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NexGenNPOESS Wind Observing Sounder: NASA/GSFC IDL Study and Findings
Prepared for
Mr. Dan Stockton, Program Executive OfficerProgram Executive Office for Environmental Satellites
Presented by
Dr. Wayman BakerNOAA/NASA/DoD Joint Center for Satellite Data Assimilation
and
Mr. Bruce GentryNASA/GSFC/Laboratory for Atmospheres
Working Group for Space Based Wind Lidar
Wintergreen, VA
2
Background Why Measure Global Winds from Space? Wind Lidar Societal Benefits NOAA Programs Requiring Atmospheric Winds Space-based Wind Lidar Roadmap GWOS/NWOS Comparisons with ADM Aeolus Instrument Development Laboratory (IDL) Study for a
NexGen NPOESS Wind Observing Sounder (NWOS) Concluding Remarks Next Steps/Recommendations
Overview
3
Background ESA planning to launch first DWL in 2009: Atmospheric Dynamics Mission (ADM) - Only has a single perspective view of the target sample volume - Only measures line-of-sight (LOS) winds A joint NASA/NOAA/DoD global wind mission offers the best opportunity for the U.S. to demonstrate a wind lidar in space in the coming decade - Measures profiles of the horizontal vector wind for the first time NASA and NOAA briefings given to:
- USAF (March 20, 2007); letter sent from AF Director of Weather on August 1, 2007 to NASA HQ stating:
- Of the 15 missions recommended by the NRC, global tropospheric wind measurements was most important for the USAF mission
- Willingness to endorse Space Experiments Review Board support via the DoD Space Test Program
- USAF Space Command (May 8, 2007)- Army (May 10, 2007)- NOAA Observing Systems Council (NOSC – June 8, 2007; June 18, 2008) - Navy (June 11, 2007); supporting letter sent on August 8, 2007- Joint Planning and Development Office and FAA (June 18, 2007)- FAA (May 16, 2008)- NOAA Research Council (May 19, 2008)
4
Background (Cont.)
The National Research Council (NRC) Decadal Survey report recommended a global wind mission
The NRC Weather Panel determined that a hybrid Doppler Wind Lidar (DWL) in low Earth orbitcould make a transformational impact onglobal tropospheric wind analyses.
“Wind profiles at all levels” is listed as the #1 priority in the strategic plan for United States Integrated Earth Observing System (USIEOS).
Cost benefit studies have identified economic benefits >$800M/year with the measurement of global wind profiles from space1,2
1 Cordes, J. (1995), “ Economic Benefits and Costs of Developing and Deploying a Space-Based Wind Lidar,
Dept of Economics, George Washington University, D-9502.
2 Miller, K. (2007), “Societal Benefits of Winds Mission,” Lidar Working Group, http://space.hsv.usra.edu/LWG/Index.html
5
Why Measure Global Windsfrom Space ?
The Numerical Weather Prediction (NWP) community
unanimously identifies global wind profiles as the
most important missing observations.
Independent modeling studies at NCEP, ESRL,
AOML, NASA and ECMWF have consistently shown
tropospheric wind profiles to be the single most
beneficial measurement now absent from the
Global Observing System.
