Once some of the councils had the historic aerial photos in digital format, needs arose for using them for particular purposes. One pressing matter was the spatial accuracy for some tasks. For some tasks it was decided that orthorectification would enhance the product.
An initial pilot was undertaken. Then, after a tender process, Imagine Map, now known as SKYVUW Limited, was given a contract to orthorectify 43 surveys which contained about 10,000 images. Only fully completed surveys were chosen to ensure there wasn't double handing at a later date. For this contract there were three of the partners involved – ECan, Bay of Plenty and the Waikato Regional Council. Bay of Plenty and the Waikato Regional Council have undertaken an additional project in 2017 and further ad hoc pieces of work have been contracted through 2018.
Other councils have also seen the need to orthorectify and have served up a number of datasets in this way to their community, such as Tasman DC.
Orthorectification can be an expensive exercise so collaboration and funding is needed. If you have a need and some funds please be in touch with the Gill Lawrence and or Glen Clarkin.