Georeferenced orthophotograph of Helsinki from 1964. The shooting has been conducted on 20th and 22nd May 1964. The flight altitude of the shoot was around 1,900 meters. The aerial photographs have been scanned into digital format and have been georeferenced with a terrain resolution of 40 centimeters.
The coordinate system of the orthophotograph is ETRS-GK25 (EPSG:3879).
The data is available as compressed TIFF/TWF file.
The compressed file (591 Mb) includes an index (PDF file, 10 Mb) as well as aerial image as 553 different compressed TIFF photo files and TFW location files. TIFF files have a size of 2500px * 2500px and a terrain resolution of 40 cm.
Format of files: orto_yyyxxx_40cm.tif and the associated orto_yyyxxx_40cm.twf
yyy is the y coordinate and xxx is the x coordinate in the ETRS-GK25 coordinate system used by the City of Helsinki.
Source: Blom Kartta Oy ja Helsingin kaupungin kiinteistövirasto