6
Why Wind Lidar?Societal Benefits at a Glance…
Improved Operational Weather Forecasts
Civilian Military
Hurricane Track Forecast Ground, Air & Sea OperationsFlight Planning Satellite LaunchesAir Quality Forecast Weapons DeliveryHomeland Security Dispersion Forecasts forEnergy Demands & Nuclear, Biological, Risk Assessment & Chemical ReleaseAgriculture Aerial RefuelingTransportationRecreation
* K. Miller, “Societal Benefits of Winds Mission,” Lidar Working Group Meeting, February 8, 2007, Miami FL, http://space.hsv.usra.edu/LWG/Index.html
** AF aviation fuel usage estimate provided by Col. M. Babcock
• Estimated potential benefits greater than $800M per year*• Including military aviation fuel savings greater than $100 M/year**
7
NOAA ProgramsRequiring Atmospheric Winds*
* Data provided by TPIO / CORL Team
GOAL Program Priority 1 Priority 2 Totals
Climate (CL) Climate Observations & Modeling (COM) 1 1
Commerce & Transportation
(C&T)
Aviation Weather (AWX) 4 4
Marine Weather (MWX) 1 1
Surface Weather (SWX) 2 2
Weather & Water (W&W)
Mission Support (MS)
Air Quality (AQL) 1 1
Hydrology (HYD) 1 1
Local Forecasts & Warnings (LFW) 3 1 4
Modeling and Observing Infrastructure (MOBI)/Environmental Modeling (EMP)
1 1
Total: 4 Goals 8 PROGRAMS 13 2 15
NexGen Hybrid Doppler Wind Lidar - NWOS
NPOESS Wind Observing System For Vertical Wind Profiles
• 3D Tropospheric Winds mission called “transformational” and ranked #1 by Weather panel. 3D Winds also prioritized by Water Cycle panel.
“The Panel strongly recommends an aggressive program early on to address the high-risk components of the instrument package, and then design, build, aircraft-test, and ultimately conduct space-based flights of a prototype Hybrid Doppler Wind Lidar (HDWL).” “The Panel recommends a phased development of the HDWL mission with the following approach:
– Stage 1: Design, develop and demonstrate a prototype HDWL system capable of global wind measurements to meet demonstration requirements that are somewhat reduced from operational threshold requirements. All of the critical laser, receiver, detector, and control technologies will be tested in the demonstration HDWL mission. Space demonstration of a prototype HDWL in LEO to take place as early as 2016.
– Stage II: Launch of a HDWL system that would meet fully-operational threshold tropospheric wind measurement requirements. It is expected that a fully operational HDWL system could be launched as early as 2022.”
GWOS
NWOS
2007 NAS Decadal SurveyRecommendations for Tropospheric
Winds
GWOS(2016)
Demo 3-D global wind
measurements
Operational 3-D global wind
measurements
NexGenNWOS(2026)
DWL Airborne Campaigns, ADM Simulations, etc.
TODWL(2002 - 2008)
TODWL: Twin Otter Doppler Wind Lidar [CIRPAS NPS/NPOESS IPO]ESA ADM: European Space Agency-Advanced Dynamics Mission (Aeolus) [ESA]GWOS: Global Winds Observing System [NASA/NOAA/DoD]NexGen: NPOESS [2nd] Generation System [PEO/NPOESS]
ADM Aeolus (2010)
Single LOS global wind
measurements
9
GWOS/NWOS Comparisons with ADM Attribute ADM GWOS NWOS
Orbit Altitude 400 400 824
Orbit Inclination 98 98 98
Day/Night Night only Day/Night Day/Night
Components per profile
Single –Model estimated second component
Two components - full horizontal vector
Two components - full horizontal vector
Horizontal Resolution
200 kmbetween single LOS’s
300 kmwith full profile both sides of ground track
300 kmwith full profile both sides of ground track
Vertical Resolution PBL 0.25 – 0.5 kmTroposphere 1 km
PBL 0.25 - 0.5km Tropo 2 – 3 km
PBL 0.25 - 0.5 Tropo 2 – 3 km
Collector Diam. 1.5 m (1x) 0.5 m (4x) 0.7 m (4x)
Instrument Design Laboratory [IDL] Studyfor a
NexGen NPOESS Wind Observing Sounder (NWOS):An Operational follow-on to the
Global Wind Observing Sounder (GWOS)Advanced Mission Concept
Sponsored by
Mr. Dan Stockton, Program Executive OfficerProgram Executive Office for Environmental Satellites
NASA Goddard Space Flight Center—Integrated Design Center11
Integrated Design Laboratory—Capabilities and Services
Capabilities:– Instrument families ranging from telescopes, cameras, geo–chemistry, lidars,
spectrometers, coronographs, etc.– Instrument spectrum support from microwave through gamma ray– LEO, GEO, libration, retrograde, drift away, lunar, deep space, balloon, sounding
rockets and UAV instrument design environments– Non-distributed and/or distributed instrument systems
Services:– End-to-end instrument architecture
concept development– Existing instrument/concept architecture
evaluations – Trade studies and evaluation – Technology, risk, and independent
technical assessments– Requirement refinement and verification– Mass/power budget allocation – Cost estimation
12
GWOS IDL Instrument
GWOS Payload Data
Telescope Modules (4)
GPS
Nadir
Star Tracker
Dimensions 1.5m x 2m x 1.8m
Mass 567 Kg
Power 1,500 W
Data Rate 4 Mbps
GWOS in Delta 2320-10 Fairing
Dimensions (mm)
• Orbit: 400 km, circ, sun-sync, 6am – 6pm• Selectively Redundant Design• +/- 16 arcsec pointing knowledge (post-processed)• X-band data downlink (150 Mbps); S-band TT&C• Total Daily Data Volume 517 Gbits
The coherent subsystem provides very accurate (<1.5m/s) observations when sufficient aerosols (and clouds) exist.
