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.