2006 Development Projects

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:

  Significant progress has been achieved this past quarter. The wedges, which are used to transmit and receive 3 horizontally displaced beams at different altitudes, have been received and the rotation assembly has been completed along with preliminary tests of this system with the wedges installed. Rotational speeds up to the operational speed of 333 rpm have successfully been demonstrated with no wobble and speed variations less than 0.25 rpm. Performance testing of the rotation timing and control data collection software is in progress. Hardware completion is tentatively scheduled for the end of October when data collection and system performance 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:

  The predecessor system to CAMS, the Difference Frequency Generation Airborne Spectrometer (DFGAS), was deployed this past spring and summer during the ARCTAS study on the NASA DC-8 to measure the trace gas formaldehyde. In addition to contributing to important science, this study provided an excellent opportunity to test the efficacy of the latest engineering and software improvements that have been incorporated to address a number of noise issues during actual airborne operation. As CAMS will operate autonomously on the GV and GV design changes are both costly and time consuming, it is important that all such issues are resolved before the final design has been established. One of the lessons learned during ARCTAS was the importance of pressure sealing the entire optical module to avoid added noise during cabin pressure changes. Although it 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 pressure sealing many of the important components. In addition, the DFGAS design is being 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 the completion of this instrument for measuring NO and NOy (the sum of various gas phase nitrogen oxide species) on the G-V. This instrument will be used in many chemistry campaigns, including the proposed DC-3 experiment.  A version of this instrument has recently flown on the NASA WB-57 during the TC4 study and a serious problem discovered in that study is now being corrected.

• Status:

  The modified instrument worked very well on the G-V during START-08 and the project is now completed.  During this process a number of modifications were implemented, including: replacement of spectral filters; the instrument was re-built using certified foam insulation; the data acquisition system was completed; the containment vessel was assembled, tested, and installed; new interconnect cables were made; and a modified HIMIL inlet was 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:

  A sensor of interest has been identified from a specific vendor. Specifications and a quote for this sensor have been received. In addition, a user of this sensor has been contacted in an effort to learn firsthand the sensor operational characteristics. This user is also providing invaluable information on construction of a stabilized platform and sensor modifications for aircraft operations. Discussions with this user are underway to explore potential collaborations on a proposal in 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 some limited feedback during the User Workshop the following recommendations have been implemented: 1) explicit wording in the Facility Request Form has been added indicating what is offered at no cost and what will cost more; and 2) an effort has begun to make more reliable what is offered. The third thrust, implementing collaborative software (video conferencing, shared display in flight planning mode, etc.) has not been pushed due to a lack of time caused by extensive 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:

  Significant progress has been achieved on this project. A test facility that will be used to introduce known water vapor mixing ratios at a variety of pressures and temperatures indicative of the surface to ~ 30 km has been designed and a design review carried out. Valuable suggestions for improvements to this design are now being incorporated in the final design. This facility will challenge two TDL systems from SWI at various intervals over a yearlong time period. Many system components have been ordered and machining of the test chamber will begin 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 tests will 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 this project, involves collection of feedback from the broader scientific community with regard to future needs for satellite products and services. This activity has been taken over by a broader NCAR/UCAR committee, but to date progress has been 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:

  The telescoping tower system for fast field deployment has been received and the study to define the soil and radiation sensors to be used has been completed along with the conceptual designs for communications and the hardware to interface to the sensors. A commercial wireless system is now being considered, as the present wireless system has not work as expected. A number of tasks remain to be completed, including testing of this new wireless system, design of the microprocessor and front end circuitry that interfaces to the sensors, integration of components, and lab and field system tests.

9. HOLODEC: Holographic Detector for Clouds

This development is the second small emerging seed project funded by TDL. The HOLODEC development is an aircraft instrument designed to obtain a 2-D profile, 2-D size and 3-D position of cloud particles in the size range of around 15 microns to 1 mm using digital holography. This type of instrument fills an important size measurement gap between instruments that size and count cloud particles by scattering (particles in the size range of 1 to 50 microns) and instruments that 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 leading parts of probe housing, because it can detect the 3-D clustering of shards of shattered particles in the sample volume. This is important as it allows us to estimate how much other instruments overestimate cloud particle densities due to counting shards of shattered particles.

• Status:

  Lenses for the optical system have been specified and ordered and the mechanical designfor the lens housing has started. Materials for both components were carefully assessed to minimize focal length changes due to the large temperature excursions both components will be exposed to. An autocollimator has been specified and ordered to facilitate lens alignment and provide data on angular deviations in the presence of vibrations. The imaging lens assembly will be completed by around mid October and performance laboratory testing will begin 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 ¹³CO₂ to ¹²CO₂ 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:

  Significant progress has been achieved on this instrument over the past several months employing a number of modifications, which will be discussed at length in an upcoming Optics Letters paper. Comprehensive precision and accuracy tests have been carried out in the laboratory using isotopic standards validated by the University of Colorado Stable Isotope Laboratory based upon isotope ratio mass spectrometry. The current performance exceeds 0.02 per mil precision for 150 seconds of averaging and achieves an accuracy of 0.05 per mil on these standards. Additional laboratory tests will be carried out to study the effects of water vapor and variable ambient carbon dioxide concentrations on the retrieved measurement accuracy. Future field tests and scientific measurements employing 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.