LGGA HISTORICAL

IMAGERY PROJECT

Background

Land Information NZ (LINZ) is responsible for the oversight of the Crown’s archive of aerial photos flown over the country since the 1930s.

 

It was decided in 2014 to undertake a project to scan/digitise the archive, a project that is expected to be completed in 2020. The project is a jointly funded project between LINZ and local authorities. The contract for the scanning has been awarded to WSP-Opus. LINZ approached a number of councils who set up syndicates to become the initial partners.


The first councils were Environment Canterbury, Environment Bay of Plenty, Waikato Regional Council and Auckland Council. Since the initial scanning other partners have joined: Tasman District Council, Hawkes Bay Regional Council, Gisborne District Council, Marlborough Regional Council, Northland Regional Council, Otago Regional Council, Southland Regional Council, Taranaki Regional Council, and Wellington Regional Council. The partners agreed priorities for their scans. LINZ manage the prioritised scans through to WSP-Opus.

Progress to date

Scanning is now at 88% with actual numbers in March 2019 being 450,000 images scanned.  The project is going as planned with Auckland, Bay of Plenty, Canterbury, Gisborne, Marlborough, Tasman, Waikato, and Wellington over 95% complete. The remaining imagery for those regions primarily being made up of 5 inch films which are being held back to the end of the project in order to preserve the condition of the scanners. This phase of the project will complete in the 2019 calendar year with all the partner regions of the Crown archive scanned.

 

WSP-Opus uses two specially refurbished scanners for this project, ongoing maintenance ensuring they both keep going steadily.

Crown scanning has been paused for two months currently to enable WSP-OPUS to run a pilot to refine cost and effort estimations for scanning the NZAM Archive.

A larger scale means that the image is clearer, and it is easier to see details. Both images below are of Christchurch Cathedral around the same time. The first image was taken at a scale of 1:5,580, the second image was taken at a scale of 1:15,900.

 

In the first image (1:5,580), paths, tram lines, building outlines and other features are clearly visible. In the second image (1:15,900) outlines are blurred, visibility of tramlines is lost in places and only vaguely visible in other places, it is difficult to distinguish between paths and roads. An image with clear detail is more useful, particularly for uses such as land contamination assessment, river channel movements, coastal erosion or accretion.

Estimated NZAM Images per Decade by Region

A larger scale means that the image is clearer, and it is easier to see details. Both images below are of Christchurch Cathedral around the same time. The first image was taken at a scale of 1:5,580, the second image was taken at a scale of 1:15,900.

 

In the first image (1:5,580), paths, tram lines, building outlines and other features are clearly visible. In the second image (1:15,900) outlines are blurred, visibility of tramlines is lost in places and only vaguely visible in other places, it is difficult to distinguish between paths and roads. An image with clear detail is more useful, particularly for uses such as land contamination assessment, river channel movements, coastal erosion or accretion.

A business case is currently being written to secure funding for this scanning. Co-funding will be required, similar to the Crown Archive model.  If you wish to find out more about the NZAM Archive either contact the LGGA or Deb Jones listed below.

Figure 1: Christchurch Cathedral – 30/05/1946 – scale 1:5580
Figure 2: Christchurch Cathedral – 16/08/1950 – scale 1:15900
Getting the images of your area scanned

If you wish to have the images for your area scanned, please make contact with Bjorn Johns, LINZ. (04 4600 580 or bjohns@linz.govt.nz)

Historic viewer - Retrolens

It's one thing to have the image scanned, but it's quite another to be able to use these effectively.  The partners found that when staff were trying to use the images it wasn’t easy to share them because of the size; it was all too easy to spend quite a bit of time opening an image only to find some time later that it was the wrong one.  

 

The size of the hard drives each quarter were also causing some consternation about storage.  How many times can you go to your IT colleagues asking for more storage space? There was also an awareness that where there are syndicate partnerships that there are a number of councils who have contributed funds and therefore should have the photos, but then there is considerable duplication. 

 

So the partners decided to set about creating a national historic imagery viewer - Retrolens.  View the Retrolens project  tab to see more details or go directly to the website  http://retrolens.nz. 

 

Othorectification 

The second pressing matter once the scanned images had been received was the spatial accuracy for some tasks.  For some tasks it was decided that orthorectification would enhance the product.

 

Go to the Orthorectification project tab to see more information about what has been undertaken so far and who to contact if you wish to undertake a project, perhaps in collaboration with others.

 

Get in touch

lggacomms@gmail.com

© 2023 by LGGA.