Air & Space Evidence

The World's First Space Detective Agency

We help clients use photographic, Earth observation and radar based imagery from satellites, drones and aircraft as evidence.

We help individuals, companies and governments with image sourcing and analysis, we advise on the use of satellite imagery to resolve disputes and legal issues and we provide expert witness testimony.

We work closely with governments on earth observation policy issues and tackling environmental problems.

Investigations - Property Intelligence - Research

Below is a list of some of our publications in this specialist area. If you are interested in seeing any of them please drop us a line.



Evidence from Earth Observation Satellites. Emerging Legal Issues, December 2012, Brill / Martinus Nijhoff , ISBN 978-9004194434, 498p (Ray Purdy, editor With Denise Leung).

Journal Articles

'Ruling on sharper satellite images poses a privacy problem we can no longer ignore'. The Conversation, 18 June 2014 (Ray Purdy).

'George Clooney isn’t the only one with an eye in the sky', The Conversation, 2 September 2013 (Ray Purdy).

Attitudes of UK and Australian farmers towards monitoring activity with satellite technologies: Lessons to be learnt’, Space Policy 27, 2011, pp202-212 (Ray Purdy).

Using Earth Observation Technologies for Better Regulatory Compliance and Enforcement of Environmental Laws Journal of Environmental Law Volume 22 Number 1, 2010, pp59-87 (Ray Purdy).

Satellites: A New Era for Environmental Compliance, Journal for European Environmental and Planning Law, Volume 3 Number 5, 2006, pp406-413 (Ray Purdy).

Satellites as a Legal Tool, Bulletin of the European Centre for Space Law, published by the Auspices of the European Space Agency, ECSL No 34, November 2006 (Ray Purdy).

The heat is on, New Law Journal Volume 156, Issue 7225, 2006, p834 (Ray Purdy).

Satellite Photographs: 21st Century Evidence? New Law Journal, March 7 2006 (Ray Purdy, with Richard Macrory).

Ray Purdy The Use of Satellite Images as Evidence in Environmental Actions in Great Britain, Droit et Ville, n° 51, June 2001 (Ray Purdy, with Richard Macrory).

Legal and Privacy Issues of Spy in the Sky Satellites, Mountbatten Journal of Legal Studies, vol 3(1), 1999 (Ray Purdy).

Contribution to Books

‘The Impact of Satellite Technologies in the International Legal Sector: The Story So Far and Implications For the Future’, Derecho Espacial, Vol. XVII, 2014, Plus Ultra Press, Argentina (Ray Purdy).

Pulling the Threads Together and Moving Forward’ in R. Purdy and D. Leung (eds.), Evidence from Earth Observation Satellites. Emerging Legal Issues, December 2012, Brill / Martinus Nijhoff, pp399-424 (Ray Purdy).


Satellite Monitoring of Environmental Laws. Lessons to be learnt from Australia (2010, Centre for Law and the Environment Report, University College London) ISBN 978-0956080615 (Ray Purdy).

Contribution to Reports

Ray Purdy was a contributor to the report - Current Legal Issues for Satellite Earth Observation, European Space Policy Institute, ESPI Report 25, 2010 (Ray Purdy).

Ray wrote the section on Earth Observation in the Manual on Compliance with and Enforcement of Multilateral Environmental Agreements (United Nations Environment Programme, 2006) (Ray Purdy).

Ray Purdy was a contributor to the report - Applications of Earth Observation to the Legal Sector, British National Space Centre publications, 2001.

Ray Purdy was a contributor to the report The APERTURE Report, European Commission, 2000.




Global monitoring: the challenges of access to data, UCL Press - Cavendish Publishing Ltd 2005, London, ISBN 18594 1950X, 229pp (Ray Harris, with R Browning).

Earth Observation Data Policy and Europe, A A Balkema, Lisse, The Netherlands, 2002, ISBN 90 5809 258 5, 211pp, editor (Ray Harris).

Earth Observation Data Policy, John Wiley & Sons Ltd, 1997, Chichester, ISBN 0 471 97188 X, 155pp (Ray Harris).

Satellite remote sensing: an introduction, Routledge and Kegan Paul, 1987,  London ISBN 0 7102 0305 5, 220pp (Ray Harris).

Remote sensing and national mapping, Remote Sensing Society, Reading, 1979) 146pp, ISBN 0 9505798 2 3 (Ray Harris, editor with J A Allan).

Journal Articles

ICSU and the challenges of data and information management for international science, CODATA Data Science Journal, 2013, available at:, DOI: 10.2481/dsj.WDS-001 (Ray Harris, with P Fox).

Reflections on the value of ethics in relation to Earth observation, 2013, International Journal of Remote Sensing, 34(4), 1207 – 1219, DOI:10.1080/01431161.2012.718466 (Ray Harris).

Earth observation and the public good, Space Policy 27 (4), 2011, 194-201, DOI information: 10.1016/j.spacepol.2011.09.010 (Ray Harris, with L Miller).

Current status and recent developments in UK and European remote sensing law and policy, Journal of Space Law 34 (1), 2008, 33-44 (Ray Harris).

The need for air space and outer space demarcation, Space Policy, 22, 2006, 3-7 (Ray Harris, with A Harris).

Changing patterns of global-scale vegetation photosynthesis, 1982-1999, International Journal of Remote Sensing, 26(20), 2005, 4537 – 4563 (Ray Harris, with S Young).

Remote sensing of agriculture change in Oman, International Journal of Remote Sensing 24(23), 2003, 4835-4852 (Ray Harris).

Global Monitoring for Environment and Security: data policy considerations, Space Policy 19(4), 2003, 265-276 (Ray Harris, with R Browning).

