consider extending NavSatFix with an optional orientation

[tfoote]

This is a follwup to the pre Foxy Message API review

• Comment: Consider replacing NavSatFix with gps_common/GPSFix or add some of the fields from GPSFix (the orientations specifically).
  This better supports dual antenna gps setups where an accurate heading can be provided and synced with the position fix.
• Suggested Action:
  Consider a extending the message with an optional orientation. Or consider a new extended message with orientation added. This message is specifically generic to all GNSS systems versus the GPS one has GPS specific data so is not suitable to be replaced.

[Ryanf55]

Could this be targeted for ROS2 Iron? The Dual-antenna GPS receivers are becoming more popular in the aerial industry.

[SteveMacenski]

I suggested potentially including a NavSatFixWithOrientation kind of message that combines them, in case we want to add a new message instead of modifying an old one. A NavSatFix by itself usually doesn't have orientation information for basic GPS systems. However, most new (non-cheapo) GNS systems in robotics have IMUs and such for better fusion, so I think that's worthy of consideration into sensor_msgs to include orientation to modernize.

@Ryanf55 can you bring this up in the GPS thread on discourse? It would be good to have everything in a single spot to compile a summary from once thoughts are collected

[Ryanf55]

I suggested potentially including a NavSatFixWithOrientation kind of message that combines them, in case we want to add a new message instead of modifying an old one. A NavSatFix by itself usually doesn't have orientation information for basic GPS systems. However, most new (non-cheapo) GNS systems in robotics have IMUs and such for better fusion, so I think that's worthy of consideration into sensor_msgs to include orientation to modernize.

@Ryanf55 can you bring this up in the GPS thread on discourse? It would be good to have everything in a single spot to compile a summary from once thoughts are collected

Reference: https://discourse.ros.org/t/future-of-ros-2-gps-support/33297/20