Merge pull request #653 from RideReport/issue-616

Resolve #616 and #589 by bringing rich telemetry data into definition of Geographic Data
openmobilityfoundation · Jul 23, 2021 · 024d553 · 024d553
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diff --git a/agency/README.md b/agency/README.md
@@ -250,8 +250,8 @@ A standard point of vehicle telemetry. References to latitude and longitude impl
 | `gps.lng`      | Double         | Required              | Longitude of the location                                    |
 | `gps.altitude` | Double         | Required if Available | Altitude above mean sea level in meters                      |
 | `gps.heading`  | Double         | Required if Available | Degrees - clockwise starting at 0 degrees at true North      |
-| `gps.speed`    | Float          | Required if Available | Speed in meters / sec                                        |
-| `gps.accuracy` | Float          | Required if Available | Accuracy in meters                                           |
+| `gps.speed`    | Float          | Required if Available | Estimated speed in meters / sec as reported by the GPS chipset                                        |
+| `gps.accuracy` | Float          | Required if Available | Horizontal accuracy, in meters                                           |
 | `gps.hdop`     | Float          | Required if Available | Horizontal GPS or GNSS accuracy value (see [hdop][hdop]) |
 | `gps.satellites` | Integer      | Required if Available | Number of GPS or GNSS satellites
 | `charge`       | Float          | Required if Applicable | Percent battery charge of vehicle, expressed between 0 and 1 |

diff --git a/general-information.md b/general-information.md
@@ -9,6 +9,7 @@ This document contains specifications that are shared between the various MDS AP
 * [Definitions](#definitions)
 * [Devices](#devices)
 * [Geographic Data][geo]
+  * [Geographic Telemetry Data](#geographic-telemetry-data)
   * [Stop-based Geographic Data](#stop-based-geographic-data)
   * [Intersection Operation](#intersection-operation)
 * [Geography-Driven Events](#geography-driven-events)
@@ -73,14 +74,32 @@ Additionally, `device_id` must remain constant for the device's lifetime of serv
 
 References to geographic datatypes (Point, MultiPolygon, etc.) imply coordinates encoded in the [WGS 84 (EPSG:4326)][wgs84] standard GPS or GNSS projection expressed as [Decimal Degrees][decimal-degrees]. When points are used, you may assume a 20 meter buffer around the point when needed.
 