The direct detection (molecular) subsystem provides observations meeting the threshold requirements above 2km, clouds permitting.
When both sample the same volume, the most accurate observation is chosen for assimilation.
The combination of direct and coherent detection yields higher data utility than either system alone.
Hybrid DWL Technology Solution
13
Hybrid DWLTechnology Maturity
Roadmap
GWOS
2 micron laser 1988
Autonomous Aircraft Oper
WB-57
Aircraft Operation DC-8
Compact Packaging
2005
Space Qualified
Pre-Launch Validation
Packaged Lidar Ground Demo. 2007
Conductive Cooling
Techn. 1999
Operational NexGen NPOESS
Autonomous Oper. Technol.2008 (Direct)
Space Qualif.
Pre-Launch Validation
2-Micron Coherent Doppler Lidar
Laser Risk Reduction Program
IIP-2004 Projects
Past Funding
Diode Pump Technology
1993
Inj. Seeding Technology
1996
Autonomous Oper. Technol. Coh.
1 micron laser
Compact Laser
Packaging 2007
Compact Molecular
Doppler Receiver 2007
Conductive Cooling Techn.
Diode Pump Technology
Inj. Seeding Technology
High Energy Technology
1997
High Energy Laser
Technology
Lifetime Validation
Lifetime Validation
0.355-Micron Direct Doppler Lidar
TRL 6 to TRL 7
2014 - 2016
2026
TRL 7 to TRL 9
2011 - 20132008 - 2012
TRL 5
ROSES-2007 Projects
NWOS IDL Study User Team
15
Key Findings
The NWOS IDL designs which follow have shown that the Hybrid Doppler Wind Lidar can be operated at a reasonable electrical power and with reasonable reliability for the 5-year mission on board the NPOESS second generation satellite, NexGen.
There are no tall poles in any of the technical developments needed in the future to develop an NWOS.
Because the proof-of-concept GWOS flight is in advance of the NWOS, there should be good opportunity to verify the assumed requirements.
NWOS IDL Study Summary Study Objectives
Study the feasibility of modifying the original IDL design for GWOS at 400 km altitude to work at an 824km altitude on an NPOESS platform
Consider 3 instrument configurations in a trade space that trades telescope aperture, laser duty cycle, pulse power/repetition rate
Examine impact of new technologies, estimate improvements in laser performance, identify technology tall poles.
Minimize power, volume, and mass, as much as possible (in that order)
Consider redundancy for a multi-year lifetime
Key Study Assumptions
824 km, sun-synchronous, dawn-dusk, 1730 ascending node local time, 98.7 deg. Inclination orbit.
