Minutes
Monterey, California
5 - 8 February 2008
Tuesday, February 5
Wayman Baker opened the 29th meeting of the Working Group on Space-Based Lidar Winds (LWG) with introductory remarks. Since 1994, the LWG has met twice yearly to bring together Doppler Wind Lidar (DWL) technologists and potential users from government, industry, academia, and international organizations to exchange information, review the latest technology developments, and build a consensus for space missions to measure the global wind field from space.
Progress continues in laser and optics technologies, instrument architectures, mission concepts, field demonstrations, and applications of wind data to numerical weather forecasting. Interagency support continues to build for airborne and space demonstrations of a hybrid DWL. The National Academy of Sciences (NAS) decadal survey report, recent NASA Earth-Sun System Technology Office (ESTO) study report, the U.S. Integrated Earth Observing System Strategic Plan, and the National Polar-orbiting Observing Environmental Satellite System (NPOESS) Integrated Program Office (IPO) assign high priority to global observations of winds at all levels. The U. S. Air Force, Navy, Army, and Federal Aviation Administration have interest in improved wind data and weather forecasts in support of their respective missions. The European Space Agency (ESA) is scheduled to launch a demonstration DWL satellite (Atmospheric Dynamics Mission--ADM) in late 2009. A US space demonstration of a hybrid bi-perspective DWL is anticipated, but not likely before 2016.
Technology readiness continues to advance. A NASA team in the Goddard Space Flight Center Instrument Design Laboratory (IDL) was scheduled for late February 2008 to develop a DWL reference design for the next generation NPOESS. (Note: The IDL did occur the week of February 25.)
Wayman reviewed the Action Items from previous meetings (see Action Items posted on the LWG website http://space.hsv.usra.edu/LWG/Index.html.
Steve Mango presented an “Integrated Program Office Perspective,” coauthored with Stan Schneider. Steve discussed the NPOESS Preparatory Project (NPP), a bridge from Earth Observing System (EOS) to NPOESS. NPP anticipates a 2010 launch. He described the restructured NPOESS program, satellites, instruments and planned launch dates from C1 in 2013 through C4 in 2022. Societal benefits areas for Global Earth Observation System of Systems (GEOSS) were shown, with wind affecting Disasters, Forecasts, Water, Climate, and Oceans areas. He discussed the global winds input to The Earth Science and Applications Decadal Survey 2007 and the survey mission recommendations for NOAA. A notional schedule showed DWL demonstration development through 2015, a Global Wind Observation Sounder (GWOS) demonstration mission circa 2016, an operational demonstration mission in 2022, and an operational mission on NexGen NPOESS beginning in 2026.
The Office for Science and Technology Planning (February 1, 2008) announced plans for enhancing Earth observation capabilities, supporting a climate sensor package, and precluding data gaps. NexGen NPOESS is under consideration by the Program Executive Office (PEO) for Environmental Monitoring through its Advanced Technology and Plans (ATP) program. Conceptual and exploratory studies include Study 1: NexGen Instrument/Mission Study and Study 2: NexGen Wind Profiles using ADM. Study 1 includes an investigation of requirements for HDWL accommodation on NPOESS NexGen, using the NASA GSFC Instrument Design Laboratory (IDL). A demonstration instrument conceptual (GWOS) for a 400 km orbit was designed in September 2006. In February 2008, IDL will extend the GWOS design to meet the same requirements, but operate at the NPOESS 824 km orbit and in an NPOESS packaging configuration. For Study 2, the ESA Atmospheric Dynamics Mission (ADM), scheduled for a late 2009 launch, is an opportunity to gain knowledge of space-based lidar wind observations, exploring benefits and assessing the instrument. In FY 11/12, NPOESS will review GWOS and NexGen operational global wind data requirements and issue refined specifications based on ADM experience.
Oliver Reitebuch presented: “The Wind Lidar Mission ADM-Aeolus: Recent Science Activities and Status of the Instrument Development,” coauthored with M. Endemann, P. Ingmann, H. Nett. Oliver reviewed the ADM-Aeolus mission and measurements. The single instrument on this mission is the Atmospheric Laser Doppler Instrument (ALADIN), which measures global line of sight (LOS) wind profiles. ADM will provide 3200 profiles per day, about three times the number of profiles produced by worldwide rawinsondes. Data will be available 3 h after observation. Launch date is late 2009 for a 39 month mission. Some specifications:
Oliver compared range-corrected power-aperture products of space lidars, showing that ALADIN’s product was much greater than Geoscience Laser Altimeter System (GLAS), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and the future ESA Atmospheric Lidar (ATLID) and comparable to Lidar In-space Technology Experiment (LITE). Due to the interferometer, however, total optical throughput is a fraction of the power-aperture product. The ground segment, data products, and ongoing science studies were discussed. An Announcement of Opportunity was issued by ESA in October 2007 for ADM-Aeolus calibration and validation. 15 proposals are being evaluated, with notification of principal investigators by the end of March 2008. ESA will organize a user workshop in late 2008. The ALADIN instrument was described, with photographs of the instrument and satellite bus under development. The power laser head dimensions were 480 x 350 x 180 mm and 27 kg. Total laser mass including electronics is 51.5 kg. Components and development status were discussed. The satellite bus integration is complete, the optical receiver integrated. The laser transmitter is in thermal-vacuum testing. All laser diodes are manufactured. Current problems include transmit / receive optics and laser operation in a vacuum. ESA plans a call for science use of ADM-Aeolus data in late 2008. ADM operational follow-on missions are under consideration with the objective of achieving denser coverage and/or sensing two wind components by two satellites. There will be a gap between the end of Aeolus (around 2013) and follow-on (after 2018).