-Whenever an individual location coordinate measurement is presented, it must be
-represented as a GeoJSON [`Feature`][geojson-feature] object with a corresponding [`timestamp`][ts] property and [`Point`][geojson-point] geometry:
+### Geographic Telemetry Data
+
+Whenever a vehicle location coordinate measurement is presented, it must be
+represented as a GeoJSON [`Feature`][geojson-feature] object with a corresponding
+`properties` object with the following properties:
+
+
+| Field          | Type           | Required/Optional     | Field Description                                            |
+| -------------- | -------------- | --------------------- | ------------------------------------------------------------ |
+| `timestamp`    | [timestamp][ts]      | Required              | Date/time that event occurred. Based on GPS or GNSS clock            |
+| `altitude` | Double         | Required if Available | Altitude above mean sea level in meters                      |
+| `heading`  | Double         | Required if Available | Degrees - clockwise starting at 0 degrees at true North      |
+| `speed`    | Float          | Required if Available | Estimated speed in meters / sec as reported by the GPS chipset                                         |
+| `accuracy` | Float          | Required if Available | Horizontal accuracy, in meters                                           |
+| `hdop`     | Float          | Required if Available | Horizontal GPS or GNSS accuracy value (see [hdop][hdop]) |
+| `satellites` | Integer      | Required if Available | Number of GPS or GNSS satellites
+
+Example of a vehicle location GeoJSON [`Feature`][geojson-feature] object:
 
 ```json
 {
     "type": "Feature",
     "properties": {
-        "timestamp": 1529968782421
+        "timestamp": 1529968782421,
+        "accuracy": 10,
+        "speed": 1.21
     },
     "geometry": {
         "type": "Point",
@@ -444,6 +463,7 @@ If an unsupported or invalid version is requested, the API must respond with a s
 
 [agency]: /agency/README.md
 [decimal-degrees]: https://en.wikipedia.org/wiki/Decimal_degrees
+[hdop]: https://en.wikipedia.org/wiki/Dilution_of_precision_(navigation)
 [gbfs-station-info]: https://github.com/NABSA/gbfs/blob/master/gbfs.md#station_informationjson
 [gbfs-station-status]: https://github.com/NABSA/gbfs/blob/master/gbfs.md#station_statusjson
 [general-stops]: /general-information.md#stops

diff --git a/provider/README.md b/provider/README.md
@@ -218,7 +218,7 @@ For the near-ish real time use cases, please use the [events][events] endpoint.
 
 ### Routes
 
-To represent a route, MDS `provider` APIs must create a GeoJSON [`FeatureCollection`][geojson-feature-collection], which includes every [observed point][geo] in the route, even those which occur outside the [municipality boundary][muni-boundary].
+To represent a route, MDS `provider` APIs must create a GeoJSON [`FeatureCollection`][geojson-feature-collection], which includes every [observed point][point-geo] in the route, even those which occur outside the [municipality boundary][muni-boundary].
 
 Routes must include at least 2 points: the start point and end point. Routes must include all possible GPS or GNSS samples collected by a Provider. Providers may round the latitude and longitude to the level of precision representing the maximum accuracy of the specific measurement. For example, [a-GPS][agps] is accurate to 5 decimal places, [differential GPS][dgps] is generally accurate to 6 decimal places. Providers may round those readings to the appropriate number for their systems.
 
@@ -290,7 +290,7 @@ Unless stated otherwise by the municipality, this endpoint must return only thos
 | `event_types` | Enum[] | Required | [Vehicle event(s)][vehicle-events] for state change, allowable values determined by `vehicle_state` |
 | `event_time` | [timestamp][ts] | Required | Date/time that event occurred at. See [Event Times][event-times] |
 | `publication_time` | [timestamp][ts] | Optional | Date/time that event became available through the status changes endpoint |
-| `event_location` | GeoJSON [Point Feature][geo] | Required | See also [Stop-based Geographic Data][stop-based-geo]. |
+| `event_location` | GeoJSON [Point Feature][point-geo] | Required | See also [Stop-based Geographic Data][stop-based-geo]. |
 | `event_geographies` | UUID[] | Optional | **[Beta feature](/general-information.md#beta-features):** *Yes (as of 1.1.0)*. Array of Geography UUIDs consisting of every Geography that contains the location of the status change. See [Geography Driven Events][geography-driven-events]. Required if `event_location` is not present. |
 | `battery_pct` | Float | Required if Applicable | Percent battery charge of device, expressed between 0 and 1 |
 | `trip_id` | UUID | Required if Applicable | Trip UUID (foreign key to Trips API), required if `event_types` contains `trip_start`, `trip_end`, `trip_cancel`, `trip_enter_jurisdiction`, or `trip_leave_jurisdiction` |
@@ -573,8 +573,8 @@ In addition to the standard [Provider payload wrapper](#response-format), respon
 | `last_event_time` | [timestamp][ts] | Required | Date/time when last state change occurred. See [Event Times][event-times] |
 | `last_vehicle_state` | Enum | Required | [Vehicle state][vehicle-states] of most recent state change. |
 | `last_event_types` | Enum[] | Required | [Vehicle event(s)][vehicle-events] of most recent state change, allowable values determined by `last_vehicle_state`. |
-| `last_event_location` | GeoJSON [Point Feature][geo]| Required | Location of vehicle's last event. See also [Stop-based Geographic Data][stop-based-geo]. |
-| `current_location` | GeoJSON [Point Feature][geo] | Required if Applicable | Current location of vehicle if different from last event, and the vehicle is not currently on a trip. See also [Stop-based Geographic Data][stop-based-geo]. |
+| `last_event_location` | GeoJSON [Point Feature][point-geo]| Required | Location of vehicle's last event. See also [Stop-based Geographic Data][stop-based-geo]. |
+| `current_location` | GeoJSON [Point Feature][point-geo] | Required if Applicable | Current location of vehicle if different from last event, and the vehicle is not currently on a trip. See also [Stop-based Geographic Data][stop-based-geo]. |
 | `battery_pct` | Float | Required if Applicable | Percent battery charge of device, expressed between 0 and 1 |
 
 [Top][toc]
@@ -590,7 +590,6 @@ In addition to the standard [Provider payload wrapper](#response-format), respon
 [event-times]: #event-times
 [gbfs]: https://github.com/NABSA/gbfs
 [general-information]: /general-information.md
-[geo]: /general-information.md#geographic-data
 [geography-driven-events]: /general-information.md#geography-driven-events
 [geojson-feature-collection]: https://tools.ietf.org/html/rfc7946#section-3.3
 [iana]: https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
@@ -599,6 +598,7 @@ In addition to the standard [Provider payload wrapper](#response-format), respon
 [json-api-pagination]: http://jsonapi.org/format/#fetching-pagination
 [json-schema]: https://json-schema.org
 [muni-boundary]: #municipality-boundary
+[point-geo]: /general-information.md#geographic-telemetry-data
 [propulsion-types]: /general-information.md#propulsion-types
 [responses]: /general-information.md#responses
 [status]: #status-changes