5 yr life, 85% reliability goal
2/1 backup lasers direct/coherent
1/0 backup laser electronics direct/coherent
1 backup receiver for each (direct & coherent)
Both coherent and direct lidars either 100% duty cycle (Configurations 1 & 3) or
50% duty cycle (Configuration 2)
Used 10-year beyond 2008 projections for laser efficiencies:x 2 (direct), x 2.25 (coherent)
Either 4 fixed telescopes (Configurations 1 & 2) or 1 holographic element
(Configuration 3)
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
Aerosol ()
DOP
Preliminary Instrument Design ResultsNexGen Hybrid Doppler Wind Lidar -
NWOSNPOESS Wind Observing System For Vertical Wind
ProfilesDesign Study Objectives
• Study the feasibility of modifying the original ISAL design for GWOS at 400 km to work at an 824km altitude on an NPOESS platform
• Consider 3 instrument configurations in a trade space that tweaks telescope aperture, direct laser duty cycle, and direct laser pulse power/rep rate
– Create multiple mechanical, thermal, and optical models
– Each discipline engineer consider the impacts of all 3 configurations to their subsystems
• Minimize power, volume, and mass, as much as possible (in that order)
• Consider redundancy for a 5 year lifetime
DOPPLER RECEIVER:Multiple Choices
drive science/technology trades• Coherent ‘heterodyne’ (e.g. SPARCLE-NASA/LaRC) • Direct detection “Double Edge” (e.g. Zephyr-NASA/GSFC)• Direct detection “Fringe Imaging” (e.g. Michigan Aerospace)
Molecular ()
Backscattered Spectrum
Frequency
Lidar BackscatterFrom Aerosols & Molecules
NWOS Wind Measurement Concept
Requirements
• Spacecraft accommodations for NWOS: (IDL Study Starting Assumptions)
– Mass - 650 kg – Power - 1000 W – Dimensions in cm (X, Y, Z) - (170,
170, 170)– Data Rates - 10 Mbps – On-orbit life - 5 years– NWOS Location – Nadir deck
• Orbital Altitude: 824km
• Ascending Node: 1730 local (Sun-synchronous dawn-dusk orbit)
• Orbital inclination: ~98.7o
• Orbital period: ~101minutes, 14 orbits/day
These requirements held for all configurations under
consideration.
NPOESS NexGen
Preliminary Instrument Design ResultsNexGen Hybrid Doppler Wind Lidar -
NWOSNPOESS Wind Observing System For Vertical Wind
ProfilesI 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
Configuration 1 and 2(Inverted GWOS)
Configuration 3(ShADOE)
NWOS HDWL Instrument Configurations
NPOESS LAN 1730 S/C Sensor Configuration
= Space Considered for NWOS
4.5 m
5.7 m
3.75 m dia.
Launch Concept for the Atlas 5 - 4 m Diameter Fairing
NPOESS 1730 LAN Spacecraft
Configuration #1
Configuration #2 Configuration #3
Optical Design
Shared, Inverted GWOS,4
azimuths 100 % Duty Cycle
Shared, Inverted
GWOS,4azimuths 50 % Duty
Cycle
Common Aperture,ShADOE,4 azimuths
100 % Duty Cycle
Mass [kg] 595 595 661
Telescope Module Dimensions(ht x dia)
100x160cm 100x160cm 127x160
Structural Assem.
Dimensions72.5 x 170 x 170cm
Telescope Primary Diameter
0.7m (0.5m
Coherent)
0.7m (0.5m Coherent)
1.24m (0.72m
Coherent)
Orbital Avg Power [W] 1382 898 1382
Peak Power [W]
1382
1382
1382Standby Power [W] 719
Warmup Power [W] 861
NWOS HDWL Instrument Trade Summary
No contingency added (+30%)
Configuration #1
Configuration #2
Configuration #3
Direct Laser - Number of Sources - Rep. Rate - Pulse energy - FOV - Detector
355nm3100 Hz 0.9 – 1J @1064nm<100uradEMCCD array
355nm2100 Hz 0.9 – 1J @1064nm<100uradEMCCD array
355nm3100 Hz 0.9 – 1J @1064nm<100uradEMCCD array
Coherent Laser - Number of Sources - Rep Rate - Pulse energy - FOV - Detector
2microns25 Hz1.2 JDiffraction LimitedInGaAs photodiode
2microns25 Hz1.2 JDiffraction LimitedInGaAs photodiode
2microns25 Hz1.2 JDiffraction LimitedInGaAs photodiode
On-board Computational Requirements
RAD6000 Processor @ 3.9Mbs
Vibrational Modes Gen.
