The Danish Agency for Climate Data has been collecting oblique aerial photographs for all of Denmark every other year since 2017. These photographs are available as open data on The Danish Data and Map Supply.
Numerous Applications
The Agency’s oblique aerial photographs are produced for use in property valuations by the Danish Property Assessment Agency, but they are made freely available so that everyone can benefit from them. This means anyone needing to view and measure buildings in their authentic surroundings can do so without physically visiting the location.
Therefore, oblique aerial photographs are used in many different professions, including by municipal employees, insurance agents, tradespeople, tree felling companies, and private drone operators.
For example, window cleaning companies have been able to use the images when preparing quotes, as the images allow them to see the number and shape of the windows. Similarly, crane and scaffolding companies have been able to use the images to assess the scope of a job, which previously would have required a physical site visit.
How We Collect Oblique Aerial Photographs
Oblique aerial photographs are collected from aircrafts equipped with cameras that can take five images: one vertical image and one oblique image in each cardinal direction.
The cameras used for these recordings are mapping cameras with stable geometry. Choosing mapping cameras means that the images can be used for surveying and mapping. In addition to the precise cameras, advanced positioning and orientation hardware is used during image capture, making use of GPS and laser gyros to accurately locate and orient the images. This means that objects on the ground can be identified in the images today with an accuracy of better than 2 metres, without post-processing.