GPX is the most commonly supported file format for the exchange of GPS / GNSS related activity data, but is useful for more than just GPS data. Handheld GNSS receivers, custom loggers, smart phones and wearables all tend to provide GPX exports + imports for GPS / GNSS and common sensor data such as heart rate or air temperatures.
The extensibility of the GPX 1.1 schema naturally lends itself to the exchange of spatio-temporal data, especially common sensor data which is by its very nature temporal. Several manufacturers have achieved this using proprietary GPX extensions for data such as heart rate + cadence, air / water temperature and water depth.
However, proprietary GPX extensions can lead to issues when exchanging data between different software applications. Although the big players in the fitness market may be unlikely to change the ways in which they exchange common sensor data, there remains a large number of wider opportunities and use-cases which would benefit from common standards.
This project has been created to capture ideas for a collection of “standard” GPX extensions, initially for data relating to fitness, sailing, aviation, and meteorology. Taking a holistic view has identified a lot of commonality, highlighting opportunities for reusability and avoidance of duplication / redundancy.
Subject to acceptance by the wider GPX community, I firmly believe a collection of “standard” extensions for GPX 1.1 will provide the foundations for the reliable exchange of GNSS + sensor data between different software / hardware providers, especially for the modern-day smart phones and wearables.
In addition to a collection of “standard” extensions, several enhancements may also be made to the core GPX schema, essentially a GPX 1.2. These enhancements should all be fully compatible with GPX 1.1, yet still implementing many of the common suggestions / requests since the release of GPX 1.1.
The contents of this project are likely to be quite fluid as it is primarily to capture ideas and thoughts for discussion within the GPX community. My approach is “commit often, perfect later, publish once” so you should regard everything in these pages as WIP, rather than a polished proposal.
In August 2023, I submitted a proposal for COG, SOG and accuracy estimates in GPX, which I nominally referred to as GPX 1.1.1. This latest project / initiative supersedes the original GPX 1.1.1 proposal, but the original content is still available within this repository as background / reference material.
It is envisaged that this project will start off being a repository for material that can be discussed in the GPX developer list and subsequently be converted into actual XSD documents that can be reviewed and tested. Existing GPX standards should also be adhered to within GPX extensions and the GPX core.
The content of the repository can been regarded as 3 independent initiatives:
Each of the topics above are documented separately, since they can be regarded as independent activities.
Simply click the links above to access the page(s) for each topic.