Fidelity of structural model not high enough to predict
Unique S/Interface IEEE 1394A
Preliminary Instrument Design ResultsNexGen Hybrid Doppler Wind Lidar -
NWOSNPOESS Wind Observing System For Vertical Wind
Profiles
NWOS HDWL Instrument Parameters
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
4.5 m
5.7 m
3.75 m dia.
Launch Concept for the Atlas 5 - 4 m Diameter Fairing
NPOESS 1730 LAN Spacecraft
Configuration 1 and 2(Inverted GWOS)
Configuration 3(ShADOE)
NWOS HDWL Instrument Configurations
Configuration #1
Configuration #2 Configuration #3
Optical Design
Shared, Inverted GWOS,4
azimuths 100 % Duty Cycle
Shared, Inverted
GWOS,4azimuths 50 % Duty
Cycle
Common Aperture,ShADOE,4 azimuths
100 % Duty Cycle
Mass [kg] 595 595 661
Telescope Module Dimensions(ht x dia)
100x160cm 100x160cm 127x160
Structural Assem.
Dimensions72.5 x 170 x 170cm
Telescope Primary Diameter
0.7m (0.5m
Coherent)
0.7m (0.5m Coherent)
1.24m (0.72m
Coherent)
Orbital Avg Power [W] 1382 898 1382
Peak Power [W]
1382
1382
1382Standby Power [W] 719
Warmup Power [W] 861
NWOS HDWL Instrument Trade Summary
No contingency added (+30%)
19
The NWOS IDL design study has shown that the Hybrid Doppler Wind Lidar can be operated at a reasonable electrical power and with reasonable reliability for the 5-year mission on board the NPOESS second generation satellite.
There are no tall poles that depend on unforeseen technical developments in the future.
Because the proof-of-concept GWOS flight is in advance of the NWOS, there should be good opportunity to verify the assumed requirements.
NWOS IDL Study Conclusions
Return
2020
NPOESS evaluation of ADM data
Participate on ESA’s ADM Aeolus Team [Launch 2009] to help establish good data/products and to enable
Aeolus data gathering/usage for NWOS studies
Perform study investigating the utility / impact of NWOS data for NexGen using Aeolus data as proxy data and the NWOS projected capabilities from the previous ADM potential impact studies
NWOS concept development
Estimate NWOS Instrument Cost - use NWOS detailed Parts List developed from IDL NWOS Study
Perform mission conceptual design study - NWOS Study User Team & GSFC MDL (Mission Design Laboratory)
Next Steps/Recommendations
21
Supporting Material
22
Observations Needed as a Function of Forecast Length
Return
23
Which Upper Air ObservationsDo We Need ?
Numerical weather prediction requires independent observations of the mass (temperature) and wind fields
The global three-dimensional mass field is well observed from space
No existing space-based observing system provides vertically resolved wind information => horizontal coverage of wind profiles is sparse
24
Current Mass & Wind Data Coverage
Upper AirMass Observations
Upper AirWind Observations
25
Mean (29 cases) 96 h 500 hPa height forecast error difference (Lidar Exper minus Control Exper) for 15 - 28 November 2003 with actual airborne DWL data. The green shading means a reduction in the error with the Lidar data compared to the Control.
The forecast impact test was performed with the ECMWF global model.
