Historic Aerial Imagery

LINZ has scanned negatives of all crown imagery that was obtained between 1936-2008. You can discover what imagery is available using several methods, ordered from easiest to most involved:

• Retrolens is probably the easiest source to find imagery. However the site stopped absorbing new scans from LINZ several years ago, so the website only offers only a subset of the actual collection.  The images are also downsampled.  However, due to the nice interface, it is a good first place to search.
• Aerial footprints on LINZ Data Service, the most up-to-date record of everything that LINZ holds. One caveat to using the footprints layer: around 40% of the records do not have associated geometries.  So, clicking a point on the map won’t find those Surveys.
• Searching the metadata in the footprints file above to see what is available. Most of the surveys will be in there with a description of their coverage. The best way to do that is to query the data in GIS software - the QGIS LINZ plugin is particularly useful for these types of processes. For surveys where we don’t hold a survey chart or geometries…it’s exceedingly difficult to determine what they cover. One way to search the dat a is to look through the survey charts and find an relevant survey, then search the metadata. If an item has been scanned it will have a  “Y” in the scanned field.  If it hasn’t, and it falls in the SN10500-13000 range, then it’s probably a negative still held by Aerial Surveys and you’d need to contact them.

LINZ currently are able to provide any of the imagery, free of charge, as a courtesy service.  If you’d like to request frames, you need to know the Survey No, Run, and Photo No for each item, preferably in a spreadsheet that can be sorted by each field. If requests are small (less than 20 images) and are sent via dropbox.  Any requests exceeding 8-10 GB will need to be sent another way, such as courier a portable hard drive. You can email them directly with requests.

Aerial Surveys are a commercial company that flies aerial surveys. For quite awhile they would scan them for a free, but we would have to inquire to see if that is still the case.

Any question get in touch: Jonathan