Via conference call, Ramesh Kakar presented “NASA Headquarters Perspective.” Ramesh presented the Science Mission Directorate (SMD) overview by teleconference. NASA funded six proposals from the Research Opportunities in Space and Earth Sciences (ROSES) 2007 Wind Lidar Science Announcement, with one more in the selectable range. Funding will be more than $3M over three years. Principal Investigators include Bruce Gentry, Michael Hardesty, Upendra Singh, Matthew McGill, Zhaoxia Pu, and Dave Emmitt. NASA plans a hurricane genesis field experiment during the 2010 hurricane season and expects a hybrid wind lidar to be the primary instrument. SMD Associate Administrator Dr. Alan Stern responded to a recent letter from Director of Weather, USAF. The USAF letter endorsed a DWL space demonstration.
Oliver Reitebuch presented “Results from the ADM-Aeolus Pre-Launch Ground and Airborne Campaigns in 2007 with the ALADIN Airborne Demonstrator (A2D),” coauthored with M. Endemann, C. Lemmerz, U. Paffrath, B. Witschas, V. Freudenthaler, V. Lehmann, D. Engelbart. Ground campaign objectives were to validate the ALADIN instrument and develop retrieval algorithms for test, verification and calibration. The work addressed radiometric and wind measurement performance, calibration procedures, quality control, ground detection, and zero-wind calibration. The ALADIN Airborne Demonstrator 355 nm DWL, the DLR 2-micron DWL, and other instruments were used at the Lindenberg ground site. Observations were also made from a nearby optical laboratory and by rawinsondes. Statistical comparisons among instruments were discussed. A2D component photographs, optical models, and laser performance were discussed. A2D laser test flights, performance, vertical sampling schemes, and observations of cirrus clouds in April 2007 were described. Major modifications were made after the October 2005 first flights, including new laser diodes for power amplifiers, a mechanical bridge between resonator mirrors, and a new cavity control technique. Radiometric performance, filter transmission, and response calibration were discussed. Nearly 300 hours of A2D observations were collected during different atmospheric conditions. Methodologies of intercomparison and deriving winds from Rayleigh spectrometer observations were validated. The Rayleigh radiometric performance model was established and validated with comparisons between simulations and measurements. A2D direct detection DWL and 2 micron coherent detection DWL were flown together on the DLR Falcon in a November 2007 airborne campaign. It is challenging to maintain laser frequency stability with aircraft vibration. More airborne campaigns with both lidars are planned in 2008 and 2009. DLR will support ADM Cal/Val with ground-based and airborne lidars.
Portions of Mike Hardesty’s presentation “Summary of the ADM Cal/Val Proposal" was presented by Sara Tucker. The proposal was submitted to ESA by Mike Hardesty and Lars Peter Riishojgaard in December 2007, and included offerings by a number of investigators. If accepted, this activity will permit U.S. investigators access to ADM data. There was a discussion of the possibility of NASA ROSES support for ADM Cal/Val and of how to propose for Unmanned Aerial Vehicle (UAV) support.
Dave Emmitt presented “Simulating GWOS, ADM, and NWOS: Coverage and Accuracy Trades,” coauthored with S. Wood. The Simpson Weather Associates Doppler Lidar Simulation Model (DLSM) is used to perform global hybrid DWL simulations. Hybrid DWL Observing System Simulation Experiments (OSSEs) are planned at the National Centers for Environmental Prediction (NCEP) using the new European Centre for Medium-range Weather Forecasts (ECMWF) T513 and T799 nature runs. Hybrid DWL OSSEs are underway now using the T213 nature run at the GSFC Software Integration and Visualization Office (SIVO). Requirements were presented for the GWOS space demonstration and the NexGen NPOESS Wind Observing Sounder (NWOS) DWLs. Instrument parameters were shown for GWOS, NWOS, and ADM. NWOS instrument parameters are not completely defined. ADM, GWOS, and NWOS coverage and performance simulation results were shown. Performance and resolution improved from ADM to GWOS to NWOS. DLSM aerosol backscatter profiles and natural variability of 2 micron backscatter were discussed. NASA ROSES07 funding is anticipated for ADM follow-on OSSEs.
Robert Atlas presented “NOAA’s New Hurricane Forecast Improvement Project (HFIP).” Hurricanes are a major national environmental threat and there is increasing vulnerability along the coasts. NOAA reduced hurricane track errors by about 50% over the last 20 years, but needs to reduce intensity forecast error. NOAA established the HFIP to lead an effort to improve this ability. HFIP has a ten year project plan. Bob identified members of the Executive Oversight Board and HFIP Team. Frank Marks is the Project Lead. Bob discussed the significance of Rapid Intensity Change (over 30 kt in 24 h) in preparation and evacuation. Efforts to improve forecasts of rapid intensity change will improve hurricane forecasts. HFIP performance metrics and goals were defined. Items in the HFIP portfolio include:
Activities in these areas were described.
Tim Miller presented “On the Improvement to H*Wind Hurricane Wind Analyses Due to the Inclusion of Future Ocean Surface Wind Measurements from Aircraft and Satellite,” coauthored with R. Atlas, P. Black, S. Chen, R. Hood, J. Johnson, L. Jones, C. Ruf, and E. Uhlhorn. Tim described the Hurricane Imaging Radiometer (HIRAD), which uses NASA Instrument Incubator Program (IIP) technology to observe sea surface wind, temperature, and rain. HIRAD helps predict hurricane intensity using synthetic thinned array technology and sensor web techniques. Airborne measurement of ocean wind speed up to 100 m/s through rain up to 10 mm/hour is expected by the end of 2008, and ocean vector wind speed with dual polarization in 2011. HIRAD uses a passive microwave C-Band radiometer with frequencies 4, 5, 6, and 7 GHz. Performance characteristics were discussed for an airborne instrument. The primary application is tropical cyclones. It does not measure low-speed winds. A HIRAD ocean surface wind OSSE using Hurricane Frances (2004) as a case study demonstrates positive impact.
