317-F · 317F cos — cos — Sin Sin cos cos cos i + cos —2 i + SlnY— J —2 i + sin —Zi + sin nC
SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA COS Science Calibration & Instrument...
-
Upload
vanessa-carol-blair -
Category
Documents
-
view
214 -
download
0
Transcript of SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA COS Science Calibration & Instrument...
SPACETELESCOPESCIENCEINSTITUTE
Operated for NASA by AURA
COS Science Calibration & Instrument Status
TIPS20 Nov 2003
Last COS TIPS Aug 2003
Friedman 2 of 25TIPS - 20 November 2003
COS Instrument Status
• Thermal vacuum & science calibration testing complete– Tests of mechanism stability continuing
• All important performance requirements have been met– Spectral resolution– Sensitivity– Flatfield quality– Scattered light– Wavelength coverage
• COS to be moved to GSFC for storage until launch preparation– Periodic functional and throughput tests to verify instrument
health
Friedman 3 of 25TIPS - 20 November 2003
Thermal Vac & Science Calibration
• All testing completed at Ball Aerospace, Boulder• Initial thermal balance tests and preliminary SI verification
(“Appendix A”) July 2-7.– 21 tests. ~500 data files.– Testing terminated to fix power converters and several other small
items.
• Detailed science calibration (“Appendix B”) Sept 20 – Oct 22.– 109 tests. ~2200 data files.– NUV first, FUV later, to allow pressure to drop to acceptable levels.
• OPUS and CALCOS processed data available with StarView.• STScI support at Ball
– Keyes, Hartig, Sembach, Leitherer, Bohlin, Wheeler, D. Stys, Friedman.
Friedman 4 of 25TIPS - 20 November 2003
COS Detectors
FUV XDL detector NUV MAMA detector
Friedman 5 of 25TIPS - 20 November 2003
Vacuum Chamber Arrangement
Calibration Delivery System external platform provided ultraviolet light sources.
RAS/Cal COS
Cal Delivery System
COS operations
Vacuum pump
RASCAL controlelectronics & computer
Vac chamber operations
pum
ps
Vacuum chamber
Green Room contained operations and data analysis facility
Friedman 6 of 25TIPS - 20 November 2003
Friedman 7 of 25TIPS - 20 November 2003
Science Calibration Test Categories
• Alignment, focus, image quality, resolution• Sensitivity• Wavelength scales• Stray & scattered light• Flat field and S/N• Detector functions• Optical stability & repeatability• Target acquisition algorithms
Friedman 8 of 25TIPS - 20 November 2003
Optical Layout
Friedman 9 of 25TIPS - 20 November 2003
Appendix B FUV Teststest test day date
number name completed
70 FUV focus sweeps2700 FUV HV variability Thur 10/09/032705 FUV HV variability Thur 10/09/032706 FUV HV variability Thur 10/09/032740 FUV dark count rate #1 Thur 10/09/03850 Repeatability monitor #1 Thur 10/09/03
2715 FUV timing threshold settings Fri 10/10/032725 FUV walk settings Fri 10/10/032710 FUV timing threshold settings Fri 10/10/032726 FUV walk settings Fri 10/10/032740 FUV dark count rate #2 Fri 10/10/033600 FUV Accum Check Fri 10/10/031700 FUV cal ss flats S/N=30 Sat 10/11/031210 FUV G130M sensitivity Sat 10/11/031220 FUV G160M sensitivity Sat 10/11/031230 FUV G140L sensitivity Sat 10/11/031240 FUV sensitivity with QE grid off Sat 10/11/033500 FUV OSM1 position checks Sat 10/11/032740 FUV dark count rate #3 Sat 10/11/032300 FUV grating stability Sun 10/12/032305 FUV grating stability Sun 10/12/032355 NUV grating stability Sun 10/12/032355 NUV grating stability Sun 10/12/031265 G225M 2nd order sensitivity Sun 10/12/032800 FUV high local count rate Sun 10/12/033300 FUV BOA throughput & resloution Sun 10/12/032735 Geometrical Correction WCA part Sun 10/12/03
1110 FUV CDS Pt-Ne Group 1 Mon 10/13/032750 FUV resolution, QE grid off Mon 10/13/031120 FUV CDS Pt-Ne Group 2 Mon 10/13/032741 FUV dark count rate, QE grid off Mon 10/13/03850 Repeatability Monitor #2 Mon 10/13/03
3000 FUV Cal SS flats, S/N = 100 Mon 10/13/032306 G130M Grating Stability #1 Mon 10/13/032805 FUV high local count rates G160M Mon 10/13/032735 Geom Corrections WCA Tues 10/14/031450 TA dispersed mode centroids Tues 10/14/031460 TA dispersed light phase 4 Tues 10/14/031470 TA dispersed light phase 5 Tues 10/14/032730 FUV geometric corrections PSA Wed 10/15/032731 Geom Corrections PSA 7x7 pinhole Wed 10/15/032306 G130M Grating Stability #2 Wed 10/15/03850 Repeatability monitor #3 Wed 10/15/03
1720 FUV flats aperture offset 2 Wed 10/15/032100 FUV CO initial spectra Wed 10/15/032110 FUV scattered light Thur 10/16/032120 FUV high quality spectra Thur 10/16/03850 Repeatability monitor 4 Thur 10/16/03
1437 NUV TA flooded aperture with Kr Thur 10/16/032740 FUV dark count rate 3 Thur 10/16/032506 NUV flats with CDS D2 lamp Thur 10/16/031730 FUV flats aperture offset 3 Fri 10/17/032307 FUV stability Fri 10/17/033700 NUV Efficiency Suplement Sat 10/18/033400 Side 2 Mechanism Verification Sat 10/18/03
50 TA1 Focus Sweeps Mon 10/20/032307 NUV stability Mon 10/20/03
50 TA1 Focus Sweeps Tues 10/21/031155 NUV G185M CDS Pt-Ne Spectra in N2 Tues 10/21/031156 NUV G225M CDS Pt-Ne Spectra in N2 Wed 10/22/03
Test Program by D. Ebbets (Ball), E. Wilkinson (CU), and IDT.
