Development of a UAV-mounted Imaging FTIR for real-time monitoring of natural and anthropogenic hazards

Natural hazards are characterised by the large area affected, rapidly changing scale and extent of the effects, and severe disruption to access and communication to the affected areas. During and after the onset of a natural disaster an accurate and immediate assessment of the extent and severity of the effects of the event is critical in order to assist the deployment of emergency services and to implement an effective mitigation strategy. The assessment requirement for anthropogenic hazards differs in that the location and spatial extent of the facility is known and is usually relatively restricted. The requirement for monitoring is therefore for high spatial and temporal resolution monitoring over extended periods over often highly complex infrastructure which can often be elevated 10s of metres off the ground. Acquisition of sampling datasets with the essential 2 and 3D spatial and temporal resolution and detection sensitivity to address the requirements of the emergency services, regulatory agencies and commercial users is a significant monitoring challenge and poses a critical market need. A diverse range of researchers, interest groups, commercial and emergency and regulatory organisations require the detection, quantification and differentiation of surface gas releases at spatial scales ranging from point source to landscape scale.

Identification of the sources and fluxes of fugitive releases of hydrocarbon gas is a critical component of a number of emergency and commercial monitoring strategies. Biogenic gas is composed almost entirely of methane whereas thermogenic (natural) hydrocarbon gas is composed of a mixture of methane, propane, butane and ethane. Gas emissions from landfill sites are a common environmental issue faced by councils and the environment agency while fugitive emissions from pipelines are a very expensive and inconvenient problem for many commercial organisations ranging from domestic supply to large-scale petro-chemical facilities.

Current methods to meet these challenges are still largely ground-based and manual. While ground-based methods are locally highly effective the limitation in the coverage of observations can often result in a poor understanding of the nature and extent of the hazard resulting in less effective containment and response strategies producing more severe and longer lasting effects. Remote-sensed based approaches have been implemented using a range of sensors and platforms however their operational utility has been severely limited as they cannot derive the most important physical parameters required for hazard monitoring (surface temperature and especially gas species identification and quantification) at the necessary ultra-high spatial resolution in real-time.

There is an urgent need for the development of a low-cost, rugged, low mass, imaging system that can be mounted on a UAV that has the capability to detect and differentiate fugitive gas escapes and resolve surface temperature accurately. Currently available imaging based gas monitoring instruments are not capable of resolving the hydrocarbon gases with sufficient accuracy. Imaging Fourier Transform Interferometers (FTIRs) have the potential to detect and quantify hydrocarbon emissions but the current design of imaging FTIRs have a very high power consumption, are very heavy and are prohibitively expensive for operational deployment on a UAV.

The aim of this project is to develop, and validate a low cost, lightweight, compact imaging Fourier Transform InfraRed (FTIR) spectrometer that can be operational mounted on a UAV that has sufficient spectral resolution and radiometric sensitivity to detect and quantify fugitive gas escapes. The ability to extract the spectral emissivity and surface temperature measurements will enable the surface temperature to be resolved much more accurately and emission spectra images will enable the presence of humans and identification of infrastructure more accurately .

This project will have a range of significant and immediate benefits for regulatory and emergency services and also a variety of opportunities for commercial development.

Emergency Services
Emergency services all over the world have the same requirement for accurate, detailed information on the nature and extent of the effects of the event over the whole of the affected area as quickly as possible. As the areas affected are often large and access and communication within the affected areas is often severely disrupted the available information is often incomplete and out-of-date. The inability to identify the location and nature of some of the most dangerous aspects of a natural disaster, e.g. gas escapes, fires and accurately locate people is a major limitation. The high spectral resolution imaging FTIR to be developed from this project will be able to be deployed on a UAV rapidly after the onset of the natural hazard. It can be deployed continuously, day and night, over hazardous localities covering extended providing ultra-high spatial resolution imagery in real-time to the emergency services. The low cost and rugged nature of the system means that it would be a viable option for emergency services around the world. The ability to detect methane and carbon dioxide emissions from volcanoes would assist the emergency services in assessing the location, scale and degree of potential volcanic hazard and provide additional early warning capabilities

Regulatory Agencies and Environmental scientists
There are a wide range of environmental monitoring activities that regulatory agencies around the world are required to implement. Monitoring the spatial extent of the dispersion of gas from landfills, sewage works and other types of contaminated land would be of immediate use to environmental scientists. The requirement for the monitoring of gas escapes from abandoned and active coal workings as well as the future requirement for extensive monitoring of proposed unconventional gas developments presents a severe challenge to regulatory agencies due to large spatial extent of the areas affected and the requirement for continuous measurement for extended periods.


There are a variety of applications for this system that would be suitable for immediate commercial development

Gas Utility and Petrochemical facilities

The extent of natural gas leaks from the mains pipeline in the UK is extensive and is a major financial and operational concern for gas suppliers . The ability to acquire ultra-high spatial resolution imagery capable of detecting these leaks would assist the gas suppliers to identify the location of these leaks. Gas pipeline leaks around the world make up a significant commercial loss particularly in countries where the pipelines are very long and the maintenance regime is not very thorough. A low cost, methodology for detecting the volume, extent and source location of gas leaks would be of very significant interest to a variety of commercial organisations. In petro-chemical facilities the three-dimensional nature of the pipework provides a very challenging environment for complete, continuous measurement of gas escapes and locations with anomalously hot pipework. The ability to continuous monitor these parameters from above would be of great health & safety as well as commercial interest.

Mineral and Hydrocarbon Exploration Geologists
The ability to detect remotely surface expressions of mineralisation and also sedimentary stratigraphy at the landscape scale would provide an exceptionally powerful first-pass exploration tool for assessing the resource potential.

Precision Agriculture
The ability to acquire emission spectral imagery coincident with atmospheric information would provide a powerful methodology to apply to precision agriculture applications

Survelliance
Emission Spectral Imaging is a significantly more sensitive methodology for the detection of people than thermal cameras.