Dave Emmitt presented “Twin Otter DWL (TODWL) Flights in Support of Model Validation / Initialization,” coauthored with S. Greco. The TODWL instrument is a 2 micron coherent detection Doppler Wind Lidar (CTI MAG 1A) with graphical user interface and realtime instrument control and data display. The instrument weighs 700 lb and uses 700 W. Model validation activities in complex terrain and coastal areas were described. Flights near Monterey CA in February 2003 included under-flight of the NPOESS Airborne Sounder Testbed (NAST) in the NASA ER-2, investigated aerosol/wind correlated structures, validated Naval Postgraduate School (NPS) MM5 model winds over complex terrain and coastline, and developed sampling strategies for The Hemispheric Observing system Research and Predictability Experiment (THORPEX) adaptive targeting and C-BLAST investigations. MM5 investigations and flights were described. TODWL flights in November 2007 addressed nocturnal atmospheric advantages for autonomous UAV flight control, nocturnal flights as part of Army SBIR project Airborne Doppler Lidar Analysis and Adaptive Targeting System (ADLAATS), preliminary test flights of the Navy-funded Integrated Lidar Mission Management System (I-LiMMS), and rawinsonde and microwave sounder comparisons for NASA/Dryden. Flight patterns, wind data, and comparisons were shown. The 2007 data sets are being prepared for distribution.
Rolf Langland presented “Plans for Evaluation of Lidar Wind Data at NRL-Monterey.” Rolf described THORPEX-Pacific Asian Regional Campaign (T-PARC) plans including the DLR Falcon and Navy P-3 aircraft, data assimilation issues, and potential benefits. The intended airport base will be in Atsugi, Japan. Flight time is 90 h plus 30 h for transfer of the aircraft, to take place over seven to eight weeks. Time in Japan will be August 24-25 to October 4, 2008. Instruments will be lidars and dropsondes. Wind lidar data resolution (for the 2 micron system on the DLR falcon) is 10 km horizontal and 100 m vertical. 5400 wind profiles are planned in Japan and 1800 on transfer through Siberia. Research interests include observation targeting, extratropical transition of tropical cyclones, downstream impact, value of lidar observations, and tropical moisture export. NRL will provide targeting guidance, adjoint-based observation impact evaluation, and conventional observation addition and denial forecast experiments. Rolf described Navy Operational Global Atmospheric Prediction System (NOGAPS) singular vector targeting guidance and an example of adjoint-based observation impact. DWL data assimilation issues included procedures for super-observing or thinning of raw data, quality control, and specification of observation and representativeness error. Potential benefits of space-based lidar observations include filling gaps in the current observing network, observing in regions of forecast error sources, increasing wind accuracy, and increasing data quantity and frequency. Maps showed current GEOSAT wind coverage, error source regions, and observations and impacts in the North Pacific Region.
Ron Gelaro presented “Examination of Observation Impacts Derived from Observing System Experiments (OSEs) and Adjoint Models,” coauthored with Yanqiu Zhu. Ron pointed out the large and growing volumes of observing systems data, suggesting the need for new approaches to ingest, process, monitor, quality control, assimilate and archive. OSEs are the traditional method of assessing impact of observations on forecast skill. This is done by removing observation subsets and comparing forecasts against a control system that includes all observations. He asks the question “what if one wants to investigate…impact of all individual channels on a given satellite…?” The adjoint (ADJ) method addresses this question. The talk addressed observation impact on NASA’s GEOS-5 Data Assimilation System. It compared ADJ and OSE results, and combined ADJ and OSE approaches. In the ADJ approach, impacts of observation subsets can be quantified relatively simply. In GEOS-5 experiments, impacts of different observation sets were shown. Localized Atmospheric Infrared Sounder (AIRS) impacts were assessed for all channels and impact by channel. All AIRS channels together had positive impact overall, but degraded forecasts in some areas. Removal of AIRS water vapor channels improved forecast scores. ADJ results were compared with OSE results and comparison points were reviewed. ADJ supports:
ADJ methods
Ted Shepherd presented “The Scientific Value of Stratospheric Wind Measurements.” The stratosphere is an important part of the climate system. Tropical stratospheric winds affect stratosphere-troposphere coupling and the interplay of ozone recovery and climate change. Improved data assimilation techniques provide estimates of tropical stratospheric winds, but require validation by direct wind measurement. Direct measurements are also needed to study long-term variability. Dynamically variable ozone fluctuations complicate ozone recovery detection, and transport’s contribution to observed changes in total ozone is not known. Ted showed a schematic of transport in the lower stratosphere and measurements of aerosol after the Mt. Pinatubo eruption. He showed differing winds results and NOy/O3 ratios in the upper troposphere and lower stratosphere from data assimilation systems and general circulation model. The quality of analyzed winds (vs. direct wind measurements) in the tropical stratosphere is poor, so that direct wind measurements from space are needed there. Models of ozone recovery, tropical upwelling estimates, and Quasi-Biennial Oscillation (QBO) in tropical zonal winds require transport confirmation by direct wind measurement.
Sara Tucker presented “Boundary Layer Mixing Heights and 2 Micron Backscatter Distributions Measured During TexAQS 2006,” coauthored with R. Banta, A. Brewer, M. Hardesty, D. Law, S. Sandberg, A. Weickmann, C. Senff. Texas Air Quality Study is a research initiative to better understand the sources of air pollution and meteorological conditions leading to ozone violation events. This work was based on measurements taken from the NOAA ship RV Brown along the Gulf Coast of Texas using the NOAA High Resolution Doppler Lidar (HRDL). Sara has presented earlier HRDL TexAQS findings in past meetings. New work includes mixing height estimation, analysis of lower level jets and ozone levels, and statistics on aerosol backscatter profiles. Mixing height findings are being used for mixing ratios and Weather Research and Forecasting (WRF) model validation. Topics included vertical velocity variance plots, mixing profiles, mixing heights, HRDL vs. Sonde mixing heights, and WRF model validation plots. Mixing height estimates had high variability over land and didn’t necessarily match gradients in the aerosol profiles, especially at night. There was less variability over the Gulf. Future work will include further study of backscatter inversion, Mie scattering model, comparison with in-situ-based backscatter, turbulence kinetic energy profiles, carrier-to-noise (CNR) ratio models, and quantification of effects on space-based lidar CNR and wind estimates.
