HOW HAS MODERN TECHNOLOGY CHANGED THE WAY WE MAP THE WORLD?

Izzi Millar (OHS)

Mankind has used maps to help navigate and understand the world from when we first started building settlements. Wall paintings showing maps of streets and houses date all the way back to 6200 BCE. When cartography was first introduced, world maps were based on religious beliefs of how people saw the world and the information that could be gained about local areas. The earliest maps were more decorative and were largely inaccurate, due to lack of information. In around the 6th century BCE, Ptolemy started using mathematical constructions to make more accurate maps of the world. In the modern day, we have many technologies such as GPS which allow us to see our location much more accurately. The advancement of technology has greatly improved how we can map and understand our world.

One of the first known world maps is a clay tablet from the Babylonian period, dating back to around the 6th century BCE. It shows the world as a disk, surrounded by the ‘Bitter River.’ Maps like this are evidently not very accurate but are still useful in showing us how ancient civilisations saw the world according to religious beliefs. Ptolemy was one of the first cartographers to chart the world accurately using mathematical techniques. He wrote eight books on how to map the world so that the maps could be redrawn. Like other early cartographers, Ptolemy divided the equator into 360° to create lines of latitude. He then created lines of longitude by choosing the Fortune Islands as longitude zero, as it was the westernmost point discovered at the time, and took Posidonius’ value for the circumference of Earth to work out the distance of one degree. As Posidonius’ value for the circumference of the Earth was inaccurate, Ptolemy’s coordinates were inaccurate too. For example, in his calculations, the Mediterranean Sea covers 62°, however we now know that it only covers 42°. Ptolemy then calculated the coordinates for around eight thousand places, using information he had gathered from previous astronomical observations. Although Ptolemy’s methods for working out coordinates were correct, due to the inaccuracy of his data, the calculations returned incorrect. Ptolemy’s instructions for mapping were used as the basis of world maps for centuries after they were written and translated into Latin by monks. They were used to make copies of maps when the printing press was invented in the 15th century, and world maps soon became more widely available. The maps were modified with the discoveries of new land and more accurate calculations of coordinates. The first map that showed a complete world was drawn by German cartographer, Waldseemüller, in 1507. The invention of the globe in 1515 gave cartographers a more detailed and accurate view of the Earth. From then, progress in cartography was based on the advancement of scientific and mathematic methods used to calculate positions and distances. The most recent advancement in cartography came with the invention of GPS, making mapping and navigation a lot easier and more precise. GPS was developed during 1970s by the US and was the first global navigation satellite system (GNSS) to be made widely available to the public. GNSS is the general term for a constellation of satellites that provide data for navigation and geo-spatial positioning. Since the 1970s, more GNSS systems have been implemented, most notably Galileo, which was launched by the European Union in 2016. GPS is made up of three elements – satellites, ground control networks, and user equipment. There are 24 GPS satellites orbiting 20,000 km above the Earth at around 8,700 miles per hour in one of six sextants that cover the entirety of Earth’s surface. The satellites are constantly sending out unique microwave signals that can be read by user equipment back on Earth. Ground control monitors the satellites and their signals, as well as providing the satellites with the data they need for time and their position in orbit. User equipment such as mobile phones and sat navs then read the signals coming from satellites. To find a location in 3D, signals must be acquired from at least four satellites. When a device receives a signal from a satellite, the distance from the device to the satellite is worked out. Distances are acquired from at least three other satellites and a position can be worked out using trilateration. This has led to the most accurate world maps being created so far. Positions can be obtained with the accuracy of 15m with GPS, and up to a matter of centimetres with Galileo. GNSS has not just revolutionised mapping and cartography, it has also greatly improved navigation. Many cars now come with built-in sat navs, which use GPS to plan routes and journeys in real time and can use traffic information. The widespread use of technology like Google maps means crowdsourcing can be used to help update maps more efficiently. For example, users can give feedback about the map when roads in their area are created or modified. This creates more accurate and up to date maps all around the world.

Technological advancement has helped change the way that we can map and understand our world. From maps that show just a few streets or the world according to religious beliefs up to an easily accessible and detailed map of the whole world. More technological advances in the future will lead to even greater accuracy in mapping the world and beyond. For example, the

invention of driverless cars relies heavily on GNSS, as the car needs to be able to plan and carry out its own route without human input. GNSS technologies are constantly being improved and upgraded, to make mapping quicker and more accurate, which give us a better understanding of the world we live in.

Bibliography https://mathshistory.st-andrews.ac.uk/HistTopics/ Cartography/ https://www.bl.uk/collection-items/ptolemy-worldmap https://www.gsa.europa.eu/european-gnss/galileo/faq https://www.geotab.com/blog/what-is-gps/ https://www.faa.gov/about/office_org/headquarters_ offices/ato/service_units/techops/navservices/gnss/ faq/gps/ https://www.geotab.com/blog/crowdsourcing-tools/