Researching your site (4) - air photographs

Air photographs provide a different perspective on your site, showing buildings and open spaces but also sometimes capturing indications of buried archaeological remains. Air photographs taken on different dates (and on the same day from other angles or in changing light) may show very different features. It is frequently important to locate any air photographs which are available, even though it may be impractical to view many as part of the research. If the site and adjacent land has been developed or been covered with trees since the mid-20th century, air photographs may have little or nothing to contribute. 
The most available source is GoogleEarth imagery, which has often been taken on three or more dates. Unfortunately the exact date of the image is not always the date given, and this reduces the precision in documenting when an outbuilding was demolished or a field ditch backfilled.
The National Monuments Record holds copies or originals of air photographs from across the country, which can be studied at Swindon or purchased. Where appropriate, my research will include commissioning a search (a fee applies) which lists any air photographs they hold. Often I will select one or more, and order copies to be included in your report (a fee applies and a charge may be levied for reproduction).  
Air photographs are also held in other national collections and by councils. These will be tracked down if proportionate to the potential impact of your proposals.
If your planning proposals affect a large area of open land where indications of archaeological remains have been identified on air photographs, the planners may request a 'sketch-plot' of the features. For this, a specialist identifies all the features of potential interest from all the available photos, and maps them to scale. I can arrange this service for you if required.  
Please always alert me to any air photographs you have of your site!