Latest Status Reports

TDF Developments Funded in FY 2007

Overview of How TDF Development Priorities have been Established

1.  Lidar Wind Profiler

This effort, which began in Jan. 2007, explores the possibility of utilizing EOL-developed eye-safe lidar technology to measure winds and possibly turbulence using a rotating wedge. Such a system potentially offers better time resolution, altitude resolution while reducing the effects of clutter (such as signals from the ground, birds, etc.) and interference from radio waves than is possible from current radar wind profilers and SODAR systems. 

• Status: 

  Significantprogress has been achieved this past quarter. The wedges, which are used totransmit and receive 3 horizontally displaced beams at different altitudes,have been received and the rotation assembly has been completed along withpreliminary tests of this system with the wedges installed. Rotational speedsup to the operational speed of 333 rpm have successfully been demonstrated withno wobble and speed variations less than 0.25 rpm. Performance testing of the rotationtiming and control data collection software is in progress. Hardware completionis tentatively scheduled for the end of October when data collection and systemperformance analysis will formally begin.

2.  CAMS Instrument for the G-V

EOL began development of the Compact Atmospheric Multi-species Spectrometer (CAMS) for the G-V in FY 2007. This new instrument will rely on the same state-of-the-art advancements employing difference frequency generation  (DFG) technology as other EOL airborne infrared absorption spectrometers, but with major upgrades and innovations for operation on the G-V platform. It is one of many important trace gas chemistry instruments being developed for the NSF/NCAR G-V for a proposed  DC-3 study (Deep Clouds, Convection & Chemistry) as well as other airborne studies in the upper troposphere/lower stratosphere. This new instrument is being specifically developed for detection of formaldehyde and potentially other trace gases such as methanol, acetylene, ethylene, formic acid, and/or ethanol.

• Status:   

  Thepredecessor system to CAMS, the Difference Frequency Generation AirborneSpectrometer (DFGAS), was deployed this past spring and summer during theARCTAS study on the NASA DC-8 to measure the trace gas formaldehyde. Inaddition to contributing to important science, this study provided an excellentopportunity to test the efficacy of the latest engineering and softwareimprovements that have been incorporated to address a number of noise issuesduring actual airborne operation. As CAMS will operate autonomously on the GV andGV design changes are both costly and time consuming, it is important that allsuch issues are resolved before the final design has been established. One ofthe lessons learned during ARCTAS was the importance of pressure sealing theentire optical module to avoid added noise during cabin pressure changes. Althoughit was not possible to pressure seal all the optical components during ARCTAS,significant reduction in both short term and long term noise was achieved by pressuresealing many of the important components. In addition, the DFGAS design isbeing further leveraged by incorporating a number of other improvements,including multi-species detection capabilities. An initial design review is tentatively scheduled for early next year.

3.  NO/NOy for the G-V

In FY 07 EOL funded thecompletion of this instrument for measuring NO and NOy (the sum of various gasphase nitrogen oxide species) on the G-V. This instrument will be used in manychemistry campaigns, including the proposed DC-3 experiment.  A version ofthis instrument has recently flown on the NASA WB-57 during the TC4 study and aserious problem discovered in that study is now being corrected.

• Status: 

  The modified instrument worked very well on theG-V during START-08 and the project is now completed.  During this process anumber of modifications were implemented, including: replacement of spectralfilters; the instrument was re-built using certified foam insulation; the dataacquisition system was completed; the containment vessel was assembled, tested,and installed; new interconnect cables were made; and a modified HIMIL inletwas fabricated and installed.

4.  Development of a plan for long-wave radiation for the G-V

In our efforts to continually produce state of the art observing technology, EOL staff is leading a development effort for an instrument to measure long-wave radiation emitted by the earth's surface from the G-V platform. Measurements of terrestrial emissions are an essential element in understanding the earth's radiative budget. Personnel in EOL are conducting surveys to define community needs for such instrumentation and devise a plan to improve upon what currently exists. Ultimately, this will lead to the development of new G-V instrument with this important capability.

• Status: 

  Asensor of interest has been identified from a specific vendor. Specificationsand a quote for this sensor have been received. In addition, a user of thissensor has been contacted in an effort to learn firsthand the sensor operationalcharacteristics. This user is also providing invaluable information on constructionof a stabilized platform and sensor modifications for aircraft operations. Discussionswith this user are underway to explore potential collaborations on a proposalin developing and carrying out an implementation plan.

5.   SATCOM software products for the G-V

In F07 EOL started gathering input from the NCAR/NSF user community about what products they desire relative to  what is currently available in regards to Satcom software products.  This project has been discussed at inter-agency working groups, but owing to difficulties in coordinating field schedules in FY 2007, no workshop other than that at the NSF-User Workshop in September was planned. A breakout session at this workshop was held, and many technical people (~ 15 - 20) with few users attended. A number of workshop suggestions were received just as the HIAPER hardware issues were being solved (increased bandwidth and solved Iridium issues). 

• Status: 

  This project has been completed and based upon somelimited feedback during the User Workshop the following recommendations havebeen implemented: 1) explicit wording in the Facility Request Form has beenadded indicating what is offered at no cost and what will cost more; and 2) aneffort has begun to make more reliable what is offered. The third thrust,implementing collaborative software (video conferencing, shared display inflight planning mode, etc.) has not been pushed due to a lack of time caused byextensive field commitments.planning mode, etc.) are being considered. After receipt of a final report this year, this project will be completed.