Doug Westphal presented “Aerosol Research and Operational Aerosol Data Assimilation and Forecasting for DoD,” coauthored with A. Bucholtz, C. Curtis, E. Hyer, M. Liu, A. Walker, and J. Reid. The presentation addressed an NRL modeling approach and programs, applications, measurements, and validation. Aerosol forecasts impact a variety of tactical and strategic planning, target acquisition, port navigation, carrier landings, and ship defense activities. Examples were shown of dust in Iran and China, and smoke in Korea. The NRL aerosol forecasting approach applies physically based regional and global models. Events are predicted as weather phenomena with emphasis on sources, transport, and aerosols that impact visibility. Multiple models and forecast system components are used. A block diagram of the Navy Aerosol Analysis and Prediction System (NAAPS) was discussed. NAAPS is operational and updates four times per day. NRL field measurements using laboratories, land, air, and sea capabilities are used for model validation and study of aerosol optical properties. Capabilities include the Micro Pulse Lidar. A study of interaction between aerosol particles and cloud microphysics was described. Validation activities were discussed. Plans include studies of additional species, field deployments, operational aerosol data assimilation, and NAAPS imbedded in NOGAPS.
Dave Emmitt presented “Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation Satellite (CALIPSO) and LITE Data for Space-Based DWL Design and Data Utility Studies: Research Plans,” coauthored with D. Winker, Y. Hu, and D. Bowdle. The proposed CALIPSO/LITE ROSES07 study used LITE and CALIPSO data and address:
Dave presented Cloud-Free Line of Sight (CFLOS) statistics from Ice, Cloud, and land Elevation Satellite (ICESat) GLAS. Topics included minimum detectable backscatter profiles for LITE and CALIPSO, global maps of cloud frequency, night and day cloud cover, cloud top distributions, lidar simulation model aerosol backscatter profiles, and natural variability of 2 micron backscatter.
Dave Bowdle presented “Enhancements to the Ground-Based Wind Measurement Capabilities Near Huntsville, Alabama: Validation Tool for Airborne and Space-Based Doppler Wind Lidars,” coauthored with K. Knupp, M. Newchurch. The Advanced Radar for Meteorological and Operational Research (ARMOR) WSR 74C Doppler radar was upgraded in 2004 through 2006. The Mobile Alabama X-band (MAX) scanning, dual polarimetric, truck mounted Doppler radar is operational. Mobile Integrated Profiling System (MIPS) includes Doppler sodar profilers, a 915 MHz wind profiler, an X-band profiling radar, and a scanning 2 micron Doppler lidar. Dave described potential wind validation activities for airborne and satellite-based Doppler lidars.
Wednesday, February 6
Michael Kavaya presented “Coherent Doppler Lidar Roadmap to Both the NRC Decadal Survey Demonstration and Operational Missions,” coauthored with J. Yu, U. Singh, and M. Petros. The NRC Decadal Survey demonstration mission is called GWOS. The GWOS design includes a hybrid DWL in a 400 km polar orbit. The operational demonstration mission is called NPOESS Wind Observing System (NWOS). The NWOS conceptual design is a hybrid DWL on an NPOESS spacecraft, at an 824 km polar orbit. Michael presented the geometries for 400 km vs. 824 km orbits, with 45 degree nadir angles and spherical Earth assumptions. Plots showed relative range squared, line of sight to horizontal velocity error magnification, and light round trip time for the two orbital altitudes. The ratio of squares of slant ranges with all effects included was 4.68. This is a key factor in translating the existing GWOS conceptual design into an NPOESS conceptual design, which is to take place at the GSFC Instrument Design Lab (IDL – conference call with them on Thursday of this meeting) in late February. NASA/NOAA wind measurement requirements for the science demonstration and an operational demonstration were presented and discussed. A formula was provided connecting coherent detection lidar parameters to measurement performance. Michael discussed the coherent detection DWL point design for a hybrid instrument for the 400 km science demonstration, and alternative point designs for a 400 km operational mission and an 824 km operational mission. He then reviewed the demonstrated performance of the LaRC 2-micron DWL and compared it with the requirements of the alternative point designs.
Bruce Gentry presented “Status of the Tropospheric Wind Lidar Technology Experiment (TWiLiTE) Instrument Incubator Program,” coauthored with M. McGill, G. Schwemmer, M. Hardesty, A. Brewer, T. Wilkerson, R. Atlas, M. Sirota, S. Lindemann, F. Hovis. TWiLiTE is a three year project that will demonstrate downward looking wind profiles from higher altitudes using an airborne direct detection scanning DWL. The primary objective is to advance the readiness of key instrument technologies. TWiLiTE will fly on the NASA WB57 or ER2 about summer 2008, and could be adapted to a Unmanned Aerial Vehicle (UAV). The 2007 National Research Council Decadal Survey recommended a tropospheric winds mission. It is recommended that NASA address the high-risk components; perform aircraft demonstration and space demonstration with a hybrid DWL. The Panel recommended a prototype global space demonstration system meeting reduced requirements, followed by a fully operational system meeting threshold requirements by 2022. The technology roadmap and TRL status of key technologies were reviewed. The conical step stare scan pattern, candidate NASA airborne science platforms, measurement requirements, and predicted error were discussed. The laser, receiver, scanning holographic telescope, and etalon were described. WB57 integration will use a pallet that can be installed and removed from the aircraft.
Bruce Gentry presented “Laser Transmitter Development for Airborne Direct Detection Wind Lidar and High Spectral Resolution Lidar Missions,” coauthored with F. Hovis, J. Edelman, T. Schum, J. Rudd, K. Andes, A. Cook, C. Hostetler, J. Hair. This program is developing a single frequency 1064 nm 20 W laser transmitter for the NASA Instrument Incubator Program (IIP), meeting the needs of both TWiLiTE and High Spectral Resolution Lidar (HSRL)/Ozone Differential Absorption Lidar (DIAL). Laser transmitter specifications, heritage for key design features, and transmitter performance were reviewed. The two laser transmitter optical layouts were shown, followed by descriptions of key components, performance, software interface, and build status.
