GPX , or GPS Exchange Format , is an XML schema designed as a general GPS data format for software applications. This can be used to describe waypoints, tracks, and routes. The format is open and usable without the need to pay license fees. Location data (and optional upgrades, time and other information) are stored in a tag and can be exchanged between a GPS device and software. Common software applications for data include viewing projected tracks to various map sources, annotating maps, and geotagging photos based on their retrieval time.
Video GPS Exchange Format
Tipe data
These are important data contained in GPX files. Ellipsis (...) means the previous element can be repeated. Additional data may be present in every markup but not shown here:
- wptType is an individual waypoint between a set of points without a sequential relationship. It consists of WGS 84 (GPS) coordinates from the point and possibly other descriptive information.
- rteType is the route, the ordered routepoint list (the path point represents a series of turning points or significant stages) leading to the destination.
- trkType is a path, created from at least one segment containing the waypoint, a list of point sequences describing the path. The Trajectory Segment lists a Tracking Point that is logically linked in sequence. To represent a GPS track in which GPS reception is lost, or a GPS receiver is turned off, start a new Track Segment for each continuous path of data path.
Conceptually, a track is a record of where a person has been and a route is a suggestion of where they will go in the future. For example, every point on a track may have a time stamp (because someone is recording where and when they are there), but the points in the route may not have time stamps (other than the estimated travel duration) is a suggestion that may never go through.
Technically:
- a track is generated from a sufficient number of trackpoints to precisely draw each bend on a bitmap. It is good
- raw output, for example, GPS captures one's journey
- or rearranging those points to remove the excess
- or data from any source as extracted from the vector map
- routes are created from points where the program must get the appropriate path from the vector map to draw it. Routepoints may be crossings or intersections or as close as the transit towns, as it makes the project a journey. Therefore, such projects can be saved and reloaded in GPX files.
- a process called routing calculates a route and can generate GPX routes created from attack points where some driver actions take place (turn left, enter roundabout, limiting speed, name of the next direction path, etc...). GPX points can contain text from these instructions.
- GPX files can contain routes and paths so the program can get the right points from the path even if it does not have access to the vector map.
The minimum properties for GPX files are latitude and longitude for each single point. All other elements are optional. Some vendors, such as Humminbird and Garmin, use extensions to GPX format to record street addresses, phone numbers, business categories, air temperature, water depth, and other parameters.
Maps GPS Exchange Format
Unit
Latitude and longitude are expressed in decimal degrees, and elevation in meters, both using WGS data 84. Date and time are not local time, but instead are Coordinated Universal Time (UTC) using ISO 8601 format.
Example GPX document
The following is a truncated GPX file (for brevity) generated by the Garmin Oregon 400t handheld GPS unit. This document does not show all the functions that can be stored in GPX format - for example, there is no waypoint or extension, and this is part of the track, not the route - but the goal is to serve as a brief illustration.
See also
- Drafts
- Places of Interest
- OpenStreetMap, a collaborative project to create free editable maps using, among other things, GPX traces.
- File format
- Redefined image file formats
- Geographic Markography Language
- KML, an equivalent format compatible with Google Earth.
- NMEA 0183
- NMEA 2000
- TCX, Garmin XML Training Center
- Software
- GPSBabel, used to upload/download/convert GPX files
References
External links
- GPX: GPS Exchange Format
Source of the article : Wikipedia
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