Instrumentation

Our aircraft currently operates with the following instrumentation.

(NB all installations are fully certified under European Aviation Safety Agency (EASA) regulations)

New for 2011!

Substantial new capabilities are being incorporated during the spring of 2011 following significant investment in new instrumentation. These include:

Hyspex VNIR1600 Hyperspectral Imager

Providing for the first time a true hyperspectral imaging capability, this new system will provide Airborne GeoSciences with truly cutting-edge remote sensing capabilities, with specialisation in very high resolution hyperspectral imaging. See HyperSpectral Imaging for more information.

Picarro G2301-m CH4, CO2 and H2O Flight Analyser

This state-of-the art gas analyser is internally temperature and pressure regulated and utilises the Cavity Ring-Down Spectroscopy (CRDS) technique, providing exceptional precision and accuracy over the wide range of environmental conditions experienced during flight, and without the need for complex and heavy in-flight calibration gas systems. Most importantly of all it provides fast (1Hz) measurement of methane (as well as carbon dioxide and water), which has hitherto represented a major measurement problem for airborne atmospheric chemistry. Please see Picarro Analyser for more information.

Current Instrumentation:

Image (click to enlarge)	Instrument	What is does
	Underwing pod	The under-wing pods house most of our instrumentation, and provide a very large carrying capacity (approx 45 kg instrumentation per pod). The under-wing location is particularly useful for allowing remote sensing equipment a clear downward view, and for mounting turbulence probes away from the influence of the propeller.
	The inside of a pod	Each pod has a basic internal metal framework, shown here painted black. We have built and certified an extension to this framework, painted yellow. Because this extended framework is now certified and of known strength etc, it greatly simplifies the mounting options and certification process for additional instrumentation. We retain the option of removing this extension if required.
	Rear Cabin Space	The aircraft is provided with substantial racking in the rear cabin, capable of carrying up to 30kg of equipment. This is currently used interchangeably for the flask sampling and spectro-radiometer systems (below). Also visible here are the dedicated scientific power distribution system and central control/display computer, mounted on racking to the rear of the cabin space.
	Observer Position	The observer position (right hand seat) is equipped with a daylight readable screen to allow the observer to monitor the progress of the flight and the running of the scientific systems. He is also able to uniquely mark up to 100 sections of data (e.g. specific transects and events) using a simple handset switch.
	Semi-Automated Flask Sampling System	One of the initial roles for the Dimona was to make routine flask sampling flights over our field site near Aberfeldy, Perthshire. We sample into 8 pairs of flasks at 8 levels from a height of about 10,000 feet to about 500 feet above the surface. The system is shown alongside the aircraft before being secured into the racking system in the rear cabin space.
	Very High Precision in-situ CO2 measurement (Li-Cor closed path infra-red gas analyser)	A modified Li6252 is mounted in the right hand under-wing pod. The gas analyzer and associated controllers, electronics and air samples are temperature controlled to ensure consistency through the wide temperature range experienced in flight, and the gas supplies are likewise carefully flow and pressure controlled. Precisely calibrated reference and span gases are used for in-flight calibrations to achieve very high accuracy.
	Best Air Turbulence (BAT) probe	The BAT probe provides accurate calculation 3D wind speeds by measuring differential pressures across the surface of a hemispherical probe. It has very fast response and so allows measurement of turbulent eddies down to less than 2m size. This permits estimation of land-atmosphere exchange of energy and gases such as CO2 by eddy covariance techniques (see also RT3003 and Li-7500 below).
	RT3003 DGPS/INS position and attitude reference	An Oxford Technical Solutions RT3003 DGPS-INS unit is used to provide highly accurate position, attitude, velocity and angular rate information. Such information is essential for the 3D wind calculation (using the BAT probe above), and for calculating pointing angles (and hence ground footprint) of remote sensing and photographic equipment. It is accurate (under good conditions) to just a few cm.
	Li-Cor open-path Infra-red gas analyser (part 1)	The primary task of the Li-7500 is to make fast response measurements of CO2 and water for estimation of surface exchange by eddy covariance, but it also provides redundancy for the in-situ CO2 measurement system. The electronics are mounted inside the pod (see left), while the sensor path itself is mounted externally (below).
	Li-Cor open-path Infra-red gas analyser (part 2)	The Li-7500 sensor path is exposed to the airflow passing the pod (left). The metal mesh evens out pressure distribution and wind speed over the Li-7500 and gives it a small element of physical protection.
	Riegl LD-90 laser altimeter	A laser altimeter is used to measure height above surface, up to a range of approximately 450m. This is very useful information during measurement of surface exchange, and also allows measurement of underlying topography and, potentially, information on vegetation structure.
	ARA Cube microcomputer / logger	ARA DataCube is based on the PC/104 architecture. It contains a PC/104 motherboard, some standard PC/104 boards (amongst them a GPS receiver for timing) and one custom-made PC/104 board with two data ports, each of them capable of ingesting any of our data streams (RS422 from the BAT-REMs, RS232, ARINC429, Collins SDB, etc.). It can also send trigger pulses for external units.
	ASD Spectro-radiometers	Two ASD FieldSpec Pro spectrometers are operated in dual field of view mode (one pointing up to measure irradiance, the other (pictured here during installation) pointing down to measure radiance from below. Each ASD acquires data in the 350 - 2500 nm spectral range. They are operated in conjunction with NERC CTCD and the NERC Field Spectroscopy Unit at The University of Edinburgh. The URL describing the instrument is here
	Canon EOS 5D	A Canon EOS 5D camera is used for vertical in-flight photography. This is invaluable both for recording the nature of the over-flown surface during gas exchange and remote sensing experiments, and for the generation of wide area high resolution photo-mosaics to support ground based field studies. Control is by software controlled from the observer position, with a semi-manual back-up.
Image coming soon.	Meteolabor Dewpoint Hygrometer	A dewpoint hygrometer continuously monitors the dewpoint throughout flight, providing vital meteorological data and information on boundary layer structure.

We are always interested to discuss opportunities for new instrumentation. Please contact Tom Wade or John Moncrieff for more information