Tom Wilkerson presented “Ultraviolet Holographic Telescope for TWiLiTE," coauthored with J. Hancock, J. Swasey, A. Shelley, G. Schwemmer, C. Marx, S. Schicker, and G. Bowen. Tom reviewed the background, design concept, and the telescope itself, which was delivered to NASA GSFC in 2007. The telescope looks 45 degrees off nadir with a rotating Holographic Optical Element (HOE) for step-stare operation. It steps in 1 to 2 sec with motor and belt drive, and requires less than 1 sec alignment time. It can turn 90 degrees in 1 sec. It has automatic boresight alignment. The telescope design, solar background predictions, and test results were presented.
Dave Emmitt presented “Shear Statistics in Lower Troposphere and Impacts on DWL Data Interpretation,” coauthored with S. Greco. Properties and climatology of wind shear were discussed. NASA wind shear study results (NASA TM 82566) and experimental aviation wind shear maps were reviewed. Twin Otter DWL (TODWL) wind speed profiles were compared to microwave tower-measured profiles. The microwave profiles of wind speed and direction and significant deviations were present in both speed and direction. Wind speed and Signal to Noise Ratio (SNR) profiles and statistics were shown from several TODWL flight legs. Model shear statistics were discussed. Midwest wind shear climate summary and variations with time of day and season were shown. For space-based observations, shear is both a target and also a signal processing challenge, causing bias in estimating average wind over a layer. Lidars with less than 100 m pulse lengths provide excellent data bases for simulating space-based DWL shear observations.
Michael Kavaya presented “Proposal for 2008 Version of the Wind Measurement Requirements.” Michael proposed a set of requirements incorporating changes that have arisen over the years and suggested the new requirement set be called the “NASA/NOAA 2008 Requirements.” Previous wind measurement requirements included
A proposed table of 2008 requirements contained Science Demonstration and Operational categories. Performance charts (percent success rate and rms error vs. altitude) were shown for a Science Demonstration Mission (2016) and an Operational Mission (2022).
Carl Weimer presented “CALIPSO On-Orbit Update,” coauthored with M. Cisewski, Y. Hu, B. Hunt, C. Trepte, D. Winker, and F. Hovis. Carl described the CALIPSO satellite and payload instruments (Wide Field Camera, Infrared Imaging Radiometer, and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP)). The satellite and payload are performing well and level 2 science data is being released see http://www-calipso.larc.nasa.gov/products/). New data products and capabilities are being developed. CALIOP uses two wavelengths (532 and 1064 nm). It collects data from -2 km to 40 km altitude with a laser footprint of 70 m on the ground. Photographs of the satellite, payload, and components were shown. Lasers continue to perform well and completed 1 billion shots on orbit on February 3. One laser is operating with the second held in reserve. CALIPSO data is being used to estimate ocean windspeed in a new application. CALIPSO measures over a smaller footprint than radar (70 m vs. 20 km), but radar has superior all-weather performance. Charts showed good correlation between Advanced Microwave Scanning Radiometer-EOS (AMSR-E AQUA) winds and CALIPSO winds.
Chris Grund presented “Supporting NOAA and NASA High-Performance Space-Based DWL Measurement Objectives with a Minimum Cost, Mass, Power and Risk Approach Employing Optical Autocovariance Wind Lidar (OAWL),” coauthored with M. Lieber, R. Pierce, M. Stephens, A. Talmor, and C. Weimer. Chris discussed an alternative instrument for measuring wind profiles from Low Earth Orbit (LEO) or Geostationary Orbit (GEO). The concept promises several attractive features, including reduced mass, cost, volume, complexity, number of lasers, simpler telescope, and mission risk. Target NASA missions start in 2012, and Ball Aerospace is working to demonstrate viable alternatives. A proof of concept system was built and demonstrated in 2006, a modeling capability and an interferometer model were completed in 2007, and an OA receiver will be fabricated in 2008. OAWL features were compared to Coherent Detection and Direct Detection features for transmitter, receiver, phenomenology, and multi-mission compatibilities. Chris provided an overview of work on the proof of concept OAWL, the new design using polarization phase delays and multiplexing, the receiver, and the integrated model. Efforts are underway to raise TRLs to 5 to 6. A proposed pallet implementation for the WB-57 aircraft was described. Practical OA performance from space was discussed with model parameters and results. A single-laser Integrated Direct Detection (IDD) lidar approach for aerosol and molecular backscatter winds was described and compared to the ADM ALADIN approach. A preliminary technology assessment was presented, comparing approaches. Chris concluded that OAWL and double-edge IDD architecture can match hybrid performance with a single laser transmitter with reduced cost and complexity, and an OA receiver may be suitable for multiple missions.
Michael Kavaya presented “Thoughts on the Lidar Operating Point for the Upcoming NexGen NPOESS Wind Mission Instrument Design at GSFC.” NASA designed a Hybrid DWL GWOS instrument for 400 km orbit in 2006 to meet GTWS demonstration requirements (or 2008 NASA/NOAA Science Demonstration Requirements). The design used four fixed telescopes instead of a single scanning telescope, thereby achieving a higher Technology Readiness Level (TRL) than previous designs. The NPOESS IPO/PEO funded an instrument conceptual design activity to take place later in February 2008 at GSFC for an NPOESS HDWL mission at 824 km orbit. This instrument concept is designated NPOESS Wind Observing Sounder (NWOS). Michael’s presentation starts from the GWOS design and proceeds to narrow down the lidar operating points for the NWOS design. 400 km and 824 km geometries were compared to develop a ratio of squares of slant ranges and ratio of pulse energies for the two missions. The formulae connecting lidar parameters to measurement performance for coherent detection and direct detection were presented. Alternative point design strategies and operating points were presented for coherent detection.
