Wayman Baker opened the 28th meeting of the Working Group on Space-Based Lidar Winds (LWG) with introductory remarks and a review of Action Items from previous meetings.
The meeting reviewed advances in lidar technology and the potential uses of its data. Since 1994, the LWG has met twice yearly to bring together potential Doppler Wind Lidar (DWL) data users and technologists, including international representatives, to exchange information, review the latest technology developments, and build a consensus for space missions.
Progress continues in technology, instrument architecture, mission concepts, benefit studies, field demonstrations, and other areas. Interagency support for a hybrid demonstration is building. The National Academy of Sciences (NAS) decadal survey report, a recent NASA Earth-Sun System Technology Office (ESTO) study report, the U.S. Integrated Earth Observing System Strategic Plan, and the National Polar-Orbiting Environmental Satellite System (NPOESS) Integrated Program Office (IPO) assign high priority to global observations of wind profiles. The U. S. Air Force, Navy, Army, and Federal Aviation Administration have indicated strong interest in improved wind data and weather forecasts in support of their respective missions. The European Space Agency (ESA) Atmospheric Dynamics Mission (ADM) DWL launch is now scheduled for mid 2009.
Technology readiness continues to advance. A recent ESTO conceptual design for a space demonstration mission was developed by the NASA Goddard Space Flight Center (GSFC) Instrument Synthesis and Analysis Laboratory (ISAL) and Integrated Mission Design Center (IMDC). This conceptual design was determined to have no technology tall poles.
Program level perspectives were provided by Steve Mango (NPOESS) and Ramesh Kakar (NASA Headquarters).
Wayman introduced Azita Lavinia, Assistant Director for Technology in the NASA Science and Exploration Directorate. Azita is chair of the NASA/NOAA/DOD Tropospheric Wind Working Group (TWWG). She was chair of the ESTO Lidar Working Group in 2006. Azita led a session on Wednesday to develop timelines for an airborne DWL campaign.
Sara Tucker presented “A Study of Range Resolution Effects on Accuracy and Precision of Velocity Estimates: Applications of Ship-Based 2 micron Doppler Lidar Data to Space-Based Lidar Performance”, coauthored with A. Brewer, M. Hardesty, S. Sandberg, A. Weickmann, and D. Law. Sara pointed out that a ship can go where we don’t normally get boundary layer wind measurements. NOAA’s High Resolution Doppler Lidar (HRDL) instrument is used to determine the potential performance of a space-based instrument over the open oceans. It measures winds, turbulence, cloud coverage, and aerosols. Aerosol comparisons with Ozone Profiling Lidar (OPAL), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation Satellite (CALIPSO), and High Spectral Resolution Lidar (HSRL) are being studied. The shipboard HRDL is fully motion compensated and maintains less than half degree of precision under heavy wave conditions. Sara described wind and aerosol products, system and processing parameters, and showed representative data plots. She defined accuracy (bias) and precision (variance). 30 meter range gate data is being reprocessed to 500 meter range gates to simulate space data. Illustrations of overlaid 30 and 500 meter wind speed and direction profiles were shown. Precision improvement from wider range gates is about a factor of 2, less than that if the averaged points were uncorrelated. The 500 meter range gates miss smaller shears and structures. Using the center of the data range in a composite range gate shows some improvement over using the average over the gate. Wind profile plots from 30 and 500 meter range gates match well up to 2500 km, although the 500 meter data misses some shear and corners. The paper includes a preliminary results table. Aerosol profile variations are studied through backscatter power, affected by:
Continuing work includes Boundary Layer heights, streak analysis and integration with models, comparison with in situ backscatter measurements, comparison with CALIPSO, and other areas. The percentage of time that enhanced aerosol conditions are present, motion compensation, and need for calibration with a hard target were discussed.
Jan Paegle presented “Forecast Sensitivity Using New Models and Special Observations,” coauthored with L. Byerle, C. Saulo, J. Ruez, and Julia Paegle. Jan discussed estimating initial state uncertainty from differences between European Centre for Medium-range Weather Forecasts (ECMWF) and NCEP analyses (Gonzalo Miguez-Macho), initializing the U. of Utah Primitive Equations (PE) model with each analysis, and studying differences in the resulting forecasts. Jan discussed difference plots and predictability curves over the northern hemisphere. Gonzalo’s results suggest that enhanced observations over North America are more valuable until about 30 hours, after which enhanced observations outside North America are more valuable. Jan investigated whether results depend on forecast model, initial state uncertainty estimates, or region and season. Current work used regional Weather Research and Forecasting (WRF) and U. of Utah models, special observations to identify uncertainty, data void over South America, and time evolution of area integrated results. He discussed forecast sensitivity to special observations over South America using WRF and new global Euler models. Plots of global radiosonde and aircraft coverage were shown illustrating sparse coverage regions. South America Low Level Jet Experiment (SALLJEX) observation enhancements over South America were shown, followed by wind prediction impacts of the enhanced observations. He showed the global evolution of wind differences from day 0 through day 14. Conclusions were:
More study is planned on forecast accuracy of Euler cases. An upcoming experiment involving the NOAA ship Ron Brown (VOCALS 2008) was discussed.
