Positioning, or Geolocation or GPS or whatever other name you want to use; it’s is so ubiquitous that we barely give it a second look. And its easy to miss how it plays out IRL; the purpose of this essay is to explain how Geolocation works, how the methods used vary, why it matters and most importantly, what is the value in decentralizing it.
For the sake of consistency, I will use the term “geolocation” as a catch-all term for positioning, localization, tracking etc.; and if not, I will say so.
With that. Lets jump into this.
Let’s start with an analogy…
Imagine a ship, in the middle of the sea back in the 1600s, trying to figure out its location. To achieve this, the navigator relies on one of two methods:
- Knowledge of celestial objects’ positions relative to the ship’s departure point and time.
- Identifiable reference points visible or accessible around the ship, with predetermined locations on a map.
In both cases, the process is similar. The navigator employs basic trigonometry and geometry to calculate their position on a map in relation to the reference points. It’s important to note that this positioning is relative, and to this day, most geolocation systems operate on similar principles.
While the art and science of geolocation is too old for use to delve into it here; it’s basic premise has remained largely consistent over time.
Datum
The relative positioning we just discussed involves establishing a reference frame for measurements. This frame of reference is formally known as a Geodetic Datum, or simply Datum. A Datum is a defined surface used to pinpoint locations in space, primarily on Earth. Interestingly, the first large-scale survey to establish a geodetic datum was conducted in India from 1802 to 1871.
With the advent of GPS, we adopted a universally coordinated Datum called the WGS84. However, various global and local datums exist for more precise positioning and specialized applications. Geodetic datums serve as the foundation for all geospatial, location-based, and other geographical sciences and services.
To emphasize their significance, consider the map of the United States projected using different datums — the discrepancies are substantial.
This is where our discussion becomes more specific. Geodetic datums play a crucial role in both conventional geolocation and emerging decentralized positioning technologies.
Geolocation
We are all familiar with GPS, which is practically synonymous with geolocation. GPS represents the earliest version of satellite-based positioning and is owned and operated by the US Department of Defense (now the Space Force). Although GPS is often used as a general term, it is just one component of satellite-based positioning. Globally, we rely on nearly six to seven different versions, with approximately 105 satellites operated by various national space programs. The collective term for these systems is GNSS (Global Navigation Satellite Systems).
Satellites in these systems are essentially highly accurate, synchronized clocks orbiting the Earth. Satellite navigation involves matching satellite positions in orbit with ground stations and utilizing these matched positions, along with signals received by your devices, to determine your location. Typically, four satellite signals are used to calculate the final location.
The heart of the matter is…
While the process may seem straightforward, GPS is susceptible to errors, and our heavy reliance on it magnifies the consequences of these errors. Various factors contribute to these errors, including atmospheric distortions of signals, distortions based on the chosen datum, clock inaccuracies, and orbital errors.
Apart from the general-errors introduced by environmental conditions, the existing GPS-GNSS infrastructure has structural problems, that pose a challenge for scaling, future-use and adaptability.
- Datum Based Distortions: As discussed earlier, GPS uses the WGS84. As a result, distortions happen across the board, based on the projections being used in relation to WGS84.
- Ephemeris (Orbital Errors)
- Clock Errors
- Environmental Errors
Additionally, a major concern with GPS is its unverifiable nature. Spoofing is really easy, and even without spoofing, verifying the accuracy of GPS data is impossible.
Pirates & Non-traditional Navigation
If we go back to the analogy of the ship and delve deeper, the means of achieving location is entirely dependent on their purpose. So the means for achieving location for a pirate can not be the same as that for a navigator.
Between 1650–1730, the North Atlantic Ocean was dominated by Pirates. With their base in the the Caribbean, and control extending Eastward till Europe through the Azores; Pirates preyed on the trade routes between European nations and South American, South Asian and African colonies.
