The MFP apparatus for the measurement of turbulent fluxes is also described thereafter. Three such systems were purchased from NOAA in 2003. Two are installed on board ISAFoM ERA aircraft, while a third one is available at IBIMET for the purposes of Carboeurope regional experiment.

Remote sensing apparatus

The acquisition device features a PC104 architecture and a Matrox Imaging 01-MET2-CL+/32 frame grabber, capable of digitizing two 10 bits taps on each channel, allowing for collecting information simultaneously from both the Duncantech 4100 RGB and the CIR cameras at full resolution.  A single Labview executable running under Windows XP operating system, featuring multiple VIs pilots the multispectral as well as the FLIR A40M thermal cameras.

An early hybrid version of such apparatus, also based on a PC104 mother board but featuring a backplane board hosting a PCI NI frame-grabber, will serve as a backup during the intensive campaign in case of failure. For extra security, FLIR and Duncantech will provide spare rental cameras, while a backup 4100 RGB is provided by Federico II University of Napoli.

All cameras are triggered by the 500 Hz TTL signal provided by the Novatel GPS, part of the onboard MFP system, which will also provide environmental parameters required for atmospheric corrections, position and attitude data.

Details and specifications of the cameras are to be found at the following URLs:

-        Duncantech 4100 Multispectral RGB and CIR : <http://www.redlake.com/spectral/mega_MS4100.html>

-        ThermoVision® A40M Infrared Camera : <http://www.flirthermography.com/cameras/camera.asp?camera_id=1040&

MFP

The MFP on the Italian Sky Arrow ERAs system consists of three major pieces of equipment, the MFP computer, the Auxiliary box, and the BAT probe assembly.

MFP Computer:

The MFP computer consists of a single-board computer and industrial chassis from American Portwell Technologies (Chassis: <http://www.portwell.com/irc-306.htm>;

Motherboard: <http://www.portwell.com/robo-698.htm>:

Backplane: <http://www.portwell.com/backplane.htm>).

Two PCI serial cards from Quatech and a custom ISA card finish the system.

Auxiliary Box:

The Auxiliary box is custom built at NOAA/ATDD.  It contains circuit boards for signal conditioning of the auxiliary REM A/D module, power distribution to the assorted discrete instruments, switching circuits for master power control, a pilot-controlled switch box, a set of orthogonal 3-D accelerometers, and a REM A/D module. The pilot-controlled switchbox provides switches for the pilot to control data file write, markers, and events.

The orthogonal 3-D accelerometer board, contains a set of 3-D orthogonal accelerometers used to measure the motion of the center of gravity of the aircraft.  These are used differentially with the 3-D orthogonal accelerometers in the BAT probe assembly to measure high-frequency pitch, roll, and heading angles.

REM Module is a data acquisition module produced by Airborne Research Australia and is capable of digitizing 16 analog channels with 16-bit resolution and providing the data via serial stream to the host MFP computer. (<http://ara.es.flinders.edu.au/;  <http://www.noaa.inel.gov/Capabilities/Bat)

BAT Probe Assembly:

The BAT probe assembly is a system of circuit boards and electronic hardware encased in a weatherproof fiberglass/carbon fiber housing that is mounted on the nose of an aircraft.  The probe assembly consists of a pressure sphere with 9 holes used to measure the magnitude and direction of the incident wind vector on the hemisphere.  A tapered cone afterbody houses a BAT-REM module that is used for digitizing the analog signals and providing a serial data stream to the host MFP computer, much like the BAT-REM module in the auxiliary box.  In addition to pressure measurements, a set of three orthogonal accelerometers is also installed in the pressure sphere to measure high frequency motion of the hemisphere in three dimensions.  High and low frequency air temperature measurements are made utilizing a PRT probe and a micro-bead thermistor.  Static pressure measurements from the pressure sphere round out the BAT probe instrument suite.

BAT-REM Module – This is a data acquisition module produced by Airborne Research Australia and is capable of digitizing 16 analog channels with 16-bit resolution and providing the data via serial stream to the host MFP computer.

The hard disk is used for primary onboard data storage. The Zip drive with IDE interface is used for secondary data storage. The pilot’s switch box contains an instrument power switch, a computer power switch, a file write switch, an event button, and a marker switch.  In addition, two LED’s are used to indicate power and system status. The pilot’s display is a color flat panel VGA display (640x480 resolution) that interfaces to a standard ISA VGA card in the computer box.  The normal mode of operation of the BATSTORE program is an 80-column by 25-row text screen.

Discrete MFP Components:

Several instruments are added to the basic system to enhance measurement capabilities.  The following are a list of instruments added to the Italian Sky Arrow ERA aircraft.  Each is interfaced either through the analog A/D BAT-REM module in the auxiliary box, or directly to the Quatech ESC-100-D9 eight-port serial card in the MFP computer.

• ATDD/FRD turbulence measurement probe (with internal REM module) (BAT-REM) (serial interface); <http://www.noaa.inel.gov/Capabilities/Bat
• Licor-7500 open-path Infrared Gas Analyzer (IRGA) CO₂/H₂O (analog interface); <http://env.licor.com/Products/GasAnalyzers/7500/7500.htm>
• Everest Interscience IR temperature sensor (analog interface);
  <http://www.everestinterscience.com/Products/4000.4ZLprod.htm>
• Riegl distance measuring laser (serial interface); <http://www.rieglusa.com/
• Edgetech dewpoint sensor (analog inteface): <http://www.edgetech.com/mh_200.htm>
• Novatel OEM-G2 RT20 GPS system (serial interface); <http://www.novatel.ca/Products/oem4g2.asp
• Javad AT-4 GPS attitude system (serial interface); <http://www.javad.com/
• UNITEC ETL2000 tick film gas analyzer CO/CH4/Nox/SO (analog interface) (only I-NCOP ISAFoM aircraft);
  <http://www.unitec-srl.com/StaticoUK/etl-busUK.htm>
• REBS Q*7 net radiometer (analog interface)
• Licor Quantum (PAR up/PAR down) (analog inteface)