Zhaoxia Pu presented “Targeted Doppler Wind Lidar Observations for Seasonal Climate Studies and High-Impact Weather Forecasting,” coauthored with B. Gentry and B. Demoz. This study addressed DWL adaptive targeting strategy from space and from aircraft. Zhaoxia illustrated uncertainties of global wind analyses. Differences between NCEP and ECMWF reanalyses are partially caused by different systems, but also by inadequate wind observations. Uncertainties in seasonal mean wind field are relatively small, mainly apparent in tropics and polar regions. Zhaoxia addressed:
She discussed impact of wind data on hurricane forecasts from simulations of Hurricane Emily (2005) sea level pressure, accumulated rainfall along track, impacts from different wind data (control with no wind data, QuikSCAT, Geostationary Operational Environmental Satellite (GOES)-11, Dropwindsonde, and combined). Wind information proved very important in the hurricane forecast. They are preparing to assimilate DWL data into the experiment to investigate requirements and sampling strategies. In discussions, Wayman Baker pointed out that adaptive targeting will be more important for 800 km (NPOESS) orbit, less for 400 km (demonstration) orbit. Bob Atlas said studies show adaptive targeting may work for weather but may not for climate analysis. Dave Emmitt recommended looking at asymmetric sampling around hurricanes, work done by Atlas and Emmitt. He asked whether there is advantage to tipping the field of regard. Lars Peter Riishojgaard commented on comparison of various methods of wind analysis.
Bruce Gentry presented “Mid-Term Status of the Tropospheric Wind Lidar Technology Experiment (TWiLiTE) Airborne Direct Detection Doppler Lidar Instrument Incubator Program (IIP) Project,” coauthored with M. McGill, G. Schwemmer, M. Hardesty, A. Brewer, T. Wilkerson, R. Atlas, M. Sirota, S. Lindemann, and F. Hovis. Bruce described TWiLiTE overview, requirements, simulations and performance, and subsystem status. A technology maturity roadmap for 2 micron and 0.355 micron technologies identified components supported by past funding, Laser Risk Reduction Program, and NASA ESTO IIP-2004 projects. For the 2 micron Doppler Airborne Wind Lidar (DAWN) subsystem, IIP-2004 activities included work on compact packaging (2005), packaged lidar ground demonstration (2007), and partial funding of aircraft operation. The 2 micron autonomous operational technology is not funded for aircraft integration or flight. For the 0.355 micron subsystem (TWiLiTE), IIP-2004 funding supported compact laser packaging (2007), compact modular receiver (2007), and autonomous operational technology. The autonomous TWiLiTE system will have three buttons: heaters on, instrument on, and laser off. TWiLiTE will demonstrate downward looking, scanned direct detection lidar wind profiles from 18 km to the surface. The instrument is designed to fly on the NASA WB-57 aircraft, and will be completed in summer 2008. Bruce described the WB-57 configuration and specifications, the instrument pallet (which is not climate controlled), and measurement specifications (including 2 m/s horizontal line of sight (HLOS) velocity accuracy, 0.25 km vertical resolution, 25 km horizontal resolution, and a 16 point step-stare Holographic Optical Element (HOE) scanner). A primary objective is to advance TRLs for key technologies. The laser transmitter, optical filters, photon counters, holographic optical element telescope, triple aperture etalons, and assembly onto a WB-57 pallet were discussed. Receiver improvements include 90% volume reduction, more stable optical paths, 60% improvement in end-to-end performance, two orders of magnitude dynamic range increase, and environmental adaptation. The 25 x 30 inch HOE is being built by Utah State University. IIP funding will include partial vacuum and vibration testing. TWiLiTE is in the 3rd qtr of the 2nd yr of a 3 yr program and is scheduled to be complete and integrated onto the WB-57 pallet in summer 2008. TWiLiTE will demonstrate measurement of wind profiles from a high altitude aircraft and could support mesoscale and hurricane research.