In theory, Pirate dominance in the sea makes no sense. They did not have proper equipment, weapons or most importantly, functioning vessels. They circumvented these weaknesses by being excellent at two things; first, the element of surprise in warfare and second, non-traditional navigation.
Colonial and trade vessels had almanacs, navigation equipment, professional navigators and information gathered from all shipping expeditions for reference. In contrast, we have pirate ships; basically patchwork vessels built from scraps of shipwrecks, barely any equipment and outdated almanacs. Despite the obvious disadvantage, Pirates would win by tilting the game in their own favor.
Navigating and moving across the ocean is a data game. For a navigator/colonial officer in a formal ship, a reference point is often imagined as a perfect entity, like a lighthouse but for the pirates, everything, ranging from a rock outcrop to a region where certain birds fly during a certain time of the year is a reference point.
Pirates would aggregate sightings, localized information and develop heuristics to determine not only where things were, but also how things might move in the ocean. From exchanging information about weather patterns in bars to understanding what reference points would emerge at what time of the year.
Pirates made the ocean their own domain. They knew it so well, that they could tell where what was by the color of the water; and that was enough for them to trap, engage and capture any vessel they wanted.
Here’s the takeaway; instead concentrating their solutions on methods and practices; the pirates treated the ocean as a field to explore, learn and understand by stitching together information piece by piece and coordinating extensively,
They built methods to gather data, to convert those data points to reference points, and localized their navigation systems around them. While the process of celestial navigation was great for putting a pin on a map; a pin on a map is not what happens IRL.
So, what’s the point here…?
The point here is two-fold.
The first, about data and the second about localization. The most accurate way to verify a location, is to be as close to it as possible. Both physically, and in terms of knowledge. GPS is like looking at ants on the porch from the roof of a house, you can track one pretty well, but you can never be sure. If you want to, you got to get down to base level and check out those ants up close.
To verify a location’s accuracy, one must get as close to it as possible, both physically and in terms of knowledge. Building a network of reference points that can be localized and communicated with is crucial for accurate location verification, just like pirates used localized information to navigate the ocean.
Proof of Location
And coming up close to base level is what Proof of Location is all about. While pirates dealt with natural elements and were limited by the tools of their time; we now have the ability to build our own reference points, create scalable tools around them and deploy them to accommodate out various requirements.
Devices with fixed locations and communication abilities, are the most obvious choices for building this network. By localizing these reference points, we are able to correct for common GPS errors caused due to atmospheric distortion, datum errors and some of the other challenges we discussed earlier. And by using decentralized networks built on-chain, we are able to incorporate trustlessness and verifiability into the process.
And while this has been attempted before, the challenge has always been scaling a network of these reference points across the world; building a globally localized datum if you will. A possible reason being the single-use nature of these devices. A network built exclusively for proof of location is severely limited in its ability to become as ubiquitous as GPS.
Taking a cue from pirates, this process is not about systematically scaling Physical Reference Points across the world; but about using everything that can be a Reference, as one. So instead of looking to build a network solely for this purpose, it would be better to set rules that help in identifying whether a network is well-suited to become our Globally-Localized Datum (GTD).
- Reference points must be fixed in space. i.e, Fixed Locations
- We should be able to communicate with these Reference points. i.e, Wireless Communication Capable
- The value of each node in the network is directly proportional to the number of spectrums it supports. i.e, Devices limited to one spectrum (for eg. LoRa Only) are of lower value and vice versa.
And while this list is not-exhaustive, we can continue to build this as the space evolves.
Conclusion
Geolocation has been an integral component of our lives for centuries. However, as we have seen, this technology is not without flaws, and its reliance on GPS has led to significant issues.
Learning from pirates and extending to Web3, we can gain insights from the past and use that knowledge to develop better ways of navigating the world around us. By creating a network of localized reference points, we build a more accurate system for verifying location. While this is a work in progress, we remain optimistic about the future.
Stay tuned on this blog and follow us on twitter to learn more about how we’re building this network.