DWL measurements reduced the 72-hour forecast error by ~3.5% This amount is ~10% of that realized at the oper. NWP centers worldwide in the past 10 years from all the improvements in modelling, observing systems, and computing power Total information content of the lidar winds was 3 times higher than for dropsondes
Forecast ImpactUsing Actual Aircraft Lidar Winds
in ECMWF Global Model(Weissmann and Cardinali, 2007)
Green denotes positive impact
26
Airborne Doppler Wind LidarsIn T-PARC/TCS-08 Experiment
in Western North Pacific Ocean (2008) to investigate tropical cyclone formation, intensification, structure change and satellite validation
ONR-funded P3DWL (1.6 um coherent) PI is Emmitt (SWA)Will co-fly with NCAR’s ELDORA and dropsondes
Wind profiles with 50 m vertical and 1 km horizontal resolution
Multi-national funded 2 um DWL on DLR Falcon PI is Weissmann (DLR) Will fly with dropsondes
T-PARC: THORPEX Pacific Asian Regional CampaignTCS-08: Tropical Cyclone Study 2008
u,v,w,TAS, T,P,q
Lidar horizontalwind speed
W'
u,vDropsondesu, v ,P, T, q
Data will be used to investigate impact of improved wind data on numerical forecasts
27
Simulated Impactof Space-based Wind Lidar Observations
on a Hurricane Track Forecast (R. Atlas et al.)
Hurricanes TracksGreen: Actual track
Red: Forecast beginning 63 h before landfall with current data
Blue: Improved forecast for same time period with simulated DWL data
Note: A significant positive impact was obtained for both land falling hurricanes in the 1999 data; the average impact for 43 oceanic tropical cyclone verifications was also significantly positive
28
• Reduce preventable property damage ~ $212 M/year 2,3
• Reduce over-warnings ~ $74 M/year 2,3
• 17% less landfall warning error for average of 2 storms/year 1
• Typically warn ~ 350 miles of coast, over-warn 220 miles • Estimate 17% reduction in over-warning with lidar winds, 37 miles• @ $1M / mile precautionary costs saves $37M/storm, $74M/year
Lidar WindsWill Improve Hurricane Forecasts
41 Storm climatology and simulations
for global 3D winds in NWP2 Cordes, J. J., “Economic Benefits
and Costs of Developing and Deploying A Space-Based Wind Lidar,” GWU, NOAA Contract 43AANW400233, March 1995
3 K. Miller, “Societal Benefits of Lidar Winds”, Lidar Working Group,” February 8, 2007
4 www.ncdc.noaa.gov/billionz.html
29
Summary of Benefits Estimates($M/year)*a
* K. Miller, “Societal Benefits of Winds Mission,” Lidar Working Group Meeting, February 8, 2007, Miami FL, http://space.hsv.usra.edu/LWG/Index.html
2006 EstHurricane Overwarning 74Preventable Hurricane Damage 212Off Shore Drilling 39General Forecasting 137Airline Aviation Fuel 243Military Aviation Fuel 101Total 806
I n t e g r a t e d D e s i g n C e n t e r / 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
30
NWOS Study Objective
•Study the feasibility of modifying the original ISAL design for GWOS at 400km to work at an 824km altitude on an NPOESS platform•Consider 3 instrument configurations in a trade space that tweaks telescope aperture, direct laser duty cycle, and direct laser pulse power/rep rate– Create multiple mechanical, thermal, and optical models
– Each discipline engineer consider the impacts of all 3 configurations to their subsystems
•Minimize power, volume, and mass, as much as possible (in that order)•Consider redundancy for a 5 year lifetimeReturn
I n t e g r a t e d D e s i g n C e n t e r / 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
Doppler Lidar Measurement Concept
DOPPLER RECEIVER - Multiple flavors - Choice drives science/technology trades• Coherent ‘heterodyne’ (e.g. SPARCLE/LaRC) • Direct detection “Double Edge” (e.g. Zephyr/GSFC)• Direct detection “Fringe Imaging” (e.g. Michigan Aerospace)
