Applications

Application	Description	Example Flight Profile (Google Earth Image)
Land-Atmosphere exchange of CO2, water and energy	By simultaneously sampling low-level atmospheric turbulence (in particular its vertical component) and the concentration of a scalar such as CO2, water or heat, it is possible to calculate the net flux of that scalar into or out of the land surface using a technique called eddy covariance. This permits spatially averaged surface fluxes to be measured over scales that are not attainable using fixed ground apparatus alone, and acts as a mechanism by which to investigate the effects of surface heterogeneity over regional scales. NB: All low level operations are conducted with the necessary low-level exemptions from the relevant aviation authorities.
Hyperspectral remote sensing	Using our two ASD spectrometers we are able to measure accurate reflectance values over the spectral range 350-2500nm, with very fine spectral resolution. This allows mapping of various vegetation indices providing information on plant productivity and stress at resolutions finer than those available from satellites, but on comparable scales. Thus we are able to provide a bridge between ground measurements and satellite earth observation. Coupled with the CO2 flux data (above) this can provide insight into the effects of plant system dynamics on land-atmosphere exchange of gases such as CO2 and water. Due to the high performance of these instruments and the limited atmospheric interference at low altitudes it is also possible to observe fluorescence resulting from certain photosynthetic processes and so gain insights into the influence of various factors on photosynthetic activity over a number of scales.
Photographic survey	G-GEOS’ aerial photography has proved to be a very popular tool for the scaling of field studies to wider areas; we are able to provide much higher resolution images than are available from satellites, but still over quite wide areas (e.g. mosaics covering 10km square grids at 20-30cm resolution, with nested grids and transects at around 2-5cm resolution). High-resolution imagery also has application within biodiversity research, for example by identifying suitable vegetation composition/structure for particular bird habitats.
Landscape – regional scale atmospheric carbon budgets	By measuring the concentration of a gas (e.g. CO2) in a mass of air flowing into a region, and measuring the concentration again as the same mass of air flows out of a region, it should be possible to estimate the amount of that gas exchanged with the surface below. This is the basis of a box-budgeting approach illustrated to the right. In real life complications occur and this technique is currently under development.
Boundary layer profiles	We are able to utilise flask samples (collected in the air and returned to the ground for very precise analysis of various species), and in-situ measurements of CO2, water and other meteorological parameters to probe the structure and composition of the atmospheric boundary layer. Applications include the monitoring of regional - continental scale carbon dynamics, as well as the study of boundary layer processes which have impact on weather and climate. The image to the right illustrates a flask sampling profile in Scotland; figure-of-eight patterns are flown at each level, with all turns directed into wind to ensure clean air is sampled.
Mapping of surface topography	While it is not a fully fledged laser-scanning device, G-GEOS’ laser altimeter does record a very large amount of data on surface elevation that can be compiled into a dataset to contribute towards a DEM. During low-level sampling flights we continuously record first return signals from the altimeter at 100Hz, resulting in vast datasets over frequently sampled field-sites. Accuracy of the instrument is stated to be 4cm; the main limit on accuracy of any resulting elevation model will therefore be the position and attitude data from the RT3003 DGPS/INS. The image shows an example of the cumulative tracks over a field-site in Finland over the course of a short field campaign.

Other Applications

There are of course an enormous number of potential applications for the aircraft, and we are very happy to discuss new ideas with interested researchers. Please contact Tom Wade or John Moncrieff.

Future applications are likely to include:

- Flight testing and development of UoE's proposed Airborne Multi-Spectral Canopy Lidar (AMSCL)

- Boundary layer flow in complex terrain

- Hyperspectral imaging of vegetation in genetic studies

- Geological and geomorphological research (e.g. photographic and hyperspectral survey and potentially laser-scanning).

- Archeological research (e.g. photographic survey)

- Snow melt mapping and snow dynamics studies

... and many more