James Ryan presented “BalloonWinds Cracks Under Pressure,” coauthored with I. Dors. BalloonWinds suffered a catastrophic failure during thermal vacuum tests at Kirtland AFB. BalloonWinds will demonstrate direct detection DWL from 30 km altitude using a balloon platform. It will validate instrument performance and atmospheric models and address scalability to space. Model validation objectives include the atmosphere model, the laser-telescope model, the optics-camera model, and the wind uncertainty model. Flights were planned to begin May 2007. The instrument was integrated to the gondola and tests were underway at the time of the previous LWG meeting. The ground station is complete and undergoing testing. Following the failure at Kirtland, damage assessment, failure analysis, redesign and chamber reviews are underway. Jim described the failure of the laser chamber lid and walls, chamber redesign, and revised schedule. Some components were damaged, although the laser and other key elements passed diagnostic tests in July. Cast aluminum material selection and bolt threading were primary causes of failure, along with inaccuracies in the stress analysis. Flights are now scheduled for May 2008.
Dave Emmitt presented “Combining Twin Otter DWL (TODWL) with Smart Towed Platform for Unique Investigation of the Marine Atmospheric Boundary Layer,” coauthored with C. O’Handley, H. Jonsson, and D. Khelif. TODWL is made simultaneous measurements with a towed aerosol flux measuring instrument to observe Marine Boundary Layer (MBL) phenomena. Wind observations are used to position the platform and select headings for MBL features of interest. The towed instrument was funded as a Navy Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Small Business Innovation Research (SBIR) project. Thirty hours of flights were conducted over water in April 2007. Targets included Organized Large Eddies (OLEs), MBL jets, coastal transitions, and multilayer situations. Dave showed photographs of the Twin Otter aircraft and instrument configurations. The Smart Towed Vehicle is a converted terrain-following cruise missile with flux sensors. Interesting conditions were discovered near shore, including fluxes near the ocean surface with wind structure context. OLEs organize aerosol flux concentrations near the ocean surface. Measurements include temperature, humidity, wind gusts, GPS, and radar. More flights are planned for spring 2008.
Dave Emmitt presented “QuikSCAT and WindSAT Underflights with TODWL,” coauthored with C. O’Handley and S. Greco. The objectives were to investigate the influence of OLEs and near surface jets on Ocean Vector Wind (OVW) measurements and air-sea flux parameters; investigate accuracy of Planetary Boundary Layer (PBL) wind profiles derived from Ocean Vector Winds; and obtain high resolution wind profiles within the footprints and processing pixels of QuikScat (scatterometer) and WindSat (multifrequency polarimetric microwave radiometer). The study addressed what QuikScat and WindSat saw and effects of OLEs on satellite measurements. Findings include:
Two underflights were conducted in April over Monterey Bay. Dave showed graphics of flight paths and observations and QuikScat and WindSat observations. There is a proposal to study synergisms between space-based DWL and OVW and Cloud Motion Vectors (CMV).
Chris Grund presented “Lidar Wind Profiling from Geostationary Orbit Using Imaging Optical Autocovariance Interferometry.” Chris discussed an alternative instrument for measuring wind profiles from Low Earth Orbit (LEO) or Geostationary Orbit (GEO). The Imaging Photon Counting Optical Autocorrelation Wind Lidar (IPC/OAWL) concept promises several attractive features, including simpler laser and receiver systems, no scanning or multiple telescopes, long integration, both aerosol and molecular measurements, full altitude profile, and compatibility with other instruments. GEO and LEO coverage can be complementary. LEO missions can provide global coverage with high vertical resolution and polar views. GEO can provide regional continuous coverage. A demonstration system architecture, brassboard, test range, and test results were described. About 1 meter per second random error with 0.6 m/s bias were demonstrated on the ground in December 2006 with 0.3 s averaging and 3 m range resolution. Chris reviewed modeled performance from LEO. The model wavelength was 355 nm, pulse energy 550 mJ, pulse rate 50 Hz, receiver diameter 1 m, horizontal resolution 75 km, orbit altitude 400 km, and vertical resolution from 250 m to 1 km. Both molecular and aerosol backscatter contribute. The modeled small instrument (0.18 m) does not meet demonstration and threshold requirements for velocity error from LEO with current laser technology. The modeled large instrument (1 m) meets demo and threshold velocity error requirements up to about 14 km. OAWL shows promise for a GEO wind mission with better than 2 m/s precision and 20 min time resolution. GEO mission applications could include such combinations as:
Michael Hardesty presented “Some Non-Weather Science Benefits of Global Winds." Winds are important in climate research, including topics such as jet streams, polar vortices, storm tracks; moisture transport; CO2 sources and sinks; and impact on cloud formation and properties. Most climate studies employ data reanalyses to fill gaps in global observational records. Reanalysis with data assimilation is the best way to interpolate data in time and space and obtain dynamical consistency. This raises the question of how good the reanalysis data is. Usefulness depends on quality and distribution. New observations can introduce fictitious trends. Mike discussed some climate trends from reanalysis data and the importance of wind in studies. It is important to identify and correct atmospheric model and observational biases, so unbiased long term wind measurements from a Global Wind Observing System are important. Wind data over data-sparse regions such as oceans and the southern hemisphere can improve reanalysis. Example studies and findings were discussed. Improvements in moisture and wind observations are critical to climate models. A long term observational strategy is needed to provide unbiased and continuous data.