Friedman 10 of 25TIPS - 20 November 2003
FUV G130M Spectral Resolution
Segment BSegment A
Friedman 11 of 25TIPS - 20 November 2003
FUV G130M Spectral Resolution
Friedman 12 of 25TIPS - 20 November 2003
NUV G225M Spectral Resolution
17000
18000
19000
20000
21000
22000
23000
24000
25000
26000
27000
28000
29000
30000
2070 2170 2270 2370 2470 2570
lam2186lam2217lam2233lam2250lam2268lam2283lam2306lam2325lam2339lam2357lam2373lam2390lam2410
Requirement
Friedman 13 of 25TIPS - 20 November 2003
Spectral Resolution Summary
• FUV channel– G130M & G160M R > 20,000– G140L R > 2,000
• NUV channel– G185M R > 16,000– G225M & G285M R > 20,000– G230L R > 1,700 (over most of bandpass)
• Bright Object Aperture (BOA) resolution degraded– Wedge in ND filter degrades resolution by factor of ~2.5 for FUV
modes and ~4 for NUV modes.
Friedman 14 of 25TIPS - 20 November 2003
FUV Sensitivity
This point falls outside the specified wavelength range and thus does not violate requirements.
Detector QESegment A
Detector QESegment B
Friedman 15 of 25TIPS - 20 November 2003
NUV Flat Structure
500 1000
500
1000
0
COS G185M NUV P-flat1.36% Poisson rms
Pixel (cross-dispersion)
Pix
el (
disp
ersi
on)
Intrinsic detector scatter (1=3.25%) within the 100x100 pixel box shown in dashed lines
20,000 - 40,000 counts per pixel in each stripe
C B A
Pix
el (
disp
ersi
on)
Friedman 16 of 25TIPS - 20 November 2003
NUV Flatfield S/N
Normalized ratio of first half of exposure to second half
Friedman 17 of 25TIPS - 20 November 2003
FUV & NUV Flat Fields
Friedman 18 of 25TIPS - 20 November 2003
NUV Spatial Resolution
Friedman 19 of 25TIPS - 20 November 2003
Optics Select Mechanism (OSM)
Optics Select Mechanism Two
• Full 360 Degree Rotation
• 101 arcsecond step size, with selectable step rate (78 steps/sec baselined)
• Coarse and fine resolvers provide position feedback
Ferris wheel mode
Friedman 20 of 25TIPS - 20 November 2003
OSM Stability with Time(typical component test results)
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Time
G160MG130M
NCM-1
G140L
~ 4 minutes
1 resel
Helicopter mode
Friedman 21 of 25TIPS - 20 November 2003
G130M Segment A – Helicopter Orientation
-0.906 Arcseconds of Drift
Friedman 22 of 25TIPS - 20 November 2003
G160M Segment A – Helicopter OrientationG160M Seg A Image Motion in Helicopter Orientation
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Time (sec)
Motion (pixels)
X-drift 1
X-drift 2
X-drift 3
X-drift 4
X-drift 5
X-drift 6
X-drift 7
X-drift 8
X-drift 9
X-drift 10
X-drift 11
X-drift 12
X-drift 13
Average
-01.069 Arcseconds of Drift
Friedman 23 of 25TIPS - 20 November 2003
G185M – Helicopter OrientationG185M Image Motion in Helicopter Orientation
-6
-5
-4
-3
-2
-1
0
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Time (secs)
Motion (pixels)
YC1
YC2
YC3
YC4
YC5
YC6
YC7
Average
-9.39 Arcseconds of Drift
Friedman 24 of 25TIPS - 20 November 2003
OSM Stability Summary
• The OSM met stability requirements in component level testing (helicopter mode).
• Science calibration (Ferris wheel mode): OSM1 & OSM2 did not meet requirements in some cases.
• Post science cal GN2 testing (helicopter mode) has shown excessive drift in some test cases.– OSM relaxation may be due to thermal effects. Bench is not thermally
controlled in helicopter mode.
• Ball conducting additional test to further characterize problem.• COWG and COS FIG groups will consider operational
changes to mitigate the problem. COS IS evaluating science impacts.
Friedman 25 of 25TIPS - 20 November 2003
COS Science Calibration Summary and Status• Science calibration complete
– All instrument modes exercised.– Instrument stimulated by continuum, emission line, and absorption line
(O2 and CO) sources.
• Performance is excellent– Resolution, sensitivity, alignment, image quality, focus.
• Flight software performed as expected• OSM stability under investigation• Expect shipment to GSFC shortly• Functional tests every 3 months; NUV throughput tests every
6 months• OPUS and CALCOS processed thermal vacuum test data in
MAST.