)
NET (3.7µm to 13.0µm)D
egre
es
0.0
1.2
1.0
0.8
0.6
0.4
0.2
1.4
Cooler On
Cooler Off
Old MAS
4.0
µm
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
NET (13.0µm to 14.5µm)
0.0
6.0
5.0
4.0
3.0
2.0
1.0
7.0
Deg
rees
Cooler On
Cooler Off
Old MAS
13.2 13.4 13.6 13.8 14.0 14.2 14.4
µm
NEdT eMAS vs Old MAS
3.70
6.73
7.29
8.22
8.49
8.56
9.70
9.71
10.1
9
10.5
4
11.0
6
11.0
7
12.0
1
12.0
9
12.5
9
12.9
4
13.3
4
13.3
5
13.6
3
13.9
0
13.9
6
14.3
1
6.0
5.0
4.0
3.0
2.0
1.0
7.0
Deg
rees
Cooler On
Cooler Off
Old MAS
MAS Flight
µm
0.220.68
0.34 0.500.19
0.23 0.22 0.29
0.91 0.87
1.57
1.97
6.49
2.51
1.450.640.48
0.310.09
0.110.09
0.121.15
µm40C 30C
20C / Controller Off
15C
3.726 0.154 0.203 0.326 / 0.213 0.424
6.733 0.284 0.309 0.443 / 0.238 0.547
7.285 0.221 0.235 0.330 / 0.176 0.405
8.222 0.286 0.285 0.396 / 0.186 0.491
8.564 0.100 0.089 0.113 / 0.185 0.134
9.713 0.123 0.120 0.155 / 0.161 0.185
10.185 0.078 0.067 0.080 / 0.162 0.096
11.062 0.181 0.178 0.229 / 0.175 0.275
12.006 0.571 0.565 0.739 / 0.238 0.884
12.591 0.553 0.540 0.697 / 0.259 0.832
13.335 1.039 1.003 1.300 / 0.500 1.563
13.631 1.568 1.528 1.985 / 0.744 2.392
13.962 4.240 4.078 5.499 / 1.564 6.784
eMAS NEdT (Varying with Target Temp)
Extended-Area BB Target Temperature (cooler on)
MAS SWIR Spectrometer
MAS VNIR Spectrometer
New eMAS-IR Spectrometer installed on optical bench
IR Spectrometer
COB Internal Wiring:Possible source of microphonics?
IR Noise Investigation
Issue: 60Hz coupling mechanism: electrical or mechanical? Tests completed:1. Turn off Stirling: noise disappears2. Turn off scan motor (digitizer running): noise remains3. Blank-off COB window (obviates any fore-optic vibration effect)
noise remains
Tests remaining:1. Run Stirling from external controller - electrical isolation test2. Isolate various grounds from digiti9zer to scanhead3. Shake table test (induce 60Hz vibration with COB cold, Stirling
off)4. Procure active compensator (~12 weeks, plus controller
development)
Other Required Tests
• Investigate NEdT dependency on scene temperature
• Investigate linearity of radiometric response
• Temperature chamber test: - View cold EABB plate (linearity test) - Simulate forced air cooling of Stirling
• Simulate flight operation timeline (~40 min gap in Stirling power)
Will attempt to accomplish these before test flights on 8/20 – 8-31
Test Flight Plan
(22 ER-2 hours available)
Implement engineering data telemetry on ER-2/NASDAT
2-Hour FCF (may extend)
1 or 2 6-hour missions: Lake Tahoe ASTER Buoys Satellite under-passes Open ocean High clouds
Notional Flight Timeline
• In Lab: Scan head in tail cone, on cart; connected to AC unit on support cart.• Tail cone and AC carts wheeled as close to ramp as possible (AC unit on
extension cord)
-0+40 Disconnect AC cart from scan head (at hangar door?)
-0+30 Mate tail cone to aircraft (AC now off)
-0+20 Engine start
-0+25 eMAS power on by pilot (no cooling)
0+00 Launch (cooling begins)
0+20 Aircraft at altitude
0+?? LWIR bands operational.
New Motor/Mirror Assembly
Port 2 Dewar Location
(temporarily removed)
SDL IR Spectrometer
Housing
Port 1 DetectoreMAS Scan Head SDL Electronics
Package
SDL IR Spectrometer
HousingSterling Cooler
SDL Electronics Package
eMAS Scan Head
Cooling Air Plenum (Ducting Removed)
New Motor/Mirror/Encoder Unit
Interim Digitizer(upgraded MAS unit)
BB ControllerPower Module
Cryo Controller
LINUX CPU
Data SSDs
Motor Controller
PCB Backplane
ESS Module
Interim Digitizer(upgraded MAS unit)
Other Issues
Can eMAS-IR and eMAS-HSI fit in same pod as CPL?
Apparent total pod-weight issue
Need exact weight of Brandywine system.
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