Molecular ()
Aerosol ()
Backscattered Spectrum
Frequency
DOP
Return
Goddard Space Flight Center 32
NWOS Hybrid Doppler Wind Lidar Measurement Geometry: 824 km
7.4 km/s
824 km1253 km
889 km
626 km
626 km
45
53
45180 ns (27 m) FWHM (76%)
8 m (86%)
1/5 s = 1319 m1/200 s = 33 m
Return light: t+6.6 ms, 62 m, 8.7 microrad
First Aft Shott + 190 s
60/2400 shots = 12 s = 78 km
90° fore/aft anglein horiz. plane
FOREAFT
Second shot: t+200 ms, 5 ms1489 m, 207 microrad37 m, 5.3 microrad
2 lines LOS wind profiles1 line “horiz” wind profiles
45 deg azimuth Doppler shiftfrom S/C velocity ±3.6 GHz ±21 GHz
Max nadir angle tostrike earth62.3 deg
Return
I n t e g r a t e d D e s i g n C e n t e r / 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
33
NWOS Requirements–Spacecraft and Orbit
• Spacecraft accommodations for NWOS: (starting assumptions)– Mass - 650 kg – Power - 1000 W – Dimensions in cm (X, Y, Z) - (170,
170, 170) cm – Data Rates - 10 Mbps – On-orbit life - 5 years– NWOS Location – Nadir deck– Reliability Goal – 85%
• Orbital Altitude: 824km• Ascending Node: 1730 local
(Sun-synchronous dawn-dusk orbit)
• Orbital inclination: ~98.7o
• Orbital period: ~101minutes, 14 orbits/day
These requirements hold for all configurations under
consideration.
Courtesy D. Evans
From GWOS Systems
Return
I n t e g r a t e d D e s i g n C e n t e r / 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
34
NWOS System Configurations(Courtesy M.Clark and D.Palace)
Configuration 1 and 2(Inverted GWOS)
Configuration 3(ShADOE)
Return
I n t e g r a t e d D e s i g n C e n t e r / 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
35
NPOESS LAN 1730 S/C Sensor Configuration
= Space Considered for NWOSReturn
I n t e g r a t e d D e s i g n C e n t e r / 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
36
3.75 m dia.
4.5 m
5.7 m
Launch Concept for the Atlas 5 - 4 m Diameter Fairing
NPOESS 1730 LAN Spacecraft
Return
I n t e g r a t e d D e s i g n C e n t e r / 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
37
NWOS System Description (1 of 2)
Configuration #1 Configuration #2 Configuration #3
Optical DesignShared, Inverted GWOS,4 azimuths100 % Duty Cycle
Shared, Inverted GWOS,4 azimuths100 % Duty Cycle
Common aperture, ShADOE, 4 azimuths100 % Duty Cycle
Mass [kg] 595 595 661
Telescope Module Dimensions
(height x diameter)100x160cm 100x160cm 127x160
Structural Assembly Dimensions 72.5 x 170 x 170cm
Telescope Primary Diameter
0.7m
(0.5m Coherent)
0.7m
(0.5m Coherent)
1.24m
(0.72m Coherent)
Orbital Average Power [W] 1382 898 1382
Peak Power [W]
1382
1382
1382Standby Power [W] 719
Warmup Power [W] 861
* No contingency added (+30%)
Return
I n t e g r a t e d D e s i g n C e n t e r / 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
38
NWOS System Description (2 of 2)
Configuration #1
Configuration #2 Configuration #3
Direct Laser
- Number of Sources
- Rep. Rate
- Pulse energy
- FOV
- Detector
355nm
3
100 Hz
0.9 – 1J @1064nm
<100urad
EMCCD array
355nm
3
100 Hz
0.9 – 1J @1064nm
<100urad
EMCCD array
355nm
3
100 Hz
0.9 – 1J @1064nm
<100urad
EMCCD array
Coherent Laser
- Number of Sources
- Rep Rate
- Pulse energy
- FOV
- Detector
2microns
2
5 Hz
1.2 J
Diffraction Limited
InGaAs photodiode
2microns
2
5 Hz
1.2 J
Diffraction Limited
InGaAs photodiode
2microns
2
5 Hz
1.2 J
Diffraction Limited
InGaAs photodiode
On-board Computational Requirements RAD6000 Processor @ 3.9Mbs
Vibrational Modes Generated
Fidelity of structural model not high enough to predict
Unique Spacecraft Interface IEEE 1394A
Return