Robert Brown presented “The Scatterometer, What It Can Do, and Prospects for QuikSCAT Follow-on.” Bob showed QuikSCAT data examples and a photograph of ASCAT on MetOP 2007-2019. He discussed QuikScat modeling of surface pressure from space, describing the present capability. NCEP real time forecasts are improved with QuikScat surface pressure analysis. It appears that a NASA QuikSCAT follow-on will not be available until 2013 at the earliest and a DWL satellite will be later still. QuikSCAT (since 1999) and ASCAT (since 2007) scatterometers are in space today. A data gap is possible before replacement. Possible scatterometer follow-on scenarios were discussed, suggesting at one extreme a combination of a scanning multi-frequency SAR-scatterometer-radiometer and lidar. Bob discussed measurements of wind in rolls, illustrating the diverse observational perspectives of towers, sondes, and lidar from space over a 2 to 5 km baseline across rolls, and the calculation of surface level pressure from surface winds. Extensive programs and fields are available on http://pbl.atmos.washington.edu.
Dave Emmitt presented “Cloud-Free Line of Sight (CFLOS) Opportunities Update with CALIPSO and Impact on Simulating GWOS and ADM in OSSEs,” coauthored with S. Greco and D. Winker. This presentation included several sections.
Evaluation of Nature Run T511 clouds: ECMWF Nature Run T511 (1 degree) cloud types and amounts are being analyzed and modification algorithms provided as needed. Techniques for deriving cloud optical properties, Cloud Motion Vector targets, and radiative transfer model inputs are being addressed. Evaluations of the T106 and T213 nature runs showed a need for additions and augmentation. A NASA-funded study of Geoscience Laser Altimeter System (GLAS) CFLOS statistics was completed in September 2006 and used to calibrate DWL simulation models. The IPO funded simulations of GLAS and DWL observations using the T213 nature run. The analysis process used T511 Nature Run data to derive zonal cloud averages for latitudinal bands and global cloud coverage. Nature Run statistics were compared with cloud climatology statistics from:
T511 cloud distributions compare best with HIRS climatology. They understate thin cirrus presence. Lidar data often show clouds higher than assigned by passive sensors. An algorithm to adjust ice cloud coverage improves comparisons with GLAS and CALIOP.
Global Cloud Statistics: Dave showed a table comparing ECMWF, HIRS, and ISCCP cloud statistics. He showed graphs of WWMCA cloud climatologies; ISCCP interannual cloud cover variability; comparison of Nature Run, ISCCP, WWMCA, and HIRS cloud cover vs. latitude; and nature run cloud cover. A table of global cloud cover percentage for the various climatologies was discussed.
GLAS/CALIOP View: Dave compared global maps, zonal cloud fraction, and zonal average cloud top for GLAS, MODIS and ISCCP for October 2003. He provided plots of clouds versus altitude and latitude for day, night, land and ocean (October 2006) from CALIOP/CALIPSO and cloud comparisons between CALIOP (October 2006) and other instruments.
Nature Run Cloud Distributions were discussed, addressing cloud types and amounts, including T511 cloud percentage as a function of latitude and liquid and ice water content.
Simulating Lidars on T213, coauthored with S. Wood: Clouds reduce accuracy of wind profiles measured from space for molecular lidars and reduce sensitivity of coherent lidars. GLAS CFLOS statistics for design of future space-based lidars were described. CALIPSO data are now being analyzed and with more thin clouds determined. This promises a better data set than GLAS for future designs. Plots of cloud statistics were reviewed. A block diagram of the DLSM model showed instrument, platform, atmosphere, signal processing, error processing, and toolkit capabilities. Simulated transmission through cirrus, cloud fraction vs. wind shear components, performance modeling with DLSM and OSSEs, and DLSM performance profiles were discussed. Performance profile charts showed effects of cloud porosity on a coherent DWL.
