An interactive photogrammetric image orientation method was used to create the following thesis. The interactive orientation method is used to determine the 3D coordinates of a desired point on a given single image. The method is performed by first determining the external orientation parameters of the image, which means placing the image in space and matching it with the projection of digital surface model (DSM). Once the optimal match was achieved, the perimeter points of the snowfield Skedenj under Prisojnik were acquired from single images in software developed at the Geodetic Institute of Slovenia. The snowfield Skedenj under Prisojnik is located in the Julian Alps in Slovenia. This procedure was repeated seven times for the 2021 images, showing changes during one melting period when the snowfield changed dramatically, as well as for seven images presenting this snowfield in different years, used to determine how the surface changes over time and how the average annual temperature affects the snowfield. Seven images presenting this snowfield in different years were taken 1906, 1915, 1972, 2007, 2008, 2016 and 2021. Additionally, data from national lidar 2014 and orthophoto from Cyclical aerial survey 2020 were used. During the time of one melting season in the year 2021 the snowfield area decreased by more than 70% between the 12th of June and the 18th of September 2021 from 9.15 ha to 2.71 ha respectively. Studying the behaviour of this snowfield in different years, I discovered that on the first two photographs (the postcards) from 1906 and 1915, the snowfield had 10,58 and 11,63 ha. In image 1972 its area was 5,0 ha. In the years between 2007 to 2021 its area was in the range of 1,97 ha to 4,26 ha. Unfortunately, due to the relatively small number of photographs used, we can not give final conclusions on the behaviour of this snowfield when compared to the average annual temperature changes.
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