Proposal for GPX
Environment
Elements such as temperature and water depth have been suggested for the GPX standard:
| Name |
Description |
| atemp |
Air temperature in degrees centigrade (° C) |
| baro |
Barometric pressure in hectopascals (hPa) |
| depth |
Depth of water in metres (m) |
| hum |
Relative humidity as a percentage (%) |
| twd |
True wind direction (TWD), relative to true north in degrees (°) |
| tws |
True wind speed (TWS) in metres per second (m/s) |
| wtemp |
Water temperature in degrees centigrade (° C) |
Omissions:
- There is no need for wind chill, because it is calculated from air temperature and wind speed
- There is no need for dew point or heat index, because they are calculated from air temperature and relative humidity
- There is no need for true wind angle (TWA), because it is calculated from true wind direction (TWD) and heading
References
- GPX developers list
- GPX proposal
- Garmin
- TrackPointExtension v2 - schema
- Sailing Terminology and Definitions - article
- ClueTrust
- GPXData - schema download - search for
<xsd:complexType name="dataPointType">
- NMEA revealed
- $WIMDA - meteorological composite
- NMEA 2000
- Sailmon
- Airmar 200WX-IPX7 - data outputs
- $WIMDA - standard meteorological composite
- $WIMWD - wind direction and speed, with respect to north
- $WIMWR - relative wind direction and speed
- $WIMWT - theoretical wind direction and speed
- $WIMWV - wind speed and angle, in relation to the vessel’s bow / centerline