Dave Emmitt presented “Prospecting for Atmospheric Energy for Autonomous Flying Machines,” coauthored with C. O’Handley. The objective is to use a DWL to autonomously prospect for vertical motions and shear near an unpiloted aircraft, develop atmospheric energy prospecting algorithms, and develop instrument specifications for UAVs. This work supports Defense Advanced Research Projects Agency (DARPA) and the National Institute of Aerospace, using the TODWL with a 2 micron DWL. TODWL, since 2002, has been used by the Navy, Army, and NOAA activities. This experiment seeks interesting wind signatures, wind structure vertical extent, and coincident structure ranking. Targets include thermals, OLEs, cloud updrafts, orographic flows, gravity waves, and jets. Dave pointed out that the albatross, with 9 m/s or more of shear, can fly indefinitely without flapping wings. Selecting target wind conditions promises more gain than adapting aircraft configurations. Flights were made in October 2006 and April 2007. Flights, terrain, wind velocity plots, flight planning, scanning strategies, and examples of wind features were shown. Airborne prospecting appears feasible. TODWL flights in November 2007 will observe nocturnal advantages including gravity waves, low level jets, and cloud updrafts.
M. Masutani presented “Progress and Plans with Joint OSSEs.” Michiko identified the many contributors from NCEP, JCSDA, NESDIS, SWA, NASA/GSFC, NOAA/ESRL, ECMWF, Royal Dutch Meteorological Institute (KNMI), and Mississippi State University GeoResources Institute (MSU/GRI). OSSEs are needed to design new instruments and data assimilation methods, but are labor intensive and require broad collaboration. The Nature Run serves as the true atmosphere for OSSEs. The new Nature Run will reduce cost and enhance comparisons and credibility for future OSSEs. The new Nature Run is being prepared by ECMWF based on recommendations from the other organizations. It will include one low resolution and two high resolution Nature Runs. Diagnostics of the Nature Run are underway in several organizations. Topics included:
Bruce Gentry presented “New Developments in Detector Technology at Wavelengths > 1 Micron,” coauthored with X. Sun, and M. Krainak. There are significant recent advances in 1 micron detection. The Edge Technique Lab Testbed (1994) demonstrates wind measurements, proves new concepts and components, and validates space simulation instrument models. The 1064 nm transmitter operates at 10 Hz with 0.12 J per pulse. The receiver diameter is 0.4 meters and quantum efficiency is 0.4 analog and 0.03 photon counting. It has a Fabry-Perot interferometer. Wind profiles (compared with rawinsonde) for single edge and double edge detectors were shown. The single edge detector did not perform well above the boundary layer (1994), and subsequent work used the double edge detector with photon counting. This configuration found aerosols up to the tropopause and improved performance. Search for a better detector led to use of 355 nm wavelength and molecular detection. The Zephyr Space Shuttle instrument design was developed in 1997-98 with an Nd:YAG laser, a 1064 nm aerosol receiver, and a 355 nm molecular receiver. Aerosol performance was limited by low detection efficiency. This mission was not completed. Under an Instrument Incubator Program (IIP), the Push-broom Laser Altimeter team is searching for improved photon counting detectors. The current state of the art is the Silicon Single Photon Counting Module (SPCM) from PerkinElmer Canada. It meets requirements, has high TRL (ICEsat), 15% Photon Detection Efficiency (PDE) at 980 nm, an absorption cliff at 1 micron, and 3% at 1064 nm. A Silicon Single Photon Avalanche Photodetectors (Si SPAD) from Micro Photon Devices, Italy, meets requirements at 532 nm, but needs to be space qualified. Transfer Electron (TE) InGaAsP (Hamamatsu) photocathode photomultiplier tubes have PDE from 4% to 8% at 1064 nm, are commercially available, improving though perhaps not good enough yet, and need to be space qualified. Photomultiplier tubes have to be cooled to near cryogenic temperatures. The most promising is the hybrid TE InGaAsP photocathode and GaAs Schottky photomultiplier tube (HPMT) from Intevac with 20-30% PDE at 1064 nm. This device appears to be space-qualifiable. Bruce discussed the testing and performance measurements of the Intevac HPMT. A device comparison table was presented. An HPMT receiver system is being developed. 1064 nm aerosol direct detection performance should be reevaluated with the improved detectors.
