Preserving historical aerial photos

Our seven-year project to scan the Crown Aerial Film Archive is now in its closing stages. Since 2014 over 600,000 images have been sourced from throughout the country, many dating as far back as the 1930s. 

Before this project, the only way to use this valuable resource was to ‘find’ the original photo prints or pay hefty amounts to scan individual photos or surveys. They are now preserved and made available, free of charge, under the Creative Commons Attribution 4.0 International licence.

Over the coming months, LINZ will work with Archives New Zealand to safeguard the original negatives and retire the scanners. Where necessary some councils are also undertaking orthorectification to enhance and correct the imagery spatially.  

 

Background 

The Crown’s Aerial Film Archive includes around 650,000 historical photo negatives, gathered from 7,300 aerial surveys flown between 1936 and 2008. The Photos were originally captured for a range of purposes, including photogrammetry and topographic mapping, Defence training, land management, and town planning.

​In 2014 we began our project to scan and digitise the archive. The project has been jointly funded by LINZ in conjunction with several local authorities, with the scanning being undertaken by WSP in Napier.  Using two increasingly rare photogrammetric Leica scanners, they have scanned negatives at resolutions of either 14 or 21 microns (depending on the original film's quality). 

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Potential applications

While our primary aim is to conserve these images as a national taonga, the new archive also creates new opportunities.

These include:

• Identifying past land use that is potentially hazardous, affecting how land can be used or treated in the future (such as horticultural sites, closed landfill sites, timber treatment, and sheep dip sites)

• Using imagery to assess historical land cover for specific periods (for example to review forest landcover prior to 1990 for the Emissions Trading Scheme)

• Tracking changes in river paths and coastal environment

 

The archive provides a unique visual reference point to how our landscape has changed (or not) over time.

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Image examples: 

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