FTS%20Test%20Definition%20Summary - PowerPoint PPT Presentation

About This Presentation
Title:

FTS%20Test%20Definition%20Summary

Description:

Cycle between SCIENCE and SLEEP mode as for nominal occultation ... Monitor channel for recurrence of problem. Contamination Monitoring (Priority 1) ... – PowerPoint PPT presentation

Number of Views:25
Avg rating:3.0/5.0
Slides: 17
Provided by: atmospPhy
Category:

less

Transcript and Presenter's Notes

Title: FTS%20Test%20Definition%20Summary


1
FTS Test Definition Summary
  • Kaley Walker
  • Test Readiness Review
  • January 29, 2003

2
What Needs to be Done
  • Performance testing of
  • Passive cooler / detectors
  • Suntracker / co-registration
  • Imagers
  • Spectrometer (ILS, FOV etc.)

3
Passive Cooler
  • Evaluate performance of passive cooler using He
    cooled target
  • Monitor detector and target temperatures
  • While cooling from room temperature
  • During instrument temperature transitions
  • Priority 1

4
Detector Temperature
  • Measure while cooling detector every 5 K from
    110 ? 70? K
  • High resolution spectra N2O gas cell
  • Examine ILS vs. T and estimate NESR
  • Retrieve temperature and pressure
  • Low resolution spectra
  • Bandpass characteristics
  • Priority 1

5
Detector Non-linearity
  • Measure while cooling detector every 5 K from
    110 ? 70? K
  • Low resolution interferograms
  • At 1750, 2250, 2750 K ( 3273 K from previous)
  • Ratio of centre burst to first side lobe to
    calculate
  • 5800 K point measured on orbit
  • Priority 1

6
Operational Cycling
  • Measure at 90 K and lowest achieved T
  • Simulate normal operational power dissipation
  • Cycle between SCIENCE and SLEEP mode as for
    nominal occultation
  • Monitor detector temperature for any changes in
    cooling rate
  • Priority 3

7
Detector Monitoring
  • InSb Instability (Priority 1)
  • Monitor channel for recurrence of problem
  • Contamination Monitoring (Priority 1)
  • Measure low resolution spectra every 12 hours
    using 2273 K HBB
  • Need criteria for when decontamination should be
    initiated

8
Suntracker
  • Sunscan exercise mode using typical scan for
    MAESTRO calibration (Priority 1)
  • Stability measure in closed loop with sunrise
    simulator (50 s occultation) (Priority 2)
  • Pointing characterize pointing over 1.5
    range using leapfrog technique (Priority 2)

9
Co-registration
  • MAESTRO to VIS (Priority 2)
  • On bench with 532 nm laser source and in TVac
    with Xe lamp and pinhole
  • FTS to NIR (Priority 2)
  • Combined QI / HBB source and pinhole
  • NIR to VIS Registration (Priority 3)
  • relative orientation and pixel offset between
    arrays

10
Imager Characterization
  • Flat Field Bench
  • Solar simulator to provides uniform illumination
    (Priority 2)
  • Flat Field TVac
  • Illuminate stepwise using QI source
    (Priority 2)
  • Non-linearity TVac
  • Stepwise illumination and vary attenuation
    (Priority 2)

11
Imager Charaterization
  • Gain characterize imager settings (Priority 2)
  • Dark Current measure versus instrument
    temperature perform prior to each test with
    imagers (Priority 2)
  • Cropping test modes with sunrise simulator and
    attenuated source (Priority 3)

12
Gas Cell Measurements
  • Combined Measure NO2 and O3 with both FTS and
    MAESTRO (Priority 2)
  • compare retrieved temperature and pressure values
  • Additional N2O measurements with FTS at
    instrument temperature plateaux (Priority 2)
  • Examine ILS vs. T and estimate NESR
  • Retrieve temperature and pressure

13
Gas Cell Measurements
  • Occultation Use suntracker to follow simulated
    occultation and measure FTS (and MAESTRO) spectra
    (Priority 3)
  • Have to step through occultation to allow for
    time for sufficient coadds
  • Suntracker pointing in closed-loop at fixed
    source
  • Somewhat unwieldy test that cannot provide test
    as we fly conditions

14
FTS Tests
  • IR FOV Move shutter stepwise across FOV and
    measure ZPD (Priority 2/3)
  • Non-uniform FOV Illumination Use split
    attenuator to observe ILS effects (Priority 3)
  • Modulation Efficiency To be done by Bomem
    (Priority 2)

15
Limit in Testing
  • HBB cavity lifetime 30-40 minutes at 3273 K and
    we only have 4 cavities
  • Almost all tests done at max. temperature
  • Priority 1 57 minutes
  • Priority 2 65 minutes
  • Priority 3 268 minutes
  • Majority of 3 is Occultation 223 minutes
  • without it we should have enough HBB lifetime to
    complete testing program

16
Issues
  • Detector Decontamination
  • Need criteria for when this should be initiated
  • Occultation test
  • Significant drain on HBB lifetime
  • Recommend deleting from test schedule
Write a Comment
User Comments (0)
About PowerShow.com