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Progress Report Geo-CAPE Coastal Ecosystem Dynamics Imager (CEDI) IRAD Repackaging Study. Jason Budinoff / GSFC Cathy Marx / GSFC May 12, 2011. Coastal Ecosystem Dynamics Imager (CEDI) Block Diagram – IDL Baseline. Volume - 7.5 m 3 Mass - 621.4 kg Power - 392 W. Aperture Cover
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Progress ReportGeo-CAPECoastal Ecosystem Dynamics Imager (CEDI)IRAD Repackaging Study • Jason Budinoff / GSFC • Cathy Marx / GSFC • May 12, 2011
Coastal Ecosystem Dynamics Imager (CEDI) Block Diagram – IDL Baseline • Volume - 7.5 m3 • Mass - 621.4 kg • Power - 392 W Aperture Cover (closed during solar cal) Aperture Door Launch Lock Primary Mirror External Baffle Calibration Source Thru-hole Enclosure Scan Mirror Detectors HyVISI TCM8050A Custom 1K x 2K HyVISI TCM8050A Custom 1K x 2K SWIR Band Optical Bench MCT H2RG 2Kx2K Slit Star Trackers (3) (orthogonally mounted) SIRU Telescope “Aft” Optics Band 2(600-900 nm) Band 1 (345-600nm)
Aperture & Calibration Covers Opened I n t e g r a t e d D e s i g n C a p a b i l i t y / I n s t r u m e n t D e s i g n L a b o r a t o r y 2-Sided Diffuser plate Solar Calibration View Lunar Calibration & Nadir Science Views Scan mirror mechanism Use or disclosure of this data is subject to the restriction on the title page of this document GEO CAPE Study Week: 1/25 – 1/29/10 Presentation Delivered: Jan 29, 2010 Mechanical Systems, p Final
Why? • Desire to reduce instrument volume to allow payload to be hosted on other missions • “Minimally acceptable scientifically viable mission”….help to define this from the bottom up • GEO-CEDI (IDL) at 7.5m2 too large to allow hosting on some platforms • Study will evaluate architecture & packaging trades to reduce volume.
Volume Comparison GEO-MDI 15.3 cubic meters GEO-CEDI (IDL) 7.5 cubic meters GEO-CEDI (IRAD) 4 cubic meters?
Trade Space • The merit function is lowest volume, then lowest cost. • Several parameters will be traded: • Alternate optical packaging, Eff F/#, folding, etc. • Reduce gimbal size, alternate gimbal architectures • PPS / Jitter control implementation • Alternate calibration schemes • Primary Mirror scaling • Some parameters will not be traded: • Instrument architecture (Offner Relay slit spectrograph) • Spectral range and channel count
Gimbal • Traditional elevation over azimuth type is baseline • Evaluate flexure suspension XY scanner; analogous to large, “slow” steering mirror • Evaluate transmissivecal with XY scanner only • Trade large air gap voice coils vs. limited angle torque actuators
Alternate Optical Packaging • Faster telescope • “out of plane” folding options to enable more space efficient packaging • Additional fold optics required • Additional optics (periscope/K mirror) may be required to maintain slit orientation after folding Current “IDL” layout shown
Out of Plane Layout Channel 2 HyViSi ROIC 600-1100 nm Channel 1 HyViSiROIC 345 – 600 nm Channel 3 H2RG 1225-2160 nm Slit channel 1+2 Slit channel 3 120mm FSM in periscope
Calibration Double sided diffuser • Specular calibration • IDL concept has deployable calibration assembly, and required 3 mechanisms for 2 specular targets • Transmissive calibration? • Can we reduce number of calibrators? Diffuser Plate Select Mechanism Launch Lock Cover Mechanism
Precision Pointing System (PPS) • Add the JHU/APL PPS which utilizes FSM+startracker+inertial reference (gyro) system to increase S/N, cancel S/C and self jitter • Coupled with scanning gimbal • How do I get smaller by adding more components?
Future Work • Complete mechanical sizing trade • Add structural, thermal, optical bench detail GEO-MDI 15.3 cubic meters GEO-CEDI (IDL) 7.5 cubic meters Still have a way to go! GEO-CEDI (IRAD) <7.5 cubic meters