gps

Horizon GPS Service

The GPS service provides location coordinates and satellite data to other Horizon services.

Input Values

This service takes no input values. By default, this service will try to use gps hardware. If it is not found, the location will be estimated using the edge node's public IP address.

RESTful API

Other Horizon services can use the GPS service by requiring it in its own service definition, and then in its code accessing the GPS REST APIs with the URL:

http://ibm.gps:8080/v1/<api-from-the-list-below>

API: GET /gps/location

---

Parameters:

none

Response:

code:

• 200 -- success
• other http codes TBD

body:

Name	Type	Description
latitude	float	the latitude of the current location
longitude	float	the longitude of the current location
elevation	float	the elevation of the current location in meters
accuracy_km	float	the location accuracy in kilometers
loc_source	string	one of: Manual, Estimated, GPS, or Searching
loc_last_update	float	the timestamp the location was read (UTC)

Example:

curl -sS -w "%{http_code}" http://ibm.gps:8080/v1/gps/location
{
  "latitude": 42.052577333,
  "longitude": -73.960314,
  "elevation": 33,
  "accuracy_km": 0,
  "loc_source": "GPS",
  "loc_last_update": 1498070507
}
200

API: GET /gps/satellites

---

Parameters:

none

Response:

code:

• 200 -- success
• other http codes TBD

body:

Name	Type	Description
satellites	json	array of data for satellites
satellites.PRN	int	PRN ID of the satellite. 1-63 are GNSS satellites, 64-96 are GLONASS satellites, 100-164 are SBAS satellites
satellites.az	int	azimuth, degrees from true north
satellites.el	int	elevation in degrees
satellites.ss	int	signal strength in dB
satellites.used	int	used in current location solution? (SBAS/WAAS/EGNOS satellites may be flagged used if the solution has corrections from them, but not all drivers make this information available)

Example:

curl -sS -w "%{http_code}" http://ibm.gps:8080/v1/gps/satellites
{
  "satellites": [
    {
      "PRN": 1,
      "az": 63,
      "el": 58,
      "ss": 23,
      "used": true
    },
    {
      "PRN": 3,
      "az": 125,
      "el": 20,
      "ss": 27,
      "used": true
    },
    ...
  ]
}