Upendra Singh presented “Advancement in 2-Micron Laser Transmitter at NASA LaRC for Coherent Doppler Wind Lidar,” coauthored with M. Kavaya, J. Yu. LaRC has an ongoing program that is making steady progress on conductively-cooled, diode-pumped high-energy and high efficiency 2-micron pulsed lasers for space-based remote sensing lidar applications. They have advanced laser materials, cavity designs, pump module designs, diode configurations, thermal management systems, mechanical designs and fabrication technologies. Upendra described steps leading to demonstration of a fully conductively cooled laser; a 1.2 Joule per pulse demonstration, a compact wind lidar receiver, and conductively cooled amplifier.
Ivan Dors presented “BalloonWinds Update: Reintegration and Modeling,” coauthored with J. Ryan. The BalloonWinds DWL is being prepared for flight after some redesign following a vacuum test failure. It is mounted on an 8’ x 8’ x12’ gondola, with total mass of 6000 lb. It is battery powered and uses 1300 W. The optical system includes a diode-pumped Nd:YAG laser, a half meter telescope and direct detection receivers. Ivan reviewed the failure, redesign, specifications, and implementation. The revised BalloonWinds schedule was discussed. Two flights are planned, on May 21 and June 11, 2008. The instrument will return to the University of New Hampshire following the flights. Instrument and performance models were discussed.
Dave Emmitt presented “DWL Operations within a Sensor Web Concept,” coauthored with S. Greco and M. Seabloom. This project goal is to
Weather forecasting predictive skill has improved steadily. The product of this project will quantify weather forecast skill impact of using different assets. Case scenarios were described, including using the GEOSS model to:
The SWS will use 3D Var data assimilation techniques. The adjoint technique and other methods will be tested for identifying sensitive regions. Simulation results for lidar duty cycle modulation and spacecraft slewing were discussed. The SWS architecture, Doppler Lidar Simulation Model, and next steps were reviewed.
Michiko Masutani presented “Progress with Joint OSSEs: Simulation of Observations.” Full OSSE will use a Nature Run produced from a free forecast running the highest resolution operational model. It will be used to estimate impact of data scenarios on forecasts. One objective is to have this Nature Run shared by researchers so that results can be compared effectively. One Low Resolution Nature Run (T511) and two High Resolution Nature Runs will be produced. Topics included archive and distribution, initial diagnostics of the Nature Run, extratropical cyclone statistics, various intercomparisons, and the simulation of various observations. Planned OSSEs include GOES data, UAS, DWL, T-PARC, Advance Technology Microwave Sounder (ATMS), and Cross-track Infrared Sounder (CrIS). Other possible experiments were identified. Meso/regional OSSEs were discussed.
Session on T-PARC DWL Impact Studies
Oliver Reitebuch presented “DLR Contribution to the THORPEX Pacific Asian Regional Campaign (T-PARC),” coauthored with M. Weissmann. The DLR Falcon aircraft will participate in T-PARC studying typhoon targeting and track prediction, investigation of extra-tropical transition of tropical cyclones and downstream impact, targeting of observations, and other areas. The Falcon payload includes a water vapor DIAL, a 2 micron lidar, and a dropsonde unit. Downstream impacts, lidar targeting, forecast improvement during Atlantic THORPEX Regional Campaign (A-TReC 2003), and assimilation of lidar observations were discussed. The DLR Falcon will be deployed in Japan for six weeks beginning in late August, and will fly up to 90 h plus 30 h of transfer flight. European collaboration was described.
Pat Harr presented “Overview of the ONR-Sponsored T-PARC/Tropical Cyclone Structure 2008 Experiments (TCS-08) and Collaborative Efforts.” This activity will study tropical cyclone formation, intensification, and structure change. Pat discussed science questions that will be addressed, analytical techniques, instruments, geographic areas, and platforms. The activity is expected to increase predictability of environmental forcing, formation, outer wind structure, and intensity. Longer term goals include reducing errors in structure and intensity forecasts and increasing warning times.
Dave Emmitt presented “The Role of the Naval Research Laboratory (NRL) P3 DWL in Tropical Cyclone Structure Field Experiment TCS-08)/T-PARC.” A replicated TODWL 1.6-micron coherent DWL is being fitted alongside the NCAR ELDORA radar in the NRL P3 for use in 2008 T-PARC. TODWL instrument and background, TCS-08 and T-PARC plans, onboard DWL processing and downlink were reviewed. P3 DWL, ELDORA radar, and dropsondes data will be used to study the generation and evolution of tropical cyclones in the western Pacific and to investigate the role of Organized Large Eddies (OLEs) in modulating fluxes from the ocean into the cyclone. The instrument, scanning options, data products, and installation were described. Onboard lidar data processing is planned. The aircraft and instruments will be checked out in May 2008 at Patuxent River Naval Air Station, with test flights in June.
Ralph Foster presented “Science Goals for DWL Data in TCS-08.” Improvement in Tropical Cyclone (TC) intensity forecasts is a major goal. TCS-08 is sponsored by the Naval Research Laboratory and the U. S. Air Force. It will be carried out in the Western North Pacific in August and September 2008 to study TC formation, structure change, and processes leading to curvature. Ralph presented evidence for linear coherent structures in TC Boundary Layers (TCBLs), the importance of TCBL fluxes and parameterization, a model for TCBL rolls and fluxes, and questions that the airborne DWL in TCS-08 can address.
Yucheng Song presented “Results from WSR 2008 and Plans for Winter Phase T-PARC 2009,” coauthored with Z. Toth. The International Polar Year (IPY) is an international experiment from March 2007 through February 2009. Studies include areas of strongest climate impact, both polar regions, and global linkages. THORPEX is a World Weather Research Program to accelerate improvements in skill and utility of one to 14 day weather forecasts. The joint THORPEX-IPY observing period offers an opportunity for collaboration. Several hypotheses were stated, addressing the important role of Rossby wave propagation, the importance of complementary data sources, adaptive configuration of the observing network, new data assimilation and modeling methods, and societal and economic value of improved forecast products. Yucheng showed examples of Ensemble Transform Kalman Filter (ETKF)-based analysis of the influence of an atmospheric river on a winter storm, proposed observing platforms, and a concept of operations. G-IV and C-130 aircraft, and an enhanced Siberian network of sensors will support the study. The Global Hawk UAV with 31 h flight duration and 65.000 ft altitude capability may be used with Lidar and dropsondes.
