The following elements can all be added to <wpt>, <rtept> and <trkpt> elements in the GPX 1.1.1 proposal.
They are all optional, although the values of <course> and <speed> as provided by the GPS / GNSS chipset are highly recommended in GPX 1.1.1 files.
| Name | Description |
|---|---|
<course> |
Course over ground (COG) in degrees is the actual direction of travel relative to true north. COG is an independent measurement from position, so it is possible (and not an error) for the difference between two successive positions to be inconsistent with the COG values. |
<speed> |
Speed over ground (SOG) in m/s is the horizontal speed calculated by the GPS / GNSS chipset. SOG is an independent measurement from position, so it is possible (and not an error) for the difference between two successive positions to be inconsistent with the SOG values. |
<roc> |
Rate of climb (ROC) in m/s is the vertical speed calculated by the GPS / GNSS chipset. ROC is an independent measurement from position, so it is possible (and not an error) for the difference between two successive positions to be inconsistent with the ROC values. |
The following accuracy elements can all be added to <wpt>, <rtept> and <trkpt> elements in the proposed GPX 1.1.1.
These are available from a variety of NMEA sentences, binary messages and location services provided by Apple and Android.
| Name | Description |
|---|---|
<hacc> |
Horizontal accuracy / error estimate in meters, such that the difference from the true position and the reported position is less than the accuracy / error estimate 68% of the time. 68% corresponds to 1-sigma of a normal distribution, but this does not imply that errors are independent or normally distributed. |
<vacc> |
Vertical accuracy / error estimate in meters, such that the difference from the true position and the reported position is less than the accuracy / error estimate 68% of the time. 68% corresponds to 1-sigma of a normal distribution, but this does not imply that errors are independent or normally distributed. |
<cacc> |
Course over ground (COG) accuracy / error estimate in degrees, such that the difference from the true COG and the reported COG is less than the accuracy / error estimate 68% of the time. 68% corresponds to 1-sigma of a normal distribution, but this does not imply that errors are independent or normally distributed. |
<sacc> |
Speed over ground (SOG) accuracy / error estimate in m/s, such that the difference from the true SOG and the reported SOG is less than the accuracy / error estimate 68% of the time. 68% corresponds to 1-sigma of a normal distribution, but this does not imply that errors are independent or normally distributed. |
<racc> |
Rate of climb (ROC) accuracy / error estimate in m/s, such that the difference from the true ROC and the reported ROC is less than the accuracy / error estimate 68% of the time. 68% corresponds to 1-sigma of a normal distribution, but this does not imply that errors are independent or normally distributed. |
GPX 1.0 and 1.1 both support <src> elements in <wpt>, <rte>, <rtept>, <trk>, and <trkpt> elements.
These are simply xsd:string types and may contain values such as “Garmin eTrex” or “Sailmon Max”.
The GPX 1.1.1 proposal introduces a more sophisticated <src> element containing <device> and <software>.
<device> contains the following optional elements:
| Name | Description |
|---|---|
<manufacturer> |
Manufacturer of the GPS device / wearable. e.g. “Samsung” |
<product> |
Product name of the GPS device / wearable, preferably without mentioning the product manufacturer. e.g. “Galaxy A53” |
<model> |
Model number of the GPS device / wearable. e.g. “SM-A536BZKNEUB” |
<serial> |
Serial number of the GPS device / wearable. e.g. “ABCDE9ABC9X” |
<name> |
Name of the GPS device / wearable, typically chosen by the owner. e.g. “Mike’s A53” |
<version> |
Firmware / software / OS version of the GPS device / wearable. e.g. “android13-5.10-A536BXXS7CWG2” |
<software> contains the following optional elements:
| Name | Description |
|---|---|
<developer> |
Developer of the software / application used to capture + export the GPS data. This may match the “creator” attribute but unlike “creator”, it should persist after (possible) post-processing. e.g. “barbeauDev” |
<application> |
Name of the software / application used to capture + export the GPS data. This may match the “creator” attribute but unlike “creator”, it should persist after (possible) post-processing. e.g. “GPSTest” |
<link> |
GPX link to the software / application used to capture + export the GPS data. e.g. <link href="https://github.com/barbeau/gpstest"><text>GitHub</text></link> |
<version> |
Version of the software / application used to capture + export the GPS data. e.g. “3.10.3” |
Note: Since the <src> element is a “mixed” type you can still include a simple string to describe the device, such as “Apple Watch Series 8”.
This approach will help ensure forward and backward compatibility with existing software.