What3Words Geocoding Extensions

Abstract

With the advent of location-based services, the demand for location data has dramatically increased. Geocoded locations have become necessary in many GIS analysis, cartography, and decision-making workflows. A reliable geocoding system that can effectively return any location on earth with sufficient accuracy is desired. This study is motivated by a need for a geocoding system to support university campus applications. Address-based geocoding systems have been used for decades. However, they present limitations in address resources, address standardization, and address database maintenance. These limitations have recently sparked an interest in developing alternative geocoding systems that apply alphanumeric codes as a reference to locations, such as Geohash, Google’s Open Location Code, and what3words to name a few. Comparing to other geocoders, what3words (w3w) has many advantages. It uses a simple format of code consisting of three words, it is less error-prone, codes are easier to memorize, and multiple languages are supported. However, its fixed resolution (consisting of 3 m by 3 m square cells) and lack of consideration of the third dimension may limit its applicability. To better support geographic applications with special requirements, the w3w geocoding system needs to be extended. This paper proposes extensions of w3w in two aspects: variable resolution and third dimension support. A geocoding processing tool that implements these extensions is being developed to support the need of a university campus’ facility management, emergency evacuation and route navigation planning, student survey data management, and other location-based services.