Thursday, February 7
Session on NWOS Instrument Design Laboratory (IDL) Planning
Bruce Gentry and Michael Kavaya led a teleconference meeting with the GSFC IDL Team and multi-agency Mission Definition Team. In a meeting open to the LWG attendees, Bruce and Michael presented the latest NWOS instrument requirements and point design information to the IDL team at GSFC and answered their questions. The meeting was part of preparation for a rapid design team exercise to scale the GWOS instrument up to NPOESS orbit altitude and configuration. The design activity will take place in the GSFC IDL on February 25-29, 2008.
Session on DWL Airborne Planning
Azita Valinia led a session on planning for airborne hybrid DWL demonstrations. These NASA demonstrations will integrate the TWiLiTE direct detection and DAWN coherent detection instruments into high altitude aircraft.
Ken Miller presented “A Possible Plan for Hybrid DWL Airborne Demonstration,” and a discussion of the latest decisions and progress. Airborne objectives are to advance instrument TRLs and demonstrate hybrid technology for a space mission. Airborne demonstration plans include combining TWiLiTE direct detection and DAWN coherent detection instruments on a single aircraft, looking down from high altitudes. Separate optics will be used for the two subsystems, with TWiLiTE planning to use a holographic optical element for scanning. This configuration will also support calibration and validation activities, cross calibrating the two subsystems as well as under-flying other instruments. The Hurricane Genesis Mission 2010 is a target mission. Preliminary NASA plans for development, flight testing, and combining TWiLiTE and DAWN in a DC-8 were discussed. Michael Kavaya projected and discussed a preliminary timeline. Time lines, interim testing configurations and other possible missions and platforms, including the WB-57 and UAV, were discussed.
Subcommittee Discussions
Sara Tucker presented a slide on the definitions of accuracy and precision as applied to DWL atmospheric observations. A group discussion followed.
Dave Bowdle discussed the possibility of significant changes in background atmospheric aerosol statistics since they were characterized. These data are used extensively in simulations and modeling. Dave suggested that increased aerosol background will improve the altitude range of the coherent DWL. Wayman Baker stated that this may not be an issue for the hybrid DWL.
Subcommittee discussions were held following these presentations.
Friday, February 8
Wayman Baker led review and updating of the Action Items list. Ken Miller will submit them for publication on the web site.
The site for the summer 2008 meeting will be Wintergreen, Virginia, near Charlottesville. The Gulf Coast area was selected for the 2009 winter meeting, and Debra Hallmark will make recommendations for a site.
The meeting was adjourned.
These minutes were prepared by Kenneth Miller.
Glossary
A2D ALADIN Airborne Demonstrator
ADJ Adjoint method of analysis
ADLAATS Airborne Doppler Lidar Analyses and Adaptive Targeting System
ADM ESA’s Atmospheric Dynamics Mission
ADMAG ADM Advisory Group
AIRS Atmospheric Infrared Sounder
ALADIN Atmospheric Laser Doppler Instrument
AMSR-E Advanced Microwave Scanning Radiometer-EOS
AMSU Advanced Microwave Sounding Unit
AO Announcement of Opportunity
ARMOR Advanced Radar for Meteorological and Operational Research
ARO Army Research Office
ASCAT Advanced Scatterometer on MetOp
ATLID ESA Atmospheric Lidar
ATMS Advanced Technology Microwave Sounder
ATP Advanced Technology and Plans
ATReC Atlantic THORPEX Regional Campaign
AVHRR Advanced Very High Resolution Radiometer
BAMS Bulletin of the American Meteorological Society
BUFR WMO BUFR format used for weather observations
CALIOP Cloud-Aerosol Lidar with Orthogonal Polarization
CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation Satellite
Cal/Val Calibration and validation
CAMEX Convection and Moisture Experiment
CCD Charge Coupled Device
CFLOS Cloud-Free Line of Sight
CIRPAS Center for Inter-Disciplinary Remotely Piloted Aircraft Studies
CLARREO Climate Absolute Radiance and Refractivity Observatory
CLIO Circle to Line Optic
CNR Carrier to Noise Ratio
CrIS Cross-track Infrared Sounder
Cv2 Velocity Variance Constant
DARPA Defense Advanced Research Projects Administration
DAWN Doppler Aerosol Wind Lidar
DESDYNI Deformation, Ecosystem Structure and Dynamics of Ice mission
DIAL Differential Absorption Lidar
DMI Doppler Michelson Interferometer
DOD Department of Defense
DOTSTAR Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region
DLR German Aerospace Centre
DLSM Doppler Lidar Simulation Model
DMSP Defense Meteorological Satellite Program
DWL Doppler Wind Lidar
ECMWF European Centre for Medium-range Weather Forecasts
ELDORA Electra Doppler Radar
EnKF Ensemble Kalman Filtering
EOS Earth Observing System
EPS EUMETSAT Polar System
ESA European Space Agency
ESRL NOAA Earth System Research Laboratory
ESSP Earth System Science Pathfinder (ESSP) program
ESTEC European Space Research and Technology Center
ESTO Earth-Sun System Technology Office
ETKF Ensemble Transform Kalman Filter
EUMETSAT European Organization for the Exploitation of Meteorological Satellites
FEA Finite Element Analysis
fvGCM finite volume General Circulation Model
GCM General Circulation Model
GEO Geosynchronous Earth Orbit
GEOSAT Geodetic Satellite
GEOSS Global Earth Observation System of Systems
GFS Global Forecast System
GLAS Geoscience Laser Altimeter System
