The aim of this article is to present how the quizzes published as part of the “Quiztime” series can be solved, which purpose is to enable the learning of GEOINT techniques with challenges on Twitter.

Posted by Fiete Stegers on March 20, 2020 on Twitter, the goal of the challenge was to determine the exact geographical position of where the following photo was taken:

Initial image of the challenge
Several answers of different levels of precision were expected:
Level 1: Is this Hamburg?
Note that it is a good idea to begin by rotating the image 90° counter-clockwise and determining the elements that seem relevant in the window reflection.

Image after rotation and specification of relevant elements
Ⓐ The environment has heavy vegetation but still looks like a city. Ⓑ & Ⓒ Two buildings with quite specific architectures and longitudinal buildings are present in the photo. Ⓓ It was not possible to identify the orange elements, but these make one think of ring buoys because of their color and therefore of a potentially river/port environment.
After switching the view to Satellite mode and 3D on Google Maps, I started my search looking for the items listed above in Hamburg, as the post subtly mentioned, possibly looking for a spot near the Elbe.
Flying over Hamburg we quickly find the two buildings Ⓑ because they overlook the city given their height.

Aerial view of buildings Ⓑ (Google Maps)
So the answer is : yes.
Level 2: At which coordinates was the picture taken?
After a few rotations by moving the image using the mouse while holding down the CTRL key on the keyboard (or CMD on MacOS) it is possible to find all the elements Ⓐ, Ⓑ, Ⓒ and Ⓓ and the place where the photo may have been taken.

Aerial view of elements Ⓐ, Ⓑ, Ⓒ and Ⓓ (Google Maps)

Comparison of initial photo and aerial view of elements Ⓐ, Ⓑ, Ⓒ and Ⓓ (Google Maps)
The photo was taken at the following GPS coordinates: 53.543356, 9.934946, from a balcony of the Nordakademie Graduate school as shown in items ① and ② below.

Comparison of the structure of the Nordakademie Graduate school with the initial photo
Level 3: …And at which height (don’t trust my GPS)?
Regarding the last level, the goal was to determine at what height the photo was taken, and it is possible to estimate it approximately by calculating it according to the element ①. Indeed, looking for photos of the facade of the Nordakademie Graduate School, we notice that small panels are present on the railing of the first floor of the school.

Panels on the first floor railing of the Nordakademie Graduate School
Not being visible on the photograph posted by Fiete Stegers, we can assume that the photo would be taken on the second floor and by admitting that the average height of a floor in Europe varies between 2.5 and 2.7 meters, we can conclude that the photo was taken approximately 7 meters high. However, more recent photos from the Nordakademie Graduate School, from the summer of 2019, show that one of the panels has been removed from the railing, so it could also be that the photo was taken from 4 meters high.