The Software

Aschauer put a huge amount of time and work into developing a program capable of computing the panoramic views; at the time, there simply wasn't an application on the market suitable for his purposes. In particular, evaluating the satellite images caused problems because legacy programs were unable to create a panoramic view in the form of a uniform river course from them.

This prompted Aschauer to develop two programs, both of which he released under the GPL and published on the GitHub platform: Satlisca [3] and Malisca [4]. A historic form of representation provided the impetus for the development of Satlisca, which is designed for working with satellite images. In historic literature on cartography dating back to the first half of the 19th century, the artist found several comparative representations of the courses of rivers that visualized the river in a symbolic way in strips (Figure 4).

Figure 4: A length comparison of long rivers dating back to 1817. Published with the kind approval of David Rumsey, Cartography Associates, San Francisco [5].

Based on this model, and using publicly accessible images from the NASA Landsat 7 program and OpenStreetMap, Aschauer developed the Satlisca application, which uses various parameters and line-scanning methods to create an image with a geographically accurately rotated image of the course of the river in question as a straight line. The artist used this approach to create satellite panoramas of rivers, including the Nile, Amazon, Yangtze, Ob, Yellow, Mekong, Ganges, Brahmaputra, Euphrates, Rhine, and Danube. Aschauer then plotted hard copies of these unusual views of the major rivers, which he exhibited in a 120x250cm format in an exhibition titled "What If You Would Pull Rivers To A Straight Line?" (sic) in 2010 and 2011.

Malisca, which is written in the C programming language, also acts as a line scanner, but it's designed for use with a movie camera. Malisca relies on the GStreamer sources, OpenGL, and various GPS libraries for this. Thanks to a small Python front end called Camcontrol, the artist was able to manage the Elphel 353 camera precisely and thus create a uniform image of the river bank independent of the actual geographic conditions. Armed with this equipment, Aschauer created panoramas of the Danube, Nile, Ganges, Brahmaputra, and Amazon rivers (Figure 5).

Figure 5: The Amazon offers a uniform panorama over long distances.

Animation

Aschauer, however, was not satisfied with the photographic renderings of the river courses to propagate his own experimental style of cartography. In a further step, he decided to transcend the boundaries between static documentation and realistic-looking animation. To do so, the video artist generated a movie from the existing static material using DCP Cinemascope; it presents the five rivers with their different characteristics in short summaries of 10 minutes each. The 51-minute movie created this way was first aired in Vienna in May 2013 [6].

Beyond this project, the programming artist also developed a web player based on the GeoDjango framework and the OpenLayers library to let viewers experience the river panorama in a realistic way in a web browser. Playing back the panoramas gives viewers the impression of traveling on a boat along the river themselves. The River View Player [7], of which version 2.0 beta now exists, also gives the viewer the ability to change the boat's speed (i.e., the speed of the animation) and set the zoom factor (Figure 6). Additionally, a topographical map based on OpenStreetMap is available to help viewers trace the route of the "river cruise" (Figure 7).

Figure 6: The River View Player by artist Michael Aschauer takes viewers on a boat trip.

Figure 7: Thanks to OpenStreetMap, the River View Player shows the viewer the current location.

Conclusions

Michael Aschauer's river studies impressively demonstrate the options offered to creative minds by free and open source software, along with hardware that offers transparent documentation. Aschauer has succeeded in transcending the borders between legacy and experimental geography, while also creating a totally new visualization approach that combines static and dynamic animated elements.

Thanks to his profound knowledge as a software developer, Aschauer was able to write his own software tools to suit the special requirements of his own style of photographic cartography. Of course, he released these programs under the GPL, thus making them freely available to anyone interested in using them. It is, not least, this willingness to contribute to the free software universe that explains its amazing development dynamic that has already outpaced proprietary solutions.