GLOBE Global Backscatter Experiment
GLOW Goddard Lidar Observatory for Winds
GOES Geostationary Operational Environmental Satellite
GPS Global Positioning System
GSFC Goddard Space Flight Center
GTS Global Telecommunications System network
GTWS Global Tropospheric Wind Sounder
GWHI GroundWinds Hawaii
GWNH GroundWinds New Hampshire
GWOLF Ground-based Wind Observing Lidar Facility
GWOS Global Wind Observing Sounder
HDWL Hybrid DWL
HFIP Hurricane Forecast Improvement Project
HIRAD Hurricane Imaging Radiometer
HIRS High Resolution Infrared Sounder
HLOS Horizontal Line of Sight
HOE Holographic Optical Element
HPMT Hybrid Photomultiplier Tube
HQ Headquarters
HRDL High Resolution Doppler Lidar
HRDI High Resolution Doppler Imager
HSRL High Spectral Resolution Lidar
ICESat Ice, Cloud, and land Elevation Satellite
IDD Integrated Direct Detection
IDL GSFC Instrument Design Laboratory
IIP Instrument Incubator Program
ILIMMS In-flight Lidar Integrated Mission Management System
IMDC GSFC Integrated Mission Design Center
INS Inertial Navigation System
IORD Integrated Operational Requirements Document
IPC/OAWL Imaging Photon Counting Optical Autocorrelation Wind Lidar
IPO Integrated Program Office that manages NPOESS
IPY International Polar Year
ISAL GSFC Instrument Synthesis and Analysis Lab
ISCCP International Satellite Cloud Climatology Project
ISS International Space Station
JCIDS Joint Capabilities Integration and Development System
JCSDA Joint Center for Satellite Data Assimilation
KNMI Royal Netherlands Meteorological Institute
LaRC Langley Research Center
LAWS Laser Atmospheric Wind Sounder
LEO Low Earth Orbit
LETKF Local Ensemble Transform Kalman Filter
LITE Lidar In-space Technology Experiment, three wavelength lidar
LOS Line of Sight
LRRP Laser Risk Reduction Program
LWG Working Group on Space-Based Lidar Winds, or Lidar Working Group
MACAWS Multi-Center Airborne Coherent Atmospheric Wind Sensor
MAX Mobile Alabama X-band radar
MBL Marine Boundary Layer
MDT Mission Definition Team
METOC Meteorological and Oceanographic
METOP ESA Meteorological Operational Satellite
MODIS Moderate-resolution Imaging Spectroradiometer
MOPA Master Oscillator Power Amplifier Lidar
MSFC Marshall Space Flight Center
MSU/GRI Mississippi State University GeoResources Institute
NAAPS Navy Aerosol Analysis and Prediction System
NAMMA NASA African Monsoon Multidisciplinary Analyses
NAS National Academy of Sciences
NASA National Aeronautics and Space Administration
NAST NPOESS Airborne Sounder Testbed
NCAR National Center for Atmospheric Research
NCEP National Centers for Environmental Prediction
NEAQS New England Air Quality Study
NESDIS National Environmental Satellite, Data, and Information Service
NexRad Next Generation Radar
NIR Near infrared region of the electromagnetic spectrum
NOGAPS Navy Operational Global Atmospheric Prediction System
NPOESS National Polar-orbiting Observing Environmental Satellite System
NPP NPOESS Preparatory Project
NPS Naval Postgraduate School
NRC National Research Council
NRL Naval Research Laboratory
NSF National Science Foundation
NWOS NPOESS Wind Observing System
NWP Numerical Weather Prediction
OA Optical Autocovariance
OAWL Optical Autocovariance Wind Lidar
OES Office of Earth Sciences
OLE Organized Large Eddy
OLR Outgoing longwave radiation
OMI Ozone Monitoring Instrument
OPAL Ozone Profiling Lidar
OPC Ocean Prediction Center
OSSE Observing System Simulation Experiment
PARC Pacific Asia Regional Campaign (THORPEX)
P3I Pre-Planned Product Improvement program (NPOESS)
PBL Planetary Boundary Layer
PDE Photon Detection Efficiency
PE Primitive Equations Model
PEO Program Executive Office
PIEW Prediction Improvement for Extreme Weather
PMT Photomultiplier Tube
Prf Pulse Repetition Frequency
QBO Quasi Biennial Oscillation
QRT Quasi-Real Time
QuikSCAT Quick Scatterometer polar orbiting satellite
RICO Rain In Cumulus Over Oceans
ROSES Research Opportunities in Space and Earth Sciences
SAIC Science Applications International Corporation
SALLJEX South America Low Level jet Experiment
SBIR Small Business Innovation Research
SiSPAD Silicon Single Photon Avalanche Detector
SIVO GSFC Software Integration and Visualization Office
SMAP Soil Moisture Active/Passive mission
SMD Science Mission Directorate
SNR Signal to Noise Ratio
SOSE Sensitivity Observing System Experiment
SPCM Single Photon Counting Module
SSMI Special Sensor Microwave Imager
STP Space Test Program
SW Solar shortwave radiation
SWA Simpson Weather Associates
SWS Sensor Web Simulator
TC Tropical Cyclone
TCS-08 Tropical Cyclone Structure Field Experiment
TCSP Tropical Cloud Systems and Processes
TE Transfer Electron
TexAQS Texas Air Quality Study
THORPEX The Hemispheric Observing system Research and Predictability Experiment
TKE Turbulent Kinetic Energy
TODWL Twin Otter DWL
TOVS TIROS Operational Vertical Sounder
T-PARC THORPEX Pacifica Area Regional Campaign
TRL Technology Readiness Level
TTL Tropical Tropopause Layer
TWiLiTE Tropospheric Wind Lidar Technology Experiment
UAH University of Alabama in Huntsville
UARS Upper Atmosphere Research Satellite
UAS Unmanned Aerial System
UAV Unmanned Aerial Vehicle
UNH University of New Hampshire
UV Ultraviolet
UWPBL University of Washington Planetary Boundary Layer model
VALIDAR Validation Lidar Facility
VIIRS Visible Infrared Imager / Radiometer Suite
WINDII Wind Imaging Interferometer
WMO World Meteorological Organization
WRF Weather Research and Forecasting model
WSR Winter Storm Reconnaissance Program
WWMCA World Wide Merged Cloud Analysis