UDP Message Structure
Each message includes a header of 6 bytes followed by a variable length payload. The header includes the protocol version, message type and payload size enabling the client software to reliably decode the payload data as required.
Field | Type [Size] | Description |
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Version | uint8_t [1] | Protocol version – indicates the revision of the protocol messages |
Message Type | uint8_t [1] | Message type – indicates the type of the payload |
Payload Length | uint32_t [4] | The length, in bytes, of the main body of the message |
Track Distribution Message
The payload of this message is a Protobuf object representing the track sighting data. For more information on Google Protocol Buffers please see reference [https://developers.google.com/protocol-buffers]. Navtech can provide Protobuf message files (.proto) on request.
Info |
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The X and Y Positions are in metres relative to the system origin set within the Witness Suite. The Latitude and Longitude coordinates are based on the WGS84 datum. |
Code Block | ||
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| ||
syntax = "proto3";
package TrackProtobuf;
message DistributionTrack {
string uniqueid = 1;
int32 trackid = 2;
int32 senderid = 3;
uint32 channelid = 4;
double speedmps = 5;
double coursedegrees = 6;
int32 classification = 7;
double classificationprobability = 8;
double xposition = 9;
double yposition = 10;
double latitude = 11;
double longitude = 12;
string tag = 13;
} |
Protobuf Fields
Field | Description |
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UniqueId | A string representation of a GUID that represents the unique Id of the track |
TrackId | User friendly numeric Id for each track. Note that this Id is not unique across the system |
SenderId | User friendly numeric Id of the radar which generated the track. This value represents the User Id which is configured in the Witness software |
ChannelId | This is the index of tracking channel from which the track was generated. Typically in ClearWay, this will represent the channel use for each carriageway |
SpeedMps | The speed of the track in metres / second |
CourseDegrees | The course of the track in degrees |
Classification | The track classification Id. Options are:
|
ClassificationProbability | The confidence level of the classification represented as a value between 0 and 1. |
XPosition | X coordinate of the track based on the local Witness site coordinate system |
YPosition | Y coordinate of the track based on the local Witness site coordinate system |
Latitude | Latitude coordinate of the track based on WGS84 datum |
Longitude | Longitude coordinate of the track based on WGS84 datum |
Tag | User friendly name / description of the track. Typically not used in ClearWay |