Martin Weissman presented “Impact Studies with Airborne Doppler Lidar Observations: A-TReC to T-PARC,” coauthored with C. Cardinali.et al. Martin described the DLR Falcon aircraft and its instrumentation, including scanning coherent 2 micron Doppler lidar, new four wavelength DIAL, and dropsondes. The DLR Falcon participated in The Hemispheric Observing System Research and Predictability Experiment (THORPEX) Atlantic Regional Campaign (14-28 November 2003). Observations, products, and statistical intercomparison of lidar and dropsondes were described. Experiments and observation influence with ECMWF T511 global model were discussed. Lidar observations showed higher observation influence and information content than dropsondes. Significant improvement of ECMWF forecasts (winds, temperature, and humidity) resulted over Europe out to 96 h. Lidar had lower assigned error than all other wind observations and higher observation influence. Martin stated that large improvement was shown in a few events but more study is needed for impact in different areas and cases, impact quantification, impact in different assimilation systems, and sensitivity to accuracy and resolution. Atlantic THORPEX Regional Campaign (A-TReC) targeting campaigns were described, observing that tests were inconclusive and more study is needed to evaluate targeted observations and impacts, conduct sensitivity studies, test targeting strategies, and derive design parameters. The DLR Falcon will participate in a THORPEX Pacific Asian Regional Campaign (T-PARC) in autumn 2008, based in Yokota Japan, pending acquisition of the remaining 20% of the $1.7M T-PARC funding. The group spent some time brainstorming possible sources for this funding, which has since been mostly obtained. Typhoon tracks and observations from the international typhoon research program Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region (DOTSTAR) and north Atlantic impact studies with DIAL data were discussed. Some targeted lidar observations are planned during COPS/E-TReC. A ground campaign is underway with the ADM demonstrator and a flight campaign may be conducted in 2008. In discussions, it was observed that NOAA’s benefit studies assumed 1% improvement in forecasts, but that the DLR experiments had shown 3% actual improvement with limited observations, a very significant finding. The Office of Naval Research P3 is expected to participate in T-PARC with radar and lidar flying together. Ramesh Kakar (NASA) is also planning a 2009 airborne campaign focused on hurricanes, similar to the CAMEX flights.
Lars Peter Riishojgaard presented “Report from the 15th ADM Advisory Group (ADMAG) Meeting and Recommendations on US - European Collaboration,” coauthored with Michael Hardesty. Lars Peter and Michael are US representatives on the ADMAG and attended the 15th meeting. The presentation covered mission status, calibration and validation (Cal/Val) plans, and US/Europe collaborations. ADM is the first space mission to measure global wind profiles and involves new technology and challenges. Hardware development and integration is well advanced, with the Aeolus bus mostly integrated. The ALADIN instrument assembly is advanced, but instrument fixes are underway, including problems with the laser. The official launch date has slipped to June 2009. An Aeolus Ground Segment Design Review was held in late 2006. Calibration and processing algorithms are being refined. Level 1B data will be disseminated immediately via the World Meteorological Organization (WMO) Global Telecommunications System (GTS) network. ESA will require proposals to use data for research. Lars Peter discussed processing and access to levels L1B and L2B data. L2B is final HLOS data, will be ingested in most systems. The L2B processor can be installed in the users’ shops – they can either get L2B and ingest directly or get L1B and process it themselves. Latency is 3 hr to end user, near real time. The baseline system has only one receiving station, at Svalbard. The ADM orbit has 3 or 4 blind passes / day, so users will have to wait 1 or 2 orbits on those. A second station could be added. Quasi Real Time (QRT) latency is 30 minutes from time of measurement, for regional and mesoscale Numerical Weather Prediction (NWP). QRT will be available for Europe if a second receiving station is added, but not for North and South America. This could be corrected with a third receiving station, and ESA may study alternative QRT scenarios. Transatlantic collaboration is considered on future DWL mission scenarios, reducing ADM data latency, OSSEs, and creation of a formal European/US working group on space-borne DWLs. Lars Peter discussed future mission scenarios. The projected ADM lifetime is 2009-2012. Post EUMETSAT Polar System (Post-EPS) will begin in 2017 to 2018, and is the earliest opportunity for a European operational system, so a data gap is assured. Post-ADM interim solutions are being considered (see Endemann briefing at Miami LWG meeting, January 2007). Possible interim approaches could include a US Global Wind Observing Sounder (GWOS) mission, since the cost of filling the data gap will be high for Europe or the US alone. There was discussion of several alternative configurations of satellites for optimal coverage and of the interest of DOD, FAA and others in actual wind profiles, not just weather forecasts. Some OSSE collaboration is ongoing, and ADMAG recommended that ESA and EUMETSAT support the Joint OSSE initiative. ADMAG supported the idea of a European/US working group to discuss these issues. It was suggested that the LWG consider an ADM Sub-group to interact with ADMAG in a formal way. ESA wants a single US proposal for Cal/Val collaboration.