Current policy issues in remote sensing: report by the International Policy Advisory Committee of ISPRS, Space Policy 19, 2003, 293-296 (Ray Harris)

Constructing a water-use model for input to the water cloud backscatter model, Agronomie 23, 2003, 711-718 (Ray Harris, with AJ Graham).

Extracting biophysical parameters from remotely sensed radar data: a review of the water cloud model, Progress in Physical Geography 27 (2), 2003, 217-229 (Ray Harris, with AJ Graham).

Scheduling irrigations by merging water-use and radar backscatter models, Irrigation Science 21, 2003, 167-171 (Ray Harris, with AJ Graham).

Earth observation and UK science policy, Space Policy 18, 2002, 205-213 (Ray Harris)

Estimating crop and waveband specific water cloud model parameters using a theoretical backscatter model, International Journal of Remote Sensing, 23 (23), 2002, 5129-5133 (Ray Harris, with AJ Graham).

The implementation of a water-use model to calculate radar backscatter with application to irrigation monitoring, International Journal of Remote Sensing, 23 (23), 2002, 5111-5116 (Ray Harris, with AJ Graham).

The effects of speckle reduction on classification of ERS SAR data, International Journal of Remote Sensing 22(18), 2001, 3627-3641 (Ray Harris, with D Capstick).

Earth observation data archiving in the USA and Europe, Space Policy 17, 2001, 35-48 (Ray Harris, with N Olby).

Earth observation data pricing policy, GIM International 14(11), 2000, 38-41 (Ray Harris)

Harris R and Olby N (2000) European perspectives on trends in public sector Earth observation data policies, Space Policy 16, 2000, 45-59 (Ray Harris, with N Olby).

Some current national and international Earth observation data policies, Space Policy 9(4), 1993, 273‑285 (Ray Harris, with R Krawec).

Earth observation data pricing policy, Space Policy 9(4), 1993, 299‑318 (Ray Harris, with R Krawec).

Satellite remote sensing: high spatial resolution, Progress in  Physical Geography 10, 1987, 515‑522 (Ray Harris).

SIR‑A image of western Kuwait, International Journal of Remote  Sensing 8(2), 1987, 127‑128 (Ray Harris)

Satellite remote sensing: low spatial resolution, Progress in  Physical Geography 9, 1986, 600‑606 (Ray Harris).

Book Chapters

Science, Policy and Evidence in Earth observation, in Purdy R and Leung D (eds) Evidence from Earth Observation Satellites – Emerging Legal Issues, Martinu Nijhoff Publishers, 2012, 43-64 (Ray Harris).

Data policies, in Encyclopedia of Remote Sensing, 2012, eds E G Njoku, M J Abrams, G Asrar, P Minnett, M T Chahine, V Salomonson, A J Chen, V Singhroy, J A Smith and J-M Dubois, Springer, available online at: (Ray Harris).

Satellite Earth observation and disaster management – lessons and needs after the Indian Ocean tsunami and the Haiti earthquake, Yearbook on Space Policy 2009/10, 2011, eds K-U Schrogl, S Pagkratis and B Barnes, Springer-Verlag, Vienna, ISBN 978 3 7091 0941 0, pp 281 – 295 (Ray Harris)

Air and space demarcation, Engineering Earth: The Impacts of Megaengineering Projects, 2011, ed S D Brunn, Springer, Dordrecht, ISBN 978-90-481-9919-8, 2159 – 2170 (Ray Harris, with A Harris)

Remote sensing policy, The SAGE Handbook of Remote Sensing, 2009 eds Warner T, Nellis M D and Foody G, Sage Publications Ltd, London, 18-29, ISBN 978-1-4129-3616-3 (Ray Harris).

Earth observation and principles on data, in Harrison C and J Holder (eds) Law and Geography. Current Legal Issues volume 5, Oxford University Press, Oxford, 2003, 539-555 (Ray Harris).

Conference Publications

(2006) Monitoring environmental degradation in Mongolia with NPP and rainfall data, GOFC-GOLD conference proceedings, Ulan Bator, Mongolia, June 2006 (Ray Harris, with M Tyburski, R Tsolmon, D Sodnomragchaa, and A Warren).

Data policy challenges for remote sensing, Remote Sensing Arabia, Riyadh, Saudi Arabia, International Society of Photogrammetry and Remote Sensing, 2005 conference proceedings (Ray Harris).

Earth observation, data policy and society, in S Kurnaz, F Ince, S Ondasioglu and S Basturk (eds) Proceedings 2nd International Conference on Recent Advances in Space Technology RAST05, 2005, Istanbul, Turkey, IEEE, ISBN 0-7803-8977-8, 78-82 (Ray Harris).

Application of clustering techniques to multispectral data over the ocean, European Space Agency ESRIN, conference proceedings, October 2005 (Ray Harris, with M Joseph, G D Quartly, C Robertson, and V Byfield).

International Charter Space and Major Disasters, Proceedings of the 12th Summer Course in Space Law and Policy, 2003, European Centre for Space Law, Paris, France, 549-552 (Ray Harris).

The role of satellite radar data in agricultural fraud detection, ISPRS Commission VII Symposium Proceedings, 2002, Hyderabad, India (Ray Harris, with AJ Graham).

Data pricing policy, Proceedings of the ISPRS Congress, 2000, Amsterdam, The Netherlands (Ray Harris).

Area estimation of the British potato crop using Earth observation and GIS, Remote Sensing in Agriculture, 2000 (Ray Harris, with J Williams, D Parker, R Turner and D Baker).



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