Bulletin No. 1

INTRODUCTION TO RAF

• Foreword

  The RAF Bulletin series is intended to guide scientists in making effective use of NCAR aircraft. Some of the topics presented here deserve more space than is available. However, we have endeavored to make the material useful to those having little or no experience in the use of an aircraft as an observing system. We invite comments from our facility users on how we might improve this presentation.

1. Introduction

   The Research Aviation Facility (RAF), located at Jefferson County Airport in Broomfield, Colorado, is operated by the National Center for Atmospheric Research (NCAR). NCAR is operated by the University Corporation for Atmospheric Research (UCAR) under the sponsorship of the National Science Foundation (NSF). NCAR aircraft support is available to the scientific community for research. The RAF's facilities are primarily allocated to the investigators of the NSF but are available to other users on a non-interference, cost-reimbursement basis. Highest priority for use of the aircraft is given to projects in the atmospheric sciences. See the EOL web page "Field Project Services:   Requesting Facilities" and the document "Policy, Procedures and Guidelines for Science Programs that Require Field Facilities" for more information.




2. Facilities Available
   
   1. Aircraft
      RAF currently operates two aircraft in support of field projects in the areas of air chemistry, cloud physics, air motion (including mass flow and turbulent flux measurements), radiation, oceanography as it relates to boundary layer processes, and other programs within the atmospheric sciences.

      Current information about RAF and the NCAR aircraft support capabilities are available through the RAF Bulletin series. These are intended to guide scientists in making effective use of this facility. A list of currently-available RAF Bulletins is provided in Appendix I.

      The aircraft available for research purposes are:

      • Gulfstream-V
        See the HIAPER Project Office home page for complete information.
      
      
      • C-130Q (click here to see a photo of the C-130):
        The Lockheed Hercules C-130Q is a four-engine, medium size transport aircraft--the largest aircraft in the NSF/NCAR/RAF fleet. It is an all metal, high wing monoplane powered by four Allison T-56-A-423 turbo-prop engines. The operating ceiling is approximately 8,000 meters above sea level. Since August 1993, the aircraft has been undergoing modifications to accommodate a wide variety of instrumentation used for geosciences research. It became available to the user community with a fairly complete set of instrumentation during the fall of 1994. With its long-range and large-payload capabilities, this aircraft is able to provide worldwide measurements in airborne geosciences research. The size and operating cost of the C-130 are such that principal investigators are encouraged to plan cooperative use whenever feasible. For specific information about this aircraft, see Research Aviation Facility Bulletin No. 3 and Research Aviation Facility Bulletin No. 6.
      
      
      • Naval Research Laboratory P-3:
        Via an arrangement between NSF/UCAR and the Naval Research Laboratory (NRL), a Lockheed P-3 operated by the NRL is being made available for the ELectra DOppler RAdar (ELDORA). More details on this aircraft and its availability will appear here soon.
   
   
   2. Basic Research Instrumentation
      The NSF/NCAR aircraft offer a wide range of sensors to measure a large array of atmospheric parameters. Users can specify instrumentation that is available or can be made available on all three aircraft, including, but not necessarily limited to, the following.
      • Instrumentation for measurement of atmospheric state parameters (temperature, pressure, humidity)
      • Gust-probe instrumentation for turbulent flux measurements
      • Cloud physics instrumentation
      • Radiometers (shortwave, longwave, and ultraviolet)
      • Radiometers for remote surface temperature measurements
      • Scanning Spectral Radiometer and Imaging Microwave Radiometer
      • Video photography equipment
      • Dropwindsonde dispensing-acquisition
      • Oceanographic dropsonde dispensing
      • Instrumentation for atmospheric trace gas sampling
      • Instrumentation for electric field strength sensing
      • Lidar for obtaining vertical profiles of aerosols and clouds

      Several special instrument packages can be made available to the turboprop aircraft users on an "as needed" basis. These must be specifically requested and their deployment depends upon resources provided by other EOL facilities or by RAF.

      Electra Doppler Radar System (ELDORA)

      ELDORA is an airborne, dual-beam, X-band, rapid-scanning radar system mounted on the tail of the aircraft. This unique, rapid-scanning, Doppler radar system allows making air-motion measurements while flying straight lines past weather events of interest. ELDORA is not a permanent part of the instrumentation payload. Installation of this facility requires separate funding approval for a given project. ELDORA is a separate facility within EOL's Research Technology Facility (RTF). RTF is responsible for its operation and for its data products. Inquiries concerning the ELDORA facility should be directed to Wen-Chau Lee, Research Technology Facility, Atmospheric Technology Division, voice: (303) 497-8814, FAX: (303) 497-2044 or via email.
      
      

      Dropwindsonde

      A light-weight dropwindsonde can be launched from the C-130 aircraft. The sondes can provide temperature, humidity, pressure, and wind data profiles while descending to the surface. Information concerning Dropwindsonde requests should be directed to David B. Parsons, Manager, Research Technology Facility, Atmospheric Technology Division, voice: (303) 497-8749, FAX: (303) 497-8770 or via email.
      