Michael Hardesty led a discussion of “Potential US Response to ESA ADM Cal/Val Announcement of Opportunity (AO),” co-led by L. Riishojgaard. Mike discussed information from the recent ADMAG meeting. The purpose of ADM Cal/Val is to quantify accuracy, characterize deviations, and make recommendations for processing improvements. No Cal/Val plan is in place now. A commissioning phase (3 months) and a routine phase (3 years) of Cal/Val are planned. A worldwide AO call will be made October 1, 2007, with proposals due in December. Proposers will provide their own funding. It was pointed out in discussion that US agencies are not aware and don’t have funding planned for this. There is time to plan since the activity will not occur till 2010. Data access in the commissioning phase will be only through the Cal/Val team. Cal/Val contributors will include scientists in the Algorithm Development Teams and accepted responses to the ESA AO. The Cal/Val process will include
Other topics included Cal/Val methods for winds and aerosols, AO scope and process, Aeolus Cal/Val website, and data products. A US Cal/Val proposal is anticipated, with Riishojgaard and Hardesty taking the lead. They will form a team and explore funding opportunities. Major elements will include direct observations and data evaluation. Validation opportunities on a 50 km scale will occur every several days. Potential direct observations were discussed, and included the TWiLiTE and DAWN airborne lidars, TODWL, and NOAA Airborne HRDL among others. Interested parties should provide input to the AO proposal outline (to Riishojgaard or Hardesty) by September. The ADMAG will act as PI for Cal/Val. Funding is needed in the FY2010 NOAA budget and possibly from NPOESS, NASA, and DOD. A US proposal will be contingent on obtaining funding. The US effort will include:
In preparing the proposal, Cal/Val approaches for LITE, CALIOP, other programs will be reviewed. Dave Emmitt will provide a list of ground based DWLs. The question was raised of who will sign the proposal if it precedes Agency confirmation. There was discussion of piggy-backing with an airborne campaign, e.g., T-PARC or Ramesh’s experiment, to reduce costs.
Ramesh Kakar presented the “NASA Headquarters Perspective.” Ramesh is the Weather Focus Area Leader in the Science Mission Directorate at NASA Headquarters. The NRC Decadal Study recommended 17 satellite missions including the DWL mission. Recommendations did not appear in time to affect the FY08 budget, but may affect the FY09 budget. NASA conducted four workshops supporting the study: Soil Moisture Active/Passive (SMAP); Climate Absolute Radiance and Refractivity Observatory (CLARREO); Deformation, Ecosystem Structure and Dynamics of Ice (DESDYNI); and ICESAT2. These missions were judged by NASA to be highly important. Thirteen proposals were received in response to the ROSES07 Wind Lidar science announcement. $1M is available and the review panel met in early August. The NASA African Monsoon Multidisciplinary Analyses (NAMMA) / Tropical Cloud Systems and Processes (TCSP) Working Group recommended a hurricane field experiment in 2009 involving airborne wind lidars. The 2009 experiment is likely to be supported if airborne wind lidars are available (see IIPs: Kavaya, Gentry). Bruce Gentry’s TWiLiTE IIP is funded for an airborne system. Michael Kavaya’s DAWN is funded for a lab demonstration that will need converted to airborne (some NOAA funding available). ROSES07 Airborne Instrument Transition has some funding, and 35 proposals were received. This activity is to transition lab instruments to airborne, not just for weather. Ramesh mentioned other ongoing or planned airborne experiments, e.g., European activities. Plans are needed for ROSES09 by September. Sharing with ADM Cal/Val is possible. NASA wants to do all the NRC-proposed missions, but current budget constraints put DWL far out in time. Advance planning is underway.
Dave Emmitt presented “TODWL and Other Navy Airborne Wind Lidar Plans Including a Nocturnal Flight Campaign in November.” TODWL plans include nocturnal “Skywalker” flights in November 2007 seeking atmospheric advantages for autonomous UAV flight, possible nocturnal flights for an Army Airborne Doppler Lidar Analysis and Adaptive Targeting System (AADLATS), possible nocturnal Smart Towed Platform experiments, and preliminary test flights of Navy-funded Integrated Lidar Mission Management System (ILIMMS). The Office of Naval Research is installing a replication of the TODWL instrument on a Naval Research Laboratory P3 aircraft to support the 2008 T-PARC with a combination of DWL and NCAR’s Electra Doppler Radar (ELDORA). Dave described the radar and showed a photograph of ELDORA on the NRL P3. There is little spatial overlap in observations from the radar and lidar. The P3 2 micron DWL will use existing subsystems where possible. It weighs 850 lb and uses 750 watts. The main outstanding issues relate to mounting a lidar scanner on the P3 door. Flights are planned near Patuxent River Naval Air Station in February 2008.