6.   Water Vapor  Reference Sounding System

This collaboration between NSF/EOL and South West Sciences Incorporated (SWI) is aimed at exploring the feasibility of balloon-borne tunable diode laser (TDL) technology for in-situ water vapor measurements with verifiable accuracy. Such measurements are badly needed by the climate community.

• Status: 

  Significantprogress has been achieved on this project. A test facility that will be usedto introduce known water vapor mixing ratios at a variety of pressures andtemperatures indicative of the surface to ~ 30 km has been designed and adesign review carried out. Valuable suggestions for improvements to this designare now being incorporated in the final design. This facility will challengetwo TDL systems from SWI at various intervals over a yearlong time period. Manysystem components have been ordered and machining of the test chamber willbegin once the two laser systems arrive at NCAR sometime within the next month.Completion of the test facility is anticipated this fall and the formal testswill commence.

7.    Meteorological Satellite Data Collection and Processing

Funding was provided to improve satellite imager and sounder data collection and processing capabilities. This objective was completed at the end of the 2006 calendar year.

• Status: 
  As indicated, the core project has been completed. A second thrust, which was not part of thisproject, involves collection of feedback from the broader scientific communitywith regard to future needs for satellite products and services. This activityhas been taken over by a broader NCAR/UCAR committee, but to date progress hasbeen slow.

8.  WISARD: Wireless Integrated Sensor ARray Demonstration

In contrast to the other 7 development efforts funded this past year, the WISARD effort represents the first small emerging investigative request (requests with a total cost under 10k) designed for small exploratory projects and feasibility studies. Accordingly, the selection process for such studies is significantly less rigorous than the regular TDF proposal effort. The WISARD effort seeks to demonstrate the viability of a next-generation near-surface facility that would wirelessly network a multi-disciplinary array of off-the-grid sensors on a highly portable, readily deployable tower.  Following this proof-of-concept (Phase I) and subsequent input from the geoscientific community (through a survey) a Phase II TDF proposal would be pursued.

• Status: 

  Thetelescoping tower system for fast field deployment has been received and thestudy to define the soil and radiation sensors to be used has been completedalong with the conceptual designs for communications and the hardware tointerface to the sensors. A commercial wireless system is now being considered,as the present wireless system has not work as expected. A number of tasksremain to be completed, including testing of this new wireless system, designof the microprocessor and front end circuitry that interfaces to the sensors, integrationof components, and lab and field system tests. 

9. HOLODEC: Holographic Detector for Clouds

This development is the second small emergingseed project funded by TDL. The HOLODEC development isan aircraft instrument designed to obtain a 2-D profile, 2-D size and 3-Dposition of cloud particles in the size range of around 15 microns to 1 mmusing digital holography. This type of instrument fills an important sizemeasurement gap between instruments that size and count cloud particles byscattering (particles in the size range of 1 to 50 microns) and instrumentsthat do the same by imaging (particles in the size range of > 100 microns).Further, it is uniquely able to detect shattering of ice crystals on leadingparts of probe housing, because it can detect the 3-D clustering of shards ofshattered particles in the sample volume. This is important as it allows us toestimate how much other instruments overestimate cloud particle densities dueto counting shards of shattered particles.

• Status: 

  Lenses for the optical system have beenspecified and ordered and the mechanical designfor the lens housing has started. Materials for both componentswere carefully assessed to minimize focal length changes due to the largetemperature excursions both components will be exposed to. An autocollimatorhas been specified and ordered to facilitate lens alignment and provide data onangular deviations in the presence of vibrations. The imaging lens assemblywill be completed by around mid October and performance laboratory testing willbegin thereafter.

Other Development Efforts Not Funded by FY 2007 TDF Funds

High Precision carbon dioxide isotopic ratio instrument - CILAS

This long-standing development project that began in FY 2002 with NSF Biocomplexity Special Funds progressed rapidly in FY 2007. This instrument will provide continuous (seconds to minutes time resolution) high precision measurements of ¹³ CO ₂ to ¹² CO ₂ using a new infrared spectroscopic instrument utilizing the same DFG technology as the airborne CAMS instrument. This will augment more traditional measurements of this ratio from high precision isotopic ratio mass spectrometry, leading to an enhanced understanding of the carbon cycle. 

• Status: 

  Significantprogress has been achieved on this instrument over the past several monthsemploying a number of modifications, which will be discussed at length in anupcoming Optics Letters paper. Comprehensive precision and accuracy tests havebeen carried out in the laboratory using isotopic standards validated by theUniversity of Colorado Stable Isotope Laboratory based upon isotope ratio massspectrometry. The current performance exceeds 0.02 per mil precision for 150seconds of averaging and achieves an accuracy of 0.05 per mil on thesestandards. Additional laboratory tests will be carried out to study the effectsof water vapor and variable ambient carbon dioxide concentrations on theretrieved measurement accuracy. Future field tests and scientific measurementsemploying this instrument are yet to be determined.

Development of a high efficiency waveguide DFG instrument

With partial support from the NCAR Director's Opportunity Fund in 2006, TDF personnel have been working with Japanese scientists and engineers from the NTT Photonics Laboratory, NTT Corporation in developing and assessing a new high performance optical frequency conversion technology based upon wave-guide DFG devices. This group published a paper on the first phase of this instrument development and assessment in FY 2007.

A second phase study using an improved device based upon EOL input has been tested and the results look very promising. A new paper describing these results will be forthcoming and plans for a third phase with additional device improvements are being formulated. Ultimately, it is anticipated that these efforts will lead to DFG devices with significantly improved performance, both in terms of higher output powers and conversion efficiencies. If successful, this will open up many new detection methods for instruments on the G-V.