Aerial photographs have been taken since the 1930’s for Helsinki’s own use. The photographs have been used for tasks such as city planning, mapping, and in the planning and treatment of the natural environment.
The City of Helsinki has been photographed yearly for maps. The photographing has mainly been done in the scale of 1:10,000 and 1:4,000.
An orthophotograph is a photograph taken from a plane straight towards the ground surface, which has been corrected for distortions and compiled into a seamless aerial photograph that has been attached to the coordinate system.
The aerial photographs have been used to produce orthophotographs and orthophotograph series. The City survey services’s orthophotograph series can be viewed by
clicking here to go to kartta.hel.fi, Helsinki’s map service.
These photographs can be used to create combinations of aerial photographs according to the needs of the customer. False-colour aerial photographs are also available from certain years.
The photographers of the City survey services have photographed Helsinki from the air for several years to accommodate the needs of customers. The number of oblique photographs taken, based on separate orders, is approximately 1,000–2,500 per year. A browsing archive with thousands of oblique photographs from different years is available at the City survey services.
Since lidar technologies became more common, lidar data has been ordered yearly in connection to the aerial photographing. Laser point cloud materials of the entire City area are available since 1999. Each year, only parts of the city are scanned, which means that the material spanning the entire City is compiled by combining scans from different years. Laser point cloud materials are available in LAS and POD file formats.