Up until the beginning of the 16th Century, most maps of cities were drawn from a hillside view, also called a side-on or birds-eye perspective. They often lacked accuracy as buildings in the forefront would appear larger than equally sized buildings in the the distance. The surrounding landscape and prominent features were often exaggerated. Many would even include mythical creatures and important figures of the time.
Today, we might view these drawings as portraits of cities rather than as maps: they conveyed an impression of the city through the eye of an artist and were less useful as accurate depictions of geography or city infrastructure.
The art of cartography changed forever when the perspective changed. That happened in 1502 when the illegitimate son of Pope Alexandre VI, the mercenary leader and Italian cardinal, Cesare Borgia, hired Leonardo da Vinci to draw the city of Imola, Italy. As a result of this commission, Leonardo would eventually create the first ichnographic map or ‘satellite’ map.
Borgia, who later became the main inspiration for Niccolò Machiavelli’s The Prince, conquered the town of Imola in 1499. He soon persuaded da Vinci to travel to Imola and work for him as a military engineer. He tasked da Vinci with drawing an accurate map of the fort of Imola.
Historians believe Leonardo drew his map by starting at a central point in the town square and using two tools at his disposal: an odometer and a compass. A compass he likely used for direction. An odometer is thought to have been used to measure out the exact dimensions of the fort’s streets and walls.
An odometer is a wheeled device that measures distance. The odometer is believed to have been first invented by Archimedes and later Vitruvius.
Vitruvius’s Ten Books on Architecture (27-23 B.C.E) is the only surviving work on architecture that survived the classical antiquity. In it Vitruvius defines Ichnography as the “appropriate use of the ruler and the compass” and “from this are obtained the descriptions of the forms of on the ground”.
Vitruvius had an influence on Leonardo da Vinci’s work and Leonardo applied this theory to the mapping of Imola. It is believed that Leonardo created several odometers for his various mapping and construction efforts. His intent was to create a map of Imola, in in which the fort “is represented as if viewed from an infinite number of viewpoints, all perpendicular to each topographical feat”.
Leonardo never saw the city from above. Using science and his imagination, Leonardo was able to create a near perfect  topographical map of Imola, without the help of aviation technology (unless we assume his helicopter idea actually worked). In similar ways, open-source investigators have been using the same principles to geolocate, map, discover, and verify, without leaving their homes.
When reading about the history of this map I could not help but draw comparisons to the use of maps in open-source, citizen-led investigative work. Both practical and theoretical.
One example that springs to mind is the effort to determine the timeframe in which an event took place using shadows and direction of the sun visible in images posted to social media or other open sources (a practice that has since been dubbed as chronolocation). The science behind using shadows to tell time has existed for millennia, yet we used it today to verify footage from, for example, conflict areas like Ukraine or Syria. Sometimes the truly innovative and important investigative work comes from appropriating old ideas and techniques to discover new truths, much like Leonardo borrowed from Vitruvius.
I imagine Leonardo would probably have been an excellent open-source investigator.
Historically, maps and cartography have been used as a tool by the powerful as a means to oppress. Edward Said, the pioneer of postcolonial studies, wrote about how maps would be used as “instruments of conquest”. Geographer Bernard Nietschmann wrote “more indigenous territory has been claimed by maps than by guns.” Da Vinci’s map, despite its ingenuity, is no different. It was drawn for military purposes, not cultural or social, but for control and power.
In May 2022, Maxar and Planet, two of the most popular satellite imagery providers were awarded contracts from the US intelligence agency worth billions. Google itself has a long history of being involved in Pentagon projects, something Google Employees have been fighting for some time. Map providers and their association with state and corporate power around the world have direct implications in citizens’ abilities to investigate crimes and human rights abuses. An infamous case is Google’s satellite imagery coverage of Israel-Palestine: Google Maps intentionally blurred imagery in much of Israel and Palestine due to a US National Security law from 1997 which prohibited all US-based companies from publishing high-res imagery (of what?) (most of Israel is still blurred today in Google Maps). In addition, it has been noted that the frequency with which satellite imagery of Israel or Palestine has been updated is much reduced in comparison with other conflict areas such as Donbass in Ukraine post-2014 and Syria post-2011.
This demonstrates that maps (including satellite imagery) continue to be a battle ground between the oppressed and the oppressors. It also illustrates the fragile space in which open-source, citizen-led investigations operate, where access to evidence and information can be determined by a company’s algorithm or a nations legislation.
That said, maps can be used as a force for good. Both Said and Nietschmann, writing in the 1990s, agree on the possibility to use maps defend or resist against the powerful. Said, in the context of Palestine, discussed creating maps as a method to reclaim colonized territory. He called such maps ‘counter-maps’ (see also ‘counter-cartography’ or ‘critical cartography’). Perhaps not in the exact way Said envisioned, maps today nonetheless are used as a ‘tool of resistance’ against state or corporate wrongdoing, whether in documenting detention facilities, accounts of police violence, or monitoring deforestation. In all of these cases, maps have been important tools for citizen-led investigations and frequently used to visualize evidence and findings.
 Sinisgalli, R. (2012). Vitruvius. In Perspective in the Visual Culture of Classical Antiquity (pp. 61-99). Cambridge: Cambridge University Press. doi:10.1017/CBO9781139198905.004
 Pinto, John A. “Origins and Development of the Ichnographic City Plan.” Journal of the Society of Architectural Historians 35, no. 1 (1976): 35–50. https://doi.org/10.2307/988969.
 Scholars that compared the finished work to previous sketches noted that da Vinci had manipulated the location of certain buildings to make the city look more balanced. Leonardo had a thing for the aesthetics, just like some contemporary investigative studios..