Massive Atmospheric Volume Instrumentation System

At the centre of this proposal lies the following concept for an atmospheric sensing system: a fleet of small, very light, instrumented gliders are released en masse from a high altitude meteorological balloon over the environment to be observed. During their autopilot-guided descent along paths optimized for sampling efficiency, they collect a dense set of readings, which can subsequently be converted into an accurate map of the quantity being observed.

The need for a large scale, affordable, distributed atmospheric sensing capability is increasingly pressing in the face of a variety of current challenges:

- minimizing the disruption caused by volcano eruptions (the Eyjafjallajökull event was estimated to have been the cause of GDP losses exceeding 4 billion pounds in 2010)
- protecting the population from major pollution events such as Fukushima and Chernobyl.
- understanding of the processes underlying atmospheric phenomena especially in remote or polar regions where data are sparse but their climatological significance is large.
- improving medium term forecasting of extreme events, such as the recent highly unpredictable landfall in the UK of the remnants of hurricane Nadine; forecast uncertainty can be reduced by targeted data assimilation.

While piloted research aircraft are capable of meeting some of these requirements, they have a number of shortfalls:

- for safety reasons, piloted operations are not possible, e.g. in the vicinity of erupting volcanoes or sources of pollution, severe storms, remote areas far from suitable emergency diversion airfields
- due to limited availability and flexibility use involves long range planning, putting data at the risk of weather and other factors
- access, where piloted aircraft require complex infra-structure (airports) and when these are not locally available, large long-endurance aircraft that are very costly to operate.

In our proposed glider fleet based system each aircraft, under autopilot control, takes an individual, pre-planned descent path such that the sampling volume of the entire fleet is maximised. Each aircraft can be programmed to land at a common collection point, e.g. the balloon launch site, or, if required, land in a distributed pattern across a target surface if the craft are expected to continue to carry on taking measurements once on the ground.

Linking the aircraft into a network enables a dynamic task. The fleet could become an adaptive swarm: if the live, constantly updated approximation model built upon the data they collect predicts high density of the measured quantity in a specific area, part of the fleet (a later tranche of the same release sequence) could be automatically re-tasked to aid in the mapping of this promising location.

Different missions require different measurement criteria, e.g. different instrumentation packages, launch heights, descent rates and ability to sample upwind of the launch point. One size, therefore, does not fit all, if such a system is to be truly efficient. Thus, instead of engineering a single vehicle, we aim to build a rapid development system, which, upon receipt of the mission requirements of a particular sampling task, enables us to design, build and test a suitable, bespoke vehicle in a matter of less than ten days. After much recent development in automated multi-disciplinary design optimization (MDO) technologies (based on high performance computer simulations) and rapid prototyping techniques, the time is now right to build such a system.

The Southampton team has long experience in both MDO and rapid prototyping of UAV airframes and on-board avionics. SAMS have in-house experience of operating robotic aircraft in harsh environments, and are closely networked to future users of such a system and in this capacity undertake to steer the development of the system in a direction where, by the end of the project, it can become a valuable national facility.

The need to deploy lightweight instruments into the atmosphere pervades many fields and there is therefore high demand for this type of capability. At present, dropsondes and weather balloon-borne radiosondes are used to meet this demand - partially. The non-recoverable nature of these systems severely limits their usefulness. The volume of data they can record is limited by the meagre bandwidth of their radio frequency data links, expensive instruments have to be thrown away each time they are launched, they are a source of pollution and their sampling capabilities are limited to vertical profiling.

The proposed framework will be capable of the rapid development of unmanned systesm that do not have any of these shortfalls and is expected to have comparable - most likely lower - costs. The operating cost will certainly be lower, as the instruments (as well as ancillary equipment, such as GPS units, batteries, etc.) will be recovered after each flight, enabling their re-use. Beyond improving capabilities for current users of radiosondes and dropsondes, the MAVIS unmanned air system proposed here as part of the ASTRA initiative is aimed at giving an atmospheric sampling capability to scientists who, at present, think that they cannot afford a dense sampling of a block of airspace, who do not wish to lose precious instruments for a single trace through the atmosphere or who would like to conduct experimental campaigns over topography that makes the deployment of existing systems awkward at best and often impossible.

Beyond the scientific uses discussed in this proposal, successful deployment of the system would, we expect, raise interest elsewhere, including the defence industry (a potential application being chemical topography of urban environments) or the nuclear industry (fallout monitoring).

This project also encompasses a broad spectrum of engineering science challenges, from trajectory optimization, through aircraft aerodynamic and structural optimization to systems design. The diversity of this effort, coupled with seeing a development project through from concept to flight testing, will present a unique professional development opportunity for the researchers involved, in particular for the PDRA. MAVIS would also enable the two existing ASTRA PhD students to see an immediate application of their reserach as part of a scientifically and industrially relevant service - the same applies to technologies previously developed by the ASTRA team, including a new aircraft geometry modelling tool (developed as part of the Southampton PI's Royal Academy of Engineering Research Fellowship), as well as the Unmanned Air Vehicle rapid manufacturing technologies developed by the Southampton Co-I (as demonstrated by SULSA, the Southampton University Laser Sintered Aeroplane).

Beyond the impact on the two scientific communities (geoscientists and engineers), MAVIS has the potential to re-engineer the ways in which local and central government agencies look at air pollution monitoring. Whether the densities of emissions from chemical plants, oil refineries, cities or even large maritime vessels need to be mapped or their spreading understood, MAVIS could provide a fast response, low cost and safe solution and through a series of open reviews scheduled for the duration of the project, we will ensure that they are made aware of these capabilities.

It is also our intention to turn MAVIS into a succesful commercial enterprise with the potential to radically change the landscape of atmospheric sampling technology.