Augmented reality (AR) has gained a great deal of media attention in recent years, helped in no small measure by the massive mainstream success of Pokemon Go. However, AR has a great deal of potential for real-world applications too, particularly for outdoor users, which has only partly been realised.

A number of geospatial AR apps have been available for some years, including Layar and Wikitude, primarily focusing on points of interest (POIs), buy many are proprietary and closed-source. One potential use of AR, little explored as-yet, is to provide navigation tools for hikers and other outdoor users, by overlaying paths and hiking trails on the camera feed of the device. An early version of the app under discussion, Hikar, was presented at the OpenStreetMap (OSM) "State of the Map" conference in 2013, with the footpaths and trails sourced from OSM, and the latest version, detailed below, has been presented at an emerging technologies event in Northern Ireland (Digital NMD, digitalnmd.org).

After a hiatus, development on Hikar has restarted in the past year, partly inspired by increased mainstream interest in AR. The app is now capable of generating virtual signposts, showing the distance and direction to nearby POIs at path junctions, helping people navigate in the field (examples will be shown in the 'Files' section when available). The talk will include an in-depth technical discussion on how the virtual signposts feature has been implemented.

The Hikar app itself is only one possible application of AR to outdoor use. While Google and Apple have recently made available their ARCore and ARKit frameworks, with impressive results, these are not open-source and (certainly in the case of ARCore) are restricted to certain higher-end devices. There is thus a need for a completely free and open-source framework aimed at outdoor, geographic AR. The presentation will invite discussion and seek collaboration on developing such a framework, which could for example use OpenCV to detect surfaces and therefore more realistically place objects in the same way that ARCore can.

Currently Hikar is restricted in coverage to Britain, Ireland and Greece. This is, however, solely due to the database on the server only containing data for those areas; it is capable of working internationally provided servers are available to provide path and elevation data (work is underway to support the XYZ tile format), has been tested in Greece, and the virtual signposts support Greek and Cyrillic alphabets.The talk will outline how interested parties can setup a Hikar server to cover their country or region of Europe and indeed other parts of the world.

Problems and issues with the app as it stands (such as the realism of the path and signpost placement, and inaccuracies with GPS and mapping data) will be discussed, along with strategies for resolving those problems.