      

      Special Air Chemistry Measurements

      Measurements of certain chemical constituents like CO₂, fast-response O₃ and other species require special arrangements with RAF before being made available for a given project. Inquiries concerning chemistry instruments should be directed to Teresa Campos, Atmospheric Chemistry Division, voice: (303) 497-1879, FAX: (303) 497-1092 or via email.

      RAF assumes responsibility for installing and maintaining RAF-supplied instruments. In addition, considerable freedom is permitted in mounting user-supplied instrumentation on the aircraft. RAF will supervise the installation of all user-supplied instrumentation to insure compatibility with existing RAF instrumentation systems and to insure aircraft safety for normal flight operations and for crash-load specifications.

      Typical research applications of airborne measurements obtained with the NCAR aircraft to the atmospheric and oceanic sciences include:
      • Boundary-layer studies, turbulence/flux studies
      • Oceanographic investigations
      • Air-sea interaction studies (Electra, C-130)
      • Cloud physics studies
      • Tropospheric profiling
      • Radiometric measurements, satellite ground truth
      • Atmospheric chemistry studies
      • Aerosol studies
      • Multi-investigator experiments requiring large payloads
      • Experiments in remote regions requiring long range flights
      
      
   3. Data Recording and Processing
      All aircraft are equipped with computer-controlled data logging and display systems that both record data on hard disk drives and provide graphical and tabular output during flight. Data generated during research flights are processed by the RAF Project and Data Support Group to produce final standard output data containing measured and derived measurements. Non-standard data formats may be accommodated only through pre-project planning between users and RAF. RAF has the capability to process raw data in a "quick-look" mode using on-site hardware and software. Although this method is not intended to produce final data for detailed analysis, it does provide both the investigator and RAF personnel the opportunity to examine data in near-real time.
   
   
   
   4. Engineering Support
      RAF can assist all users in the design and fabrication of user-supplied equipment to insure that this equipment meets size, weight, and structural integrity requirements established by RAF.

      Assistance to the user is available in the areas of aeronautical, mechanical, and electrical engineering and design. RAF will provide guidance in atmospheric sampling and atmospheric measurements during the pre-operational phases of the programs. After project completion, RAF personnel are available for guidance in interpreting specific measurements when necessary.

   5. Operational and Scientific Support
      An RAF Project Manager is assigned to serve as the primary interface with the user scientist and to work with him/her to plan the most effective scientific experiment possible. From his knowledge of the program's scientific requirements, the Project Manager may assist in defining particular sensors for the instrumentation package, the design of flight profiles, or the most applicable data processing techniques. The level of scientific participation by RAF is normally limited to project planning, operational assistance, quality control for sensor and data system performance, data processing, and final data delivery to the user.

      On occasion, more extensive scientific participation may be arranged, up to and including RAF's taking "principal investigator" responsibility for the aircraft phase of the program. Usually this level of participation would include responsibility for planning, execution, and analysis of the aircraft measurements within a larger multi-institutional research program. Intermediate levels of scientific participation at the co-investigator level are encouraged where expertise exists at RAF. Participation beyond what RAF defines as normal would be at the request of the user.

      RAF pilots will work with investigators through the RAF Project Manager in planning missions, obtaining FAA clearances, and meeting any special requests concerning flight operations. Requests for diplomatic clearances, required when operating in most foreign countries, will be initiated by RAF.

3. Operational Program Participation

   Scientific investigators are required to guide and participate in the in-flight conduct of the research. This may be done through delegation to another qualified member of the scientific group or through delegation to a qualified member of the RAF support team. RAF provides instrumentation personnel routinely on the large, multi-user aircraft.

   In all such cases, it is necessary for the scientific investigator and the investigator's group to visit RAF prior to the field program to receive orientation and training in the use of the instrumentation and data systems. These individuals will also participate in the instrumentation flight tests which are conducted prior to the scientific field-phase of the program.

1.    Introduction to RAF (This bulletin)

3.    The NSF/NCAR Hercules C-130Q: Overview and Summary of Capabilities

4.    The NSF/NCAR Electra: Overview and Summary of Capabilities

6.    Flight Planning: The NSF/NCAR Hercules C-130Q

7.    Flight Planning: The NSF/NCAR Electra

8.    ADS Input and Output Signal Interface Description

9.    Standard Output Data Products from the NCAR Research Aviation Facility

12.    Mounting User-Supplied Equipment on the NSF/NCAR L-188C Electra

13.    Design, Fabrication, and Approval of User-Supplied Equipment for NSF/NCAR Aircraft

RAF Design Guide RAF-DG-00-001, Non-metallic materials usage aboard NSF/NCAR aircraft

21.    Pressure Measurement from NCAR Aircraft (Oct. 1991 edition)

22.    Airborne Humidity Measurements (Oct. 1987 edition)

23.    Measurement Techniques: Air Motion Sensing (Nov. 1989 edition)

24.    Airborne Measurements for Cloud Microphysics (Jan. 1989 edition)

25.    Radiation Measurements from NCAR Aircraft