The gps_trajectory.proto Format

by Chen Chen , Yang Li

Dependency

Google Protocol Buffers

https://developers.google.com/protocol-buffers

Compile protobuf class

Go to proto/, compile the format file gps_trajectory.proto

protoc -I=. --cpp_out=. gps_trajectory.proto

This will generate proto/gps_trajectory.pb.h and proto/gps_trajectory.pb.cc

Compile & run example

In the project root, create a build directory

mkdir build;
cd build;

Call cmake and make

cmake ..;
make;

Inside build/, call gpsproto on a test trajectory file:

./gpsproto ../test.pbf test_out.pbf

test.pbf and test_out.pbf should be the same.

Notes

Each GPS sample can be annotated with the following attributes:

• int32 car_id: car/driver id
• uint32 timestamp: linux time stamp of sample
• int32 lon: longitude x 10^5
• int32 lat: latitude x 10^5
• int32 head: heading angle in degrees
• int32 speed: speed in meter/second
• float x: easting in meters (e.g UTM coordinates)
• float y; northing in meters (e.g UTM coordinates)