Azita Valinia led a discussion on “Roadmap for Possible DWL Airborne Campaigns.” Azita reviewed a NASA ESTO Laser-Lidar Technology Roadmap and ESTO Laser/Lidar working group activities from 2006. The tropospheric wind demonstration mission was listed as a near term mission by the working group and needs funding now for lidars and for an airborne campaign. Azita believes an airborne campaign is important now for selling a space-based wind lidar mission. Stakeholders who use the data in operations need to see the benefits and develop enthusiasm. The airborne campaign should demonstrate societal benefits to stakeholders through targeted observations and assimilation, as a step to space. Ground validation and limited airborne demonstrations of DWL have been underway for several years. An airborne hybrid lidar is the next step to space. Azita recommended that we define the campaign and milestones now. An outline showed possibilities:
In discussions, it was pointed out that Weissman reported 3% experimental forecast improvement with actual airborne data with a very small number of observations. Airborne coverage can’t match space coverage, so data will be very sparse and require careful target planning. The ADM mission will be important in demonstrating operational value. Risk of expecting too much from ADM was discussed - there was concern that ADM benefits may not be revolutionary because of its single-LOS limitations. There was discussion of the use of airborne observations to simulate single vs. dual LOS for comparisons.
Winter storm and hurricane airborne campaigns were discussed for 2008 and 2009.
There was a discussion of possible campaigns with targeted measurements, outlined below.
Subcommittee Discussions –
Meetings were held to formulate action items.
Mike Hardesty led an ADM Cal/Val Planning Session, attended by Wayman Baker, Bob Brown, Jeremy Dobler, Dave Emmitt, Bruce Gentry, Mike Hardesty, Kenneth Miller, Lars Peter Riishojgaard, James Ryan, Sara Tucker, and Martin Weissman. The proposal for Cal/Val support, due to ESA by December 15, 2007, was discussed. The proposal has to be self-funded and the period of activity is uncertain. ESA needs to find out what resources will be available, and there is no ESA funding for Cal/Val. Dave Emmitt prepared a formal Cal/Val plan for SPARCLE and will find a copy. The question was raised as to whether there was a Zephyr plan. Activities will include:
The ADM Commissioning Phase will last 3 months and show that data and processing are good. Access to data will be restricted to participants. The Routine Phase will address ongoing improvements, stability, and scientific uses. Data access will be opened to qualified users.
Methods include soundings, aircraft, airborne DWLs, ground DWLs, assimilation models, and others. For clouds and aerosols, extensions to the CALIOP Cal/Val methodology were discussed.
Bruce Gentry discussed an ISAL conceptual design for an NPOESS Next Generation DWL. The ISAL is scheduled for late October 2007. Plans will be reviewed by conference call.
Presentation of Short Subjects
There were no short presentations.
Subcommittee Reports and Recommendations
There were no subcommittee reports.
Wayman Baker chaired a review of Action Items, which were discussed and finalized. See the Action Items tab on the LWG website for a complete list.
There was discussion of:
Next Meetings
The Winter 2008 meeting will be held in Monterey, California on February 5-8, 2007.
Debra will check on Snowmass, Bar Harbor, Wintergreen, New Hampshire, Mt. Rainier, and Boston as possible sites for the Summer 2008 meeting.
The meeting was adjourned.
These minutes were prepared by Kenneth Miller.
Glossary
A2D ALADIN Airborne Demonstrator
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
ARO Army Research Office
ASCAT Advanced Scatterometer on MetOp
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
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
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
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
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
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
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
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
NAMMA NASA African Monsoon Multidisciplinary Analyses
NAS National Academy of Sciences
NASA National Aeronautics and Space Administration
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
NPOESS National Polar-orbiting Observing Environmental Satellite System
NPP NPOESS Preparatory Project
NPS Naval Postgraduate School
NRL Naval Research Laboratory
NSF National Science Foundation
NWP Numerical Weather Prediction
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
PIEW Prediction Improvement for Extreme Weather
PMT Photomultiplier Tube
Prf Pulse Repetition Frequency
QRT Quasi-Real Time
QuikSCAT Quick Scatterometer polar orbiting satellite
RICO Rain In Cumulus Over Oceans
SAIC Science Applications International Corporation
SALLJEX South America Low Level jet Experiment
SBIR Small Business Innovation Research
SiSPAD Silicon Single Photon Avalanche Detector
SMAP Soil Moisture Active/Passive mission
SNR Signal to Noise Ratio
SOSE Sensitivity Observing System Experiment
SPCM Single Photon Counting Module
SPORT NASA Short-term Prediction Research and Transition Center
SSMI Special Sensor Microwave Imager
STC Science and Technology Corporation
STP Space Test Program
SW Solar shortwave radiation
SWA Simpson Weather Associates
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
UAV Unmanned Aerial Vehicles
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