HISTORICAL

IMAGERY PROJECT

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). 

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.

Image examples: 

 

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EvansBay2.png
Evans Bay Wellington 1943

Evans Bay Wellington 2021

A large area of reclaimed land includes two schools, high-density housing, a hotel, commercial spaces and a large sporting arena.

 

CC-BY 4.0 - Wellington City Council

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Tauranga 1943
Tauranga2.png
Tauranga 2020
Urbanisation, also coastal vegetation growth

 

CC-BY 4.0 - BOPLASS Limited

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Wairarapa 1994

Wairarapa 2021

Move from pastoral to forestry

 

CC-BY 4.0 – Greater Wellington Regional Council

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Waiau2.png
Waiau Uwha River 1985

Waiau Uwha River 2016

River alignment

 

CC-BY 4.0 –ECAN

How to access archived imagery
 
Retrolens 

The council partners have developed a free online tool to support access, sharing, and searching for images.  Retrolens has most of the Crown aerial surveys available to preview and download.  Support for Retrolens is provided by Abley (who manages the site).

Visit retrolens.co.nz for more information. 

Note that Retrolens content only includes scans made to mid-2021 and is no longer being updated.

The LINZ Data Service

The LINZ Data service includes records of what images have been scanned, which includes the date that each image was taken in the layer; NZ Aerial Photo Footprints, Mainland NZ, (1936-2005)

https://data.linz.govt.nz/layer/51002-nz-aerial-photos-photo-footprints-1936-2005

You can also request full-resolution TIFF files of the images available from LINZ by emailing topography@linz.govt.nz. Please use the with the subject line “Historical Imagery” and provide the Survey Number, Run, and Photo Number of each image desired.